387 results on '"SOLUBILITY PARAMETERS"'
Search Results
2. Molecular dynamics simulation of CO2 in organic solvent and polymer–solvent solutions
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Liu, Jiaxiang, Wang, Wenjuan, and Li, Jixiang
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- 2025
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3. Extraction, recovery, and characterization of lignin from industrial corn stover lignin cake
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Bécsy-Jakab, Villő Enikő, Savoy, Anthony, Saulnier, Brian K., Singh, Sandip K., and Hodge, David B.
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- 2024
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4. Separation of wax fraction in asphalt binder by an improved method and determination of its molecular structure
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Ding, Haibo, Zhang, Haopeng, Zhang, Hong, Liu, Dongrui, Qiu, Yanjun, and Hussain, Arshad
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- 2022
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5. Ionic liquids alkyl-imidazolium thiocyanates: Comprehensive thermochemical study
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Zaitsau, Dzmitry H., Yermalayeu, Andrei V., and Verevkin, Sergey P.
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- 2021
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6. Controlling the micro-structure of disperse water-based inks for ink-jet printing
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Gao, Chengyong, Zhang, Zhaoling, Xing, Tieling, Hou, Xueni, and Chen, Guoqiang
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- 2020
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7. Thermodynamic Assessment of the Pyrazinamide Dissolution Process in Some Organic Solvents.
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Tovar-Amézquita, Jesus, Rincón-Guio, Cristian, Torres-Suarez, Francy Elaine, Florez, Magda Melissa, Ortiz, Claudia Patricia, Martinez, Fleming, and Delgado, Daniel Ricardo
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THERMODYNAMICS , *DRUG solubility , *THERMODYNAMIC functions , *PYRAZINAMIDE , *MEDICAL sciences , *ORGANIC solvents - Abstract
Pyrazinamide is a first line drug used for the treatment of tuberculosis, a pathology that caused the death of more than 1.3 million people in the world during 2022, according to WHO, being a drug of current interest due to its relevance in pharmaceutical and medical sciences. In this context, solubility is one of the most important physicochemical parameters in the development and/or optimization of new pharmaceutical forms, so the present work aims to present a thermodynamic study of the solubility of pyrazinamide in nine organic solvents of pharmaceutical interest. Using the shake-flask method and UV/Vis spectrophotometry, the solubility of this drug was determined at 9 temperatures; the maximum solubility was obtained in dimethyl sulfoxide at 318.15 K ( x 2 = 0.0816 ± 0.004 ) and the minimum in cyclohexane at 283.15 K ( 1.73 ± 0.05 × 10 − 5 ). From the apparent solubility data, the thermodynamic functions of solution and mixing were calculated, indicating an endothermic process. In addition, the solubility parameter of pyrazinamide was calculated using the Hoftyzer-van Krevelen (32.90 MPa1/2) and Bustamante (28.14 MPa1/2) methods. The maximum solubility was reached in dimethyl sulfoxide and the minimum in cyclohexane. As for the thermodynamic functions, the entropy drives the solution process in all cases. In relation to the solubility parameter, it can be analyzed that the mathematical models offer approximations; however, the experimental data are still primordial at the time of inferring any process. [ABSTRACT FROM AUTHOR]
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- 2024
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8. The Increase in the Plasticity of Microcrystalline Cellulose Spheres' When Loaded with a Plasticizer.
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Paulausks, Artūrs, Kolisnyk, Tetiana, and Mohylyuk, Valentyn
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PLASTICIZERS , *CELLULOSE , *COMPACTING , *SOLUBILITY , *SOLVENTS - Abstract
Compaction pressure can induce an undesirable solid-state polymorphic transition in drugs, fragmentation, loss of coated pellet integrity, and the decreased viability and vitality of microorganisms. Thus, the excipients with increased plasticity can be considered as an option to decrease the undesirable effects of compaction pressure. This study aims to increase the plasticity (to reduce the mean yield pressure; Py) of dried microcrystalline cellulose (MCC) by loading it with a specially selected plasticizer. Diethyl citrate (DEC), water, and glycerol were the considered plasticizers. Computation of solubility parameters was used to predict the miscibility of MCC with plasticizers (possible plasticization effect). Plasticizer-loaded MCC spheres with 5.0 wt.% of water, 5.2 wt.% of DEC, and 4.2 wt.% glycerol were obtained via the solvent method, followed by solvent evaporation. Plasticizer-loaded formulations were characterised by TGA, DSC, pXRD, FTIR, pressure-displacement profiles, and in-die Heckel plots. Py was derived from the in-die Heckel analysis and was used as a plasticity parameter. In comparison with non-plasticized MCC (Py = 136.5 MPa), the plasticity of plasticizer-loaded formulations increased (and Py decreased) from DEC (124.7 MPa) to water (106.6 MPa) and glycerol (99.9 MPa), and that was in full accordance with the predicted miscibility likeliness order based on solubility parameters. Therefore, water and glycerol were able to decrease the Py of non-plasticized MCC spheres by 16.3 and 30.0%, respectively. This feasibility study showed the possibility of modifying the plasticity of MCC by loading it with a specially selected plasticizer. [ABSTRACT FROM AUTHOR]
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- 2024
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9. Study on the Compatibility of SBR and Asphalt Base Based on Molecular Simulation.
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Jiao, Xiaolei, Huang, Dandan, Zhao, Song, and Ouyang, Jian
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ASPHALT , *ASPHALT modifiers , *STYRENE-butadiene rubber , *MOLECULAR dynamics , *SCANNING electron microscopes , *ROAD construction - Abstract
In the field of highway construction, the application of styrene–butadiene rubber (SBR)-modified asphalt has gained popularity across different levels of road surfaces. A crucial aspect in ensuring the efficacy of this modification lies in the compatibility between SBR and the matrix asphalt. To address this, the current study utilizes molecular dynamics simulation as a technique. By establishing a model for the SBR-modified asphalt mixture, the research quantifies the compatibility level between the SBR modifier and the asphalt. The aim is to uncover the underlying mechanisms of compatibility between the SBR modifier and the base asphalt, ultimately contributing to the improvement of the storage stability of SBR-modified asphalt, which holds significant importance. The investigation began with the creation of models for both the base asphalt and the SBR modifier. A model for the SBR-modified asphalt blending system was then formulated based on these initial models. After undergoing geometry optimization and annealing procedures, the model attained its lowest energy state, providing a reliable basis for examining the performance of SBR-modified asphalt. The study proceeded to calculate solubility parameters and interaction energies of the system to evaluate the compatibility between the SBR modifier and the base asphalt at various temperatures. The analysis of these parameters shed light on the compatibility mechanism between the two components. Notably, it was found that at a temperature of 160 ℃, the compatibility was significantly enhanced. The findings were further corroborated through scanning electron microscope and rheological tests. The outcomes of this research offer theoretical guidance for the application of SBR-modified asphalt. [ABSTRACT FROM AUTHOR]
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- 2024
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10. Evaluation of solubility parameters and relative energy difference (RED) on the preparation of polysulfone/polyethylene glycol membrane: A study on the casting solution and coagulation bath.
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Dehghan, Rahim, Kordkatooli, Zahra, and Barzin, Jalal
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POLYETHYLENE glycol , *COAGULATION , *SOLUBILITY , *MOLECULAR weights , *PERMEABILITY , *MIXTURES - Abstract
Solubility parameters are effective factors for controlling membrane preparation based on hydrophilic/hydrophobic polymers. Hansen solubility parameters (HSPs) of a polysulfone/polyethylene glycol (PSU/PEG) in increasing PEG molecular weights and binary coagulation bath of solvent/non-solvent mixtures are investigated. The results revealed that with increased PEG molecular weight in the casting solution, the relative energy difference (RED) of the solution increases, and subsequently its instability increases too. On the other hand, by increasing the solvent in the coagulation bath, RED decreases. Findings demonstrated that by increasing PEG molecular weight to 15,000 g /mol and increasing solvent to 60 wt% in the coagulation bath, an interconnected sponge-like structure with maximum mean pore size (120 nm) was achieved. With increased PEG molecular weight, membrane morphology tended toward to a sponge-like structure due to delayed demixing in the phase inversion stage. Furthermore, pure water permeability and rejection capability of membranes exhibited that with increasing RED of casting solution and reducing RED of coagulation bath, the highest permeability (2199 L/m2h and the lowest rejection capability (33%) of the membrane were attained. This study confirmed that, for the PSU/PEG system, by controlling the solubility parameters, RED value of casting solution and coagulation bath, membrane characteristics can be controlled. [ABSTRACT FROM AUTHOR]
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- 2024
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11. Flavonoids in the Spotlight: Bridging the Gap between Physicochemical Properties and Formulation Strategies.
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Berga, Marta, Logviss, Konstantins, Lauberte, Liga, Paulausks, Artūrs, and Mohylyuk, Valentyn
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FLAVONOIDS , *FLAVONOID glycosides , *MELTING points , *PLANT polyphenols , *DIETARY supplements , *PLANT health - Abstract
Flavonoids are hydroxylated polyphenols that are widely distributed in plants with diverse health benefits. Despite their popularity, the bioavailability of flavonoids is often overlooked, impacting their efficacy and the comparison of products. The study discusses the bioavailability-related physicochemical properties of flavonoids, with a focus on the poorly soluble compounds commonly found in dietary supplements and herbal products. This review sums up the values of pKa, log P, solubility, permeability, and melting temperature of flavonoids. Experimental and calculated data were compiled for various flavonoid subclasses, revealing variations in their physicochemical properties. The investigation highlights the challenges posed by poorly soluble flavonoids and underscores the need for enabling formulation approaches to enhance their bioavailability and therapeutic potential. Compared to aglycones, flavonoid glycosides (with sugar moieties) tend to be more hydrophilic. Most of the reviewed aglycones and glycosides exhibit relatively low log P and high melting points, making them "brick dust" candidates. To improve solubility and absorption, strategies like size reduction, the potential use of solid dispersions and carriers, as well as lipid-based formulations have been discussed. [ABSTRACT FROM AUTHOR]
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- 2023
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12. Hansen Solubility Parameters (HSPs): A Reliable Tool for Assessing the Selectivity of Pristine and Hybrid Polymer Nanocomposites in the Presence of Volatile Organic Compounds (VOCs) Mixtures.
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Ollé, Enric Perarnau, Casals‐Terré, Jasmina, Martínez, Joan Antoni López, and Farré‐Lladós, Josep
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VOLATILE organic compounds , *POLYMERIC nanocomposites , *MULTIWALLED carbon nanotubes , *POLYMERIC membranes , *SOLUBILITY , *GAS detectors , *CHEMICAL affinity - Abstract
Polymeric materials are widely employed for monitoring volatile organic compounds (VOCs). Compared to other sensitive materials, polymers can provide a certain degree of selectivity, based on their chemical affinity with organic solvents. The addition of conductive nanoparticles within the polymer layer is a common practice in recent years to improve the sensitivity of these materials. However, it is still unclear the effect that the nanoparticles have on the selectivity of the polymer membrane and vice versa. The current work proposes a methodology based on the Hansen solubility parameters, for assessing the selectivity of both pristine and hybrid polymer nanocomposites. The impedance response of thin polydimethylsiloxane (PDMS) films is compared to the response of hybrid polymer films, based on the addition of multi‐walled carbon nanotubes (MWCNTs). With the addition of just 1 wt.% of MWCNTs, fabricated sensors showcased a significant improvement in sensitivity, faster response times, as well as enhanced classification of non‐polar analytes (>22% increase) compared to single PDMS layers. The methodology proposed in this work can be employed in the future to assess and predict the selectivity of polymers in single or array‐based gas sensors, microfluidic channels, and other analytical devices for the purpose of VOCs discrimination. [ABSTRACT FROM AUTHOR]
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- 2023
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13. Nanostructured Lipid Carriers of Eperisone Hydrochloride using Quality By Design Approach.
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Bagde, Shapali and Mamidi, Hemanth Kumar
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LIPIDS ,ZETA potential ,FACTORIAL experiment designs ,DATA release ,INDEPENDENT variables - Abstract
Objective: The current work involves formulation development of nanostructured lipid carrier (NLC) of eperisone hydrochloride (EPE) using quality by design (QbD) approach. Materials and Methods: Initial screening of solid and liquid lipids was performed based on the Hansen solubility parameters of EPE and the lipids and later confirmed using saturation solubility studies. The optimum formulation was identified using three-squared randomized full factorial design. High shear homogenization coupled with ultrasonication was used to prepare the NLCs. The effect of the independent variables on the dependent variables was analyzed using response surface graphs and ANOVA. The optimized formulation is characterized for mean particle size, zeta potential, entrapment efficiency, in vitro drug release and subjected to stability testing. Results and Discussion: Precirol® ATO 5, CapryolTM 90, and Pluronic® F127 are found to be ideal solid lipid, liquid lipid and surfactant respectively based on the initial screening. Amount of lipid mixture (X1) and the amount of surfactant (X2) were selected as independent variables and the entrapment efficiency (Y1), mean particle size (Y2) and zeta potential (Y3) were selected as dependent variables. The optimized NLC formulation has mean particle size of 175 nm, zeta potential -24.4 mV and entrapment efficiency of 78.64%. The in vitro drug release data suggested that the drug release follows Quasi-Fickian diffusion. The stability data showed that the NLCs are stable up to 3 months at refrigerated conditions. Conclusions: The Hansen solubility parameter approach coupled with QbD is a powerful tool for formulation of sustained release NLCs of highly soluble poorly soluble drugs. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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14. Isothermal compressibilities of l-leucine, L-asparagine and glycylglycine in aqueous electrolyte solutions
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Bansal, G. K.
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- 2022
15. A Homogenous, Photocrosslinkable Poly(dimethylsiloxane‐co‐methylvinylsiloxane) Solution in an Acrylate Monomer.
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Park, Seung Koo, Park, Bong Je, Shin, Eun Jin, Choi, Meejeong, Park, Suntak, and Shin, Hyung Cheol
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MONOMERS , *PLATINUM group catalysts , *VINYL polymers , *MOIETIES (Chemistry) , *PHOTOCHEMICAL curing , *CONDUCTING polymers , *ELASTOMERS - Abstract
In this study, a simple photocuring method is proposed for preparing PDMS elastomers using a homogenous poly(dimethylsiloxane) (PDMS) solution in tert‐butyl acrylate (tBA) as an alternative way of mechanically blending two kinds of PDMS respectively containing vinyl and hydridosilyl groups over a platinum catalyst. Poly(dimethylsiloxane‐co‐methylvinylsiloxane) (PDMSc) with 30 mol% of vinyl moieties is synthesized. The functionalized PDMS is estimated to be soluble in tBA from theoretical calculations of solubility parameters of PDMS and several liquid monomers. The PDMS solution is satisfactorily photocured under a conventional photoinitiator. Initial modulus and strain of the photocured films increase from 144 to 552 MPa and decrease from 3.96 to 1.84, respectively, as the tBA content rises from 5 to 30 wt%. They are extremely transparent in a visible region (T > 94%) regardless of the amount of tBA. The unreacted vinyl groups in PDMSc are inter‐ or intrareacted near 200 °C and γ‐hydrogen transfer reactions from the tert‐butyl groups in poly(tert‐butyl acrylate) occur over 250 °C. One of the photocrosslinked films exhibits outstanding performance as an electroactive polymer in application. In essence, this study will initiate a new methodological research into provision of PDMS elastomers using an easily formulated photocrosslinkable PDMS solution. [ABSTRACT FROM AUTHOR]
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- 2023
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16. Linking intermolecular interactions and rheological behaviour in capillary suspensions.
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Jarray, Ahmed, Feichtinger, Annika, and Scholten, Elke
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INTERMOLECULAR interactions , *CAPILLARIES , *INTERFACIAL tension , *MOLECULAR dynamics , *SUSPENSIONS (Chemistry) , *CRITICAL point (Thermodynamics) , *COLLOIDAL suspensions - Abstract
[Display omitted] Capillary suspensions feature networks of particles connected by liquid bridges, which are obtained by adding a small amount of a second immiscible liquid to a suspension. It is possible to link the network formation as well as the rheological behaviour of capillary suspensions to the intermolecular interactions of their constituents. Through a combination of experimental and numerical methods, we present a novel approach, based on Hansen solubility parameters computed from Molecular Dynamics (MD) simulations, to rationalize and predict the rheological behaviour of capillary suspensions. We investigated the formation of capillary suspensions for various combinations of bulk and secondary liquids mixed with hydrophilic silica particles. The predictions were confirmed experimentally by rheological analysis, interfacial tension measurements and microscopy (CLSM) imaging. Numerical and experimental results show that the Hansen solubility parameters theory allows to predict the formation of capillary suspensions, whose strength exponentially decays with decreasing intermolecular interactions between the secondary liquids and the dispersed particles. High immiscibility between the bulk and secondary liquid strengthens the gel up to a critical immiscibility point, above which the strength of the gel remains mostly affected by the affinity between the secondary liquids and the dispersed particles. Furthermore, we find that hydrogen-bonding and polar interactions control the formation of capillary suspensions. This simple approach can guide the selection of adequate solvents and immiscible secondary liquids, allowing an easy formulation of new particulate-based gels. [ABSTRACT FROM AUTHOR]
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- 2022
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17. Fully Atomistic Molecular Dynamics Simulation of the Structure and Morphology of Small‐Molecular Additives in Rubber Matrices.
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Liu, Peilei, Duan, Pengwei, Zhao, Hengheng, Li, Sai, and Liu, Jun
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MOLECULAR dynamics , *RUBBER , *DIFFUSION coefficients , *SMALL molecules , *BINDING energy - Abstract
This work investigates the compatibility of ten commercially available accelerators and ten antioxidants with three types of rubber by using molecular dynamics simulation. By constructing fully atomistic models of rubber and small molecules, firstly, the length and number of polymer chains, as well as the number of small molecules are optimized by calculating the solubility parameter. All simulated systems are guaranteed to reach equilibrium by checking the change of the density and energy. Then this work shows that the simulated results match well with each other, which are obtained from the value and the difference of the binding energy of the rubber systems, fractional free volume of the rubber systems, and self‐diffusion coefficient of small molecules calculated from the mean square displacement–time curve. And some small molecules which are more compatible with rubbers are found. More importantly, this study can further determine their compatibility preference by calculating the partition coefficients of small molecules in the rubber blends. Meanwhile, the temperature effect on the change of the compatibility is as well examined. In general, this work provides some guidance for determining the compatibility between rubber and small‐molecule additives, enabling the design of high‐performance rubber materials. [ABSTRACT FROM AUTHOR]
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- 2022
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18. Effect of Solvent Pretreatment of Polyester Fiber on its Dye-Uptake Based on the Concept of Solubility Parameters.
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Adeakin, Olanibugbe Adeniyi Samuel, Popoola, Adeola Victor, and Ajekwene, Kingsley Kema
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The present work investigates the effect of solvents with known solubility parameters on polyester filament yarn. The polyethylene terephthalate (PET) fibers were pretreated in 10 different solvents initially at 30 °C and 50 °C before dyeing procedure. The degree to which the solvents affected the morphological structure of the PET fibers was examined using scanning electron microscopy (SEM). The degree of cracks and voids increased for all the samples after pretreatment. The development of cracks and voids was much more for benzyl alcohol treated samples. The degree of liquid retention was least in chloroform, acetone, and n-hexane treated samples while the highest retention was observed in benzyl alcohol treated samples. This is attributed to their solubility parameters in relation to that of the polyester fiber. The specific stress and dye exhaustion was determined as a function of time of treatment. The dyeing kinetics for all the solvent pretreated samples showed similar pattern. However, an optimum dye exhaustion of about 25 % was obtained for the untreated sample (control). The dye exhaustion obtained for benzyl alcohol and dimethyl formamide treated samples was 94 % and 82 %, respectively, which was very high compared to the other pretreated samples. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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19. Molecular recognition at interfaces. Adhesion, wetting and bond scrambling
- Author
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Alberto Ciferri
- Subjects
cohesive energy ,surface energy ,solubility parameters ,binding constants ,adhesion ,wetting ,Chemistry ,QD1-999 - Abstract
The quantitative description of the supramolecular interaction occurring at the adhesion surfaces of different polymers has enabled elaborate dissections of contributions to cohesive and surface energies. An alternative analysis is proposed here based on solubility parameters and binding constants that traditionally describe the weakest and relatively larger association energies in polymer blends. The article emphasizes a feature of supramolecular polymers that has not received adequate consideration: The dynamic bond scrambling that allows a most efficient molecular recognition over significant areas of synthetic and biological surfaces.
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- 2022
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20. Enhancing 3DSPs estimation: The dispersive solubility parameter adjusted by means of molar refraction, coordination number and molar volume using the DiPEVa model.
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Nunes Pereira, Claudio, Cañete Vebber, Guilherme, Pierozan Bernardes, Giordano, and Bianchi, Otávio
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MOLECULAR volume , *MOLECULAR polarizability , *REFRACTIVE index , *SURFACE phenomenon , *CHEMICAL processes - Abstract
[Display omitted] • Three-dimensional solubility parameters (3DSP) of organic molecules are refined for surface tension adjustments using the DiPEVa optimization method. • The DiPEVa model is enhanced to compute dispersive solubility parameters (δ D) by integrating molecular polarizability measures adjusted via ratio of coordination numbers and molar volume. • The findings are relevant for applications involving surface and interfacial phenomena and dielectric properties. This study comprehensively analyzes the empirical relationships between polarizability measurements, such as refractivity index and molar refraction, or the length of the homologous chain (HCL), and the dispersive solubility parameter (δ D). The authors investigated the correlation between these parameters by utilizing a database encompassing various chemical groups across a range of aliphatic and aromatic molecules. An innovative approache enhaces the well known relationship between the the dispersive solubility parameter (δ D) and the Lorentz-Lorenz function, adjusting the dispersive solubility parameters by the ratio of coordination numbers and molar volumes as correction factors. Notably, the adjusted δ D demonstrated a strong linear correlation with MR, suggesting that MR can be a reliable predictor for δ D. This was further substantiated by the strong correlation coefficients obtained (such as an adjusted R-Square of 0.866), indicating the robustness of our empirical models. In conclusion, our research provides new insights into the solubility behaviour of molecules with the derived empirical relationships offering a valuable tool for predicting solubility parameters. These findings have practical implications for solvent selection, understanding liquid behaviours, and the design of chemical processes and materials. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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21. Adopting a Residual‐Energy‐Based Approach to Calculate the Solubility Parameters of n‐Alkanes.
- Author
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Khorsand Movaghar, Mohammad Reza, Humand, Mohammad, Peiro Ahmady Langeroudy, Kiana, Khajehvandi, Ebrahim, and Behnoud, Parisa
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EQUATIONS of state , *SOLUBILITY , *PENG-Robinson equation , *MOLECULAR volume , *ALKANES , *VAPOR pressure - Abstract
Two different paths were followed to calculate the solubility parameters (SP) of 133 alkanes. The first approach calculates SP from the points of view of internal pressure and residual energy, whereby Soave‐Redlich‐Kwong and Peng‐Robinson equations of state (EOSs) are employed with and without the volume‐shift correction. In the second approach, the cohesive energy concept is used and the saturation pressure and saturated liquid molar volume are separately computed by different models and coupled to one another. The results indicated that Approach 1 predicts SP with an error of 2.24 %, which is in the same order as that of Approach 2 but slightly better. The performance of Approach 1 was assessed by estimating the SP values of 33 substances from various families and comparing the results to an EOS‐based study. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
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22. Effect of XlogP and hansen solubility parameters on the prediction of small molecule modified docetaxel, doxorubicin and irinotecan conjugates forming stable nanoparticles
- Author
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Mei-Qi Xu, Ting Zhong, Xin Yao, Zhuo-Yue Li, Hui Li, Jing-Ru Wang, Zhen-Han Feng, and Xuan Zhang
- Subjects
docetaxel ,doxorubicin ,irinotecan ,hydrophobic parameters (xlogp) ,solubility parameters ,conjugate ,nanoparticles ,prediction ,Therapeutics. Pharmacology ,RM1-950 - Abstract
Small molecule-chemotherapeutic drug conjugate nanoparticles (SMCDC NPs) has a great advantage in improving drug loading. However, the factors which influence these conjugates forming stable nanoparticles (NPs) are currently unclear. In our previous studies, we synthesized a series of fatty acid-paclitaxel conjugates and suggested that the changes in the hydrophobic parameters (XlogP), solubility parameters and crystallinity of these fatty acid-paclitaxel conjugates were the key factors for affecting these small molecule-chemotherapeutic drug conjugates (SMCDCs) forming stable NPs in water. Here, we selected clinically widely used chemotherapeutic drug (docetaxel (DTX), doxorubicin (DOX) and irinotecan (Ir)) as model drug, and chose three straight-chain fatty acids (acetic acid (Ac), hexanoic acid (HA) and stearic acid (SA)) and one branched small molecule (N-(tert-butoxycarbonyl) glycine (B-G)) to synthesize 12 SMCDCs. Our results indicated that our prediction criterions obtained from paclitaxel conjugates were also appropriated for these synthesized SMCDCs. We suggested that the present studies expanded the scope of application of the above-mentioned influencing factors, provided research ideas for the rational design of SMCDC forming NPs and a basis for screening NPs with good anticancer activity.
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- 2021
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23. Interphase-Controlled Inkjet Printing of MicroInlaid OLEDs: Effects of Solvent- and Solute-Polymer Interactions.
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Park J, Kim W, Kim M, Jeong H, Lee K, Kil J, Yang S, Choi EH, and Park B
- Abstract
Inkjet printing, a highly promising technique for the cost-effective fabrication of large-scale organic light-emitting devices (OLEDs), typically necessitates the intricate alignment of precisely patterned insulating layers. Recently, we introduced a unique single-step inkjet printing process that produces well-patterned microinlaid spots of functional compounds through insulating polymer layers. This approach exploits lateral phase separation between the solute of functional compounds and the polymer, allowing the simultaneous spatial etching of the polymer and the infilling of the solute using a single inkjet-printed sessile droplet. Here, we demonstrate that the interaction between the solvent and polymer, as well as the solute and polymer, critically determines the precision and efficiency of printing. This is particularly evident when using either the insulating poly(vinylpyridine) isomer of poly(4-vinylpyridine) (P4VP) or poly(2-vinylpyridine) (P2VP) with chloroform as a solvent, which allows for a detailed examination of these interactions based on certain solubility parameters. Micro-Raman spectroscopy reveals that the self-organizing capability of the microinlaid spots with P4VP is superior to that with P2VP. This is due to the fact that P2VP shows higher affinity to the solvent and causes imperfect phase separation as compared to P4VP. As a result, a performance evaluation demonstrates enhanced device performance for inkjet-printed green micro-OLEDs with P4VP, exhibiting a higher external quantum efficiency of 3.3% compared to that of 2.3% achieved with P2VP. These findings elucidate the important roles of solvent-polymer and solute-polymer interactions in the inkjet printing process, leading to interfacial control of inkjet printing technique for the cost-effective production of high-performance and high-resolution micro-OLEDs.
- Published
- 2024
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24. Molecular Features Behind Formation of α or β Co-Crystalline and Nanoporous-Crystalline Phases of PPO
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Manohar Golla, Antonietta Cozzolino, Baku Nagendra, Emanuele Vignola, Christophe Daniel, Paola Rizzo, Gaetano Guerra, Finizia Auriemma, and Massimo Christian D’Alterio
- Subjects
guest molecular volume ,guest solubility in water ,solubility parameters ,DFT calculations ,dispersive energy calculations ,Chemistry ,QD1-999 - Abstract
Guest molecular features determining the formation of α and β phases of poly(2-6-dimethyl-1,4-phenylene) oxide (PPO) are explored by collecting literature data and adding many new film preparations, both by solution casting and by guest sorption in amorphous films. Independently of the considered preparation method, the α-form is favored by the hydrophobic and bulky guest molecules, while the hydrophilic and small guest molecules favor the β-form. Furthermore, molecular modeling studies indicate that the β-form inducer guests establish stronger dispersive interactions with the PPO units than the α-form inducer guests. Thus, the achievement of co-crystalline (and derived nanoporous crystalline) α- and β-forms would result from differences in energy gain due to the host–guest interactions established at the local scale.
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- 2022
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25. Mechanistic insights into the stabilisation of biopharmaceuticals using glycine derivatives : the effect of glycine derivatives on the crystallisation, physical properties and behaviour of commonly used excipients to stabilise antigens, adjuvants and proteins in the solid state
- Author
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Bright, Andrew G.
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615.1 ,Freeze drying ,Glycine derivatives ,Differential scanning calorimetry (DSC) ,Powder X-Ray diffraction (P-XRD) ,Raman spectroscopy ,Crystallisation ,Water loss ,Vaccines ,Adjuvant ,Stabilisation ,Amorphous ,Gordon-Taylor equation ,Solubility parameters ,Karl Fischer ,Excipients ,Proteins ,DLS (Dynamic Light Scattering) ,Polymorphs ,Vaccines ,Formulation ,Mannitol ,Sucrose ,Biopharmaceuticals - Abstract
This dissertation has focused on studying the effect of four glycine derivatives on the solid state properties of mannitol, glycine, and sucrose when freeze dried into blended mixtures. The primary goal was to assess their value for use in the stabilisation of vaccines in the solid state, by examining key physical and chemical characteristics, which have been documented to be beneficial to the stabilisation of biopharmaceutical formulations. The novel excipients; dimethyl glycine, and trimethyl glycine, were shown to retard the crystallisation and increase the overall glass transition temperature, of mannitol, when freeze dried as evidenced by DSC and Powder X-ray diffraction. Mannitol’s glass transition temperature increased from 100C to 12.650C and 13.610C when mixed with methyl-glycine and dimethyl glycine respectively. The glycine derivatives did not show the same effect on sucrose which remained amorphous regardless of the concentration of the other excipient. The different behaviour with the sucrose system was thought to be due to relatively high glass transition temperature of sucrose. Conversely glycine remained highly crystalline due it’s relatively low glass transition temperature. The novel excipient formulations were also assessed for their effect on the aggregation of the adjuvant aluminium hydroxide when freeze dried by Dynamic Light Scattering (DLS).The formulations containing the glycine derivatives all caused a decrease in the aggregation size of the adjuvant from ~26 μm, to 185 nm in the presence of methyl glycine. The effects of lysozyme and viral antigen on the adjuvants were also examined showing that the addition of the virus did not affect the size of the aggregates formed, however lysozyme showed significant decreases in the aggregates formed. Examination of the freezing method were also made showing that faster freezing rates produced smaller aggregates of the adjuvant. When investigating the rate at which the excipients lost water during secondary drying there was evidence of the formation of hydrates of glycine, trimethyl glycine, and mannitol has shown that the glycine derivatives have attributes which would be beneficial in stabilising vaccines in the solid state when freeze dried.
- Published
- 2015
26. ОЦІНЮВАННЯ СТІЙКОСТІ ГУМОВИХ УЩІЛЬНЮВАЧІВ ДВИГУНІВ ДО ДІЇ СУМІШЕВОГО ДИЗЕЛЬНОГО ПАЛИВА
- Author
-
Шевченко, О. Б., Зибайло, C. M., Сухий, К. М., Головенко, В. О., and Попитайленко, Д. В.
- Abstract
Copyright of Issues of Chemistry & Chemical Technology / Voprosy Khimii & Khimicheskoi Tekhnologii is the property of Ukrainian State University of Chemical Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2021
- Full Text
- View/download PDF
27. Application of Thermodynamic Phase Diagrams and Gibbs Free Energy of Mixing for Screening of Polymers for Their Use in Amorphous Solid Dispersion Formulation of a Non-Glass-Forming Drug.
- Author
-
Mamidi, Hemanth K. and Rohera, Bhagwan D.
- Subjects
- *
GIBBS' free energy , *DRUG solubility , *AMORPHOUS substances , *FLORY-Huggins theory , *MELTING points , *DISPERSION (Chemistry) , *PHASE diagrams - Abstract
The objective of the present investigations was to assess the use of thermodynamic phase diagrams and the Gibbs free energy of mixing, ΔG mix , for the screening of the polymeric carriers by determining the ideal drug-loading for an amorphous solid dispersion formulation and optimum processing temperature for the hot-melt extrusion of a non-glass-forming drug. Mefenamic acid (MFA) was used as a model non-glass-forming drug and four chemically distinct polymers with close values of the solubility parameters, viz. Kollidon® VA64, Soluplus®, Pluronic® F68, and Eudragit® EPO, were used as carriers. The thermodynamic phase diagrams were constructed using the melting point depression data, Flory-Huggins theory, and Gordan-Taylor equation. The Gibbs free energy of mixing was estimated using the values of the drug-polymer interaction parameter, χ, and Flory-Huggins theory. The rank order miscibility of MFA in the four polymeric carriers estimated based on the difference in the values of their solubility parameters, Δδ, did not correlate well with the thermodynamic phase diagrams and Gibbs free energy plots. The study highlights the limitation of using the solubility parameter method in screening the polymeric carriers for poorly glass-forming drugs and reiterates the applicability of thermodynamic phase diagrams and Gibbs free energy plots in determining the ideal drug-loading and optimum processing temperature for hot-melt extrusion. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
28. Compatibility between Drugs and Polymer in Nanoparticles Produced by the Miniemulsion‐Solvent Evaporation Technique.
- Author
-
Niyom, Yupaporn, Crespy, Daniel, and Flood, Adrian E.
- Subjects
- *
MISCIBILITY , *POLYMERS , *DRUG solubility , *DIFFERENTIAL scanning calorimetry , *DRUG bioavailability , *METHYL formate , *NANOPARTICLES , *TRICLOCARBAN - Abstract
Encapsulation of poorly soluble drugs in polymer nanoparticles is a common strategy to increase bioavailability of drugs. The miniemulsion‐solvent evaporation technique is widely used for encapsulating drugs in polymer nanoparticles because it is a versatile process, allowing many drug–polymer pair combinations. However, above a critical concentration of drug, which depends on the drug and polymer, nanoparticles tend to precipitate. Herein, the importance of drug solubility and miscibility in the polymer phase for selecting the optimal polymer matrix is investigated. Ibuprofen, naproxen methyl ester, and naproxen, as models for poorly soluble drugs, are encapsulated with various loadings in polycaprolactone nanoparticles by the miniemulsion‐solvent evaporation method. The miscibility between drug and polymer is estimated by calculating Flory–Huggins interaction parameters (χ) from differential scanning calorimetry measurements and calculating the difference in Hansen solubility parameter of drugs and polymer. Both values can be used for determining the feasibility of the drug encapsulation in polymer nanoparticles. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
29. Effect of Polarity of Solvent on Silanization of Halloysite Nanoclay Using (3-Glycidyloxy propyl) Trimethoxy Silane.
- Author
-
Abu El-Soad, A. M., Lazzara, G., Pestov, A. V., Cavallaro, G., Martemyanov, N. A., and Kovaleva, E. G.
- Subjects
- *
SILANE , *HALLOYSITE , *PROTOGENIC solvents , *POLAR solvents , *SILANIZATION , *MATERIALS science , *FOURIER transform infrared spectroscopy , *APROTIC solvents - Abstract
The grafting of silane groups on clay surfaces has been recently investigated in order to fabricate versatile compounds with new potential applications in materials science and ecological engineering. This work explored the influence of variety of solvents with variable polarity on the silanization of halloysite nanoclay (HNT) surface by (3-Glycidyloxy propyl) trimethoxy silane. To this purpose, the functionalization of HNT by 3-Glycidyloxypropyltrimethoxysilane (GOPTMS) has been conducted in Ethanol (polar protic solvent), Tetrahydrofuran (THF) and Acetonitrile (polar aprotic solvents), and Hexane, 1,4-Dioxane and Toluene (non polar solvents). The silane grafted materials were characterized by using several techniques, including Fourier Transform Infrared Spectroscopy (FT-IR), elemental analysis, Scanning Electron Microscopy (SEM), Thermogravimetry (TGA), X-ray Diffraction Analysis (XRD) and Nitrogen adsorption/desorption isotherms. The largest silane loading has been detected for the hybrid nanomaterials prepared in Hexane as a dispersing medium. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
30. Composições de solventes de baixa toxicidade para formulação de vernizes de uso em restauro.
- Author
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BOELSUMS, MARIAH, DE FIGUEIREDO JUNIOR, JOÃO CURA D'ARS, and CRUZ SOUZA, LUIZ ANTÔNIO
- Subjects
MEASUREMENT of viscosity ,CHEMICAL labeling ,VAPOR pressure ,PRESSURE measurement ,SOLUBILITY ,ETHYL acetate - Abstract
Copyright of Conservar Património is the property of Associacao Profissional de Conservadores-Restauradores de Portugal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2021
- Full Text
- View/download PDF
31. The use of solubility parameters to predict the behaviour of a co-crystalline drug dispersed in a polymeric vehicle : approaches to the prediction of the interactions of co-crystals and their components with hypromellose acetate succinate and the characterization of that interaction using crystallographic, microscopic, thermal, and vibrational analysis
- Author
-
Isreb, Abdullah, Forbes, Robert T., and Bonner, Michael C.
- Subjects
615.1 ,Co-crystals ,Polymer ,Caffeine ,Malonic acid ,Ibuprofen ,Nicotinamide ,HPMCAS ,Solvent effect ,Solubility parameters - Abstract
Dispersing co-crystals in a polymeric carrier may improve their physicochemical properties such as dissolution rate and solubility. Additionally co-crystal stability may be enhanced. However, such dispersions have been little investigated to date. This study focuses on the feasibility of dispersing co-crystals in a polymeric carrier and theoretical calculations to predict their stability. Acetone/chloroform, ethanol/water, and acetonitrile were used to load and grow co-crystals in a HPMCAS film. Caffeine-malonic acid and ibuprofennicotinamide co-crystals were prepared using solvent evaporation method. The interactions between each of the co-crystals components and their mixtures with the polymer were studied. A solvent evaporation approach was used to incorporate each compound, a mixture, and co-crystals into HPMCAS films. Differential scanning calorimetry data revealed a higher affinity of the polymer to acidic compounds than their basic counterparts as noticed by the depression of the glass transition temperature (Tg). Moreover, the same drug loading produced films with different Tgs when different solvents were used. Solubility parameter values (SP) of the solvents were employed to predict that effect on the depression of polymer Tg with relative success. SP values were more successful in predicting the preferential affinity of two acidic compounds to interact with the polymer. This was confirmed using binary mixtures of naproxen, flurbiprofen, malonic acid, and ibuprofen. On the other hand, dispersing basic compounds such as caffeine or nicotinamide with malonic acid in HPMCAS film revealed the growth of co-crystals. A dissolution study showed that the average release of caffeine from films containing caffeine-malonic acid was not significantly different to that of films containing similar caffeine concentration. The stability of the caffeine-malonic acid co-crystals in HPMC-AS was prolonged to 8 weeks at 95% relative humidity and 45°C. The theory developed in this project, that an acidic drug with a SP value closer to the polymer will dominate the interaction process and prevent the majority of the other material from interacting with the polymer, may have utility in designing co-crystal systems in polymeric vehicles
- Published
- 2012
32. Solvent accommodation effect on dispersibility of metal oxide nanoparticle with chemisorbed organic shell.
- Author
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Tomai, Takaaki, Tajima, Naoya, Kimura, Motoyuki, Yoko, Akira, Seong, Gimyeong, and Adschiri, Tadafumi
- Subjects
- *
METALLIC oxides , *SOLVENTS , *MOLECULAR size , *ORGANIC solvents , *PROPERTY rights - Abstract
The dispersibility of nanoparticles in solvents remains difficult to predict and control. In this paper, the dispersibility of organically-modified nanoparticles in various solvents with different solvent properties and molecular sizes are investigated. The study indicates that solvent molecular size, in addition to the affinity between organic modifier and solvent molecules, affects the dispersibility of the nanoparticles. The experimental results imply that solvents with molecular size small enough can disperse nanoparticles more efficiently. In addition, based on the concept that solvent accommodation induces the enhancement of dispersibility, two approaches to improve nanoparticle dispersibility in desired solvents are proposed. One is the addition of a small amount of solvent with the right size and properties to both penetrate the modifier shell and to act as intermediate between the desired solvent and the organic modifier molecules. The other is dual-molecule modification to create additional space at modifier-shell surface for the penetration of the desired solvent molecules. The results of these approaches based on the concept of the solvent accommodation can enhance the dispersibility trends. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
33. Molecularly imprinted macroporous polymer monolithic layers for L‐phenylalanine recognition in complex biological fluids.
- Author
-
Antipchik, Mariia, Dzhuzha, Apollinariia, Sirotov, Vasilii, Tennikova, Tatiana, and Korzhikova‐Vlakh, Evgenia
- Subjects
IMPRINTED polymers ,MACROPOROUS polymers ,COMPLEX fluids ,MOLECULAR imprinting ,PORE size (Materials) ,BUFFER solutions - Abstract
In present work, the development of macroporous monolithic layers bearing the artificial recognition sites toward L‐phenylalanine has been carried out. The set of macroporous poly(2‐aminoethyl methacrylate‐co‐2‐hydroxyethyl methacrylate‐co‐ethylene glycol dimethacrylate) materials with average pore size ranged in 340–1200 nm was synthesized. The applicability of Hildebrand's and Hansen's theories for the prediction of polymer compatibility with porogenic solvents was evaluated. The dependences of average pore size on theoretically calculated parameters were plotted. The linear trend detected for Hansen's theory has indicated the high suitability of this approach to select appropriate porogens. The synthesized monolithic MIP layers were tested toward the ability to rebind phenylalanine‐derivative in microarray format. The influence of such factors as average pore size of the material, the concentration of template molecule in polymerization mixture, interaction time of analyte with its imprinted sites on binding efficiency were studied. The developed materials demonstrated good analyte rebinding from buffer solution with recognition factors 2.5–3.4 depending on the MIP sample. The comparable rebinding efficiency was also detected when the analysis was carried using complex biological media. The selectivity of phenylalanine binding from the equimolar mixture of structural analogues was 81.9% for free amino acid and 91.2% for labeled one. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
34. Generation of Flexible Multifunctional Electronic Textile Displaying Appropriate Fastness Properties Utilizing Single-Stage Inkjet Printing onto Cotton Fabric Pre-treated with PVC
- Author
-
Ali Goudarzi, Atasheh Soleimani-Gorgani, and Ozan Avinc
- Subjects
Energy ,DMF and PVC ,Solubility Parameters ,Polymers and Plastics ,THF interlayer ,General Chemical Engineering ,Temperature ,Cotton ,General Chemistry ,PVC ,Conductive Inks ,Inkjet printing ,Particles ,E-textile ,Facile ,Poly(Vinyl Chloride) ,Solvent ,Nanoparticles ,Silver Nanoparticles - Abstract
Electrically conductive printed textiles are gaining increasing interest and demand worldwide. Cotton fabric's porosity and high surface roughness avoid electrically conductive printed patterns on the fabrics. This paper reports the in-situ solution deposition of silver free particles inkjet ink via an aqueous single-stage inkjet printing process, which improved electrical conductivity and fastness properties with a new approach. The cotton fabrics were pre-treated with different polyvinylchloride (PVC) solutions prepared in various solvents such as tetrahydrofuran (THF) and dimethylformamide (DMF) that differed in boiling temperature. Afterward, PVC-pre-treated fabrics were printed through the HP Deskjet inkjet printer. The results showed that the PVC-pre-treatment of cotton fabrics significantly improved the electrical conductivity (< 2 ohm/), antibacterial activity, thermal management, droplets repellency, adhesion, abrasion, and washing fastness properties, as well as flexibility properties. The solvent type in PVC solutions affects the physical properties of the pre-treated cotton fabric. The comparison in rheological behavior of PVC solutions in DMF and THF at different temperatures displayed the significant difference in viscosity at gel-point for THF and DMF solution. THF solution with higher viscosity cannot diffuse more into porosities of cotton fabric than the DMF solution, which affects the silver nanoparticles' average crystal size and the final electrical conductivity of the printed fabric. It is the first time using an economical polymer layer on cotton fabrics to provide robust electronic printed patterns by single-stage inkjet printing. The results confirm that the flexible electronic printed fabric can be used as a multifunctional electronic textile.
- Published
- 2023
- Full Text
- View/download PDF
35. Structures of Coal, Kerogen, and Asphaltenes
- Author
-
Burnham, Alan K. and Burnham, Alan K.
- Published
- 2017
- Full Text
- View/download PDF
36. Poly(dodecyl methacrylate-co-2-(diethylamino)ethyl methacrylate) Gels: Characterization and Solubility Parameters.
- Author
-
ÖZDEMIR, F. and ÇAVUS, S.
- Subjects
- *
METHACRYLATES , *COLLOIDS , *FOURIER transform infrared spectroscopy , *THERMOGRAVIMETRY , *SCANNING electron microscopy techniques , *IMPRINTED polymers , *MOLECULAR imprinting - Abstract
In this work, a copolymer gel with hydrophobic character was synthesized from dodecyl methacrylate (DDMA) and 2-(diethylamino) ethyl methacrylate (DEAEMA) monomers in ethanol at 70 °C for 24 h using free radical crosslinking polymerization method. In the synthesis procedure, azobisisobutyronitrile and ethylene glycol dimethacrylate were used as the initiator and cross-linker, respectively. The gel was also prepared in the presence of a pore forming agent (poly(ethylene glycol), PEG) at the same conditions to compare its effect on the swelling and structural/ thermal characteristics. The swelling behaviour of the gels was investigated in different solvents and their solubility parameters were found. Solubility parameters of P(DDMA-co-DEAEMA) and P(DDMA-co-DEAEMA)- PEG gels were calculated as 8.2 and 7.7 (cal/cm3)1/2, respectively. The gels were characterized by the Fourier transform infrared spectroscopy, thermal gravimetric analysis, and scanning electron microscopy techniques. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
37. Experimental Adhesives with Different Hydrophilicity: Microshear Test in after 1, 7, and 90 Days' Storage.
- Author
-
Hori, A. B. Frederico Seidi and De Carvalho, Rubens Côrte Real
- Subjects
DENTAL adhesives ,SHEAR strength ,HYDROPHILIC compounds ,DENTAL acid etching ,POLYBUTADIENE ,DENTIN ,ANALYSIS of variance ,DENTAL resins ,COLLAGEN - Abstract
Purpose: To assess the microshear bond strength of 3 experimental adhesives with different degrees of hydrophilicity after 1, 7 and 90 days of storage. Materials and Methods: The bonding effectiveness of three experimental two-step etch-and-rinse adhesives (bis- GMA, bis-EMA/bis-GMA, polybutadiene [C
6 H12 ]) and one commercial adhesive (Single Bond) to sound hydrated dentin was determined using the microshear test with delimitation of the adhesive area after 1, 7, and 90 days of storage in water at 37°C. Two-way ANOVA was performed at the 0.05 probability level. The fractures were classified as adhesive, cohesive in dentin, cohesive in resin, and mixed. Results: The experimental adhesives showed values in the range of 11.31 to 12.96 MPa, with polybutadiene (PBH) showing the lowest bond strengths, bis-GMA the highest, and bis-EMA/bis-GMA intermediary values. Single Bond yielded bond strengths of approximately 24 MPa. Water storage decreased the bond strength in all adhesives. Adhesive fractures were predominant in experimental adhesives, while mixed fractures were the most frequent type in the Single Bond group. Conclusion: The experimental dentin adhesives of this study were able to form resin tags, but they could not penetrate into the collagen fibers and form hybrid layers. The resulting low bond strength decreased with in- creasing length of storage. [ABSTRACT FROM AUTHOR]- Published
- 2012
- Full Text
- View/download PDF
38. Surface properties of carbon black functionalized with pyrrole compounds.
- Author
-
Bernardi, Andrea, Moriggi, Francesco, Gentile, Davide, Marku, Rexhina, Brambilla, Luigi, Barbera, Vincenzina, and Galimberti, Maurizio
- Subjects
- *
SURFACE properties , *PYRROLES , *CARBON-black , *COMPOSITE materials , *ACETIC acid , *SURFACE area - Abstract
Carbon black (CB) is among the most important chemicals in the world and it is predominantly used as a pigment or reinforcing agent. The compatibility between CB and the matrix plays a key role in achieving the best performance of the composite material, mainly due to the surface properties of the CB. In this work, the surface characteristics of a furnace CB (N234) were modified by performing a solid state functionalization of CB with the following pyrrole compounds (PyCs): 2-(2,5-dimethyl-1 H -pyrrol-1-yl)propane-1,3-diol (serinol pyrrole, SP), 2,5-dimethyl-1-octadecyl-1 H -pyrrole (octadecylpyrrole, ODcP), 1-(triethoxysilyl)propyl)-2,5-dimethyl-1 H -pyrrole ((3-amino)propyltriethoxypyrrole, APTESP), 2-(2,5-dimethyl-1 H -pyrrol-1-yl)acetic acid (glycilpyrrole, GlyP), 1,2,5-trimethyl-1 H -pyrrole (trimethylpyrrole, TMP). The synthesis of PyC and CB modification, with PyC content in the adducts ranging from about 6 % to 10 % by mass, were characterized by high atom efficiency and by very low E-Factor, resulting in a minimal amount of waste. The presence of PyC on the CB surface caused a reduction in the surface area and a change in the site energy distribution. The solubility parameters of CB/PyC adducts were found to be PyC dependent: stable dispersions of CB/PyC in water were obtained with the more hydrophilic SP and GlyP. This work presents a reliable and efficient method for controlling the surface properties of carbon black, potentially achieving matrix compatibility in different environments. [Display omitted] • Surface characteristics of furnace CB were modified using solid-state functionalization with pyrrole compounds (PyCs). • Synthesis of PyCs and CB modification demonstrated high atom efficiency. • Presence of PyCs on CB surface led to reduced surface area and altered site energy distribution. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
39. Evaluation des Copolymers P(VDF-TrFE) als elektrogesponnene piezoelektrische Filtrationsmembran zur Foulingreduzierung
- Author
-
Glasmacher, Birgit, Institut für Mehrphasenprozesse, Kuhn, Antonia Isabel, Glasmacher, Birgit, Institut für Mehrphasenprozesse, and Kuhn, Antonia Isabel
- Abstract
Die Antifouling-Wirkung von piezoelektrischen Filtrationsmembranen gilt in der Membrantechnik als ein vielversprechender Ansatz, um Verschmutzungen der Membranoberflächen während der Filtrationsprozesse zuvorzukommen und die Filtrationsleistung zu steigern. Hierzu wird die Eignung einer elektrogesponnenen Mikrofiltrationsmembran aus dem piezoelektrischen Copolymer Poly(vinylidenfluorid-co-trifluorethylen) evaluiert. Maßgeblich für die piezoelektrische Phasenbildung und den resultierenden Eigenschaften der Polymerlösung für die Membranherstellung im Elektrospinnprozess ist der Einfluss von Lösemitteln und -gemischen. Durch die Untersuchung der Löslichkeitsparameter des Copolymers werden gezielt Lösemittelkombinationen und Volumenverhältnisse variiert, um deren Auswirkungen auf die Bildung des piezoelektrischen Beta-Phasenanteils zu analysieren. Zur Bestimmung der Membran-Resonanzfrequenz werden Vibrometermessungen genutzt. Diese Frequenz ist ausschlaggebend zur piezoelektrischen Anregung der Membran und damit zur Realisierung einer Antifouling-Wirkung. Die anschließende Überprüfung von leistungssteigernden Filtrationsmaßnahmen erfolgt über die transportspezifische Charakterisierung des Transmembranfluxes und –drucks in einem zur piezoelektrischen Anregung konstruierten Dead-End-Filtrationssystem durch Filtrationsversuche mit und ohne angelegte Wechselspannung., In membrane technology, the antifouling-effect of piezoelectric filtration membranes to increase filtration performance is promising. It could reduce fouling of membrane surfaces during filtration processes. This thesis evaluates the effectiveness of an electrospun microfiltration membrane made from piezoelectric copolymer poly(vinylidene fluoride-co-trifluoroethylene). The influence of solvents and solvent mixtures is relevant for the piezoelectric phase formation and the resulting properties of the polymer solution for membrane production in the electrospinning process. Through studying the solubility parameters of copolymer, the impact that all these parameters have on the formation of the piezoelectric beta phase fraction is specifically analysed. Vibrometer measurements are used to determine the membrane resonance frequency. This frequency is crucial for optimising the piezoelectric oscillation of the membrane, and is therefore critical in order to achieve the desired antifouling-effect. The subsequent verification of filtration performance enhancements is conducted using transport-specific characterisation of the transmembrane flux and pressure. This is done in a dead-end filtration system designed for piezoelectric actuation through filtration experiments with and without alternating voltage.
- Published
- 2023
40. Porous Structure of Polymer Films Optimized by Rationally Tuning Phase Separation for Passive All-Day Radiative Cooling.
- Author
-
Li L, Liu G, Zhang Q, Zhao H, Shi R, Wang C, Li Z, Zhou B, and Zhang Y
- Abstract
Passive all-day radiative cooling (PARC) films with porous structures prepared via nonsolvent-induced phase separation (NIPS) have attracted considerable attention owing to their cost-effectiveness and wide applicability. The PARC performances of the films correlate with their porous structures. However, the porous structure formed using the NIPS process cannot be finely regulated. In this study, we prepared polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) films with porous structures optimized by rationally tuning the phase separation, which was achieved by adjusting the proportions of two good solvents with varying solubility parameters. The optimized PVDF-HFP film with a hierarchically porous structure exhibited a high solar reflectance of 97.7% and an infrared emissivity of 96.7%. The film with excellent durability achieved an average subambient cooling temperature of approximately 5.4 °C under a solar irradiance of 945 W·m
-2 as well as a temperature of 11.2 °C at nighttime, thus demonstrating all-day radiative cooling. The results indicate that the proposed films present a promising platform for large-scale applications in green building cooling and achieving carbon neutrality.- Published
- 2024
- Full Text
- View/download PDF
41. Computing solubility parameters of deep eutectic solvents from Molecular Dynamics simulations.
- Author
-
Salehi, Hirad S., Ramdin, Mahinder, Moultos, Othonas A., and Vlugt, Thijs J.H.
- Subjects
- *
EUTECTICS , *MOLECULAR dynamics , *SOLUBILITY , *SOLVENTS , *POLAR solvents , *HYDROGEN bonding - Abstract
The solubility parameter (SP) of a solvent is a key property that measures the polarity and quantifies the 'like-dissolves-like' principle, which is an important rule in chemistry for screening solvents for separation processes. It is challenging to experimentally obtain solubility parameters of non-volatile solvents like ionic liquids (ILs), deep eutectic solvents (DESs), and polymers. Here, Molecular Dynamics (MD) simulations have been used to compute the Hildebrand and Hansen solubility parameters of DESs, which are green solvents with potential applications in many different fields. The results from MD simulations are compared with limited available experimental data and commonly used SP correlations for non-volatile solvents. Very limited information is available in literature for the vapor phase composition of DESs. Solubility parameters are computed based on the vaporization of hydrogen bond donor (HBD) and hydrogen bond acceptor (HBA) components of the DESs as well as clusters, consisting of HBD and HBA components. The relatively large SPs computed from MD indicate that the investigated choline chloride-based DESs are polar solvents. The values of SPs are not significantly affected by temperature. A comparison of vaporization enthalpies of HBD, HBA and clusters from the DES mixture suggests that it is more likely for HBD molecules to vaporize from the DES mixture and dominate the vapor phase. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
42. Molecular dynamics simulation of CO2 dissolution in heavy oil resin-asphaltene.
- Author
-
Li, Bingfan, Liu, Gang, Xing, Xiao, Chen, Lei, Lu, Xingguo, Teng, Houxing, and Wang, Jian
- Subjects
MOLECULAR dynamics ,HEAVY oil ,PETROLEUM ,MECHANICAL energy ,MOLECULAR weights ,MOLECULAR association ,GUMS & resins - Abstract
• Under different temperatures and pressures, the density distribution and adsorption capacity of CO2 in the association systems of resin, resin-asphaltene and asphaltene were investigated. • The dependence of CO2 dissolution on mechanical interaction energy has been revealed in this paper, which provides a direct explanation for the swelling of dissolved crude oils. • According to the free volume of each association system and the interaction between CO2 and the association system, the solubility parameters of CO2 and the mechanism of CO2 dissolution were analyzed. Based on the molecular dynamics method, association systems for resin, resin-asphaltene and asphaltene were constructed respectively. Under different temperatures and pressures, the density distribution and adsorption capacity of CO 2 in each association system were investigated. According to the free volume of each association system and the interaction between CO 2 and the association system, the solubility parameters of CO 2 and the mechanism of CO 2 dissolution were analyzed. The results demonstrate that many voids exist in the three association systems. The voids in the resin association system and the resin-asphaltene association system are relatively close and continuous, while dispersed in the asphaltene association system. The dissolved gases are mainly concentrated in the asphaltene association system. The larger the free volume fraction, the larger the space of dissolved gas molecules. The CO 2 interaction strength in a descent order is resin, resin-asphaltene and asphaltene. In addition, the dependence of CO 2 dissolution on mechanical interaction energy was also revealed, which provides a direct explanation for the swelling of dissolved crude oils. The solubility parameter increases with the molecular weight of the association system in the ascent order of resin, resin-asphaltene and asphaltene. Accordingly, the order of the CO 2 solubility in the three association systems from high to low is resin, resin - asphaltene and asphaltene. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
43. Enhanced Skin Permeation of Hydrocortisone Using Nanoemulsion as Potential Vehicle.
- Author
-
Altamimi, Mohammad, Haq, Nazrul, Alshehri, Sultan, Qamar, Wajhul, and Shakeel, Faiyaz
- Subjects
- *
HYDROCORTISONE , *DRUG solubility , *EMULSIONS (Pharmacy) , *TRANSMISSION electron microscopy , *SKIN , *REFRACTIVE index , *ZETA potential , *CLINICAL drug trials - Abstract
The current work was performed to estimate the solubility and Hansen solubility parameters of a poorly soluble corticosteroid hydrocortisone (HCN) in various components of nanoemulsion and to enhance the skin permeation rate of HCN using nanoemulsions as potential vehicles. Screening studies suggested the use of Capryol‐90 (oil), Triton‐X100 (surfactant) and Transcutol‐HP (cosurfactant) in the preparation of HCN nanoemulsions. HCN nanoemulsions were developed using low energy emulsification technique and characterized for droplet size, plolydispersity index (PDI), zeta potential (ZP), refractive index (RI), percent of transmittance (% T) and transmission electron microscopy (TEM) and evaluated for drug release behavior. Selected nanoemulsions and control (HCN suspension) were subjected to in vitro skin permeation studies. Optimized formula HSN8 showed droplet size of 52.6 nm, PDI of 0.109, ZP of −33.72 mV, RI of 1.337 and % T of 97.68%. TEM confirmed spherical‐shaped droplets in nanometer range. In vitro drug release evaluation suggested significant release of HCN from optimized nanoemulsion (98.52%) compared with control (35.85%). Skin permeation profile of HCN from optimized nanoemulsion was also significant compared with control. These results suggested the potential of nanoemulsion in enhancing the transdermal delivery of HCN via rat skin. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
44. Methods for Determining the Solubility Parameter of Additives for Lubricating oils.
- Author
-
STANCIU, IOANA
- Subjects
LUBRICATING oils ,INTRINSIC viscosity - Abstract
In this article I have been working for the determination of the solubility parameter by two methods for an additive KELTAN 4200 used in lubricating oils. To determine the solubility parameter, it is necessary to know the intrinsic viscosities of the polymer in as many solvents with different solubility parameters. Determination of the partial and global solubility parameters was done, first, using the Hansen method, then by an improved method. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
45. Estimation of surface free energy and solubility parameters of Mg[sbnd]Al layered double hydroxides.
- Author
-
Yu, Weiyan, Li, Haiping, Du, Na, and Hou, Wanguo
- Subjects
- *
HYDROXIDES , *SURFACE energy , *LAYERED double hydroxides , *FREE surfaces , *SOLUBILITY , *CONTACT angle - Abstract
The characteristic parameters, surface free energy (γ) and solubility parameters (δ), of Mg 2 Al NO 3 , Mg 3 Al NO 3 , Mg 4 Al NO 3 , Mg 3 Al Cl, and Mg 3 Al CO 3 layered double hydroxides (LDHs) were estimated using contact angle and liquid phase exfoliation (LPE) methods. The γ parameters include total (γ s t ), dispersive (γ s d ), and polar (γ s p ) ones. The δ parameters include the Hildebrand parameter (δ t , s ) and the Hansen dispersive (δ d , s ), polar (δ p , s ), and hydrogen-bonding (δ h , s ) ones. Results show that the γ s t , γ s d , and γ s p of the five LDHs are ∼50.9–56.9, 35.2–39.4, and 15.6–18.8 mJ/m2, respectively, and the δ t , s , δ d , s , δ p , s and δ h , s of the LDHs except for the Mg 3 Al CO 3 LDH are ∼31.4–32.9, 17.2, 9.5–10.0, and 24.5–26.1 MPa1/2, respectively. The compositions of LDHs have no obvious impact on all the characteristic parameters. In comparison with van de Waals attraction-bonded materials, the electrostatic attraction-bonded LDHs exhibit higher γ s t and δ t , s values and, especially, much larger δ h , s values. The characteristic parameter matching principle and the mixed-solvent strategy are suitable for the LPE of LDHs. Non-toxic glycol/PEG200 mixed liquids are found to be a good medium for the direct LPE of LDHs, producing monolayer nanosheets. To the best of our knowledge, this is the first report on the γ and δ parameters of LDHs. This work not only deepens the understanding of the feature of LDHs, but also provides effective liquid media for the direct LPE of LDHs. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
46. Using Solubility Parameter Analysis to Understand Delignification of Poplar and Rice Straw with Catalyzed Organosolv Fractionation Processes.
- Author
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Fangchao Cheng, Tulong Ouyang, Jianping Sun, Tao Jiang, and Jianju Luo
- Subjects
- *
SOLUBILITY , *DELIGNIFICATION , *RICE straw , *LIGNOCELLULOSE , *SOLUTION (Chemistry) , *ALKANOLAMINES - Abstract
Biomass fractionation is important for the further conversion of the cellulosic fraction and the effective utilization of the lignin fraction for the production of biofuels and value-added products. Solvent properties play a crucial role on the fractionation efficiency of lignocellulosics using an organosolv fractionation process catalyzed by acidic ionic liquids (AILs). Herein, 12 organic solvents were selected as co-solvents with water based on their solubility parameters for lignin dissolution, including alcohols, alcohol ethers, lactones, and alkanolamines, in order to fractionate poplar and rice straw. Effects of fractionation liquor solubility parameters on the delignification efficiency of organosolv fractionation were investigated under the same conditions. Relative energy differences (REDs) of the cosolvent systems for lignin dissolution were closely related to the degree of delignification with adjusted coefficients of determination of 0.899 and 0.800 for poplar and rice straw processes, respectively. The application of solubility parameter analysis may provide a rational way to screen solvent or co-solvent fractionation systems for biomass fractionation process. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
47. Understanding Covalent Grafting of Nanotubes onto Polymer Nanocomposites: Molecular Dynamics Simulation Study
- Author
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Seunghwa Yang
- Subjects
carbon nanotube ,nanocomposites ,molecular dynamics simulations ,covalent grafting ,solubility parameters ,Chemical technology ,TP1-1185 - Abstract
Here, we systematically interrogate the effects of grafting single-walled (SWNT) and multi-walled carbon nanotubes (MWNT) to polymer matrices by using molecular dynamics (MD) simulations. We specifically investigate key material properties that include interfacial load transfer, alteration of nanotube properties, and dispersion of nanotubes in the polymer matrix. Simulations are conducted on a periodic unit cell model of the nanocomposite with a straight carbon nanotube and an amorphous polyethylene terephthalate (PET) matrix. For each type of nanotube, either 0%, 1.55%, or 3.1% of the carbon atoms in the outermost nanotubes are covalently grafted onto the carbon atoms of the PET matrix. Stress-strain curves and the elastic moduli of nanotubes and nanocomposites are determined based on the density of covalent grafting. Covalent grafting promotes two rivalling effects with respect to altering nanotube properties, and improvements in interfacial load transfer in the nanocomposites are clearly observed. The enhanced interface enables external loads applied to the nanocomposites to be efficiently transferred to the grafted nanotubes. Covalent functionalization of the nanotube surface with PET molecules can alter the solubility of nanotubes and improve dispersibility. Finally, we discuss the current limitations and challenges in using molecular modelling strategies to accurately predict properties on the nanotube and polymers systems studied here.
- Published
- 2021
- Full Text
- View/download PDF
48. Determination of carbon nanoparticle dispersion solubility parameters using the classic Hansen and the DiPEVa method.
- Author
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Pereira, Claudio Nunes, Paim, Lucas, da Cruz, Joziel Aparecido, Dall Agnol, Lucas, Mauler, Raquel S., and Bianchi, Otávio
- Subjects
- *
NANOPARTICLES , *SOLUBILITY , *QUANTUM dots , *DISPERSION (Chemistry) , *BIOMASS liquefaction , *CARBON nanotubes , *GRAPHENE oxide - Abstract
[Display omitted] • Comparative analysis of Hansen's three-dimensional Solubility Parameter (3DSP) and the recently introduced DiPEVa method for assessing nanoparticle dispersibility in 32 solvents. • Evaluation of solubility parameters of carbon nanoparticles, including graphene oxide, carbon quantum dots, graphene nanoplatelets, and carbon nanotubes. • DiPEVa method demonstrated superior performance over the Hansen method, except in the case of carbon quantum dot obtained from Spirulina pyrolysis. Hansen's three-dimensional Solubility Parameter (3DSP) are widely recognized for assessing the compatibility of a dispersed phase with a continuous phase. A modified approach, known as the DiPEVa method, has recently emerged in the literature. This method refines 3DSP by incorporating surface tension considerations. Given the presence of these two similar methodologies, the objective of this study is to conduct a comparative analysis between the two approaches, employing carbon nanoparticles, including graphene oxide, carbon quantum dots (produced via microwave pyrolysis of Spirulina microalgae, and the reaction between citric acid and ethylenediamine), graphene nanoplatelets, and carbon nanotubes as the focal subjects. To achieve this, assessing solubility parameters involved dispersing these nanoparticles in 32 organic solvents with well-established solubility parameters. Subsequently, the collected data underwent a genetic algorithm optimization, facilitating the computation of the Hansen 3D dispersibility sphere. This process included the calculation of the 3DSP for the sphere's central point and its interaction radius (R 0). Quality-of-fit metrics, such as DataFit values and the percentage of outliers, were computed to assess the accuracy of the models. As a result, it was evident that the DiPEVa method outperformed the Hansen method in most cases, except for carbon quantum dot dispersion obtained through Spirulina pyrolysis, where both methods yielded comparable results. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
49. Novel method for the prediction of distribution and elution characteristic of several drugs in cellulose diacetate-water system: Interaction between mixed solvent and cellulose diacetate.
- Author
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Pak, Hyon-Tae, Choe, Jin-A, Ju, Kyong-Sik, and Rim, Yong-Son
- Subjects
- *
PENICILLIN G , *INTRINSIC viscosity , *CELLULOSE , *MEASUREMENT of viscosity , *POLYMER solutions , *ACETONE , *ETHANOL - Abstract
[Display omitted] • Drug-conjugated cellulose diacetate membranes were prepared by dissolving cellulose diacetate. • The release properties of drugs in drug-conjugated CDA membranes were examined. • The release rates of drugs from CDA membrane can be controlled by changing the composition. Drug-loaded cellulose diacetate (CDA) membranes were prepared by dissolving cellulose diacetate in a mixed solvent of acetone and ethanol, adding the drug to it, pouring it on a glass plate and evaporating the solvent. In this study, it was prepared CDA membranes varying composition of the mixed solvent (the mass ratio of acetone (ACE) to ethanol (EtOH)) and investigated their microstructure and performance. The release properties of drugs in drug-loaded CDA membranes were examined in correlation with the composition of the mixed solvent and a method to be able to predict the release properties of drugs was proposed. Penicillin G potassium, streptomycin sulfate and ampicillin were used as drugs. The microstructure of the membranes was determined using SEM analysis and the release properties of drugs were measured using spectrofluorophotometer. It was shown that the composition of the mixed solvent can have a significant effect on the overall performance of CDA membrane. The intrinsic viscosity measurements and solubility parameter analysis proved that the intrinsic viscosity of CDA in polymer solutions with mixed solvents and the solubility parameter difference (Δδ) between mixed solvents and CDA were relative with the release properties of drugs. The release rates of drugs from the membrane related to △δ directly and the intrinsic viscosity inversely. Therefore, the release rates of drugs from CDA membrane can be controlled by changing the composition of the solvent used for the preparation of the polymer membrane. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
50. Determination of Alkali Lignin Solubility Parameters by Inverse Gas Chromatography and Hansen Solubility Parameters
- Author
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Haiyue Ni, Shixue Ren, Guizhen Fang, and Yanli Ma
- Subjects
Inverse gas chromatography ,Alkali lignin ,Hansen solubility parameters ,Solubility parameters ,Biotechnology ,TP248.13-248.65 - Abstract
The physicochemical properties of alkali lignin are crucial to its potential applications and recyclability, as it is one of the most important natural polymer materials. In this study, the solubility parameter (δ) of alkali lignin was determined using Hansen solubility parameters (HSP) theory and inverse gas chromatography (IGC). The δ of alkali lignin was determined by the IGC technique. Solute retention volumes (Vg0) of 6 solutes were determined using alkali lignin as the stationary phase. From 50 to 110 ºC, the δ of alkali lignin varied from 24.47 to 24.15 MPa1/2. Hansen solubility spheres were plotted using the data from the literature for the interactions of alkali lignin with 36 solutes to determine the three dimensional solubility parameter of alkali lignin at 25 to 100 ºC. These determined δ values were consistent with those calculated experimentally via IGC. Acetone was a moderate solvent for the alkali lignin.
- Published
- 2016
- Full Text
- View/download PDF
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