123 results on '"interfacial properties"'
Search Results
2. Interfacial Properties and Structure of Emulsions and Foams Co-Stabilized by Span Emulsifiers of Varying Carbon Chain Lengths and Egg Yolk Granules.
- Author
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Liu, Wenyan, Cao, Jingxia, Zhang, Qixin, Wang, Weiqin, Ye, Yuanping, Zhang, Senwang, and Wu, Leiyan
- Subjects
EGG yolk ,FOOD emulsifiers ,INTERFACE dynamics ,INTERFACIAL tension ,SURFACE active agents - Abstract
Interfacial properties significantly influence emulsifying and foaming stability. We here explore the interfacial behavior of egg yolk granules (EYGs) combined with various Span emulsifiers (Span 20, 40, 60, 80) to assess their solution properties, interface dynamics, and effects on emulsifying and foaming stability. The results unveiled that as the Span concentration increased, particle size decreased from 7028 to 1200 nm, absolute zeta potential increased from 4.86 to 9.26 mv, and the structure became increasingly loosened. This loose structure of EYGs-Span complexes resulted in reduced interfacial tension (γ), higher adsorption rate (Kd), and improved interfacial composite modulus (E) compared with native EYGs. These effects were more pronounced with shorter hydrophobic chain Spans but diminished with longer chain lengths. Enhanced interfacial properties contributed to better emulsification and foaming stability, with EYGs-Span complexes displaying increased emulsifying ability and stability compared with natural EYGs. Emulsifying and foaming stability improved in the order of Span 20 > Span 40 > Span 60 > Span 80 as the Span concentration increased. The correlation analysis (p > 0.05) indicated that emulsifying stability was positively associated with interfacial composite modulus and negatively correlated with particle size. Consequently, EYGs-Span composites demonstrate considerable potential for use as effective emulsifiers in food industry applications. [ABSTRACT FROM AUTHOR]
- Published
- 2025
- Full Text
- View/download PDF
3. Enhanced Interfacial Properties of Carbon Fiber/Polymerization of Monomers Reactants Method Polyimide Composite by Polyimide Sizing.
- Author
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Huang, Chengyu, Sun, Jinsong, Liu, Zhiwei, Li, Bo, Sun, Mingchen, Liu, Hansong, Zhao, Yan, Zhang, Peng, and Bao, Jianwen
- Abstract
Carbon fiber (CF)-reinforced polyimide (PI) resin matrix composites have great application potential in areas such as rail transport, medical devices, and aerospace due to their excellent thermal stability, dielectric properties, solvent resistance, and mechanical properties. However, the epoxy sizing agent used for traditional carbon fiber cannot withstand the processing temperature of polyimide resin, of up to 350 °C, resulting in the formation of pores or defects at the interface between the fiber and the resin matrix, leading to the degradation of the overall composite properties. To overcome this problem, in this study, a low-molecular-weight thermosetting polyimide sizing agent was prepared and the processability of the sized carbon fiber was optimized by a thermoplastic polyimide. Compared with the unsized carbon fiber polyimide composites, the interfacial properties of the composites after the polyimide sizing treatment were significantly improved, with the interfacial shear strength (IFSS) increasing from 82.08 MPa to 136.27 MPa, the interlaminar shear strength (ILSS) increasing from 103.7 to 124.9 MPa, and the bending strength increasing from 2262.2 MPa to 2562.1 MPa. The sizing agent acts as a bridge between the carbon fiber and polyimide resin, with anchorage and bonding at the interface between the fiber and resin, which are beneficial for enhancing the interface performance of composites. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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4. Unlocking the Potential of Food Waste: A Review of Multifunctional Pectins.
- Author
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Tsirigotis-Maniecka, Marta, Górska, Ewa, Mazurek-Hołys, Aleksandra, and Pawlaczyk-Graja, Izabela
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FOOD waste , *PECTINS , *GALACTURONIC acid , *FOOD science , *RHEOLOGY - Abstract
This review comprehensively explores the multifunctional applications of pectins derived from food waste and by-products, emphasizing their role as versatile biomaterials in the medical-related sectors. Pectins, known for their polyelectrolytic nature and ability to form hydrogels, influence the chemical composition, sensory properties, and overall acceptability of food and pharmaceutical products. The study presents an in-depth analysis of molecular parameters and structural features of pectins, such as the degree of esterification (DE), monosaccharide composition, galacturonic acid (GalA) content, and relative amounts of homogalacturonan (HG) and rhamnogalacturonan I (RG-I), which are critical for their technofunctional properties and biological activity. Emphasis is placed on pectins obtained from various waste sources, including fruits, vegetables, herbs, and nuts. The review also highlights the importance of structure–function relationships, especially with respect to the interfacial properties and rheological behavior of pectin solutions and gels. Biological applications, including antioxidant, immunomodulatory, anticancer, and antimicrobial activities, are also discussed, positioning pectins as promising biomaterials for various functional and therapeutic applications. Recalled pectins can also support the growth of probiotic bacteria, thus increasing the health benefits of the final product. This detailed review highlights the potential of using pectins from food waste to develop advanced and sustainable biopolymer-based products. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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5. Lactone-Terminated Self-Assembled Monolayers for Mimicking Nanoscale Polyester Surfaces.
- Author
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Tajalli, Pooria, Hernandez Rivera, Jennifer M., Omidiyan, Mina, Lee, Jong Moon, Tran, Hung-Vu, and Lee, T. Randall
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SURFACE reconstruction , *X-ray photoelectron spectroscopy , *CONTACT angle , *NUCLEAR magnetic resonance , *GLYCOLIC acid - Abstract
Two series of lactone-terminated alkanethiol adsorbates with five- and six-membered lactone groups, γ-COCnSH and δ-COCnSH (n = 11, 12), were synthesized and employed to create nanoscale self-assembled monolayers (SAMs) on gold substrates to mimic the properties of commercially available poly(lactic-co-glycolic acid) (PLGA) and poly(glycolic acid) (PGA) surfaces. 1H and 13C nuclear magnetic resonance (NMR) were employed to characterize the adsorbate molecules. The thicknesses of the corresponding self-assembled monolayers (SAMs) were evaluated by ellipsometry. The conformational characteristics of the SAMs were analyzed using polarization modulation infrared reflection adsorption spectroscopy (PM-IRRAS), with a focus on the C-H antisymmetric stretching vibrations of the alkyl spacers. To evaluate the packing densities of the monolayers, X-ray photoelectron spectroscopy (XPS) measurements were performed. Separately, contact angle measurements provided insights into the wettability of the surfaces. Remarkably, the contact angle data across a broad range of probe liquids for the γ-COC11SH and γ-COC12SH SAMs were consistently similar to each other and to the contact angle values of the PLGA surface, rather than to PGA. This finding suggests that the lactone-terminated SAMs investigated in this study effectively mimic nanoscale polyester surfaces, enabling the exploration of interfacial properties of polyesters in the absence of swelling and/or surface reconstruction phenomena. [ABSTRACT FROM AUTHOR]
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- 2024
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6. Review of the Interfacial Structure and Properties of Surfactants in Petroleum Production and Geological Storage Systems from a Molecular Scale Perspective.
- Author
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Jia, Jihui, Yang, Shu, Li, Jingwei, Liang, Yunfeng, Li, Rongjuan, Tsuji, Takeshi, Niu, Ben, and Peng, Bo
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PETROLEUM production , *INTERFACIAL tension , *ENHANCED oil recovery , *SURFACE active agents , *MOLECULAR structure , *PORE fluids - Abstract
Surfactants play a crucial role in tertiary oil recovery by reducing the interfacial tension between immiscible phases, altering surface wettability, and improving foam film stability. Oil reservoirs have high temperatures and high pressures, making it difficult and hazardous to conduct lab experiments. In this context, molecular dynamics (MD) simulation is a valuable tool for complementing experiments. It can effectively study the microscopic behaviors (such as diffusion, adsorption, and aggregation) of the surfactant molecules in the pore fluids and predict the thermodynamics and kinetics of these systems with a high degree of accuracy. MD simulation also overcomes the limitations of traditional experiments, which often lack the necessary temporal–spatial resolution. Comparing simulated results with experimental data can provide a comprehensive explanation from a microscopic standpoint. This article reviews the state-of-the-art MD simulations of surfactant adsorption and resulting interfacial properties at gas/oil–water interfaces. Initially, the article discusses interfacial properties and methods for evaluating surfactant-formed monolayers, considering variations in interfacial concentration, molecular structure of the surfactants, and synergistic effect of surfactant mixtures. Then, it covers methods for characterizing microstructure at various interfaces and the evolution process of the monolayers' packing state as a function of interfacial concentration and the surfactants' molecular structure. Next, it examines the interactions between surfactants and the aqueous phase, focusing on headgroup solvation and counterion condensation. Finally, it analyzes the influence of hydrophobic phase molecular composition on interactions between surfactants and the hydrophobic phase. This review deepened our understanding of the micro-level mechanisms of oil displacement by surfactants and is beneficial for screening and designing surfactants for oil field applications. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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7. Grafting Carbon Fibers with Graphene via a One-Pot Aryl Diazonium Reaction to Refine the Interface Performance of T1100-Grade CF/BMI Composites.
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Li, Weidong, Duan, Ziqi, Sun, Mingchen, Shen, Pengfei, Yang, Huanzhi, Zhong, Xiangyu, Zhang, Yang, Hu, Xiaolan, and Bao, Jianwen
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GRAPHENE , *CARBON fibers , *TENSILE tests , *CHEMICAL bonds , *TENSILE strength , *CONTACT angle - Abstract
In this study, a one-pot aryl diazonium reaction was used as a simple and mild method to graft graphene onto the smooth and inert surface of T1100-grade carbon fiber (CF) through covalent bonding without any damage on CF, to refine the interface performance of CF/bismaleimide (BMI) composites. XPS, SEM, AFM, and dynamic contact angle testing (DCAT) were used to characterize chemical activity, morphologies, and wettability on untreated and grafted CF surfaces. Meanwhile, the impact of the graft method on the tensile strength of CF was also examined using the monofilament tensile test. IFSS between CF grafted with graphene and BMI resin achieved 104.2 MPa after modification, increasing from 85.5 MPa by 21.8%, while the tensile strength did not decrease compared to the pristine CF. The mechanism of this interface enhancement might be better chemical bonding and mechanical interlock between CF grafted with graphene and BMI resin, which is generated from the high surface chemical activity and rough structure of graphene. This study may propose a simple and mild method to functionalize the CF surface and enhance the interface performance of composites without compromising the tensile properties of T1100-grade CF. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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8. The Microstructure and Mechanical Properties of Si 3 N 4f /BN/SiBCN Microcomposites Fabricated by the PIP Process.
- Author
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Gong, Zhiyou, Xu, Zhongkai, Zhang, Jian, Guo, Ruisong, Han, Yao, Sun, Xiaohong, Yuan, Zhuang, Zhao, Xinqi, Zhang, Bingqing, and Zheng, Chunming
- Subjects
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FIBER-matrix interfaces , *CERAMIC materials , *MICROSTRUCTURE , *CREEP (Materials) , *CERAMIC-matrix composites , *TENSILE strength - Abstract
SiBCN ceramics based on SiC, BN and Si3N4 structures have good comprehensive properties such as high-temperature resistance, oxidation resistance, creep resistance and long life, which makes it one of the very promising ceramic material systems in military and aerospace fields, etc. In this study, SiBCN ceramics, as well as Si3N4f/BN/SiBCN microcomposites, were prepared by a polymer infiltration pyrolysis method using PBSZ as the polymer precursor. The PBSZ was completely ceramized by pyrolysis at 900 °C. The weight loss and elemental bonding forms of the products after the pyrolysis of the precursors hardly changed from 600 °C to 900 °C. After pyrolysis at 600 °C for 4 h and using the BN coating obtained from twice deposition as the interfacial phase, a more desirable weak interface of fiber/matrix with a binding strength of 21.96 ± 2.01 MPa can be obtained. Si3N4f/BN/SiBCN ceramic matrix microcomposites prepared under the same pyrolysis conditions have a relatively good tensile strength of 111.10 MPa while retaining a weak interface between the fibers and the matrix. The results of the study provide more theoretical and methodological support for the application of new composite structural ceramic material systems. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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9. Incorporation of Graphene Nanoplatelets into Fiber-Reinforced Polymer Composites in the Presence of Highly Branched Waterborne Polyurethanes.
- Author
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Durmuş-Sayar, Ayşe, Tansan, Murat, Çinko-Çoban, Tuğçe, Serttan, Dilay, Dizman, Bekir, Yildiz, Mehmet, and Ünal, Serkan
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FIBER-reinforced plastics , *FIBROUS composites , *NANOPARTICLES , *FIBER-matrix interfaces , *GRAPHENE , *POLYURETHANE elastomers , *POLYURETHANES - Abstract
Enhancing interfacial interactions in fiber-reinforced polymer composites (FRPCs) is crucial for improving their mechanical properties. This can be achieved through the incorporation of nanomaterials or chemically functional agents into FRPCs. This study reports the tailoring of the fiber–matrix interface in FRPCs using non-functionalized graphene nanoplatelets (GNPs) in combination with a waterborne, highly branched, multi-functional polyurethane dispersion (HBPUD). A unique ultrasonic spray deposition technique was utilized to deposit aqueous mixtures of GNP/HBPUDs onto the surfaces of carbon fiber fabrics, which were used to prepare epoxy-prepreg sheets and corresponding FRPC laminates. The influence of the polyurethane (PU) and GNP content and their ratio at the fiber–matrix interface on the tensile properties of resulting high-performance composites was systematically investigated using stress–strain analysis of the produced FRPC plates and SEM analysis of their fractured surfaces. A synergistic stiffening and toughening effect was observed when as low as 20 to 30 mg of GNPs was deposited per square meter of each side of the carbon fiber fabrics in the presence of the multi-functional PU layer. This resulted in a significant improvement in the tensile strength from 908 to 1022 MPa, while maintaining or slightly improving the initial Young's modulus from approximately 63 to 66 MPa. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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10. Microcapsule Triggering Mechanics in Cementitious Materials: A Modelling and Machine Learning Approach.
- Author
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Ricketts, Evan John, de Souza, Lívia Ribeiro, Freeman, Brubeck Lee, Jefferson, Anthony, and Al-Tabbaa, Abir
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MACHINE learning , *SELF-healing materials , *INTERFACIAL bonding , *CONTINUUM damage mechanics , *MACHINING , *CONCRETE mixing , *DAMAGE models - Abstract
Self-healing cementitious materials containing microcapsules filled with healing agents can autonomously seal cracks and restore structural integrity. However, optimising the microcapsule mechanical properties to survive concrete mixing whilst still rupturing at the cracked interface to release the healing agent remains challenging. This study develops an integrated numerical modelling and machine learning approach for tailoring acrylate-based microcapsules for triggering within cementitious matrices. Microfluidics is first utilised to produce microcapsules with systematically varied shell thickness, strength, and cement compatibility. The capsules are characterised and simulated using a continuum damage mechanics model that is able to simulate cracking. A parametric study investigates the key microcapsule and interfacial properties governing shell rupture versus matrix failure. The simulation results are used to train an artificial neural network to rapidly predict the triggering behaviour based on capsule properties. The machine learning model produces design curves relating the microcapsule strength, toughness, and interfacial bond to its propensity for fracture. By combining advanced simulations and data science, the framework connects tailored microcapsule properties to their intended performance in complex cementitious environments for more robust self-healing concrete systems. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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11. Properties of Heat-Assisted pH Shifting and Compounded Chitosan from Insoluble Rice Peptide Precipitate and Its Application in the Curcumin-Loaded Pickering Emulsions.
- Author
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Yang, Zhenyu, Li, Zhiying, Xu, Zitong, Kong, Zhihao, Qiao, Xin, Zhang, Liwen, Dai, Lei, Wang, Yanfei, Sun, Qingjie, McClements, David Julian, and Xu, Xingfeng
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PEPTIDES ,QUARTZ crystal microbalances ,EMULSIONS ,CHEMICAL stability ,FOOD emulsifiers ,CHITOSAN ,CHITIN - Abstract
Curcumin exhibits antioxidant and antitumor properties, but its poor chemical stability limits its application. Insoluble peptide precipitates formed by proteolysis of rice glutelin are usually discarded, resulting in resource waste. The coupled treatment of heat-assisted pH shifting and compounded chitosan (CS) was used to fabricate rice peptide aggregate–chitosan complexes (RPA–CS). The structure, interfacial behavior, emulsion properties, and digestibility of curcumin-loaded RPA–CS Pickering emulsions were investigated. Increasing the CS concentration led to lower interfacial tension but larger particle size, and the three-phase contact angle of the RPA–CS complexes approached 90°. Quartz crystal microbalance with dissipation (QCM–D) indicated that RPA–CS complexes with 6 g·kg
−1 of CS (RPA–CS6 ) had the highest K1 (0.592 × 106 Hz−1 ) and K4 (0.487 × 106 Hz−1 ), suggesting that the softest interfacial layers were formed. The solid–liquid balance of RPA–RPA–CS emulsions was lower than 0.5, declaring that they had more elastic behavior than that of RPA emulsions. RPA–RPA–CS4 -and RPA–CS6 emulsions had better storage stability, lower FFA release (79.8% and 76.3%, respectively), and higher curcumin bioaccessibility (65.2% and 68.2%, respectively) than RPA emulsions. This study showed that a low-value insoluble rice peptide precipitate could be used as a valuable emulsifier in foods, which may increase the economics and sustainability of the food supply. [ABSTRACT FROM AUTHOR]- Published
- 2023
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12. Interfacial Bond Properties of Underwater Concrete Coated with Bisphenol A Epoxy Resins.
- Author
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Kim, Sungwon, Yi, Jin-Hak, Hong, Hyemin, Choi, Seoung Ik, Kim, Dongchan, and Kim, Min Ook
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EPOXY coatings , *INTERFACIAL bonding , *EPOXY resins , *BOND strengths , *CONCRETE , *DRINKING water - Abstract
This study investigated changes in the interfacial properties of epoxy-coated concrete exposed to various conditions, regarding the epoxy type, coating equipment, and exposure environment and period. The measured coating thickness and pull-off bond strength exhibited diverse trends, depending on the exposure period and conditions. In the real sea (RS) environment, the average bond strengths for bisphenol A (BPA) (E1), BPA with zinc powder (E2), and BPA with cresyl glycidyl ether (E3) were 1.26, 1.93, and 1.92 MPa, respectively. The coating method did not significantly affect the measured coating thickness and strength values. The conventional roller (D1) exhibited the highest thickness variation, with a value of 214.45 μm. The RS condition significantly increased the coating thickness (34% to 158%) compared to the tap water (TW) condition. The exposure conditions had little impact on bond strength except for E3, which showed an increased strength (2.71 MPa) over 7–91 days, especially under RS conditions, while E2 remained constant at approximately 1.82 MPa. This study offers insights into factors influencing marine concrete coating performance and discusses limitations and future work. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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13. Interfacial Tuning of Polymeric Composite Materials for High-Performance Energy Devices.
- Author
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Vedhanarayanan, Balaraman, Lakshmi, K. C. Seetha, and Lin, Tsung-Wu
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POLYMERIC composites ,POLYMER blends ,CHARGE transfer kinetics ,POLYMERS ,INORGANIC polymers ,ENERGY conversion ,CHEMICAL stability ,COMPOSITE materials - Abstract
Polymeric composite materials attracted attention when pristine polymers alone could not fulfill the necessity of high-performance functional materials for wide applications. Mixing two or more polymers (blends) together or compositing the polymers with inorganic compounds/carbon-based nanomaterials greatly solved the problem associated with the mechanical, thermal, and electronic properties along with the chemical stability, which paves a new pathway for optimizing the functional properties of active materials. However, a mere mixing of individual components sometimes would not provide enhanced properties due to the formation of phase-separated, larger domains of components. In particular, the grain boundaries of components, also known as "interfaces", actually determine the properties of these composite materials. The tuning of interfacial properties is significant to achieve composites with higher electrical conductivity and better charge transfer kinetics if they are targeted toward high-performance energy devices. This review aims to provide an overview of recent advancements in the area of polymeric composite materials with tuned interfacial characteristics towards energy conversion (solar cells, photocatalytic hydrogen production, and nanogenerators) and energy storage (supercapacitors and metal-ion batteries) devices with very recent representative examples. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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14. The Stability, Rheological Properties and Interfacial Properties of Oil-in-Water (O/W) Emulsions Prepared from Dielectric Barrier Discharge (DBD) Cold Plasma-Treated Chickpea Protein Isolate and Myofibrillar Protein Complexes.
- Author
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Zhao, Dianbo, Zhou, Yanfang, Sun, Lixue, Tian, Jinfeng, Xiang, Qisen, and Li, Ke
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EMULSIONS ,RHEOLOGY ,CHICKPEA ,PARTICLE size distribution ,INTERFACIAL tension ,SCANNING electron microscopy - Abstract
In order to increase the development and utilization of chickpea protein isolate (CPI) and improve the stability of myofibrillar protein (MP) emulsions, the effect of dielectric barrier discharge (DBD) plasma-modified CPI on the emulsifying properties of MP was investigated. Three different O/W emulsions were prepared using MP, MP + CPI complex, or MP + DBD-treated CPI complex as the emulsifier. Compared with the emulsion prepared from MP, the emulsifying activity index and stability of DBD-treated CPI and MP complex (MP + CPI
DBD ) were increased (p < 0.05) from 55.17 m2 /g to 74.99 m2 /g and 66.31% to 99.87%, respectively. MP + CPIDBD produced more stable emulsions with the lowest Turbiscan stability index (TSI) values for a given 3600 s. At shear rates from 0 to 1000−1 , MP + CPIDBD -stabilized emulsions had higher viscosities, which helped to reduce the chance of aggregation between oil droplets. The optical microscope and particle size distribution of emulsions showed that MP + CPIDBD emulsions had the lowest droplet size (d4,3 ) and exhibited more uniform distribution. MP + CPIDBD emulsions had lower interfacial tension. DBD pretreatment increased the adsorbed protein content in the emulsion stabilized by MP + CPIDBD as compared to the MP + CPI complex and promoted the adsorption of CPI by higher ratios of adsorbed proteins as indicated by its intensity in SDS-PAGE. Scanning electron microscopy confirmed that the emulsion prepared from MP + CPIDBD had smaller particle size and more uniform dispersion. Therefore, using DBD-modified CPI could enhance the stability of MP emulsions. [ABSTRACT FROM AUTHOR]- Published
- 2023
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15. Preparation and Application of a Multifunctional Interfacial Modifier for Ramie Fiber/Epoxy Resin Composites.
- Author
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Zhang, Liyue, Liu, Jingkai, Dai, Jinyue, Zhang, Xufeng, Liu, Xiaoling, Liu, Xiaoqing, and Yi, Xiaosu
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FIBROUS composites , *FIRE resistant polymers , *RAMIE , *EPOXY resins , *ATOMIC force microscopes , *FIREPROOFING agents , *FLEXURAL modulus , *FIBERS - Abstract
A multi-functional modifier, which could improve the mechanical and thermal performance simultaneously, is significant in composites production. Herein, inspired by the chemistry of mussel, an interfacial modifier named FPD was designed and synthesized through one simple step, which was attached by three functional groups (including catechol, N-H bond, and DOPO). Due to the innate properties of each functional group, FPD played multiple roles: adhere to the ramie fibers from catechol and cure with the epoxy resin from -NH-, an antiflaming property from DOPO, and the compatibilizer between ramie fibers and epoxy resin was also improved by changing the polarity of ramie fiber. All of the above functions can be proved by means of water contact angle (WCA), atomic force microscope (AFM), and scanning electron microscopy (SEM), etc. After solidification, the ramie fiber/epoxy composites demonstrated superior performances in terms of good mechanical properties and excellent flame retardant property. With the addition of 30 wt.% FPD, the tensile strength and modulus of the ramie/epoxy composite showed an improvement of 37.1% and 60.9%, and flexural strength and modulus of the composite were improved by 8.9% and 19.3% comparing with no addition composite. Moreover, the composite could achieve the goal for V-0 rating in the UL-94 test and LOI value was 34.6% when the addition of FPD reached 30 wt.%. This work provided us with an efficient method for fabricating nature fiber/epoxy composites with good properties. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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16. Influence of Chemical Pretreatment on the Mechanical, Chemical, and Interfacial Properties of 3D-Printed, Rice-Husk-Fiber-Reinforced Composites.
- Author
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Surendran, Athira Nair, Malayil, Sreesha, Satyavolu, Jagannadh, and Kate, Kunal
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RICE hulls ,NATURAL fibers ,MEASUREMENT of viscosity ,SULFURIC acid ,FIBROUS composites ,TENSILE tests - Abstract
This article explores using biomass, namely rice husks, as a reinforcement material in thermoplastic copolyester (TPC) composites. Rice husks were subjected to three chemical pretreatments: single-stage sulfuric acid hydrolysis, first-stage sulfuric acid hydrolysis followed by a second-stage methanesulfonic acid (MSA) treatment, and first-stage sulfuric acid hydrolysis followed by a second-stage sodium hydroxide alkali treatment. We studied the effects of these treatments on the rheological, thermal, interfacial, and mechanical properties of composites. The fibers were mixed with polymers at high shear rates and temperatures, and 3D-printed filaments were produced using a desktop 3D printer. The printed parts were analyzed using tensile tests, torque and viscosity measurements, and thermogravimetric analysis to obtain their mechanical, rheological, and thermal properties. SEM imaging was performed to understand the fiber–polymer interface and how it affects the other properties. The results showed that first-stage sulfuric acid hydrolysis followed by a second-stage pretreatment of the fibers with MSA showed better fiber–polymer adhesion and a 20.4% increase in stress at 5% strain, a 30% increase in stress at 50% strain, and a 22.6% increase in the elastic modulus as compared to untreated rice husk composites. These findings indicate that readily available and inexpensive rice husks have significant potential for use in natural fiber-reinforced composites when pretreated using dilute sulfuric acid followed by methane sulfonic acid hydrolysis. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
17. Study on the Overmolding Process of Carbon-Fiber-Reinforced Poly (Aryl Ether Ketone) (PAEK)/Poly (Ether Ether Ketone) (PEEK) Thermoplastic Composites.
- Author
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Zhao, Ziyue, Zhang, Jindong, Bi, Ran, Chen, Chunhai, Yao, Jianan, and Liu, Gang
- Subjects
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POLYETHERS , *THERMOPLASTIC composites , *KETONES , *INTERFACIAL bonding , *SHEAR strength , *ETHERS - Abstract
This paper used poly (aryl ether ketone) (PAEK) resin with a low melting temperature to prepare laminate via the compression-molding process for continuous-carbon-fiber-reinforced composites (CCF-PAEK). Then, poly (ether ether ketone) (PEEK), or a short-carbon-fiber-reinforced poly (ether ether ketone) (SCF-PEEK) with a high melting temperature, was injected to prepare the overmolding composites. The shear strength of short beams was used to characterize the interface bonding strength of composites. The results showed that the interface properties of the composite were affected by the interface temperature, which was adjusted by mold temperature. PAEK and PEEK formed a better interfacial bonding at higher interface temperatures. The shear strength of the SCF-PEEK/CCF-PAEK short beam was 77 MPa when the mold temperature was 220 °C and 85 MPa when the mold temperature was raised to 260 °C. The melting temperature did not significantly affect the shear strength of SCF-PEEK/CCF-PAEK short beams. For the melting temperature increasing from 380 °C to 420 °C, the shear strength of the SCF-PEEK/CCF-PAEK short beam ranged from 83 MPa to 87 MPa. The microstructure and failure morphology of the composite was observed using an optical microscope. A molecular dynamics model was established to simulate the adhesion of PAEK and PEEK at different mold temperatures. The interfacial bonding energy and diffusion coefficient agreed with the experimental results. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
18. The Effect of Silica Particle Size on the Mechanical Enhancement of Polymer Nanocomposites.
- Author
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Kontou, Evagelia, Christopoulos, Angelos, Koralli, Panagiota, and Mouzakis, Dionysios E.
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POLYMERIC nanocomposites , *NANOPARTICLES , *DYNAMIC mechanical analysis , *EPOXY resins , *YOUNG'S modulus , *FINITE element method - Abstract
In the present work, SiO2micro/nanocomposites based on poly-lactic acid (PLA) and an epoxy resin were prepared and experimentally studied. The silica particles were of varying sizes from the nano to micro scale at the same loading. The mechanical and thermomechanical performance, in terms of dynamic mechanical analysis, of the composites prepared was studied in combination with scanning electron microscopy (SEM). Finite element analysis (FEA) has been performed to analyze the Young's modulus of the composites. A comparison with the results of a well-known analytical model, taking into account the filler's size and the presence of interphase, was also performed. The general trend is that the reinforcement is higher for the nanosized particles, but it is important to conduct supplementary studies on the combined effect of the matrix type, the size of the nanoparticles, and the dispersion quality. A significant mechanical enhancement was obtained, particularly in the Resin/based nanocomposites. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
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19. Spectroscopic Ellipsometry Studies on Solution-Processed OLED Devices: Optical Properties and Interfacial Layers.
- Author
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Gioti, Maria
- Subjects
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ORGANIC light emitting diodes , *OPTICAL devices , *ELLIPSOMETRY , *OPTICAL properties , *INDIUM tin oxide , *INK-jet printing , *EXCIMERS - Abstract
Τhe fabrication of organic light-emitting diodes (OLEDs) from solution involves the major problem of stack integrity, setting the determination of the composition and the characteristics of the resulting interfaces prerequisite for the optimization of the growth processes and the achievement of high devices' performance. In this work, a poly(9,9-dioctylfluorene) (F8) and poly(9,9-dioctylfluorene-alt-benzothiadiazole) (F8BT) blend is used for the emissive layer (EML), poly-3,4-ethylene dioxythiophene; poly-styrene sulfonate (PEDOT:PSS) is used for a hole transport layer (HTL), and Poly(9,9-bis(3′-(N,N-dimethyl)-N-ethylammoinium-propyl-2,7-fluorene)-alt-2,7-(9,9-dioctylfluore-ne))dibromide (PFN-Br) for an electron transport layer (ETL) to produce the OLED device. All the layers are developed using the slot-die process, onto indium tin oxide (ITO)-coated polyethylene terephthalate (PET) flexible substrates, whereas Ag cathode was formed by ink-jet printing under ambient conditions. Spectroscopic ellipsometry measurements were performed upon completion of the successive films' growth, in sequential steps, for the multilayer OLED development. Ellipsometry analysis using different models demonstrate the degree of intermixing within the layers and provide information about the interfaces. These interfacial properties are correlated with the emission characteristics as well as the final performance of the OLED devices. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
20. Interfacial Properties of Pea Protein Hydrolysate: The Effect of Ionic Strength.
- Author
-
Sarigiannidou, Krystalia, Odelli, Davide, Jessen, Flemming, Mohammadifar, Mohammad Amin, Ajalloueian, Fatemeh, Vall-llosera, Mar, de Carvalho, Antonio Fernandes, and Casanova, Federico
- Subjects
PEA proteins ,IONIC strength ,HYDROLYSIS ,POLYPEPTIDES ,PARTICLE size distribution - Abstract
The effect of a tryptic hydrolysis as well as the effect of ionic strength (0–0.4 M NaCl) was investigated on the oil/water interfacial properties of soluble pea protein hydrolysate (SPPH) at neutral pH and room temperature (20 ± 0.01 °C). SEC-MALS and SDS-Page analysis showed that tryptic hydrolysis created a lower molecular weight polypeptide mixture, whereas FTIR analysis and DSC thermograms demonstrated a more disordered and flexible structure. The bulk properties of SPPH were studied in terms of hydrodynamic diameter and turbidity, where higher particle size (+ ~13 nm) and turbidity were observed at 0.4 M NaCl. Regarding the interfacial properties, the surface activity of SPPH improved by increasing ionic strength, with maximum interfacial pressure (14.28 mN/m) at 0.4 M NaCl. Nevertheless, the addition of NaCl negatively affected the elasticity and strength of the interfacial film, where the sample without salt exhibited the highest dilatational and shear storage modulus in all the frequencies considered. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
21. Molecular Dynamics Study of Interfacial Properties for Crude Oil with Pure and Impure CH 4.
- Author
-
Dong, Zhenzhen, Ma, Xinle, Xu, Haobin, Li, Weirong, Qian, Shihao, Wang, Zhengbo, Liu, Zhaoxia, and Lei, Gang
- Subjects
PETROLEUM ,MOLECULAR dynamics ,INTERFACE dynamics ,HEAVY oil ,INTERFACIAL tension ,TERNARY system - Abstract
Gas injection has received increasing attention as one of the key technologies to enhance oil recovery. When gas is dissolved in crude oil, it will accelerate the flow of crude oil by reducing the density, viscosity, interfacial tension (IFT), and other properties of crude oil, so IFT is one of the main factors affecting the recovery of the gas drive. The interfacial properties of CH
4 , one of the principal associated hydrocarbon gases, with crude oil remain unclear. In this study, molecular dynamics (MD) simulations were used to determine the IFTs of pure and impure CH4 with n-decane as well as the IFTs of the ternary systems CH4 + n-hexane + n-decane and CH4 + n-decane + n-nonadecane. Additionally, investigating factors including pressure, temperature, gas composition, and crude oil composition reveals the mechanisms affecting the interfacial properties of CH4 and crude oil. The results demonstrate that CO2 significantly lowers the IFT of CH4 + n-decane; the effect of crude oil components on IFT varies with the properties of the crude oil and, generally speaking, IFT is greater for crude oils containing heavy components than for those containing light components; the effect of temperature on the IFT of the CH4 + n-decane system is more pronounced at low pressure and decreases with increasing pressure. This study contributes to understanding the behavior of CH4 and oil systems in the formation and could be used to enhance the oil recovery technology. [ABSTRACT FROM AUTHOR]- Published
- 2022
- Full Text
- View/download PDF
22. Langmuir Trough Study of the Interactions of Tear Mimetic Eyedrop Formulation with Human Meibum Films.
- Author
-
Eftimov, Petar, Yokoi, Norihiko, Tsuji, Kazuhiro, Peev, Nikola, and Georgiev, Georgi As.
- Subjects
BREWSTER'S angle ,MEIBOMIAN glands ,NANOSATELLITES ,POLAR molecules ,DRY eye syndromes ,VISCOELASTICITY - Abstract
Meibomian gland disease is associated with quantitative or qualitative deficiencies of meibum (MGS) that result in tear film instability. Thus, there is great demand for ophthalmic nanoemulsions that can replenish MGS and recover its performance at the air/tear surface. Rohto Dry Aid (RDA) utilizes TEARSHIELD TECHNOLOGY
TM implementing a complex oil phase of non-polar and polar lipid-like molecules. Therefore, the interactions of RDA with MGS surface films deserve further study as they may provide valuable insights (i) into the mechanisms behind the nanoemulsion therapeutic action and (ii) for the design of novel ophthalmic formulations. Pseudobinary meibum/RDA films were formed at the air–water surface of the Langmuir trough. Surface pressure-area isocycles and stress relaxations were employed to probe the layer (i) reorganization upon cycling and (ii) dilatational elasticity, respectively. Film morphology was accessed by Brewster angle microscopy and the spreading properties of RDA-supplemented meibum were also probed. The diverse ingredients of the nanoemulsion oil phase complemented the non-polar and polar lipid constituents of the meibomian layers, which resulted in enhanced continuity of the MGS duplex film structure and facilitated the MGS spread and viscoelasticity. Nanoemulsions deserve further study as a potent tool for MGS-oriented therapy for dry eyes. [ABSTRACT FROM AUTHOR]- Published
- 2022
- Full Text
- View/download PDF
23. Interfacial Strengthening and Self-Monitoring in Carbon Fiber-Reinforced Composites via Carbon Nanotube-Based Damage Sensors.
- Author
-
Hu, Wenlong, Sun, Zijie, Yang, Lulu, Hu, Chaojie, Zhang, Shuzheng, Wang, Fangxin, Yang, Bin, and Cang, Yu
- Subjects
- *
CARBON fibers , *CARBON composites , *FIBROUS composites , *CARBON fiber-reinforced plastics , *AEROSPACE materials , *MULTIWALLED carbon nanotubes - Abstract
Carbon fiber-reinforced polymers are important constituents of aerospace materials. However, due to the inert surface of CFs, their interfacial property is relatively weak, which severely hinders their practical applications. Here, we deposited multi-walled carbon nanotubes (MWCNTs) along with a coupling agent on the surface of carbon fiber to improve the interfacial properties of the carbon fiber/resin. Via a simple dip-coating method, the MWCNTs were uniformly distributed on the CF surface with the assistance of the pre-coated coupling agent. The interfacial shear strength between the fiber and the matrix was significant enhanceed when the CF was loaded with the coupling agent and the MWCNTs. In addition, the MWCNTs were used as sensors to in-situ monitor the interfacial state in order to elucidate the interfacial strengthening mechanism. It revealed that the collaborative contribution of the coupling agent and the MWCNTs in the interphase region is the key to the high interfacial strength. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
24. Interfacial Properties and Melt Processability of Cellulose Acetate Propionate Composites by Melt Blending of Biofillers.
- Author
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Lee, Ji-Eun, Shim, Seung-Bo, Park, Jae-Hyung, and Chung, Ildoo
- Subjects
- *
NATURAL fibers , *CELLULOSE acetate , *INTERFACIAL bonding , *FLEXURAL strength , *PROPIONATES , *TENSILE strength - Abstract
A series of eco-friendly biocomposites with improved mechanical properties and interfacial interaction were prepared by melt-mixing natural fibers using a cellulose acetate derivative as a polymer matrix and used to evaluate their mechanical, thermal, and morphological properties. The natural fiber used as a biofiller was pre-surface-treated by a refining process using alkali and natural enzymes to improve compatibility and increase interfacial bonding with biopolymer substrate. To increase the processability of the cellulose material, the raw material was plasticized and the composition prepared in the form of pellets in a twin-screw extruder by mixing with an additive before being molded through an injection process. For each composition, the interfacial bonding force between different materials was confirmed through morphology analysis and evaluation of mechanical and thermal properties. When biofillers and a viscosity modifier were used at the same time, the fabricated biocomposites had controllable crystallinity, stiffness, and elasticity and showed improved mechanical strength, such as tensile strength and flexural strength. These results indicated that interfacial properties could be increased through interfacial interactions between two different components due to appropriate surface treatment. In addition, it was confirmed that a composition having interfacial interaction, not a simple mixture, could be prepared by lowering both glass transition and melting temperature. The lowering of glass transition temperature increased the elasticity of the biocomposites, which have the potential advantage of easier melt processing when applied to various injection parts. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
25. Structural Characterization and Evaluation of Interfacial Properties of Pea Protein Isolate–EGCG Molecular Complexes.
- Author
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Han, Shuang, Cui, Fengzhan, McClements, David Julian, Xu, Xingfeng, Ma, Cuicui, Wang, Yutang, Liu, Xuebo, and Liu, Fuguo
- Abstract
Highlights: Pea protein isolate (PPI) and EGCG spontaneously formed complexes. Protein–polyphenol complexation was mainly driven by hydrogen bonding. The binding of EGCG influenced the structure and functionality of PPI. PPI-EGCG complexes had better emulsifier properties than PPI. There is increasing interest in using plant-derived proteins in foods and beverages for environmental, health, and ethical reasons. However, the inherent physicochemical properties and functional performance of many plant proteins limit their widespread application. Here, we prepared pea protein isolate (PPI) dispersions using a combined pH-shift/heat treatment method, and then, prepared PPI-epigallocatechin-3-gallate (EGCG) complexes under neutral conditions. Spectroscopy, calorimetry, molecular docking, and light scattering analysis demonstrated that the molecular complexes formed spontaneously. This was primarily ascribed to hydrogen bonds and van der Waals forces. The complexation of EGCG caused changes in the secondary structure of PPI, including the reduction in the α-helix and increase in the β-sheet and disordered regions. These changes slightly decreased the thermal stability of the protein. With the accretion of EGCG, the hydrophilicity of the complexes increased significantly, which improved the functional attributes of the protein. Optimization of the PPI-to-EGCG ratio led to the complexes having better foaming and emulsifying properties than the protein alone. This study could broaden the utilization of pea proteins as functional ingredients in foods. Moreover, protein–polyphenol complexes can be used as multifunctional ingredients, such as antioxidants or nutraceutical emulsifiers. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
26. Constructing a Superior Interfacial Microstructure on Carbon Fiber for High Interfacial and Mechanical Properties of Epoxy Composites.
- Author
-
Han, Ping, Yang, Lina, Zhang, Susu, and Gu, Zheng
- Subjects
- *
CARBON fibers , *CARBON fiber-reinforced plastics , *MICROSTRUCTURE , *EPOXY resins , *ATOMIC force microscopy , *DYNAMIC mechanical analysis , *IMPACT strength - Abstract
The interface quality is crucial for the properties of carbon fiber-reinforced polymer- matrix composites (CFRPs). In order to improve the interfacial and mechanical properties of CFRPs, a superior gradient modulus interfacial microstructure is constructed on the carbon fiber (CF) surface by chemically grafting a self-assembly carboxyl-terminated hyperbranched polymer (HP-COOH). A monofilament debonding test, a short beam shear test, an impact test and a dynamic mechanical thermal analysis (DMTA) were conducted to investigate the properties of the modified composite. Prominent improvements of 79.6% for the interfacial shear strength, 51.5% for the interlaminar shear strength, and 49.2% for the impact strength, as well as superior heat-resistance properties are achieved for composites with the gradient modulus interface over those of the untreated CF composites. The mechanism for performance improvement is mainly attributed to the enhanced CF surface energy, mechanical interlocking, and chemical bonding interactions. In particular, an atomic force microscopy (AFM) test proved that the gradient modulus interfacial microstructure formed by HP–COOH could widen the interface layer thickness and buffer the sharp variations in the modulus from CF to resin, thereby transmitting an external force and reducing the stress concentration. This work provides a facile and efficient strategy for constructing a superior and versatile interface for high- performance composites. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
27. Molecular Dynamics Simulation of Coiled Carbon Nanotube Pull-Out from Matrix.
- Author
-
Huang, Feng and Zhou, Shuai
- Subjects
- *
MOLECULAR dynamics , *CARBON nanotubes , *FIBROUS composites , *POLYMERIC nanocomposites , *INTERFACIAL stresses , *TUBES , *SHEARING force - Abstract
The interaction between coiled carbon nanotubes (CCNT) and the polymer matrix is important in the mechanical, thermal, and electrical properties of the CCNT reinforced nanocomposite. In this study, molecular dynamics (MD) simulations were performed to study the interfacial characteristics of polymer nanocomposites (PNCs). Furthermore, the influence of the geometries of the CCNTs on the load transfer mechanism is evaluated. Pullout simulations considering different geometries of CCNTs are carried out to examine the tensile force and the interfacial shear stress (ISS). The results reveal that the maximal tensile force is reduced by increasing CCNT inner diameters, increasing the helix angles, and decreasing nanotube diameters. The distance between CCNTs and the polymer matrix is varied, and the interfacial distance favors greater ISS. Decreasing the inner diameter of the CCNT, the helix angle, and the tube diameter increases the ISS. The enhancement mechanism of CCNT/polymer composites has also been illustrated. Due to a lack of experimental results, only numerical results are given. The present study helps to understand the interfacial adhesion behavior between the polymer matrix and CCNTs and is expected to contribute to the development of CCNT reinforced polymer composites. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
28. Improvement of Surface Coating and Interfacial Properties of Hot-Waxed Wood Using Maleic Anhydride Grafted Polypropylene Wax.
- Author
-
Wang, Xuting and Song, Kuiyan
- Subjects
MALEIC anhydride ,WOOD ,SURFACE coatings ,POLYPROPYLENE ,HYDROPHOBIC surfaces ,WAXES ,ENGINEERED wood ,GALVANIZING - Abstract
Beeswax is used on wood furniture surfaces in China. Beeswax is expensive and has a low melting temperature, and the wax film is easily softened and destroyed. To overcome these problems, a modified polypropylene wax grafted with maleic anhydride, with a high melting temperature and low price, was used in hot-waxed wood. The adhesion, hardness, hydrophobic properties, heat resistance, color, and gloss of hot-waxed woods were also examined. The surface and interfacial properties were characterized by FTIR, XRD, and SEM. The modified polypropylene wax showed a higher melting temperature than beeswax by DSC, and the heat resistance of hot-waxed wood using it was revealed by TG. The adhesion for the modified polypropylene wax hot-waxed wood surface was shown to achieve grade 1. In addition, it maintained original grades in adhesion after soaking in water and was greater than beeswax hot-waxed wood. The hot-waxed wood surfaces become hydrophobic compared with untreated wood, and the hydrophobicity of the modified polypropylene wax hot-waxed wood surfaces, with a decreased water contact angle, were slightly weaker than beeswax hot-waxed wood and polypropylene wax hot-waxed wood. Moreover, in hardness, the modified polypropylene wax hot-waxed wood surfaces (2H) were harder than beeswax hot-waxed wood (3B), representing stronger scratch resistance and performing well in decorative characteristics, such as color and gloss. The results of SEM, FTIR, and XRD showed mechanical and weak chemical bonding between the waxes and the surface of the wood with the presence of wax in a wood structure. Therefore, the modified polypropylene wax could be used in hot-waxed wood with great heat resistance, adhesion, and surface performance. The study is beneficial for the application of wood coatings using synthetic wax in the future. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
29. Hydrophobicity Enhances the Formation of Protein-Stabilized Foams.
- Author
-
Delahaije, Roy J. B. M. and Wierenga, Peter A.
- Subjects
- *
FOAM , *HEAT treatment , *EMULSIONS , *LYSOZYMES - Abstract
Screening proteins for their potential use in foam applications is very laborious and time consuming. It would be beneficial if the foam properties could be predicted based on their molecular properties, but this is currently not possible. For protein-stabilized emulsions, a model was recently introduced to predict the emulsion properties from the protein molecular properties. Since the fundamental mechanisms for foam and emulsion formation are very similar, it is of interest to determine whether the link to molecular properties defined in that model is also applicable to foams. This study aims to link the exposed hydrophobicity with the foam ability and foam stability, using lysozyme variants with altered hydrophobicity, obtained from controlled heat treatment (77 °C for 0–120 min). To establish this link, the molecular characteristics, interfacial properties, and foam ability and stability (at different concentrations) were analysed. The increasing hydrophobicity resulted in an increased adsorption rate constant, and for concentrations in the protein-poor regime, the increasing hydrophobicity enhanced foam ability (i.e., interfacial area created). At higher relative exposed hydrophobicity (i.e., ~2–5 times higher than native lysozyme), the adsorption rate constant and foam ability became independent of hydrophobicity. The foam stability (i.e., foam collapse) was affected by the initial foam structure. In the protein-rich regime—with nearly identical foam structure—the hydrophobicity did not affect the foam stability. The link between exposed hydrophobicity and foam ability confirms the similarity between protein-stabilized foams and emulsions, and thereby indicates that the model proposed for emulsions can be used to predict foam properties in the future. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
30. Synthesis, Characterization, and Modeling of Aligned ZnO Nanowire-Enhanced Carbon-Fiber-Reinforced Composites.
- Author
-
Wang, Jingyu, Marashizadeh, Parisa, Weng, Binbin, Larson, Preston, Altan, M. Cengiz, and Liu, Yingtao
- Subjects
- *
MECHANICAL behavior of materials , *FIBER-matrix interfaces , *ATOMIC layer deposition , *CARBON nanowires , *ZINC oxide , *CARBON fiber-reinforced plastics - Abstract
This paper presents the synthesis, characterization, and multiscale modeling of hybrid composites with enhanced interfacial properties consisting of aligned zinc oxide (ZnO) nanowires and continuous carbon fibers. The atomic layer deposition method was employed to uniformly synthesize nanoscale ZnO seeds on carbon fibers. Vertically aligned ZnO nanowires were grown from the deposited nanoscale seeds using the low-temperature hydrothermal method. Morphology and chemical compositions of ZnO nanowires were characterized to evaluate the quality of synthesized ZnO nanowires in hybrid fiber-reinforced composites. Single fiber fragmentation tests reveal that the interfacial shear strength (IFSS) in epoxy composites improved by 286%. Additionally, a multiscale modeling framework was developed to investigate the IFSS of hybrid composites with radially aligned ZnO nanowires. The cohesive zone model (CZM) was implemented to model the interface between fiber and matrix. The damage behavior of fiber was simulated using the ABAQUS user subroutine to define a material's mechanical behavior (UMAT). Both experimental and analytical results indicate that the hierarchical carbon fibers enhanced by aligned ZnO nanowires are effective in improving the key mechanical properties of hybrid fiber-reinforced composites. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
31. Interfacial Properties of H 2 O+CO 2 +Oil Three-Phase Systems: A Density Gradient Theory Study.
- Author
-
Yang, Yafan, Zhu, Weiwei, Ji, Yukun, Wang, Tao, and Zhao, Guangsi
- Subjects
- *
CARBON sequestration , *INTERFACIAL tension , *EQUATIONS of state , *PETROLEUM , *DENSITY , *CARBON dioxide - Abstract
The interfacial property of H 2 O+CO 2 +oil three-phase systems is crucial for CO 2 flooding and sequestration processes but was not well understood. Density gradient theory coupled with PC-SAFT equation of state was applied to investigate the interfacial tension (IFT) of H 2 O+CO 2 +oil (hexane, cyclohexane, and benzene) systems under three-phase conditions (temperature in the range of 323–423 K and pressure in the range of 1–10 MPa). The IFTs of the aqueous phase+vapor phase in H 2 O+CO 2 +oil three-phase systems were smaller than the IFTs in H 2 O+CO 2 two-phase systems, which could be explained by enrichment of oil in the interfacial region. The difference between IFTs of aqueous phase+vapor phase in the three-phase system and IFTs in H 2 O+CO 2 two-phase system was largest in the benzene case and smallest in the cyclohexane case due to different degrees of oil enrichment in the interface. Meanwhile, CO 2 enrichment was observed in the interfacial region of the aqueous phase+oil-rich phase, which led to the reduction of IFT with increasing pressure while different pressure effects were observed in the H 2 O+oil two-phase systems. The effect of CO 2 on the IFTs of aqueous phase+benzene-rich phase interface was small in contrast to that on the IFTs of aqueous phase+alkane (hexane or cyclohexane)-rich phase interface. H 2 O had little effect on the interfacial properties of the oil-rich phase+vapor phase due to the low H 2 O solubilities in the oil and vapor phase. Further, the spreading coefficients of H 2 O+CO 2 in the presence of different oil followed this sequence: benzene > hexane > cyclohexane. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
32. Oil Droplet Coalescence in W/O/W Double Emulsions Examined in Models from Micrometer- to Millimeter-Sized Droplets.
- Author
-
Leister, Nico, Yan, Chenhui, and Karbstein, Heike Petra
- Subjects
COALESCENCE (Chemistry) ,MICROMETERS ,HYDROPHILIC surfaces ,MICROFLUIDICS ,EMULSIONS - Abstract
Water-in-oil-in-water (W
1 /O/W2 ) double emulsions must resist W1 –W1 , O–O and W1 –W2 coalescence to be suitable for applications. This work isolates the stability of the oil droplets in a double emulsion, focusing on the impact of the concentration of the hydrophilic surfactant. The stability against coalescence was measured on droplets ranging in size from millimeters to micrometers, evaluating three different measurement methods. The time between the contact and coalescence of millimeter-sized droplets at a planar interface was compared to the number of coalescence events in a microfluidic emulsion and to the change in the droplet size distributions of micrometer-sized single and double emulsions. For the examined formulations, the same stability trends were found in all three droplet sizes. When the concentration of the hydrophilic surfactant is reduced drastically, lipophilic surfactants can help to increase the oil droplets' stability against coalescence. This article also provides recommendations as to which purpose each of the model experiments is suited and discusses advantages and limitations compared to previous research carried out directly on double emulsions. [ABSTRACT FROM AUTHOR]- Published
- 2022
- Full Text
- View/download PDF
33. Fibronectin-Enriched Biomaterials, Biofunctionalization, and Proactivity: A Review.
- Author
-
Palomino-Durand, Carla, Pauthe, Emmanuel, and Gand, Adeline
- Subjects
BIOMATERIALS ,ARTIFICIAL implants ,EXTRACELLULAR matrix ,CELL differentiation ,SYSTEMS development ,MEDICAL innovations - Abstract
Modern innovation in reconstructive medicine implies the proposition of material-based strategies suitable for tissue repair and regeneration. The development of such systems necessitates the design of advanced materials and the control of their interactions with their surrounding cellular and molecular microenvironments. Biomaterials must actively engage cellular matter to direct and modulate biological responses at implant sites and beyond. Indeed, it is essential that a true dialogue exists between the implanted device and the cells. Biomaterial engineering implies the knowledge and control of cell fate considering the globality of the adhesion process, from initial cell attachment to differentiation. The extracellular matrix (ECM) represents a complex microenvironment able to meet these essential needs to establish a relationship between the material and the contacting cells. The ECM exhibits specific physical, chemical, and biochemical characteristics. Considering the complexity, heterogeneity, and versatility of ECM actors, fibronectin (Fn) has emerged among the ECM protagonists as the most pertinent representative key actor. The following review focuses on and synthesizes the research supporting the potential to use Fn in biomaterial functionalization to mimic the ECM and enhance cell–material interactions. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
34. Interfacial Properties of Bamboo Fiber-Reinforced High-Density Polyethylene Composites by Different Methods for Adding Nano Calcium Carbonate.
- Author
-
Cuicui Wang, Yu Xian, Smith, Lee M., Ge Wang, Haitao Cheng, and Shuangbao Zhang
- Subjects
- *
HIGH density polyethylene , *EXTRUSION molding , *CALCIUM carbonate , *FREE energy (Thermodynamics) , *SURFACE energy ,BAMBOO anatomy - Abstract
The focus of this study was to observe the effect of nano calcium carbonate (CaCO3) modification methods on bamboo fiber (BF) used in BF-reinforced high-density polyethylene (HDPE) composites manufactured by extrusion molding. Two methods were used to introduce the nano CaCO3 into the BF for modification; the first was blending modification (BM) and the second was impregnation modification (IM). In order to determine the effects of the modification methods, the water absorption, surface free energy and interfacial properties of the unmodified composites were compared to those of the composites made from the two modification methods. The results revealed that the percentage increase in the weight of the composite treated by nano CaCO3 decreased and that of the IMBF/HDPE composite was the lowest over the seven months of time. The results obtained by the acid-base model according to the Lewis and Owens-Wendt- Rabel-Kaelble (OWRK) equations indicated that the surface energy of the composites was between 40 and 50 mJ/m2. When compared to the control sample, the maximum storage modulus (E'max) of the BMBF/HDPE and IMBF/HDPE composites increased 1.43- and 1.53-fold, respectively. The values of the phase-to-phase interaction parameter B and the k value of the modified composites were higher than those of the unmodified composites, while the apparent activation energy Ea and interface parameter A were lower in the modified composites. It can be concluded that nano CaCO3 had an effect on the interfacial properties of BF-reinforced HDPE composites, and the interface bonding between IMBF and HDPE was greatest among the composites. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
35. Impacts of the Oxygen Precursor on the Interfacial Properties of LaxAlyO Films Grown by Atomic Layer Deposition on Ge.
- Author
-
Lu Zhao, Hongxia Liu, Xing Wang, Yongte Wang, and Shulong Wang
- Subjects
- *
OXYGEN , *THIN films , *ATOMIC layer deposition , *GERMANIUM , *OXIDIZING agents - Abstract
Amorphous LaxAlyO films were grown on n-type Ge substrate by atomic layer deposition using O3 and H2O as oxidant, respectively. A comparison of the XPS results indicated that a thicker interfacial layer with the component of LaGeOx and GeOx was formed at O3-based LaxAlyO/Ge interface, causing lower band gap value as well as the conduction band offset (CBO) value relative to Ge substrate for O3-based LaxAlyO film, with a concomitant degeneration in the interfacial properties. In contrast, for the H2O-based film, the leakage current of more than one order of magnitude less than that of O3-based LaxAlyO film was obtained. All the results indicated that H2O is a more appropriate oxidant for improving the interfacial properties in the atomic-layer-deposited LaxAlyO dielectric on Ge. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
36. Bacteria Cell Hydrophobicity and Interfacial Properties Relationships: A New MEOR Approach
- Author
-
Reinhard Miller, Moein Jahanbani Veshareh, Shahab Ayatollahi, Ehsan Ganji-Azad, and Aliyar Javadi
- Subjects
Diffusion and adsorption ,Microorganism ,Emulsion stability ,Bacterial cell structure ,Surface tension ,chemistry.chemical_compound ,salinity effects ,Dilational visco-elasticity ,Colloid and Surface Chemistry ,Adsorption ,Microbial enhanced oil recovery (MEOR) ,dilational visco-elasticity ,Hydrophobicity of bacteria cells ,interfacial properties ,QD1-999 ,microbial enhanced oil recovery (MEOR) ,hydrophobicity of bacteria cells ,Heptane ,Interfacial properties ,Aqueous two-phase system ,emulsion stability ,diffusion and adsorption ,Chemistry ,Microbial enhanced oil recovery ,chemistry ,Chemical engineering ,Chemistry (miscellaneous) ,Emulsion ,Salinity effects - Abstract
For microbial enhanced oil recovery (MEOR), different mechanisms have been introduced. In some of these papers, the phenomena and mechanisms related to biosurfactants produced by certain microorganisms were discussed, while others studied the direct impacts of the properties of microorganisms on the related mechanisms. However, there are only very few papers dealing with the direct impacts of microorganisms on interfacial properties. In the present work, the interfacial properties of three bacteria MJ02 (Bacillus Subtilis type), MJ03 (Pseudomonas Aeruginosa type), and RAG1 (Acinetobacter Calcoaceticus type) with the hydrophobicity factors 2, 34, and 79% were studied, along with their direct impact on the water/heptane interfacial tension (IFT), dilational interfacial visco-elasticity, and emulsion stability. A relationship between the adsorption dynamics and IFT reduction with the hydrophobicity of the bacteria cells is found. The cells with highest hydrophobicity (79%) exhibit a very fast dynamic of adsorption and lead to relatively large interfacial elasticity values at short adsorption time. The maximum elasticity values (at the studied frequencies) are observed for bacteria cells with the intermediate hydrophobicity factor (34%), however, at longer adsorption times. The emulsification studies show that among the three bacteria, just RAG1 provides a good capability to stabilize crude oil in brine emulsions, which correlates with the observed fast dynamics of adsorption and high elasticity values at short times. The salinity of the aqueous phase is also discussed as an important factor for the emulsion formation and stabilization.
- Published
- 2022
- Full Text
- View/download PDF
37. Pressure Tensor of Nanoscopic Liquid Drops.
- Author
-
Segovia-López, José G. and Carbajal-Domínguez, Adrian
- Subjects
- *
DROPLETS , *PRESSURE , *INHOMOGENEOUS materials , *INTERFACIAL stresses , *DENSITY functional theory , *TENSOR fields - Abstract
This study describes the structure of an inhomogeneous fluid of one or several components that forms a spherical interface. Using the stress tensor of Percus-Romero, which depends on the density of one particle and the intermolecular potential, it provides an analytical development leading to the microscopic expressions of the pressure differences and the interfacial properties of both systems. The results are compared with a previous study and agree with the description of the mean field. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
38. Effects of Graphene Oxidation on Interaction Energy and Interfacial Thermal Conductivity of Polymer Nanocomposite: A Molecular Dynamics Approach
- Author
-
Carlos Sáenz Ezquerro, Agustín Chiminelli, Francesco Maria Bellussi, and Manuel Laspalas
- Subjects
Materials science ,graphene ,interaction energy ,interfacial properties ,kapitza resistance ,molecular dynamics ,polymer nanocomposite ,Polymer nanocomposite ,General Chemical Engineering ,Oxide ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Article ,law.invention ,chemistry.chemical_compound ,law ,Interfacial thermal resistance ,General Materials Science ,QD1-999 ,chemistry.chemical_classification ,Polypropylene ,Graphene ,Epoxy ,Polymer ,Interaction energy ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Chemistry ,chemistry ,Chemical engineering ,visual_art ,visual_art.visual_art_medium ,0210 nano-technology - Abstract
Interfacial characteristics of polymer nanocomposites represent a crucial aspect to understand their global properties and to evaluate the interaction between nanofillers and matrix. In this work we used a molecular dynamics (MD) approach to characterize the interfacial region at the atomistic scale of graphene-based polymer nanocomposites. Three different polymer matrixes were considered, polylactic acid (PLA), polypropylene (PP) and epoxy resin (EPO), which were reinforced with three types of graphene fillers: pristine graphene (G), graphene oxide (GO) and reduced graphene oxide (rGO). In particular, the compatibility of the nanofillers in polymer matrixes were evaluated in terms of the interaction energy, while the interfacial thermal resistance (Kapitza resistance) between matrices and fillers was calculated with a nonequilibrium molecular dynamics (NEMD) method. Results showed that the oxidation degree plays an important role on the studied properties of the interfacial region. In particular, it was observed that the Kapitza resistance is decreased in the oxidized graphene (GO and rGO), while interaction energy depended on the polarity of the polymer matrix molecules and the contribution of the Coulombic component.
- Published
- 2021
39. Bolaamphiphiles Derived from Alkenyl L-Rhamnosides and Alkenyl D-Xylosides: Importance of the Hydrophilic Head.
- Author
-
Gatard, Sylvain, Nasir, Mehmet Nail, Deleu, Magali, Klai, Nadia, Legrand, Vincent, and Bouquillon, Sandrine
- Subjects
- *
HYDROPHILIC compounds , *CONFORMATIONAL analysis , *XYLOSIDE , *RHAMNOSIDES , *FOURIER transform infrared spectroscopy - Abstract
The two step synthesis of a new bolaamphiphile derived from alkenyl L-rhamnosides was described. The general synthetic strategy of bolaamphiphiles derived from L-rhamnose was based on a previous work describing the synthesis of bolaamphiphiles derived from D-xylose. The conformational properties of this new compound were investigated by FTIR spectroscopy in an aqueous film in order to obtain a reference for further studies about the membrane-interacting properties. Moreover, the surface activity of this new bolaamphiphile was analyzed by Langmuir balance technology and was compared with that of the analogous bolaamphiphile derived from alkenyl D-xylosides. The findings indicate that the rhamnoside-based bolaform has an increased surface activity and a better ability to form aggregates than xyloside-based one. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
40. Interfacial Structures and Properties of Organic Materials for Biosensors: An Overview.
- Author
-
Yan Zhou, Cheng-Wei Chiu, and Hong Liang
- Subjects
- *
BIOSENSORS , *MOLECULAR self-assembly , *SENSITIVITY analysis , *CHEMICAL kinetics , *CARBON nanotubes , *CONDUCTING polymers - Abstract
Abstract: The capabilities of biosensors for bio-environmental monitoring have profound influences on medical, pharmaceutical, and environmental applications. This paper provides an overview on the background and applications of the state-of-the-art biosensors. Different types of biosensors are summarized and sensing mechanisms are discussed. A review of organic materials used in biosensors is given. Specifically, this review focuses on self-assembled monolayers (SAM) due to their high sensitivity and high versatility. The kinetics, chemistry, and the immobilization strategies of biomolecules are discussed. Other representative organic materials, such as graphene, carbon nanotubes (CNTs), and conductive polymers are also introduced in this review. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
41. Interaction between Fish Skin Gelatin and Pea Protein at Air-Water Interface after Ultrasound Treatment.
- Author
-
Odelli, Davide, Sarigiannidou, Krystalia, Soliani, Alberto, Marie, Rodolphe, Mohammadifar, Mohammad Amin, Jessen, Flemming, Spigno, Giorgia, Vall-llosera, Mar, de Carvalho, Antonio Fernandes, Verni, Michela, and Casanova, Federico
- Subjects
AIR-water interfaces ,FISH skin ,PEA proteins ,GELATIN ,MOLECULAR weights - Abstract
The interaction between fish skin gelatin (FG) and pea protein isolate (PPI) was investigated at the air-water interface (A-W) before and after a high intensity (275 W, 5 min) ultrasound treatment (US). We analyzed the properties of the single protein suspensions as well as an equal ratio of FG:PPI (MIX), in terms of ζ-potential, particle size, molecular weight, bulk viscosity and interfacial tension. The foaming properties were then evaluated by visual analysis and by Turbiscan Tower. Confocal laser scanning microscopy (CLSM) was employed to explore the role of the proteins on the microstructure of foams. The results showed that the ultrasound treatment slightly influenced physicochemical properties of the proteins, while in general, did not significantly affect their behavior both in bulk and at the air-water interface. In particular, PPI aggregate size was reduced (−48 nm) while their negative charges were increased (−1 mV) after the treatment. However, when the proteins were combined, higher molecular weight of aggregates, higher foam stability values (+14%) and lower interfacial tension (IFT) values (47.2 ± 0.2 mN/m) were obtained, leading us to assume that a weak interaction was developed between them. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
42. Molecular Dynamics Simulation on the Effect of Self-Resistance Electric Heating on Carbon Fiber Surface Chemical Properties and Fiber/PP Interfacial Behavior.
- Author
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He, Qingzhu, Liu, Jiaqing, Zhang, Muhan, Zhai, Zhanyu, and Jiang, Bingyan
- Subjects
- *
ELECTRIC heating , *MOLECULAR dynamics , *CARBON fibers , *CHEMICAL properties , *SURFACE properties , *RADIAL distribution function , *DOUBLE walled carbon nanotubes , *INTERFACIAL bonding - Abstract
Carbon fiber-reinforced thermoplastic (CFRT) composites have been dramatically employed in the automotive field on account of their superior performances, such as being light weight and high-strength. Self-resistance electric (SRE) heating provides a solution to the problem of high energy consumption in the conventional process of CFRT composites. The effect of SRE heating on the surface chemical properties of carbon fiber (CF) was investigated by X-ray photoelectron spectroscopy (XPS). XPS analysis suggests that the C-O-C epoxy group, the CF surface, would be degraded after SRE heating with strong current intensity, while there are weak changes in the content of -C-OH, -C-O-C-, -C-NH2 and -COOH groups with current intensity. The interfacial bonding properties and the radial distribution function (RDF) of CF–PP interfaces were carried out by molecular dynamics (MD) simulation. The simulation results show that the adhesion between the PP and the E44 sizing agent is weaker than that between CF and PP. There are no interaction modes between the PP and E44 sizing agent except van der Waals and electrostatic adsorption. The presence of the E44 sizing agent does not change the bonding mechanism at the interface of CF/PP. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
43. Surfactant-Like Behavior for the Adsorption of Mixtures of a Polycation and Two Different Zwitterionic Surfactants at the Water/Vapor Interface
- Author
-
Eduardo Guzmán, Ramón G. Rubio, Francisco Ortega, Laura Fernández-Peña, and Andrew Akanno
- Subjects
Polymers ,Surface Properties ,surfactant ,complexation ,Pharmaceutical Science ,Chloride ,Micelle ,Article ,Analytical Chemistry ,lcsh:QD241-441 ,Surface tension ,Surface-Active Agents ,chemistry.chemical_compound ,Adsorption ,lcsh:Organic chemistry ,Pulmonary surfactant ,Drug Discovery ,medicine ,Química física ,interfacial properties ,Physical and Theoretical Chemistry ,polyelectrolyte ,Chemistry ,Organic Chemistry ,fluid interfaces ,Polyelectrolytes ,Polyelectrolyte ,Steam ,Electrophoresis ,Monomer ,Chemical engineering ,adsorption ,Chemistry (miscellaneous) ,Molecular Medicine ,medicine.drug - Abstract
The bulk and interfacial properties of solutions formed by a polycation (i.e., poly(diallyl-dimethylammonium chloride), PDADMAC) and two different zwitterionic surfactants (i.e., coco-betaine (CB) and cocoamidopropyl-betaine (CAPB)) have been studied. The bulk aggregation of the polyelectrolyte and the two surfactants was analyzed by turbidity and electrophoretic mobility measurements, and the adsorption of the solutions at the fluid interface was studied by surface tension and interfacial dilational rheology measurements. Evidence of polymer&ndash, surfactant complex formation in bulk was only found when the number of surfactant molecules was closer to the number of charged monomers in solutions, which suggests that the electrostatic repulsion associated with the presence of a positively charged group in the surfactant hinders the association between PDADMAC and the zwitterionic surfactant for concentrations in which there are no micelles in solution. This lack of interaction in bulk is reflected in the absence of an influence of the polyelectrolyte in the interfacial properties of the mixtures, with the behavior being controlled by the presence of surfactant. This work has evidenced the significant importance of the different interactions involved in the system for controlling the interaction and complexation mechanisms of in polyelectrolyte&ndash, surfactant mixtures.
- Published
- 2019
44. Recent Progress Using Solid-State Materials for Hydrogen Storage: A Short Review.
- Author
-
Lee, Seul-Yi, Lee, Jong-Hoon, Kim, Yeong-Hun, Kim, Jong-Woo, Lee, Kyu-Jae, and Park, Soo-Jin
- Subjects
HYDROGEN storage ,INTERMOLECULAR forces ,PHYSISORPTION ,SURFACES (Technology) ,ADSORPTION kinetics ,POROUS materials ,SORBENTS - Abstract
With the rapid growth in demand for effective and renewable energy, the hydrogen era has begun. To meet commercial requirements, efficient hydrogen storage techniques are required. So far, four techniques have been suggested for hydrogen storage: compressed storage, hydrogen liquefaction, chemical absorption, and physical adsorption. Currently, high-pressure compressed tanks are used in the industry; however, certain limitations such as high costs, safety concerns, undesirable amounts of occupied space, and low storage capacities are still challenges. Physical hydrogen adsorption is one of the most promising techniques; it uses porous adsorbents, which have material benefits such as low costs, high storage densities, and fast charging–discharging kinetics. During adsorption on material surfaces, hydrogen molecules weakly adsorb at the surface of adsorbents via long-range dispersion forces. The largest challenge in the hydrogen era is the development of progressive materials for efficient hydrogen storage. In designing efficient adsorbents, understanding interfacial interactions between hydrogen molecules and porous material surfaces is important. In this review, we briefly summarize a hydrogen storage technique based on US DOE classifications and examine hydrogen storage targets for feasible commercialization. We also address recent trends in the development of hydrogen storage materials. Lastly, we propose spillover mechanisms for efficient hydrogen storage using solid-state adsorbents. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
45. Surface Chemistry Study of the Interactions of Sesame Oil with Meibomian Films.
- Author
-
Eftimov, Petar, Yokoi, Norihiko, and Georgiev, Georgi As.
- Subjects
- *
SESAME oil , *SURFACE chemistry , *VEGETABLE oils , *MEIBOMIAN glands , *BREWSTER'S angle , *SURFACE pressure - Abstract
A possible approach for the treatment of meibomian gland disease (MGD) can be the supplementation of meibomian gland secretion (MGS) with nonpolar lipids (NPL) rich plant oils. Sesame oil (SO), approximately equal in monounsaturated fat (oleic acid, 40% of total) and polyunsaturated fat (linoleic acid, 42% of total), has shown multiple health benefits due to its anti-inflammatory and antioxidant effects. Thus, the interactions between SO and MGS in surface layers deserve further study. Therefore, pseudobinary films were formed with controlled MGS/SO molar ratios (0%, 10%, 30%, 50%, and 100% SO) at the air/water surface of the Langmuir trough over phosphate buffered saline (pH 7.4) subphase. Surface pressure (π)-area (A) isotherms and Brewster angle microscopy observations showed nonideal interactions where SO aggregates with MGS and complements the NPL stratum of the meibomian layers. The analysis of stress relaxation transients with Kohlrausch–Williams–Watts equation revealed that the supplementation of fixed amount of MGS with excess lipids via SO altered the dilatational elasticity of the films as reflected by the increase of the exponent β. Thus, SO with its unique combination of high oxidative stability and abundance of long polyunsaturated acyl chains might be a useful supplement to MGS layers. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
46. Surfactant-Like Behavior for the Adsorption of Mixtures of a Polycation and Two Different Zwitterionic Surfactants at the Water/Vapor Interface
- Author
-
Akanno, Andrew, Guzmán Solis, Eduardo, Fernández Peña, Laura, Ortega Gómez, Francisco, González Rubio, Ramón, Akanno, Andrew, Guzmán Solis, Eduardo, Fernández Peña, Laura, Ortega Gómez, Francisco, and González Rubio, Ramón
- Abstract
The bulk and interfacial properties of solutions formed by a polycation (i.e., poly(diallyl-dimethylammonium chloride), PDADMAC) and two different zwitterionic surfactants (i.e., coco-betaine (CB) and cocoamidopropyl-betaine (CAPB)) have been studied. The bulk aggregation of the polyelectrolyte and the two surfactants was analyzed by turbidity and electrophoretic mobility measurements, and the adsorption of the solutions at the fluid interface was studied by surface tension and interfacial dilational rheology measurements. Evidence of polymer–surfactant complex formation in bulk was only found when the number of surfactant molecules was closer to the number of charged monomers in solutions, which suggests that the electrostatic repulsion associated with the presence of a positively charged group in the surfactant hinders the association between PDADMAC and the zwitterionic surfactant for concentrations in which there are no micelles in solution. This lack of interaction in bulk is reflected in the absence of an influence of the polyelectrolyte in the interfacial properties of the mixtures, with the behavior being controlled by the presence of surfactant. This work has evidenced the significant importance of the different interactions involved in the system for controlling the interaction and complexation mechanisms of in polyelectrolyte–surfactant mixtures., Ministerio de Economía y Competitividad (MINECO), Depto. de Química Física, Fac. de Ciencias Químicas, TRUE, pub
- Published
- 2019
47. Pressure-Assisted Development and Characterization of Al-Fe Interface for Bimetallic Composite Castings: An Experimental and Statistical Investigation for a Low-Pressure Regime.
- Author
-
Rashid, Tayyiba, Qaiser Saleem, Muhammad, Ahmad Mufti, Nadeem, Asif, Noman, Ishfaq, M. Kashif, and Naqvi, Maham
- Subjects
GREY relational analysis ,CHEMICAL affinity ,INTERMETALLIC compounds ,DYNAMIC loads ,ALUMINUM castings ,ALUMINUM composites - Abstract
A review of the available literature indicates that the development of metal-reinforced castings present intriguing prospects but carry inherent challenges owing to differences in thermal coefficients, chemical affinities, diffusion issues and the varying nature of intermetallic compounds. It is supported that pressure application during solidification may favorably influence the dynamics of the aforementioned issues; nevertheless, not only certain limitations have been cited, but also some pressure and process regimes have not yet been investigated and optimized. This work employs the pressure-assisted approach for bimetallic steel-reinforced aluminum composite castings at a low-pressure regime and thoroughly investigates the role of three process parameters, namely pouring temperature (800–900 °C), pressure (10–20 bars) and holding time (10–20 s), for producing sound interfaces. The Taguchi L9 orthogonal array has been employed as the Design of the Experiment, while dominant factors have been determined via analysis of variance and the grey relational analysis multi-objective optimization technique. Supplementary analysis through optical micrographs, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) has been utilized to quantify interfacial layer thicknesses and to study microstructural and compositional aspects of the interface. Nano-indentation tests under static and dynamic loading have also been performed for mechanical strength characterization. It has been found that uniform interfaces with verifiable diffusion are obtainable, with the pouring temperature being the most influential parameter (percentage contribution 92.84%) in this pressure regime. The experiments performed at optimum conditions of pouring temperature, applied pressure and holding time produced a ~328% thicker interface layer, 19.42% better nano-hardness and a 19.10% improved cooling rate as compared to the minimum input values of the said parameters. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
48. Comparative Study on Foaming Properties of Egg White with Yolk Fractions and Their Hydrolysates.
- Author
-
Li, Xin, Wang, Yue-Meng, Sun, Cheng-Feng, Lv, Jian-Hao, and Yang, Yan-Jun
- Subjects
EGG yolk ,EGG whites ,FOAM ,SURFACE active agents ,MANUFACTURING processes ,COMPARATIVE studies ,LIPASES - Abstract
As an excellent foaming agent, egg white protein (EWP) is always contaminated by egg yolk in the industrial processing, therefore, decreasing its foaming properties. The aim of this study was to simulate the industrial EWP (egg white protein with 0.5% w/w of egg yolk) and characterize their foaming and structural properties when hydrolyzed by two types of esterase (lipase and phospholipase A
2 ). Results showed that egg yolk plasma might have been the main fraction, which led to the poor foaming properties of the contaminated egg white protein compared with egg yolk granules. After hydrolyzation, both foamability and foam stability of investigated systems thereof (egg white protein with egg yolk, egg white protein with egg yolk plasma, and egg white protein with egg yolk granules) increased significantly compared with unhydrolyzed ones. However, phospholipids A2 (PLP) seemed to be more effective on increasing their foaming properties as compared to those systems hydrolyzed by lipase (LP). The schematic diagrams of yolk fractions were proposed to explain the aggregation and dispersed behavior exposed in their changes of structures after hydrolysis, suggesting the aggregated effects of LP on yolk plasma and destructive effects of PLP on yolk granules, which may directly influence their foaming properties. [ABSTRACT FROM AUTHOR]- Published
- 2021
- Full Text
- View/download PDF
49. Droplet Microfluidics for Food and Nutrition Applications.
- Author
-
Schroen, Karin, Berton-Carabin, Claire, Renard, Denis, Marquis, Mélanie, Boire, Adeline, Cochereau, Rémy, Amine, Chloé, and Marze, Sébastien
- Subjects
MICROFLUIDICS ,APPLIED sciences ,MICROFLUIDIC devices ,FOOD science ,CHEMICAL kinetics ,DIGESTION ,NUTRITION - Abstract
Droplet microfluidics revolutionizes the way experiments and analyses are conducted in many fields of science, based on decades of basic research. Applied sciences are also impacted, opening new perspectives on how we look at complex matter. In particular, food and nutritional sciences still have many research questions unsolved, and conventional laboratory methods are not always suitable to answer them. In this review, we present how microfluidics have been used in these fields to produce and investigate various droplet-based systems, namely simple and double emulsions, microgels, microparticles, and microcapsules with food-grade compositions. We show that droplet microfluidic devices enable unprecedented control over their production and properties, and can be integrated in lab-on-chip platforms for in situ and time-resolved analyses. This approach is illustrated for on-chip measurements of droplet interfacial properties, droplet–droplet coalescence, phase behavior of biopolymer mixtures, and reaction kinetics related to food digestion and nutrient absorption. As a perspective, we present promising developments in the adjacent fields of biochemistry and microbiology, as well as advanced microfluidics–analytical instrument coupling, all of which could be applied to solve research questions at the interface of food and nutritional sciences. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
50. Effects of Graphene Oxidation on Interaction Energy and Interfacial Thermal Conductivity of Polymer Nanocomposite: A Molecular Dynamics Approach.
- Author
-
Bellussi, Francesco Maria, Sáenz Ezquerro, Carlos, Laspalas, Manuel, and Chiminelli, Agustín
- Subjects
- *
MOLECULAR dynamics , *POLYLACTIC acid , *THERMAL conductivity , *INTERFACIAL resistance , *POLYMERS , *POLYMERIC nanocomposites , *NANOCOMPOSITE materials - Abstract
Interfacial characteristics of polymer nanocomposites represent a crucial aspect to understand their global properties and to evaluate the interaction between nanofillers and matrix. In this work we used a molecular dynamics (MD) approach to characterize the interfacial region at the atomistic scale of graphene-based polymer nanocomposites. Three different polymer matrixes were considered, polylactic acid (PLA), polypropylene (PP) and epoxy resin (EPO), which were reinforced with three types of graphene fillers: pristine graphene (G), graphene oxide (GO) and reduced graphene oxide (rGO). In particular, the compatibility of the nanofillers in polymer matrixes were evaluated in terms of the interaction energy, while the interfacial thermal resistance (Kapitza resistance) between matrices and fillers was calculated with a nonequilibrium molecular dynamics (NEMD) method. Results showed that the oxidation degree plays an important role on the studied properties of the interfacial region. In particular, it was observed that the Kapitza resistance is decreased in the oxidized graphene (GO and rGO), while interaction energy depended on the polarity of the polymer matrix molecules and the contribution of the Coulombic component. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
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