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Diffusion-controlled deactivation of excited phenanthrene and oxidation of triplet aryl-nitrene by molecular oxygen were used to determine the energetics of oxygen jump rates in the set of glassy polymers: poly(methyl methacrylate), poly(n-butyl methacrylate), polycarbonate, polystyrene, and polysulfone. To interpret experimental results, a simple model based on the transition state theory of diffusion jump has been used. The kinetic Monte Carlo simulations of phenanthrene deactivation and nitrene oxidation were carried out in a cubic lattice that modeled a polymer matrix. The bonds of the lattice were assigned to be activation barriers for the diffusion jumps of oxygen molecules from one site of the lattice to another. The standard deviation, σ‡, and spatial correlation length, rc, of the free energy of diffusion jump have been determined. It is shown that the spatial correlation of oxygen jump rates on a nanometer scale and the entropic nature of the dynamic heterogeneity are common features of all the studied polymers. [ABSTRACT FROM AUTHOR]

The work demonstrates, for the first time, thermo-responsive, water-insoluble, hydrogel-based, nano-fibrous filter media comprised of copolymers of N-isopropylacrylamide (NIPAM) and methyl methacrylate formed by electrospinning. Moreover, a comprehensive novel physical explanation of all aspects responsible for the physical mechanisms resulting in the thermo-responsive regulation of the water flow rate and an enhanced interception of nanoparticles by such filter membranes is given. They are the wettable-non-wettable transition, pore, and fiber-size changes, as well as a diminishing filter thickness at the lower critical solution temperature (LCST) of the copolymers developed here, which interplay with a significant reduction in the water viscosity with temperature. Poly(N-isopropylacrylamide) (PNIPAM) hydrogel is an attractive material because of its thermo-responsive properties. Its wettability changes with water temperature. This characteristic holds great promise for the development of advanced filter media and related responsive materials. In this study, PNIPAM hydrogels were designed and transformed into filter membranes for applications in water filtration in biomedical and other related systems. These thermo-responsive filter membranes offer the potential for enhanced filtration efficiency, selectivity, and the overall system performance. Here, two different procedures were adopted to form water-insoluble thermo-responsive filter media based on PNIPAM hydrogels. The PNIPAM-based hydrogels were electrospun, resulting in the formation of thermo-responsive water-insoluble nanofiber membranes. These membranes underwent a series of comprehensive experiments to assess their performance and characteristics, including mass loss, water droplets for the wettability assessment, filtration tests, shrinkage measurements, and microscopic observations. These diverse experiments yield a full understanding of the PNIPAM-based nanofiber membranes' properties and their potential applications. [ABSTRACT FROM AUTHOR]

Polymer chains at a buried interface with an inorganic solid play a critical role in the performance of polymer nanocomposites and adhesives. Sum frequency generation (SFG) vibrational spectroscopy with a sub-nanometer depth resolution provides valuable information regarding the orientation angle of functional groups at interfaces. However, in the case of conventional SFG, since the signal intensity is proportional to the square of the second-order nonlinear optical susceptibility and thereby loses phase information, it cannot be unambiguously determined whether the functional groups face upward or downward. This problem can be solved by phase-sensitive SFG (ps-SFG). We here applied ps-SFG to poly(methyl methacrylate) (PMMA) chains in direct contact with a quartz surface, shedding light on the local conformation of chains adsorbed onto the solid surface. The measurements made it possible to determine the absolute orientation of the ester methyl groups of PMMA, which were oriented toward the quartz interface. Combining ps-SFG with all-atomistic molecular dynamics simulation, the distribution of the local conformation and the driving force are also discussed. [ABSTRACT FROM AUTHOR]

Controlling the dispersion state of nanoparticles in a polymer matrix is necessary to produce polymer nanocomposites. The surface modification of nanoparticles is used to enable their dispersion in polymers. Moreover, molecular dynamics (MD) simulations are useful for revealing the interfacial properties between nanoparticles and polymers to aid in the design of materials. In this study, the effect of surface coverage, modifier length, and polymer species on the interfacial structure and affinity between surface-modified Al2O3 and polymer melts were investigated using all-atom MD simulations. Hexanoic, decanoic, and tetradecanoic acids were used as surface modifiers, and polypropylene (PP), polystyrene (PS), and poly (methyl methacrylate) (PMMA) were used as polymers. The work of adhesion Wadh and the work of immersion Wimm were selected as quantitative measures of affinity. Wadh was calculated using the phantom-wall approach, and Wimm was calculated by simply subtracting the surface tension of polymers γL from Wadh. The results showed that Wadh and Wimm were improved by surface modification with low coverage, owing to a good penetration of the polymer. The effect of modifier length on Wadh and Wimm was small. Whereas Wadh increased in the following order: PP < PS < PMMA, Wimm increased as follows: PMMA < PS < PP. Finally, the trend of Wadh and Wimm was organized using the Flory–Huggins interaction parameter χ between the modifier and the polymer. This study demonstrates that the interfacial affinity can be improved by tuning the surface coverage and modifier species depending on the polymer matrix. [ABSTRACT FROM AUTHOR]

In this work, using the combination of atom transfer radical polymerization and click chemistry, the graft copolymer polysulfone‐graft‐poly (methyl methacrylate) (PSf‐g‐PMMA) was synthesized as a modifying agent. The copolymer was embedded in the PSf substrate using a nonsolvent phase inversion method. Then, the modified substrate was used to make thin film composite forward osmosis (TFC‐FO) membranes using the interfacial polymerization method. Also, the effect of PSf‐g‐PMMA copolymer content on the surface properties of the membrane, as well as the filtration performance, was investigated. The increase in hydrophilicity, porosity, and average pore diameter indicated the favorable effect of PSf‐g‐PMMA copolymer on the characteristics of modified substrates. In addition, the improvement in the membrane morphology (an increase in the length and number of finger‐like pores) provided a substrate with low tortuosity and structure parameters. Therefore, the pure water permeability increased from 79.9 LMH/bar for the control membrane to 372.1 LMH/bar for the membrane containing 20 wt.% of PSf‐g‐PMMA copolymer. Investigating the FO separation properties of TFC‐FO membranes showed an increase in water flux and selectivity due to an improvement in the morphology of the modified substrate with low structural parameters. The new TFC‐FO membranes have been optimized, and water flux has significantly improved. Compared with the control membrane, which did not have copolymer blending, the new membranes have a triply enhanced water flux of 17.1 LMH. In addition, the selectivity of these optimized membranes has improved when 1 M NaCl is used as the draw, and DI water is used as the feed in the FO mode. [ABSTRACT FROM AUTHOR]

The performance of electrochemical supercapacitors is greatly affected by electrodes, which are considered one of the most significant components. This article sheds light on manganese dioxide (MnO2)-incorporated poly(methyl methacrylate) (PMMA) membranes as electrodes for supercapacitor applications. The interaction between MnO2 and PMMA is justified by Fourier transform infrared spectroscopy. The surface morphology of MnO2@PMMA membranes was observed using scanning electron microscopy and atomic force microscopy. Techniques such as cyclic voltammetry and electrochemical impedance spectroscopy indicated that a 7.5 wt% MnO2@PMMA membrane exhibited the highest electrochemical performance. GCD tests revealed that the 7.5 wt% MnO2@PMMA membrane showed a maximum specific capacitance of 361 F g−1 at a current density of 125 mA g−1 with a maximum energy density of 144 W h kg−1 and maximum power density of 1135 W kg−1. The membrane displayed 87% capacitance retention after 5000 cycles. The fabricated interdigital microsupercapacitor device revealed the highest specific capacitance of 528 mF g−1 at a current density of 0.15 mA g−1 with a maximum energy density of 47 mW h kg−1 and maximum power density of 400 mW kg−1. [ABSTRACT FROM AUTHOR]

The fast advancements in technology have generated significant interest in optoelectronic materials. Nevertheless, the difficulty of creating affordable materials with exceptional optical characteristics is an ongoing challenge. Therefore, the objective of this work was to tune the optical properties of poly(methyl methacrylate) (PMMA) by embedding silver vanadate (SV) in the polymer matrix. Moreover, the wettability test of the fabricated composite membranes showed a hydrophobic behavior, with the PMMA film containing 0.6 wt.% SV showed a contact angle of 86.75 ± 0.7°. Furthermore, SV showed high thermal stability with a maximum weight loss of 0.74% at 830°C, which is very high thermal stability at high temperatures. In addition, the 0.6 wt.% SV@PMMA film exhibited a maximum weight loss of 96.7% at 785°C. Moreover, the 0.6 wt.% SV@PMMA film showed the lowest indirect band gap energy (2.02 eV) compared to the other films and pure SV NPs. The findings demonstrate the potential of the synthesized films for optoelectronic applications. [ABSTRACT FROM AUTHOR]

An emissive organic–inorganic hybrid material is obtained by a cationic metathesis between a blue fluorescent tetraphenylethylene‐based salt: [TPEIm2]I2, and a red‐NIR phosphorescent octahedral molybdenum cluster compound: Cs2[Mo6I8(OCOC2F5)6]. As demonstrated by Single Crystal X‐Ray Diffraction, the hybrid [TPEIm2][Mo6I8(OCOC2F5)6] crystallizes as a 2:2 dimer and emits in the red‐NIR area. Its emission properties are studied in the solid state and once embedded in poly(methylmethacrylate) by steady state and time dependent photoluminescence spectroscopy. They are further compared to the case in which the two starting salts are directly integrated in the polymer matrix. Obtained nanocomposites show evanescent UV‐2A optical writing and reading behavior, with color contrasts depending on how emitters have been introduced. [ABSTRACT FROM AUTHOR]

A simple and green method for the recovery of methyl methacrylate (MMA) has been developed by recycling waste sheets of poly-(methyl methacrylate) without using any catalyst. The liquefaction yield was 97.33% while the purity of recovered MMA was up to 92%. The recovered monomer utilized for the synthesis of methylmethacrylate-copolymer-divinylbenzene at 20% cross-linking in the presence of different porogens (methyl isobutyl ketone, cyclohexane, toluene, and cyclohexanone) by suspension polymerization. The same copolymer was also synthesized but with different cross-linking percentages such as 4, 10, 15, 20, 25, 30, and 40% in the presence of a single porogen (methyl isobutyl ketone). Different copolymers having pore volumes in the range of 0.120–0.682 mL/g were obtained. The pendant –COOCH3 groups within the polymeric chain were converted to –COOH groups via acid hydrolysis, accompanied by the attachment of –SO3H groups to phenyl rings. ATR-FTIR, UV–Vis spectrometry, and HPLC techniques were used for qualitative and quantitative analyses of –COOH and –SO3H groups. The obtained results were compared with copolymers and resin synthesized using commercial MMA, displaying similar behavior. The resin derived from the recovered monomer was utilized for Co2+ ion removal at various pH, demonstrating excellent removal performance. [ABSTRACT FROM AUTHOR]

This paper reports new experimental data involving density (ρ), viscosity (η), and ultrasonic velocity (u) for four binary mixtures consisting of methyl methacrylate (MMA) with heptane, decane, dodecane, and tridecane at temperatures 303.15, 308.15, and 313.15 K and atmospheric pressure measured over entire composition range. The experimental data have been used to calculate excess or deviation parameters such as excess molar volume , deviation in viscosity (Δη) and the acoustical parameters namely isentropic compressibility (Ks), free volume (Vf), free length (Lf), and internal pressure (πi). The excess or deviation properties have been fitted to the Redlich–Kister polynomials and the variation of these parameters with composition were discussed from the viewpoint of molecular interactions prevailing in the mixtures. The properties reported are found to be either positive or negative depending upon nature of liquid mixture and associated molecular interactions of the binary mixtures. [ABSTRACT FROM AUTHOR]

The reversible bonding of microfluidic chips has been developing rapidly with the requirement of reusable microfluidic devices or the need to obtain the samples inside the chip. Traditional bonding methods for polymer‐based microfluidics, e.g., thermal bonding, permanently attach the substrate and cover plate. Sometimes, once the chip flow channel is blocked, it is difficult to clean and affect the reusability of the chip. This study proposes a new reversible bonding method for poly (methyl methacrylate) (PMMA) microfluidic chips with the help of stretch release adhesive strips. The designed microchannels were fabricated on the surface of PMMA plates using CO2 laser irradiation. Then, stretch release adhesive strips were used as an intermediate layer between the substrate (with microchannels) and another flat PMMA/PS/PC plate to seal the microchannel. The assembled chip sets were bonded at room temperature with bonding strength comparable with other permanent bonding methods. Experimental results show that simply pulling the adhesive layer by applying a shear force can easily detach the intermediate adhesive layer from both the substrate and cover plate to separate the bonded chipset. The proposed reversible bonding method is simple, rapid and has low residue and high bonding strength. Bacterial culture experiments were also conducted to verify the biocompatibility of the proposed bonding method. The proposed reversible bonding technique can be used for polymer‐based microfluidic devices that require sample recovery or chip reuse. Highlights: The stretch release adhesive strip can provide high bond strength.It allows easy peeling for reversible bonding.It bonds at room temperature with simple operation.It has good transparency for easy observation of experiments.It has good biocompatibility. [ABSTRACT FROM AUTHOR]

This research article focused on the blending of poly(lactic acid)/poly(methyl methacrylate) (PLA/PMMA) polymer materials to overcome PLA's inherent weaknesses, such as low glass transition temperature, brittleness, and lack of melt strength. Consolidated feasible characteristic investigations, such as mechanical, thermal, and aging behavior, were carried out for PLA/PMMA blended polymer materials. Initially, the miscibility of PLA/PMMA blend filaments was prepared at various blend ratios (91/9, 82/18, and 73/27) and samples were printed by fused deposition modeling (FDM). Differential scanning calorimetry (DSC) and Fourier infrared spectroscopy (FTIR) analysis have been utilized to evaluate the glass transition temperature (Tg) and intermolecular interaction, respectively, on blended polymer materials. Experimental tensile, compression, and flexural strength testing were performed on neat polymers and blended polymer composites. Compared to neat PLA materials, blended composites had 13.24% and 19.07% higher flexural and compression strengths. Besides, the interfacial interaction of neat and blended polymers has been done using dynamic mechanical analysis (DMA). Furthermore, Tg, storage modulus, and aging behavior of blended polymer materials have significantly improved over neat PLA materials. Altogether, the development of PMMA/PLA blends as sustainable biomaterials for dental applications aligns with environmental concerns and the need for biocompatible materials in dentistry. Highlights: Blending of PLA and PMMA helps mitigate the inherent constraints of PLA.Blended composites exhibited greater compressive and flexural strengths.Better glass transition temperature and intermolecular interaction.Excellent thermal stability and water aging imply viable dental biomaterials. [ABSTRACT FROM AUTHOR]

Comprehensive Summary Aluminum nanoparticles (Al NPs) have significant potential applications in various fields due to their unique LSPR. Significant advancements have been achieved in controlling the size and morphology of Al NPs. However, the efficient modification of Al NPs with polymers has not been implemented. Herein, we report a facile and efficient free‐radical polymerization induced grafting‐to (FRPIGt) method for grafting polymer chains onto Al NPs. By optimizing polymerization conditions, we were able to achieve a polymer brush layer with a weight loss fraction of up to 43.3%, which was higher than those of other polymers with carboxyl or primary amine end groups. Moreover, a broad range of vinyl monomers, including styrene, methacrylate, and methyl methacrylate, can be applied using the FRPIGt method to modify Al NPs. In addition, the FRPIGt method can be extended to photoinduced organocatalyzed atom‐transfer‐radical polymerization. This work paves a new path for the preparation of a wide range of polymer‐functionalized Al NPs and their polymer composites to be utilized in various fields. [ABSTRACT FROM AUTHOR]

Background: Methyl methacrylate (MMA) is a key precursor of polymethyl methacrylate, extensively used as a transparent thermoplastic in various industries. Conventional MMA production poses health and environmental risks; hence, citramalate serves as an alternative bacterial compound precursor for MMA production. The highest citramalate titer was previously achieved by Escherichia coli BW25113. However, studies on further improving citramalate production through metabolic engineering are limited, and phage contamination is a persistent problem in E. coli fermentation. Results: This study aimed to construct a phage-resistant E. coli BW25113 strain capable of producing high citramalate titers from glucose. First, promoters and heterologous cimA genes were screened, and an effective biosynthetic pathway for citramalate was established by overexpressing MjcimA3.7, a mutated cimA gene from Methanococcus jannaschii, regulated by the BBa_J23100 promoter in E. coli. Subsequently, a phage-resistant E. coli strain was engineered by integrating the Ssp defense system into the genome and mutating key components of the phage infection cycle. Then, the strain was engineered to include the non-oxidative glycolysis pathway while removing the acetate synthesis pathway to enhance the supply of acetyl-CoA. Furthermore, glucose utilization by the strain improved, thereby increasing citramalate production. Ultimately, 110.2 g/L of citramalate was obtained after 80 h fed-batch fermentation. The citramalate yield from glucose and productivity were 0.4 g/g glucose and 1.4 g/(L·h), respectively. Conclusion: This is the highest reported citramalate titer and productivity in E. coli without the addition of expensive yeast extract and additional induction in fed-bath fermentation, emphasizing its potential for practical applications in producing citramalate and its derivatives. [ABSTRACT FROM AUTHOR]

Since acrylate‐based materials are widely used in dentistry, their drawbacks such as low impact resistance and hardness, require continuous research in the field of materials science in order to avoid sudden fracture caused by chewing or fall. In this study, auto‐polymerizing poly(methyl methacrylate) (PMMA), commonly used as denture base material, was reinforced with poly(4‐styrenesulfonic acid‐co‐maleic anhydride) sodium salt (PSSMA) and strontium titanate (STO), with the aim of improving impact behavior and microhardness. Morphological analysis confirmed formation of phase‐separated and co‐continuous microscopic structures of PSSMA in PMMA, without visible agglomerates of STO nanoparticles, indicating that PSSMA‐STO interaction contributed to a better distribution of nanoparticles. Fourier transformed infrared spectroscopy revealed that PSSMA and STO did not interfere in the polymerization of methyl methacrylate. This was further supported by thermal analysis, which also showed that the addition of PSSMA and STO had no significant influence on thermal degradation. On the other side, PSSMA and STO significantly enhanced mechanical performance of PMMA. The modulus of elasticity increased by up to 48.6%, total absorbed impact energy improved by up to 108.4%, and microhardness increased by up to 272.8% when PSSMA was combined with STO for reinforcing denture PMMA. These results demonstrate the significant potential of PSSMA, which could be combined with other ceramic nanoparticles for denture reinforcement in the future. Highlights: This research presents novel dental hybrid composite.Influence of strontium titanate (STO) and poly(4‐styrenesulfonic acid‐co‐maleic anhydride) sodium salt (PSSMA) on poly(methyl methacrylate) (PMMA) was investigated.PSSMA/STO improved modulus of elasticity, microhardness and impact resistance.Sample with 5 wt% PSSMA and 1 wt% STO showed the highest improvement compared to PMMA.Presented hybrid composite could use as denture base material. [ABSTRACT FROM AUTHOR]

Highlights SrAl2O4 co‐doped with Eu2+ and Dy3+ ions (SAOED) have great potential in lighting field due to the unique light energy absorption‐storage‐released properties. In this work, a series of SAOED/poly(methyl methacrylate) (PMMA) luminescent composites were prepared and investigated. The maximum afterglow intensity of SAOED/PMMA composites was reached when the SAOED particle size was 26 μm, the mass ratio of SAOED to PMMA was 0.6 and the thickness of composites was 4.3 mm. Meanwhile, the tensile strength and modulus of the SAOED/PMMA composites were 22.06 MPa and 3.92 GPa, respectively. After being reexcited by a 3.5 W white diode used as normal functional lighting, SAOED/PMMA composites were able to achieve the requirement on landscape lighting (>2 lx), which showed promising engineering prospects in alternative lighting. The particle size, mass ratio and thickness effected the afterglow intensity. The optimal composites presented promising long persistent luminescence. Resulting SrAl2O4 co‐doped with Eu2+ and Dy3+ ions (SAOED)/poly(methyl methacrylate) (PMMA) composites possessed high tensile performance. The SAOED/PMMA composites showed great potential in alternative lighting. [ABSTRACT FROM AUTHOR]

Diabetes is a common chronic metabolic disease with a wide range of clinical symptoms and consequences and one of the main causes of death. For the management of diabetes, painless and continuous interstitial fluid (ISF) glucose monitoring is ideal. Here, we demonstrate continuous diabetes monitoring using an integrated microneedle (MN) biosensor with an emergency alert system. MNs are a novel technique in the field of biomedical engineering because of their ability to analyze bioinformation with minimal invasion. In this work we developed a poly(methyl methacrylate) (PMMA) based MN glucose sensor. The device was produced by the 3D printing technique, microfabrication, electrodeposition, and enzyme immobilization step. The in vitro test for the glucose MN sensor showed a linear range from 1.5 to 14 mM with a sensitivity of 1.51 μA mM−1, limit of detection (LOD) of 0.35 mM and good selectivity. Highly repeatable sensing is observed with good reproducibility. The interference-free detection of glucose in the presence of physiologically relevant concentrations of ascorbic acid, uric acid, and mannose is demonstrated, along with the operational stability of the array. After resolving the biofouling consequences linked to on-body sensing, this MN platform would be appealing for minimally invasive electrochemical glucose monitoring. An alert is sent to confidants via email or SMS when the values are abnormal. The application is also able to display the recorded values in the form of a graph to help determine the state of health of the user over a period of time. It can be concluded that continuous monitoring and an emergency alert system are important for keeping an eye on diabetic patients and can send alert in case of an abnormal situation of the patient. [ABSTRACT FROM AUTHOR]

Current families of reversible photochemical reactions present challenges for light‐controlled polymers of either photostationary states, which are common in photoinduced cycloaddition/cycloreversion reactions, or exclusively intramolecular bond changes, which characterize most photochromic units. In response to these challenges, here the concept of “proximal photocleavage” is presented, which combines photochemical crosslinking with a photocleavable linker, enabling a one‐time bond formation/cleavage sequence. Proximal photocleavage methacrylate monomers comprising, in series along the pendant of the methacrylate, a coumarin unit for crosslinking and either a phenacyl or ortho‐nitrobenzyl photocleavable group for decrosslinking are reported. The photophysical properties of these monomers and their statistical copolymers with methyl methacrylate are described, and wavelength selective crosslinking and de‐crosslinking of thin polymer films are demonstrated. [ABSTRACT FROM AUTHOR]

Acrylic pressure‐sensitive adhesives (PSAs) were synthesized using a solvent‐free ultraviolet‐induced polymerization method. The monomers n‐(isobutoxymethyl) acrylamide, 2‐ethylhexyl acrylate, 2‐hydroxyethyl acrylate, and methyl methacrylate and an initiator, hydroxy dimethyl acetophenone, were used to prepare acrylic copolymers as prepolymers. A multifunctional monomer, trimethylolpropane triacrylate, was added to form a semi‐interpenetrating network, leading to an increase in the modulus and elasticity of the prepolymer. This decreased the peel strength, which is suitable for temporary protective films. Rheological data from small‐amplitude oscillatory shear measurements also revealed consistent results suitable for removable PSAs. The plasticizers, such as dioctyl phthalate and dioctyl terephthalate, possessing favorable interactions with the main resins were found to exhibit transparency, clear debonding, and ultralow release, which are essential features for temporary protective films. [ABSTRACT FROM AUTHOR]

The control of Candida albicans biofilm formation on dentures made of poly(methyl methacrylate) (PMMA) is an important challenge due to the high resistance to antifungal drugs. Interestingly, the natural compounds undecylenic acid (UDA) and farnesol (FAR) both prevent C. albicans biofilm formation and could have a synergetic effect. We therefore modified PMMA with a combination of UDA and FAR (UDA+FAR), aiming to obtain the antifungal PMMA_UDA+FAR composites. Equal concentrations of FAR and UDA were added to PMMA to reach 3%, 6%, and 9% in total of both compounds in composites. The physico-chemical properties of the composites were characterized by Fourier-transform infrared spectroscopy and water contact angle measurement. The antifungal activity of the composites was tested on both biofilm and planktonic cells with an XTT test 0 and 6 days after the composites' preparation. The effect of the UDA+FAR combination on C. albicans filamentation was studied in agar containing 0.0125% and 0.4% UDA+FAR after 24 h and 48 h of incubation. The results showed the presence of UDA and FAR on the composite and decreases in the water contact angle and metabolic activity of both the biofilm and planktonic cells at both time points at non-toxic UDA+FAR concentrations. Thus, the modification of PMMA with a combination of UDA+FAR reduces C. albicans biofilm formation on dentures and could be a promising anti-Candida strategy. [ABSTRACT FROM AUTHOR]

The presented work concerns computational investigations of the physical properties of composite materials based on polymer matrix and nonlinear optical (NLO) active chromophores. The structural, electronic, and optical properties of selected tetrathiafulvalene (TTF)-based chromophores have been calculated using quantum chemical methods. The polymer matrix changes the physical properties of the inserted chromophores influencing their optical parameters. To explain the mechanism of the NLO signal occurrence from the composites based on poly(methyl methacrylate) (PMMA) matrix and TTF chromophores, their structures are modeled using the classical molecular dynamics. In consequence, the structural properties of the composites are discussed according to the NLO requirements. By developing the theoretical model based on a discrete multipole local field approach, the impact of polymer matrix on the optical properties of chromophores is explained. [ABSTRACT FROM AUTHOR]

Mercury (Hg) is a toxic element which impacts on biological systems and ecosystems. Because the toxicity of Hg species is highly dependent on their concentration levels and chemical forms, the sensitive identification of the chemical forms of Hg—i.e., Hg speciation—is of major significance in providing meaningful information about the sources of Hg exposure. In this study, a microfluidic-based device made of high-clarity poly(methyl methacrylate) (PMMA) was fabricated. Then, titanium dioxide nanoparticles (nano-TiO2s) were attached to the treated channel's interior with the aid of poly(diallyldimethylammonium chloride) (PDADMAC). After coupling the nano-TiO2-coated microfluidic-based photocatalyst-assisted reduction device (the nano-TiO2-coated microfluidic-based PCARD) with high-performance liquid chromatography (HPLC) and inductively coupled plasma mass spectrometry (ICP-MS), a selective and sensitive, hyphenated system for Hg speciation was established. Validation procedures demonstrated that the method could be satisfactorily applied to the determination of mercury ions (Hg2+) and methylmercury ions (CH3Hg+) in both human urine and water samples. Remarkably, the zeta potential measured clearly indicated that the PDADMAC-capped nano-TiO2s with a predominance of positive charges indeed provided a steady force for firm attachment to the negatively charged device channel. The cause of the durability of the nano-TiO2-coated microfluidic-based PCARD was clarified thus. [ABSTRACT FROM AUTHOR]

In this study, core/shell‐structured mesoporous hybrid silica gel particles were synthesized for the selective adsorption of hyaluronic acid. A non‐ionic amphiphilic polymer core consisting of poly(methyl methacrylate) and poly(ethylene glycol) blocks were coated with SiO2 using the Stöber method in the presence of non‐ionic and cationic surfactants to obtain mesoporous core‐shell silica particles. The surface of silica particles was functionalized through modification of L‐aspartic acid to improve their affinity against the targeted analyte, hyaluronic acid. Physico‐chemical methods including Fourier transform infrared spectroscopy, thermal gravimetric analysis, zeta‐size measurements, and transmission‐ and scanning‐electron microscopies were utilized to evaluate the properties of core‐silica particles. The surface functionalized core/shell particles have an average size of 254.7 (±33.1) nm as confirmed by TEM analysis. The hyaluronic acid adsorption performance of the modified core‐shell silica particles was optimized through varying pH, concentration, temperature, and contact time parameters. Thermodynamic parameters were estimated by applying adsorption isotherm and kinetics models to assess the favorability of the adsorption process. The models revealed that the hyaluronic acid adsorption processes follow monolayer adsorption (Langmuir model) and chemisorption (pseudo‐second‐order kinetics) processes. [ABSTRACT FROM AUTHOR]

In the process of unconventional oil and gas exploitation, the invasion of a large amount of drilling fluid into the formation is one of the most critical reasons leading to wellbore instability. A temperature‐sensitive polymer (AOS) was synthesized from acrylamide, oligo (ethylene glycol) methyl ether methacrylate (OEGMA), and sodium p‐styrene sulfonate by emulsion polymerization. The material is a solid‐free fluid with good fluidity at room temperature, after injection into the formation, the fluid is gradually transformed into hard gel above the lower critical solution temperature (LCST) (90°C), thus blocking micro‐fractures and improving wellbore stability. Infrared and NMR characterization confirmed the successful preparation of the target product. The transmittance of AOS with ambient temperature was measured by UV–vis spectrophotometer, and the LCST behavior of AOS was verified by rheological and viscoelastic measurements. The interaction mechanism between AOS and sodium bentonite was evaluated according to the American Petroleum Institute standard. The results show that after aging at 180°C, the filtration loss is reduced by 93%, and the medium permeability (100, 200 mD) formation is effectively plugged, with a plugging efficiency is as high as 74.7%. [ABSTRACT FROM AUTHOR]

Smart polymers undergo significant physical or chemical changes in response to stimuli like temperature and pH. Achieving a narrow molecular weight distribution is crucial for their sensitivity. Reversible addition–fragmentation chain transfer (RAFT) in ionic liquids is an effective method for synthesizing such polymers due to its favorable kinetics and environmental benefits. Most studies use imidazolium ionic liquids, while pyridinium ionic liquids are less common despite their easy synthesis. This study reports the first successful RAFT copolymerization of di(ethylene glycol) methyl ether methacrylate (DEGMEMA) and methyl methacrylate in N‐hexylpyridinium hexafluorophosphate ([HPY][PF6]). Both linear and hyperbranched copolymers (Mn > 25,000) with narrow molecular weight distribution were synthesized, showing observable temperature responses and biocompatibility. The linear copolymers had a desirable dispersity (Ð) of less than 1.10, while the hyperbranched copolymer had a Ð of 2.034. The lower critical solution temperatures (LCSTs) of the copolymers were close to or below the LCST of PDEGMEMA (26°C). This study indicates that pyridinium ionic liquids can be explored as a suitable solvent for synthesizing methacrylate‐based smart polymers. [ABSTRACT FROM AUTHOR]

Reversible addition–fragmentation chain transfer (RAFT) emulsion polymerization of methyl methacrylate (MMA) is successfully performed in water in the presence of a poly(methacrylic acid) (PMAA) macromolecular chain transfer agent (macroCTA) leading to the formation of self‐stabilized PMAA‐b‐PMMA amphiphilic block copolymer particles. At pH 3.7, the reactions are well‐controlled with narrow molar mass distributions. Increasing the initial pH, particularly above 5.6, results in a partial loss of reactivity of the PMAA macroCTA. The effect of the degree of polymerization (DPn) of the PMMA block, the solids content, the nature of the hydrophobic segment, and the pH on the morphology of the obtained diblock copolymer particles is then investigated. Worm‐like micelles are formed for a DPn of PMMA of 20 (PMMA20), while "onion‐like" particles and spherical vesicles are obtained for PMMA30 and PMMA50, respectively. In contrast, spherical particles are obtained for the DPns higher than 150. This unusual evolution of particle morphologies upon increasing the DPn of the PMMA block seems to be related to hydrogen bonds between hydrophilic MAA and hydrophobic MMA units. [ABSTRACT FROM AUTHOR]

Configurational and conformational analysis of the biologically relevant natural product artemisinin was conducted using carbon–carbon residual dipolar couplings (1DCC RDCs) at natural abundance. These RDCs were measured through the 2D‐INADEQUATE NMR experiment using a sample aligned in a compressed poly (methyl methacrylate) (PMMA) gel swollen in CDCl3. Singular value decomposition (SVD) fitting analysis of all carbon–carbon bonds, 1DCC RDCs, in relation to the full configuration/conformational space (32 diastereoisomers) of artemisinin, unambiguously identified the correct configuration of artemisinin. [ABSTRACT FROM AUTHOR]

As a result of the adsorption of copolymer 5-(4-nitro)phenylazo-8-methacryloxyquinoline with methyl methacrylate on the surface of mesoporous silica gel, a new polymer-inorganic composite material was obtained. Based on the comparison of the sorption capacity of the synthesized composite and the composite based on silica gel with in situ immobilized poly-5-(4-nitro)phenylazo-8-methacryloxyquinoline, it was concluded that the method of in situ immobilization of complex-forming polymers on the surface of silica gel is more effective compared to their physical adsorption. [ABSTRACT FROM AUTHOR]

This paper outlines an experimental investigation into the durability of large-scale adhesively bonded joints with a thick layer of methyl methacrylate adhesive (MMA). Ageing has been performed by immersion in a 3.5 wt% NaCl solution for 10 weeks at 50°C. Two aged and one unaged specimen were subjected to tensile testing, and three aged and one unaged specimen were loaded up to ~ 3.5 million fatigue cycles followed by a residual tensile test. The ductility of the adhesive is affected by ageing and fatigue testing. Despite a decrease in ductility, the plastic zone development was adequate for the required strain redistribution without compromising the joint performance (strength and stiffness) demonstrating the fatigue tolerance of the joint. The shear, longitudinal, and peel strain values in the adhesive bulk are evaluated by digital image correlation. The shear strength values are significantly higher than the requirements following from the design. All specimens failed by sudden delamination of the composite plate. Post-mortem analysis showed no corrosion travel at the interface of steel and adhesive. [ABSTRACT FROM AUTHOR]

Poly(vinylidene fluoride) (PVDF) based conducting polymer composites with carbon nanomaterials can be used for mechanical energy harvesting through piezoelectric or triboelectric effect. This study aims to investigate the influence of PMMA molecular weight on the electrical, thermal, and wetting properties of PVDF/40 wt.% PMMA blend nanocomposites reinforced with expanded graphite (ExGr). The blend nanocomposites with 40 wt.% PMMA have been prepared by solution blending method by using two different molecular weights of PMMA whose melt flow indices are 2 g/10 min and 2.3 g/10 min. The coexistence of the electroactive gamma and non-polar alpha phases of PVDF in the blend nanocomposites has been confirmed by X-ray diffraction, Fourier transform infrared spectroscopy and differential scanning calorimetry analyses. While overall crystallinity (%) of low molecular weight PMMA employed blend nanocomposites is lower than that of high molecular weight PMMA blended nanocomposites, the electroactive gamma phase has been found to increase in the former blend nanocomposites. The dispersion of graphite nanosheets has been observed to be better in high molecular weight PMMA employed blend nanocomposites which results in higher electrical conductivity. Impedance analysis of PVDF-40 wt.% PMMA-2 wt.% ExGr blend nanocomposite with high molecular weight PMMA results in enhanced interjunction capacitance (74.5 pF) in comparison to low molecular weight PMMA mixed blend nanocomposites (68 pF). Water contact angle (WCA) increases with molecular weight of PMMA and ExGr loading level. Thermogravimetric analysis has shown that the char content (above 500°C) is slightly higher for the blend with low molecular weight PMMA than with high molecular weight PMMA. [ABSTRACT FROM AUTHOR]

Protein denaturation and aggregation resulting from the effects of interfacial stress, often enhanced by flow and shear stress, pose significant challenges in the production of therapeutic proteins and monoclonal antibodies. The influence of flow on protein stability is closely intertwined with interfacial effects. In this study, we have developed a microfluidic device capable of exposing low volume (< 320 µL) protein solutions to highly uniform shear. To disentangle the synergistic impact of flow and interfaces on protein aggregation, we fabricated two devices composed of different materials, namely poly(methyl methacrylate) (PMMA) and stainless steel. Upon application of shear, we observed formation of protein particles in the micron-size range. Notably, The number of particles generated in the steel devices was ∼ 3.5 fold lower than in the PMMA device, hinting at an interface-mediated effect. With increasing the protein concentration from 1 to 50 mg/mL we observed a saturation in the amount of aggregates, further confirming the key role of solid-liquid interfaces in inducing particle formation. Introduction of non-ionic surfactants prevented protein aggregation, even at the highest tested protein concentration and low surfactant concentrations of 0.05 mg/mL. Overall, our findings corroborate the synergistic impact of shear and interface effects on protein aggregation. The device developed in this study offers a small-scale platform for assessing the stability of antibody formulations throughout various stages of the development and manufacturing process. [ABSTRACT FROM AUTHOR]

We report the facile synthesis of asymmetric perylene diimides (asym−PDIs) using readily available reagents, demonstrating their distinct photoluminescent properties. In CHCl3, asym−PDIs exhibit higher solubility compared to traditional perylene dyes, of which solubilities can be varied by substituent selections. Among them, UV‐vis absorption spectra of CPE in CHCl3 solution displayed no aggregate peaks in the ground state, maintaining high photoluminescent quantum yields. Also, CPE can be readily dispersed into poly(methyl methacrylate) PMMA (CPE−PMMA), forming thin films without aggregate formation. Importantly, the emission color of CPE−PMMA thin films significantly changes with the addition of polycyclic aromatic hydrocarbons (PAHs). These color changes should be strongly correlated with the HOMO level of the added PAHs. [ABSTRACT FROM AUTHOR]

To study the service performance of polymer bilayer sheets, this experimental study focuses on the thermal and mechanical characterization of sheets composed of two polymer layers (named ABS/PMMA), an Acrylonitrile–Butadiene–Styrene layer and a 15% Poly(Methyl Methacrylate) layer. These sheets are used in many industrial components subjected to thermal and mechanical strain. The studied bilayer sheets were obtained by a co-extrusion process. Thermal properties were measured through Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC). Mechanical behavior was determined via uniaxial tensile tests at various temperatures less than the glass transition temperature and using two strain rates of 3.33 × 10−4 s−1 and 1.66 × 10−2 s−1. Furthermore, the viscoelastic properties are determined via Dynamic Mechanical Analysis (DMA) using two frequencies. The findings revealed substantial ABS/PMMA bilayer thermal stability. The obtained glass transition temperature of this bilayer was 111 °C. Its viscoelastic behavior was described by determining the storage and loss modulus. Furthermore, the influence of temperature and strain rate parameters on the tensile behavior of the ABS/PMMA bilayer was also determined showing high dependence of mechanical behavior on these two parameters. This bilayer exhibits brittleness at room temperature and high total strain exceeding 62% at 90 °C. [ABSTRACT FROM AUTHOR]

This work aims to demonstrate the effect of ZrO 2 and MgO inclusion into the Poly(methyl methacrylate) (PMMA). To fabricate novel hybrid composites via heat cure method, various composites (PZM2, PZM4 and PZM6) were synthesized in the system [(95-x) PMMA + 5 ZrO 2 + x MgO] (x = 2, 4, and 6) respectively. Density of the prepared composites were determined and varying between 1.035–1.152 g/cm3. X-ray Diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) followed by EDAX and mechanical testing were performed to evaluate the fabricated composite properties. Moreover, to explore the structure of the fabricated composites the 13 C CP-MAS SSNMR and 1 H-13 C Phase-Modulated Lee Goldberg (PMLG) HETCOR Spectrum were recorded which clarify chemical shifting and motional dynamics of the composites. Mechanical tests were performed by UTM and the obtained parameters such as compressive strength, Young's modulus, fracture toughness, brittleness coefficient, flexural strength and flexural modulus are found to be in the range of 91–100 MPa, 0.48–0.51 GPa, 9.122–9.705 MPa.m1/2 , 0.66–0.815, 51.03–42.78 MPa and 499–663 MPa respectively. Some more mechanical parameters such as proportional limit, elastic limit, failure strength, modulus of resilience and modulus of toughness were also calculated. Furthermore, tribological properties were also determined and the coefficient of friction (COF) was decreased by 17.4 % and 38 % for composite PZM6 at 20 N and 40 N as compared to the composite PZM2 and the lowest wear volume of 1.55 mm3 was observed for PZM2, whereas the maximum volume loss of 5.64 mm3 is observed for composite PZM6. To check out the biocompatibility, cytotoxicity and genotoxicity of the fabricated composites the Trypan-blue assay was also performed for PZM2 and PZM6 composites. Dissection on the gut of larvae was also performed on the both composites followed by DAPI and DCFH-DA staining. Therefore, these synthesized samples can be used for the fabrication of denture materials. [Display omitted] • Synthesis of ZrO 2 and MgO reinforced denture-based resin composites via heat cure method. • Density of the composites were determined and varying between 1.035-1.152 g/cm3. • The structure of the fabricated composites was studied using the 13 C CP-MAS SSNMR and 1 H-13 C Phase-Modulated Lee Goldberg (PMLG) HETCOR spectrum. • The PZM6 composite shows the maximum compressive strength, 100 MPa. • To check out the biocompatibility, cytotoxicity and genotoxicity, the Trypan-blue assay was performed. [ABSTRACT FROM AUTHOR]

A new type of UV-curable pressure-sensitive adhesive containing Si atoms (Si-PSAs) was prepared by a solution-free UV-initiated telomerization process of n-butyl acrylate, acrylic acid, methyl methacrylate, and 4-acrylooxybenzophenone using triethylsilane (TES) as a telogen and an acylphosphine oxide (APO) as a radical photoinitiator. Selected commercial adhesion promoters were tested as additives in the formulation of adhesive compositions, i.e., (i) an organic copolymer with polar groups (carboxyl and hydroxyl); (ii) a hydroxymetal-organic compound; and (iii) a quaternary ammonium salt and (iv) a chlorinated polyolefin. No fillers, crosslinking agents, or photoinitiators were used in the adhesive compositions. NMR techniques confirmed the incorporation of silicon atoms into the polyacrylate structure. The influence of adhesion promoters on the kinetics of the UV-crosslinking process of Si-PSAs was investigated by a photo-DSC technique. The obtained Si-PSAs were characterized by adhesion (to steel, glass, PMMA, and PE), tack, and cohesion at 20 °C. Finally, the wetting angle of Si-PSAs with water was checked and their thermal stability was proved (TGA). Unexpectedly, the quaternary ammonium salt had the most favorable effect on improving the thermal stability of Si-PSAs (302 °C) and adhesion to glass and PMMA. In contrast, Si-PSAs containing the hydroxymetal-organic compound showed excellent adhesion to steel. [ABSTRACT FROM AUTHOR]

A series of poly(alkyl methacrylate)s and poly(oligo(ethylene glycol) methyl ether methacrylate)s labeled with 1-pyrenebutanol were referred to as the PyC4-PCnMA samples with n = 1, 4, 6, 8, 12, and 18 and the PyC4-PEGnMA samples with n = 0–5, 9, 16, and 19, respectively. Pyrene excimer formation (PEF) upon the encounter between an excited and a ground-state pyrenyl labels was employed to determine their persistence length (lp) in o-xylene. The fluorescence decays of the PyC4-PCnMA and PyC4-PEGnMA samples were acquired and analyzed with the fluorescence blob model to yield the number (Nblob) of structural units in the volume probed by an excited pyrenyl label. Nblob was found to decrease with an increasing number (NS) of non-hydrogen atoms in the side chain, reaching a plateau for the PyC4-PEGnMA samples with a longer side chain (n = 16 and 19). The Nblob values were used to determine lp. The lp values for the PyC4-PCnMA and PyC4-PEGnMA samples increased linearly with increasing NS2 as predicted theoretically, which agreed with the lp values obtained by viscometry for a series of PCnMA samples. The good agreement between the lp values retrieved by PEF and viscometry served to validate the PEF-based methodology for determining lp for linear polymers. [ABSTRACT FROM AUTHOR]

Aqueous solutions of a thermoresponsive diblock copolymer poly(di-[ethylene glycol] methyl ether methacrylate)-b-poly(2-[diisopropylamino] ethyl methacrylate) (PDEGMA-b-PDIPAEMA) were studied by static, dynamic and electrophoretic light scattering, small-angle X-ray scattering and differential scanning calorimetry. Thermoresponsive behavior of PDEGMA-b-PDIPAEMA was investigated at two pH values, pH = 2, at which the terminal carboxylic group of the PDEGMA chain and the PDIPAEMA block are protonated, and pH = 7, where the carboxyl terminal group is ionized while the PDIPAEMA block is partially deprotonated and more hydrophobic. Both at pH = 2 and 7, PDEGMA-b-PDIPAEMA copolymer underwent extensive association (the size of the aggregates was between 100 and 300 nm), indicating strong interchain interactions. While the measurements confirmed thermoresponsive behavior of PDEGMA-b-PDIPAEMA at pH = 7, no changes in the association with temperature were observed at pH 2 as the thermoresponsivity of PDEGMA was suppressed by hydrogen bonding between carboxylic groups and PDEGMA segments, as well as due to the increased hydrophilicity of the PDIPAEMA block. Fluorescence measurements with pyrene as a fluorescent probe showed that both at pH = 2 and pH = 7 the associates were able to solubilize hydrophobic substances. [ABSTRACT FROM AUTHOR]

In this study, zinc oxide (ZnO) nanoparticle (NP) and bismuth oxide (Bi2O3) nanoparticles were synthesized by the thermal decomposition method. Different amounts of each NP (1% W/V, 3% W/V, and 5% W/V) were used separately to combine with polymethyl methacrylate (PMMA) to prepare composite nanofibers using a simple, fast, and cost-effective electrospinning method. Characterization of NPs and nanofibers was investigated by scanning electron microscopy (SEM) to determine morphology and size, energy dispersive X-ray (EDX) to check chemical structure, Fourier transform infrared spectroscopy (FTIR) to study functional groups, X-ray diffraction (XRD) to evaluate crystal structure, and dynamic light scattering (DLS) to show size and distribution size. According to the results, a mixture of 3% ZnO NPs and 3% Bi2O3 NPs incorporated in PMMA was selected as the best nanofiber due to smooth and fine morphology without any knot or adhesion with low diameter distributions. Based on the Debye–Scherrer equation, the average size was obtained for ZnO NPs, Bi2O3 NPs, and PMMA congaing 3% W/V ZnO NPs and 3% W/V Bi2O3 NP as 32.93, 76.82, and 21.52 nm, respectively. The hydrophilicity test was performed by measuring the contact angle of PMMA, PMMA congaing 3% W/V ZnO NPs, PMMA congaing 3% W/V Bi2O3 NPs, PMMA congaing 3% W/V ZnO NPs and 3% W/V Bi2O3 NPs, which were obtained 132.56°, 74.13°, 128.24°, and 132.70°, respectively. The result the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) show that PMMA congaing 3% W/V ZnO NPs, PMMA congaing 3% W/V Bi2O3 NPs can be inhibiting Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) bacteria. The fabricated composite nanofibers have good potential for the treatment of skin infections, tissue engineering, and biomedical and industrial applications as a transdermal antibacterial patch. [ABSTRACT FROM AUTHOR]

A Ti3C2TxMXene-based biosensor has been developed and the photocatalytic atom transfer radical polymerization (photo ATRP) amplification strategy applied to detect target miRNA-21 (tRNA). Initially, Ti3C2TxMXene nanosheets were synthesized from the Ti3AlC2 MAX precursor via selective aluminum etching. Then, functionalization of Ti3C2TxMXene nanosheets with 3-aminopropyl triethoxysilane (APTES) via silylation reactions to facilitate covalent bonding with hairpin DNA biomolecules specifically designed for tRNA detection. Upon binding with the tRNA, the hairpin DNA liberated the azide (N₃) group, initiating a click reaction to affix to the photo ATRP initiator. Through the ATRP photoreaction, facilitated by an organic photoredox catalyst and light, a significant amount of ferrocenyl methyl methacrylate (FMMA) monomer was immobilized on the electrode. Therefore, the electrochemical signal is amplified. The electrochemical efficacy of the biosensor was assessed using square wave voltammetry (SWV). Under optimized conditions, the biosensor demonstrated remarkable sensitivity in detecting tRNA, with a linear detection range from 0.01 fM to 10 pM and a detection limit of 2.81 aM. The findings elucidate that the developed biosensor, in conjunction with the photo ATRP strategy, offers reproducibility, stability, and increased sensitivity, underscoring its potential applications within the experimental medical sector of the biomolecular industry. [ABSTRACT FROM AUTHOR]

Surface-modified bacterial cellulose, namely, BC-g-PMMA fiber, was synthesized by graft polymerization. The BC-g-PMMA fiber was employed as a surface modifying agent for a porous polylactic acid (PLA) scaffold, which was prepared through phase inversion. In this study, BC-g-PMMA 1:1 (BC: MMA mole ratio of 1:1), BC-g-PMMA 1:3 (BC: MMA mole ratio of 1:3), and BC-g-PMMA 1:6 (BC: MMA mole ratio of 1:6) were prepared using methyl methacrylate (MMA) as a grafting monomer under sonication-assisted reactions. Various characterization methods, including FTIR, DSC, and TGA, were employed to confirm that BC-g-PMMA exhibited an amphiphilic structure. Next, the PLA/BC-g-PMMA composite scaffold was successfully prepared using a solvent-induced phase inversion technique involving a solvent exchange step (dioxane diffused out while water diffused in); due to this process, the honeycomb structure of the PLA/BC-g-PMMA composite contained amphiphilic surfaces, and the wettability and cell adhesion behavior of the porous material were manipulated. In the absence of BC-g-PMMA, porous PLA exhibited a hydrophobic surface and no wicking properties. In contrast, the PLA/BC-g-PMMA composites showed an ability to wick, which was related to the grafted PMMA moiety; the higher the grafted PMMA ratio was, the slower the wicking ability due to the decrease in the surface energy of the composites. Due to their tailored surface chemistry, these materials played a role in the adherence of the composites to proteins and human gingival fibroblasts. Therefore, amphiphilic spongy PLA/BC-g-PMMA composites are promising materials for tissue engineering and spheroid (3D cell structure) scaffolds. [ABSTRACT FROM AUTHOR]

Presented in this study is a validated semiempirical model of the effects of femtosecond laser pulse energy on the effective z-position of the resulting cut after laser-induced optical breakdown. Different energy levels (for the same spot spacings, i.e., different doses) running from 1.07 × (~60 nJ) to 3.8 × (~215 nJ) of the laser-induced optical breakdown (LIOB) threshold (~56 nJ) were used to perform flat cuts within flat poly(methyl methacrylate) (PMMA) samples at the same nominal focus position (depth within the material). The z-locations of the effective cut and the anterior surface of the PMMA were confocally determined. The difference (PMMA_surface—Cut_plane) was used as a surrogate for the effective shift in the z-position of the cut. A consistent and continuous shift towards less deep cuts was observed for increasing pulse energies. The z-shift spreads by up to 22 µm thinner cuts for the largest pulse energy (3.8× LIOBTh, ~215 nJ). Higher pulse energies seem to significantly reduce the cutting depth. The results for PMMA are in good agreement with the moving LIOB model. [ABSTRACT FROM AUTHOR]

In this study, the influence that the monomer composition of hydroxyethyl caprolactone acrylate/methyl methacrylate (HECLA/MMA) has on the properties of the latex films, including contact angle, thermogravimetric analysis, and mechanical properties was evaluated. The polymerization process to obtain small particle sizes, good colloidal stability, and polymer films was optimized through the use of pullulan (Pull) and different ratios of HECLA and MMA. The results revealed a substantial impact of the monomer composition and polymerization processes on the particle size and latex film properties. The use of seed latex obtained in situ reduces particle size and particle size distribution. Additionally, it was observed that the contact angle of the polymer films increased as the concentration of HECLA increased. Furthermore, the water absorption of the polymer films exhibited a decreasing trend after reaching an 80/20 monomer composition of HECLA/MMA. An increase in HECLA contents in the recipe showed a reduction in tensile strength, elastic modulus, hardness, and elongation at break. Conversely, higher HECLA contents contributed to improving the thermal properties of the polymer films. Finally, the optimal ratio of HECLA/MMA to improve the thermal degradation and tensile mechanical properties of the polymer film was 50/50 wt%. The results found in this work allow additional data for producing poly(HECLA‐co‐MMA)‐g‐Pull latexes by manipulating the ratios of HECLA and MMA, which can create new potential applications in various industrial settings for a wide range of polysaccharides. Highlights: Poly(HECLA‐co‐MMA)‐g‐Pull with different ratios of HECLA/MMA were successfully obtained.The use of Pull after molar mass reduction had a significant effect on colloidal stability.A reduction in tensile strength and elongation at break was obtained by increasing the amount of HECLA.Thermal stability of the latex films showed a direct relationship with the content of HECLA.Poly(HECLA‐co‐MMA)‐g‐Pull latexes can be used in agricultural applications. [ABSTRACT FROM AUTHOR]

This study investigated the physical aging behavior of commodity polymers, specifically polystyrene (PS) and poly(methyl methacrylate) (PMMA), across various molecular weights (MWs). Using ellipsometry, we examine the physical aging behavior of bulk polymer films supported on silicon across a wide range of quench depths below glass transition temperature. At shallow quench depths, where the physical aging behavior is thermodynamically controlled, we observe that the physical aging rate for both PS and PMMA increases with decreasing MW. The MW dependence of the physical aging rate in the thermodynamic‐control region is hypothesized to originate from the MW dependence of the fractional free volume. In support of this hypothesis, we observe that the difference in thermal expansivity between the rubbery state and the glassy state (αrubbery − αglassy), which has been demonstrated to be positively related to fractional free volume, exhibits a similar MW dependence as the physical aging behavior. This correlation lends support to the free volume model of physical aging. Building on the free volume model, we propose a method to tune the physical aging behavior, demonstrating that incorporating flexible chain ends alters the physical aging behavior in a manner akin to reducing MW. Highlights: Polystyrene and poly(methyl methacrylate) have maximum physical aging rates at specific quench depths.Physical aging behavior is thermodynamically or kinetically controlled.With thermodynamic control, the aging rate increases with a reduction in molecular weight.With thermodynamic control, the aging rate correlates with free volume.Aging behavior can be tuned by blending with low MW polymer with highly flexible chain ends. [ABSTRACT FROM AUTHOR]

The primary objective of this research is to fabricate semi‐interpenetrating polymer networks (semi‐IPNs) via in‐situ polymerization of methyl methacrylate (MMA) within a polyurethane (PU) framework. To produce polymethyl methacrylate (PMMA) from MMA in the PU matrix, solution polymerization was utilized in the following weight ratios: 30/70, 50/50, 70/30, and 90/10. The effective formation of semi‐IPNs of PU/PMMA was confirmed by several techniques. Fourier transform infrared (FTIR) proves that no new chemical bonds formed between the semi‐IPNs, and only physical interactions were present, and X‐ray diffraction (XRD) techniques tell about the amorphous nature of these semi‐IPNs. The field emission scanning electron microscope (FESEM) and atomic force microscope (AFM) were utilized to examine the morphology of PU/PMMA semi‐IPNs. In contrast to alternative semi‐IPNs, 70/30 and 90/10 PU/PMMA exhibit a uniform morphology devoid of phase separation. Furthermore, the significant thermal stability and transitions of these semi‐IPNs were assessed using a thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Additionally, the mechanical analysis indicates that among the different percentages of PU/PMMA, 70/30 PU/PMMA exhibits the highest tensile strength of approximately 50.5 MPa. The observed enhancement in mechanical strength can be attributed to interpenetrating networks (IPNs) formed between the constituents. The synthesized PU/PMMA semi‐IPNs have potential in various fields, including medical devices, automotive components, sports, and other advanced applications. [ABSTRACT FROM AUTHOR]

Low‐cost and high‐performance electronics based on synthetically simple materials are required to fuel the deployment of smart packaging and wearable electronics. Metal phthalocyanines (MPcs) are promising semiconductors for use in n‐type organic thin film transistors (OTFTs) but often require high operating voltages. The first silicon phthalocyanine‐based OTFT with a polymer dielectric is reported as an alternative to traditional metal oxide dielectrics. Incorporating poly(methyl methacrylate) (PMMA) as the dielectric successfully reduces the threshold voltage (VT) of bispentafluorophenoxy SiPc (F10‐SiPc) from 14.9V to 7.3V while retaining high mobility. Further reduction in VT is obtained by using copolymers and blends of PMMA and dimethylamino ethyl methacrylate (DMAEMA)‐containing polymers, where a higher molar fraction of DMAEMA leads to a consistent drop in VT to ‐0.7 V. The electron‐donating groups of the tertiary amines in the DMAEMA show clear interfacial doping of the semiconductor, reducing the voltage required to populate the dielectric/semiconductor interface with charge carriers and turn on the device. Blending trace amounts of DMAEMA‐containing copolymers with PMMA proves to be an effective strategy for reducing the VT while keeping the charge mobility high, unlike when using pure copolymers with elevated DMAEMA content. Time of flight secondary ion mass spectroscopy (ToF‐SIMS) and X‐ray photoelectron spectroscopy (XPS) demonstrate that the DMAEMA‐containing copolymer is floating to the surface of the PMMA blend at the dielectric–semiconductor interface, which explains the reduced VT. Synchrotron scanning transmission X‐ray microscopy (STXM) demonstrates that PMMA promotes a more edge‐on orientation of F10‐SiPc films, compared to the more face‐on orientation when deposited on the DMAEMA containing copolymer. This study demonstrates a straightforward process for designing dielectric polymers and their blends for the reduction in VT for n‐type OTFTs. [ABSTRACT FROM AUTHOR]

Anthropogenic particles in sea surface water of the semi-enclosed Osaka Bay were identified using stereomicroscopy, classified according to polymer type using Fourier-transform infrared spectroscopy (FTIR), and categorized according to their physical characteristics. A total of 565.1 particles were detected in the water samples. However, plastic particles accounted for only 22.4% of the particles. Microplastic abundance in Osaka Bay showed seasonal variance from 8.9 ± 1.4 (in May) to 22.8 ± 6.5 particles/L (in July), which is consistent with previous reports in other semi-enclosed bays. Microplastics were mainly fragmented and fiber shaped, with gray and colorless/white coloration. The dominant polymer types were polypropylene, poly(methylmethacrylate), polyester, polyethylene, and polyethylene terephthalate. Generally, there were considerably higher abundances of microplastics at offshore sites compared with nearshore sites. The results of this study suggest that local river effluents and marine-related activities are probable sources of microplastics in Osaka Bay. [ABSTRACT FROM AUTHOR]

This research presents the optical limiting properties of a novel axially linked D‐A type compound, LaPc‐C60(OH)n, where lanthanide phthalocyanine serves as the donor and fullerenol as the acceptor. The incorporation of fullerenol expands the π‐conjugated system, decreases the aggregation of the phthalocyanine, and significantly increases the solubility of the compound. The establishment of this D‐A system promotes intramolecular electron transfer, effectively improving both the non‐linear optical (NLO) response and optical limiting properties. In addition, homogeneous poly(methyl methacrylate) (PMMA) composite films (LaPc‐C60(OH)n/PMMA) are prepared using a simple solution casting method. Compared to fullerenol or lanthanum phthalocyanine individually, LaPc‐C60(OH)n exhibited a superior NLO response both in solution and in the solid composite film. In particular, LaPc‐C60(OH)n/PMMA demonstrated an increase in the non‐linear absorption coefficient (2050 cm GW−1) and a larger third‐order magnetization (1.84 × 10−8 esu). In addition to exhibiting an excellent NLO response at 532 nm, LaPc‐C60(OH)n also shows significant NLO enhancement at 1064 nm, extending the limiting range into the near‐infrared region. This behavior is attributed to different nonlinear absorption mechanisms and the synergistic effect that arise from the photo‐induced electron transfer process between the fullerenol and LaPc. [ABSTRACT FROM AUTHOR]

Solid‐state lithium metal batteries are under development for higher energy density and better safety. A key is to develop new electrolyte systems that are readily processible and capable to improve electrochemical cycling stability. In this study, A quasi‐solid‐state composite electrolyte based on low‐molecular‐weight polyethylene glycol dimethyl ether (PEGDME) in situ confined within polymerized methyl methacrylate (PMMA) backbone is designed and presented. The new design of the polymer matrix, together with Li+‐conducting ceramic fillers and appropriate lithium salts, has satisfactory Li‐ionic conductivity (1.1 × 10−4 S cm−1 at 30 C and 1.0 × 10−3 S cm−1 at 80 °C), good electrochemical stability (>4.7 V vs Li+/Li), and high compatibility with lithium metal anode, enabling room‐temperature operation and stable long‐term cycling of both Li||Li symmetric cells and lithium‐metal full cells (including LiFePO4 or LiCoO2 cathode). This work can extend the design boundaries of composite electrolytes meaningfully, and the idea of in situ polymerization limiting applies to almost all low‐molecular‐weight polymers, high‐molecular‐weight backbones, ceramic fillers, lithium salts, and additives in future development of room‐temperature solid‐state lithium metal batteries. [ABSTRACT FROM AUTHOR]