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The self-assembly of high-χ low-N block copolymers (BCPs) can give patterns with sub-10 nm full pitch, serving as a promising alternative to photolithographic methods. In this work, we synthesized poly(solketal methacrylate)-block-polystyrene copolymers, PSM-b-PS, with various volume ratios of the two blocks. After hydrolysis of the PSM block into poly(glycerol monomethacrylate), PGM, the BCPs had both lamellar and cylindrical microdomain morphologies in the bulk phase and in thin films. In addition to our previously developed solid-state hydrolysis strategy involving trifluoroacetic acid vapor, we developed a new photoinduced solid-state hydrolysis using photoacid generators, PAGs, embedded within the polymer films. After exposure to UV followed by a postexposure baking or solvent vapor annealing, the BCPs transitioned from the disordered, phase-mixed state into laterally ordered cylindrical patterns. In comparison to linear BCPs that rely on a random copolymer layer to modify interfacial interactions with the substrate to promote an orientation of the microdomains normal to the interface, we found that the microdomains in bottlebrush multiblock copolymers oriented normal to the interface absent substrate modification due to the chain architecture.

An emerging cellular engineering method creates synthetic polymer matrices inside cells. By contrast with classical genetic, enzymatic, or radioactive techniques, this materials-based approach introduces non-natural polymers inside cells, thus modifying cellular states and functionalities. Here, we cover various materials and chemistries that have been exploited to create intracellular polymer matrices. In addition, we discuss emergent cellular properties due to the intracellular polymerization, including nonreplicating but active metabolism, maintenance of membrane integrity, and resistance to environmental stressors. We also discuss past work and future opportunities for developing and applying synthetic cells that contain intracellular polymers. The materials-based approach will usher in new applications of synthetic cells for broad biotechnological applications.

The liquid-liquid interface provides a promising platform to construct supramolecular polymers and materials with advanced functions. However, supramolecular polymerization at the interface usually requires monomers with different or even orthogonal solubilities, which significantly limit the number of usable monomers. Here, we report a new strategy to construct supramolecular polymer networks at the oil-water interface using a water-soluble catechol-iron complex and an oil-soluble diend-functionalized polymer. Owing to the dynamic catechol-iron coordination bond and imine bond, the resulting supramolecular polymer networks demonstrate excellent dynamic features and responsiveness to different stimuli including the pH, redox, competing ligands, and temperature. With a supramolecular polymer network serving as a building block, emulsions and 2D films can be generated that have potential applications in encapsulation, release, and molecular separation.

Future exploitation of marine resources in a sustainable and eco-friendly way requires autonomous underwater robotics with human-like perception. However, the development of such intelligent robots is now impeded by the lack of adequate underwater haptic sensing technology. Inspired by the populational coding strategy of the human tactile system, we harness the giant magnetoelasticity in soft polymer systems as an innovative platform technology to construct a multimodal underwater robotic skin for marine object recognition with intrinsic waterproofness and a simple configuration. The bioinspired magnetoelastic artificial skin enables multiplexed tactile modality in each single taxel and obtains an impressive classification rate of 95% in identifying seven types of marine creatures and marine litter. By introducing another degree of freedom in underwater haptic sensing, this work represents a milestone toward sustainable marine resource exploitation.

High-molecular-weight linear polymers (HMWLPs) have earned the name "drag-reducing polymers" because of their ability to reduce drag in turbulent flows. Recently, these polymers have become popular in bioengineering applications. This study investigated whether the addition of HMWLP in a venoarterial extracorporeal circulation (ECC) model could improve microvascular perfusion and oxygenation. Golden Syrian hamsters were instrumented with a dorsal skinfold window chamber and subjected to ECC using a circuit comprised of a peristaltic pump and a bubble trap. The circuit was primed with lactated Ringer solution (LR) containing either 5 ppm of polyethylene glycol (PEG) with a low molecular weight of 500 kDa (PEG500k) or 5 ppm of PEG with a high molecular weight of 3,500 kDa (PEG3500k). After 90 min of ECC at 15% of the animal's cardiac output, the results showed that the addition of PEG3500k to LR improved microvascular blood flow in arterioles and venules acutely (2 h after ECC), whereas functional capillary density showed improvement up to 24 h after ECC. Similarly, PEG3500k improved venular hemoglobin O2 saturation on the following day after ECC. The serum and various excised organs all displayed reduced inflammation with the addition of PEG3500k, and several of these organs also had a reduction in markers of damage with the HMWLPs compared to LR alone. These promising results suggest that the addition of small amounts of PEG3500k can help mitigate the loss of microcirculatory function and reduce the inflammatory response from ECC procedures.NEW & NOTEWORTHY High-molecular-weight linear polymers have gained traction in bioengineering applications. The addition of PEG3500k to lactated Ringer solution (LR) improved microvascular blood flow in arterioles and venules acutely after extracorporeal circulation (ECC) in a hamster model and improved functional capillary density up to 24 h after ECC. PEG3500k improved venular hemoglobin O2 saturation and oxygen delivery acutely after ECC and reduced inflammation in various organs compared to LR alone.

The development of new type of hydrogels featuring enhanced properties is a recent topic and of particular interest for a wide range of industrial applications, especially in biomedical sector. The present contribution focuses on the mutliscale modeling of hydrogels that are treated by the enzymatic mineralization and thus enriched with calcium phosphate. More specifically, the calcium phosphate forms spherical or honeycomb structures in the hydrogel matrix, which significantly improves effective material properties such as stiffness and strength. The chosen multiscale finite element method (FEM) homogenization strategy uses the Hill–Mandel macrohomogeneity condition for bridging two scales: the macroscopic boundary value problem (BVP) simulates the specimen behavior, whereas the microscopic BVP investigates the representative volume element (RVE) depicting the heterogeneous multiphase microstructure. The approach proposed uses the Ogden model to simulate the hydrogel and the neo‐Hooke model for the calcium phosphate phase. It varies the RVE type and the macroscopic tests in order to study the influence of the microstructure on the effective behavior and uses experimental data to determine missing microscopic material parameters. Chosen numerical examples demonstrate the applicability of the numerical tool for the estimation of the optimal microscopic arrangement of phases. [ABSTRACT FROM AUTHOR]

Plastics are omnipresent in our everyday life, and accumulation of post‐consumer plastic waste in our environment represents a major societal challenge. Hence, methods for plastic waste recycling are in high demand for a future circular economy. Specifically, the degradation of post‐consumer polymers towards value‐added small molecules constitutes a sustainable strategy for a carbon circular economy. Despite of recent advances, chemical polymer degradation continues to be largely limited to chemical redox agents or low energy efficiency in photochemical processes. We herein report a powerful iron‐catalyzed degradation of high molecular weight polystyrenes through electrochemistry to efficiently deliver monomeric benzoyl products. The robustness of the ferraelectrocatalysis was mirrored by the degradation of various real‐life post‐consumer plastics, also on gram scale. The cathodic half reaction was largely represented by the hydrogen evolution reaction (HER). The scalable electro‐polymer degradation could be solely fueled by solar energy through a commercially available solar panel, indicating an outstanding potential for a decentralized green hydrogen economy. [ABSTRACT FROM AUTHOR]

Bottlebrush polymers have a variety of useful properties including a high entanglement molecular weight, low Young's modulus, and rapid kinetics for self‐assembly. However, the translation of bottlebrushes to real‐world applications is limited by complex, multi‐step synthetic pathways and polymerization reactions that rely on air‐sensitive catalysts. Additionally, most bottlebrushes are non‐degradable. Herein, we report an inexpensive, versatile, and simple approach to synthesize degradable bottlebrush polymers under mild reaction conditions. Our approach relies on the "grafting‐through" polymerization of α‐lipoic acid (LA)‐functionalized macromonomers. These macromonomers can be polymerized under mild, catalyst‐free conditions, and due to reversibility of the disulfide bond in LA, the resulting bottlebrush polymers can be depolymerized by cleaving disulfide backbone bonds. Bottlebrushes with various side‐chain chemistries can be prepared through the atom transfer radical polymerization (ATRP) of LA‐functionalized macromonomers, and the backbone length is governed by the macromonomer molecular weight and solvent polarity. We also demonstrate that LA‐functionalized macromonomers can be copolymerized with acrylates to form degradable bottlebrush networks. This work demonstrates the preparation of degradable bottlebrush polymers with a variety of side‐chain chemistries and provides insight into the light‐mediated grafting‐through polymerization of dithiolane‐functionalized macromonomers. [ABSTRACT FROM AUTHOR]

Polymer-based composites, due to their versatility and tunable properties, have become essential in sorption, energy storage, and sensing applications. This review explores the fundamental chemistry underlying phase transitions within polymer matrices during composites formation, examining how anisotropic and isotropic fillers influence the mechanical, thermal, and functional properties of polymer-based composites. The role of phase transitions is emphasized as a key factor shaping the composite properties, while porosity is highlighted as a crucial attribute impacting sorption processes (absorption and adsorption) which enhances the utility of these materials in diverse modern applications. The transformations within polymer matrices during composites development and their resultant applications in sorption, sensing, and energy storage are investigated. It is examined how filler types and morphologies affect the porosity and functional performance of polymer-based composites. Future challenges and strategies for advancing the performance and sustainability of these materials are also outlined, offering insights that support ongoing research and development in advanced polymer-based composites. The review provides an analysis of current advancements and also offers guidance for future research, making it valuable for both emerging and established researchers in the field. [ABSTRACT FROM AUTHOR]

Highlights The use of polyacrylic acid‐polypropylene‐polyacrylic acid triblock copolymers (PAA‐iPP‐PAA, abbreviated as iPP‐PAA) with different acrylic acid contents (9, 19.5, 29 wt%) as compatibilizers for carbon fiber (CF)/polypropylene (PP) composites and their effect on the tensile properties of the composites were investigated. The addition of iPP‐PAA improved the tensile properties of the CF/PP composites. This enhancement in mechanical properties was considered to be due to the hydrogen bonding network between iPP‐PAAs, which improved the mechanical properties of the matrix resin itself, and to hydrogen bonding between carbon fiber surface and iPP‐PAAs, which improved the interfacial adhesion. A higher acrylic acid content of iPP‐PAA resulted in better interfacial properties; however, excessive acrylic acid content adversely affected the crystallinity and tensile properties of the composite, which suggests that there is an optimum acrylic acid content for the iPP‐PAA. The results indicated that iPP‐PAA is an effective compatibilizer in CF/PP composites, and the iPP‐PAA with the best performance had an acrylic acid content of 19.5%. PAA‐PP‐PAA copolymers used as compatibilizers for CF/PP composites. Acrylic acid content of PAA‐PP‐PAA varied as 9%, 19.5%, and 29%. Tensile properties of CF/PP composites enhanced by iPP‐PAA addition. Hydrogen bonding improved mechanical properties of matrix resin and CF‐resin adhesion. Optimum acrylic acid content for CF/PP composite was 19.5%. [ABSTRACT FROM AUTHOR]

The unique structure of [2.2]paracyclophane (PCP) with its rigidity, stability, and planar chirality has gained significant attention in polymer and material research. In this work, the incorporation of amino‐functionalized PCPs within polymers of intrinsic microporosity (PIMs) is reported for the first time. Three different PCP‐PIMs were prepared via a Tröger's base formation mechanism, and their structures characterized via solid‐state NMR, MALDI‐TOF, and SEM. Their porosity was evaluated using gas adsorption (N2 and CO2) based on theoretical calculations such as Brunauer–Emmett–Teller (BET), NLDFT pore size distribution (PSD) and ideal IAST CO2/N2 selectivity (15/85), a crucial separation when considering the capture of CO2 from flue gas. The surface areas were found to be between 200–230 m2 g−1 while the selectivity for CO2/N2 ranged from 46 to 70. [ABSTRACT FROM AUTHOR]

We have successfully constructed a machine learning framework to predict the important properties of MOF-loaded (metal–organic framework) polymer composites. Our classification models have obtained promising predictive performance. The analysis of feature importance has revealed the relationship between MOFs and the properties of polymer composites, guiding the research focus for MOF's application in the fire safety field. [ABSTRACT FROM AUTHOR]

Two CoII-coordination polymers were controllably obtained by the solvothermal reaction of C3 symmetric 5-bromo-1,3-benzenedicarboxylic acid (Br-1,3-H2BDC), 4,4′,4′′-(2,4,6-trimethylbenzene-1,3,5-triyl)tripyridine (4-TMTBT) ligand, and CoII salts. Co-CP-1 displayed a 3D net based on a mononuclear CoII center linked by Br-1,3-BDC2− and 4-TMTBT mixed ligands. Co-CP-2 featured a 3D network based on a trinuclear Co3(μ3-OH)(HCOO)(COO)4 unit and Br-1,3-BDC2− and 4-TMTBT ligands, which could be regarded as a new (3,7)-connected topology net. Interestingly, the two Co-CPs showed good catalytic activities for the alkene oxyalkylation reaction. In particular, Co-CP-2 exhibited higher catalytic performance and could be recycled at least for four cycles without loss of activity and structural integrity. [ABSTRACT FROM AUTHOR]

Levulinic acid(LA) is produced through acid-catalyzed hydrolysis and dehydration of lignocellulosic biomass. It is a key platform chemical used as an intermediate in various industries including biofuels, cosmetics, pharmaceuticals, and polymers. Traditional LA production uses chemical conversion, which requires high temperatures and pressures, strong acids, and produces undesirable side reactions, repolymerization products, and waste problems Therefore, we designed an integrated process to produce LA from glucose through metabolic engineering of Pseudomonas putida KT2440. As a metabolic engineering strategy, codon optimized phospho-2-dehydro-3-deoxyheptonate aldolase (AroG), 3-dehydroshikimate dehydratase (AsbF), and acetoacetate decarboxylase (Adc) were introduced to express genes of the shikimate and β-ketoadipic acid pathways, and the 3-oxoadipate CoA-transferase (pcaIJ) gene was deleted to prevent loss of biosynthetic intermediates. To increase the accumulation of the produced LA, the lva operon encoding levulinyl-CoA synthetase (LvaE) was deleted resulting in the high LA-producing strain P. putida HP203. Culture conditions such as medium, temperature, glucose concentration, and nitrogen source were optimized, and under optimal conditions, P. putida HP203 strain biosynthesized 36.3 mM (4.2 g/L) LA from glucose in a fed-batch fermentation system. When lignocellulosic biomass hydrolysate was used as the substrate, this strain produced 7.31 mM of LA. This is the first report of microbial production of LA from glucose by P. putida. This study suggests the possibility of manipulating biosynthetic pathway to produce biological products from glucose for various applications. • A strategy to produce levulinic acid from glucose was developed in P. putida KT2440. • Introducing aroG , asbF , and adc genes enabled levulinic acid production from glucose. • Deleting the pcaIJ and lvaE genes increased levulinic acid production in P. putida. • A levulinic acid yield of 36.3 mM (4.2 g/L) was achieved in fed-batch fermentation. • This is the first report of microbial levulinic acid production from glucose. [ABSTRACT FROM AUTHOR]

Atomic force microscopy (AFM) was used to characterize how water capillary forces impact polymer‐substrate adhesion in ambient conditions. We analyzed hydrophobic poly(styrene‐co‐butadiene) interacting with mica, silicon, and graphite substrates, each with distinct surface properties. Using polymer‐coated AFM tips/blank substrates, and vice versa, we explored the roles of water capillary forces and polymer‐substrate interactions on adhesion. When force spectroscopy experiments were conducted using polymer‐coated tips, adhesion was the largest on mica due to substantial water capillary forces between the tip and hydrophilic substrate. However, when using a blank tip and polymer‐coated substrates, the adhesion was largest on graphite and smallest on mica. This is because the blank tip interacted with the same hydrophobic polymer film for each experiment; therefore, water capillary forces had an equal magnitude on each substrate, allowing polymer‐substrate interactions to be compared even within ambient conditions. Moreover, single‐chain desorption events were consistently observed in these force‐distance curves since water capillary forces were significantly reduced. This study elucidated several aspects of how water capillary forces impact polymer‐substrate adhesion, which benefits applications reliant on polymer adhesion in ambient conditions and contributes to the fundamental understanding of polymer interface interactions. [ABSTRACT FROM AUTHOR]

In the process of curing or service, epoxy resin is prone to crack damage due to complex stress, resulting in material performance degradation and other catastrophic accidents. Self‐healing microcapsules offer an effective strategy to address the aforementioned issues and enhance the long‐term durability of materials. However, traditional microcapsules face challenges in achieving non‐contact repair, as the healing agent requires high temperature or other extreme conditions to achieve curing, which necessitates the artificial provision of these conditions. Moreover, such extreme conditions may accelerate equipment aging or negatively impact the matrix material. To address these issues, this paper reports a photosensitive microcapsule that can achieve healing by natural light for non‐contact self‐healing of insulating composites. In particular, SiO2 nanoparticles are incorporated into the shell of the microcapsules to construct a UV shielding layer, effectively preventing premature curing and failure of the untriggered microcapsules. Experimental results indicate that the proposed photosensitive microcapsule@SiO2 exhibits excellent thermal stability, remaining intact at temperatures up to 200°C. With a healing agent content of approximately 77.5%, the photosensitive microcapsule@SiO2 ensures effective repair. Furthermore, when cross‐linked with epoxy resin, it has minimal negative impact on the epoxy matrix, with a slight improvement in mechanical properties. The composites demonstrate outstanding self‐healing performance in response to mechanical scratch damage. Without the need for any artificial stimuli, the healing process can be easily activated by natural light, facilitating intelligent, contactless, and autonomous self‐healing. [ABSTRACT FROM AUTHOR]

Tuning full‐color emission of polymers holds significant promise. However, preparing unconventional luminescence polymers with color‐tunability in dilute solution and understanding the relationship between non‐covalent interactions and luminescent behavior remains a great challenge. We report two emitters (P1 and P2) incorporating tetracoordinate boron. The P1 with non‐conjugated D‐π‐A structure, exhibited red delayed fluorescence at 645 nm with quantum yield of 9.15 % in aggregates. Notably, the emission wavelength of P1 can be tuned from 418 to 588 nm at different solvent. Similarly, the emission wavelength of P2 can also be adjusted by manipulating the interactions between the solvent and fluorophore. Experimental characterization and theoretical calculations indicate that the B←N bond and electronic interactions between solvent and fluorophore significantly regulate the equilibrium the electrostatic potential (ESP) and the intramolecular O⋅⋅⋅O interactions of P1, thereby modulating its emission wavelength. Additionally, these polymers showed excellent potential in fluoride ions detection. This work provides new insights into the complex effects of intermolecular interactions on luminescent properties. [ABSTRACT FROM AUTHOR]

All‐polymer solar cells (all‐PSCs) present compelling advantages for commercial applications, including mechanical durability and optical and thermal stability. However, progress in developing high‐performance polymer donors has trailed behind the emergence of excellent polymer acceptors. In this study, we report a new electron‐deficient arene, fluorinated bithiophene imide (F‐BTI) and its polymer donor SA1, in which two fluorine atoms are introduced at the outer β‐positions in the thiophene rings of BTI to fine‐tune the energy levels and aggregation of the resulting polymers. SA1 exhibits a deep HOMO level of −5.51 eV, a wide bandgap of 1.81 eV and suitable miscibility with the polymer acceptor. Polymer chains incorporating F‐BTI result in a highly ordered π–π stacking and favorable phase‐separated morphology within the all‐polymer active layer. Thus, SA1 : PY‐IT‐based all‐PSCs exhibit an efficiency of 16.31 % with excellent stability, which is further enhanced to a record value of 19.33 % (certified: 19.17 %) by constructing ternary device. This work demonstrates that F‐BTI offers an effective route for developing new polymer materials with improved optoelectronic properties, and the emergence of F‐BTI will change the scenario in terms of developing polymer donor for high‐performance and stable all‐PSCs. [ABSTRACT FROM AUTHOR]

Carbodiimides and pyridines form reversible adducts that slowly deliver carbodiimide "fuels" to out-of-equilibrium reaction networks, slowing activation kinetics and elongating transient state lifetimes. More-nucleophilic pyridines give more adduct under typical conditions. This approach can be used to extend the lifetimes of transient polymer hydrogels. [ABSTRACT FROM AUTHOR]

The development of methods that aim to increase the water use efficiency in agricultural systems should be part of the objectives of research, and the cultivation of plants of lower water requirements, such as cactus pear, can be a good option. The purpose of this study was to evaluate the effect of the association of potassium (K) and nitrogen (N) levels from coated urea, in two harvest years, on the agronomic characteristics and nutritive value of Nopalea cochenillifera cv Doce. A randomized block design in a 2 × 4 × 2 factorial arrangement was adopted. The factors corresponded to two levels of K (40 kg and 60 kg ha−1 year−1), four levels of N (0, 60, 120, and 240 kg ha−1 year−1) and two harvest years (Years I and II). The plants were evaluated for growth, yield, chemical, and mineral composition, and nutritive value. The levels of K affected only plant height and K content in the plant. The agronomic variables and contents of ether extract and crude protein (CP) linearly increased along with the levels of N from the coated urea. There was a significant effect of interaction between N levels and harvest year on the contents of NDF, NDFap, NFC, fraction A+B1, Ca, and Mg. The level of 40 kg K ha−1 year−1 associated with 240 kg N ha−1 year−1 from coated urea provided the best results for the characteristics of growth, yield, and nutritive value of the cactus pear. [ABSTRACT FROM AUTHOR]

Organic photovoltaics (OPVs) have great potential to drive low‐power consumption electronic devices under indoor light due to their highly tunable optoelectronic properties. Thick devices (>300 nm photo‐active junctions) are desirable to maximize photocurrent and to manufacture large‐scale modules via solution‐processing. However, thick devices usually suffer from severe charge recombination, deteriorating device performances. Herein, the study demonstrates excellent thickness tolerance of all‐polymer‐based PVs for efficient and stable indoor applications. Under indoor light, device performance is less dependent on photoactive layer thickness, exhibiting the best maximum power output in thick devices (34.7 µW cm−2 in 320–475 nm devices). Thick devices also exhibit much better photostability compared with thin devices. Such high thickness tolerance of all‐polymer‐based PV devices under indoor operation is attributed to strongly suppressed space‐charge effects, leading to reduced bimolecular recombination losses in thick devices. The unbalanced charge carrier mobilities are identified as the main cause for significant space‐charge effects, which is confirmed by drift‐diffusion simulations. This work suggests that all‐polymer‐based PVs, even with unbalanced mobilities, are highly desirable for thick, efficient, and stable devices for indoor applications. [ABSTRACT FROM AUTHOR]

Phosphite antioxidants exhibit superior anti‐aging and color‐stabilizing properties when incorporated into polymer materials. Their synergistic antioxidative effects are particularly noteworthy when used in combination with hindered phenol antioxidants and other primary antioxidants, serving as effective secondary antioxidants, displaying noteworthy synergistic antioxidation effects. This review systematically classifies the synthetic methods for phosphite antioxidants into three distinct categories based on the types of starting materials: synthesis from phosphorus trichloride, phosphorus‐containing esters, and white phosphorus. Additionally, it delineates the reaction mechanisms associated with these approaches and provides an overview of future potential research directions and applications for organophosphorus antioxidants. [ABSTRACT FROM AUTHOR]

In recent years, there is a growing interest in developing ultralong organic room‐temperature phosphorescence (ORTP) with lifetimes in the range of seconds. As one of the important three primary colors, ultralong blue ORTP is an indispensable core component in RTP regulation and application, however, the large Stokes shift characteristics pose certain challenges in developing ultralong blue ORTP. Here, a new family of blue phosphors are synthesized and ultralong blue ORTP are realized through crystal assembly in water and organic phase. Remarkably, compared to crystal materials obtained in organic phases, assembly materials obtained in water enabled long‐lived blue ORTP with lifetimes up to 2.3 s and phosphorescence quantum yield reached as high as 29.27%. In addition to the efficient and green assembly form, such dark blue ORTP materials possessed high thermal stability and flexible tunability. Moreover, the superiority of the selected assembly components is demonstrated by comparing them with polymer assembly and the proposed blue ORTP materials show great potential in an organic programmable information encryption/anti‐counterfeiting. [ABSTRACT FROM AUTHOR]

Though polyvinylidene fluoride (PVDF) is widely‐used binder for conventional lithium‐sulfur (Li–S) batteries, it still encounters challenges of severe electrode fracture involved by drastic volume change upon repeating cycling, and lack of extended‐functions like trapping dissolved polysulfides and smoothing Li+ transfer. Herein, a methodology of grafting sulfophilic hydrogen‐bond donor and lithiophilic hydrogen‐bond acceptor to the polymer binder (named as PIL), function as gear teethes and tooth spaces, is reported. When cracks occur, the engaged gears driven by dynamic hydrogen bonds are separated, which are spontaneously reformed owing to the automatic meshing of gears, and thus accelerate the healing of cracks. At the molecular level, the synergetic effect of sulfophilic hydrogen‐bond donor and lithiophilic hydrogen‐bond acceptor enables polysulfides immobilization through "push‐pull effect", facilitating the subsequent redox kinetics. Accordingly, the cross‐link network of hydrogen bonds endows the elaborated designed polymer binder with strong adhesive strength and rapid Li+ migration. Attributed to these beneficial properties, the PIL‐based sulfur cathode exhibits excellent rate performance and superior cycling durability (an ultralow capacity fading rate of 0.062% per cycle over 800 cycles at 2 C). Even with high sulfur loading of 9.27 mg cm−2, a high areal capacity of 8.71 mAh cm−2 can be achieved, verifying its potential application. [ABSTRACT FROM AUTHOR]

Cyclodextrin‐based polyrotaxanes (CD‐PRs) are gaining attention for their dynamic sliding rings along the polymer axis, enabling various applications in molecular shuttles, drug delivery, and durable polymers with slidable cross‐links. However, the conventional synthesis of CD‐PRs with tunable threading ratios is typically laborious, time‐consuming, and complicated, which limits their scalability and cost‐effectiveness. Herein, we highlight the great potential of planetary centrifugal mixing, a process that significantly accelerates and simplifies the initial synthesis of polypseudorotaxanes (PPRs), followed by a thiol‐ene click reaction as an efficient end‐capping reaction for the synthesis of PRs. Notably, PRs synthesized with glutathione (GSH) as the end‐capping reagent are in a metastable state, where GSH act as a molecular bumper that significantly prevent de‐threading of α‐CD rings at room temperature. Moreover, the rate of ring de‐threading can be precisely controlled by heating, enabling the preparation of metastable PRs with tunable threading ratios over a wide range. The developed strategy is of great significance to the efficient synthesis of CD‐PRs, thus marking a significant step towards their practical application in advanced functional materials and devices. [ABSTRACT FROM AUTHOR]

A completely new type of nitrogen-doped polymer nanosphere and the derived nitrogen-doped porous carbon nanospheres were produced by taking 2,4-diamino-6-hydroxypyrimidine as the precursor. When functioning as electrode materials, they demonstrated extraordinary electrochemical performance, offering a powerful candidate for supercapacitors. [ABSTRACT FROM AUTHOR]

Polymers when confined to a dimension comparable to the length scale of polymer chain coils such as thin films, often lead to molecular relaxation processes distinct from their bulk counterpart. Often observed as thermal and mechanical responses such relaxation has been frequently associated with the squeezing of polymer chains having conformations trapped far from thermodynamic equilibrium and subsequently generating processing‐induced molecular recoiling stress. Relaxation in polymer films can be modified by tuning the molecular recoiling stress, which is directly influenced by the preparation conditions of the polymer thin films. Hence a comprehensive understanding of the genesis and relaxation of molecular recoiling stress becomes necessary. Here, we provide insights into the nonequilibrium nature observed in polymer thin films, focusing majorly on the investigations into the molecular recoiling stress using the dewetting technique. The impact of various factors like temperature of dewetting, thickness of films, molecular weight of polymers, and physical aging affecting the relaxation of molecular recoiling stress is discussed. In addition, discussions on the possible mechanisms of relaxation and modification of molecular recoiling stress by varying the spin‐coating speed and addition of plasticizers are also provided. An alternate approach which gives a new perspective into the relaxation of molecular recoiling stress considering the entropy generated during the dewetting of polymer films is also included. The present work is expected to give the reader a comprehensive understanding of the characteristics of molecular recoiling stress relaxation occurring in polymer thin films. [ABSTRACT FROM AUTHOR]

The current work describes the preparation of silver nanoparticles loaded with tapioca starch nanofibers using the electrospinning method. Green synthesis of silver nanoparticles was successfully carried out by the aqueous pulp extract of Limonia acidissima (wood apple) with sunlight acting as the catalyst. The resulting silver nanoparticles were characterized by UV–visible spectrophotometer, Fourier transform infrared (FTIR) spectroscopy, high-resolution transmission electron microscopy (HRTEM), powder X-ray diffraction study (PXRD), energy-dispersive analysis (EDAX), particle size, and zeta potential analysis using the disc diffusion technique, and the antibacterial activity of the produced nanofibers was tested against Gram-positive and Gram-negative foodborne pathogens. [ABSTRACT FROM AUTHOR]

In series‐connected tandem organic solar cells (TOSCs), various light‐harvesting molecules with complementary absorptions are explored with the aim of collaboratively utilizing solar light to the maximum extent. In sharp contrast to the small molecular acceptors that possessing almost the successively tunable bandgaps, high‐performance wide‐bandgap (WBG) polymer donors in TOSCs are quite scarce, with only PM6 (optical bandgaps, Egopt = 1.80 eV) and D18 (Egopt = 1.98 eV) being widely used. Herein, to develop WBG polymer donors with large open‐circuit voltages (VOC) and high‐energy photon absorption, two pyrazinyl polymer donors, PPy1 and PPy2, are synthesized with branched 2‐butyloctyl and n‐dodecyl chains on polymeric backbones, respectively, demonstrating the downshifted highest occupied molecular orbital energy levels of ≈−5.60 eV and thus afford Egopt over 2.0 eV. Consequently, when blending with a WBG acceptor F‐ThCl, PPy2:F‐ThCl‐based devices exhibit a higher power conversion efficiency (PCE) of 14.50% and fill factor of 77.66%. In light of its large VOC of 1.07 V, TOSCs based on PPy2 are further fabricated and exhibit an impressive PCE of 19.35% by using a narrow bandgap blend of PM6:CH1007:F‐2F as a rear cell. This work demonstrates the great potential of pyrazine units in constructing WBG polymer donors for achieving record‐breaking TOSCs. [ABSTRACT FROM AUTHOR]

The primary interactions of polypropylene (PP), poly(vinyl acetate) (PVA), ethylene‐vinyl acetate (EVA), polyvinyl chloride (PVC), polychloroprene (CR) and polyurethane (PUR) polymers preferred in the nuclear industry with gamma and neutron radiations, secondary radiations formed after neutron interactions and damages given to polymers by these ionizing radiations are investigated. The gamma interaction parameters Were determined in the photon energy range of 0.03‐20 MeV using WinXCOM, GEANT4 and FLUKA methods. Also, energy absorption and exposure buildup factors and Kerma parameters are calculated at different photon energies. To investigate the interactions of the studied polymers with neutron, the effective removal cross‐section for fast neutrons with theoretical and the partial neutron rates passing through the studied polymer at 4.5 MeV, 100 eV and 0.025 eV energies are determined with simulation codes. The numbers of secondary gamma‐rays and neutrons Were obtained with GEANT4. The Total Ionizing Dose and Displacements per Atom parameters are studied with the help of FLUKA simulation. It is observed that the interaction of PVC polymer with gamma radiation and PP polymer with neutron particles is higher than the others. The secondary radiation from PVC and CR is less. The PP, PVA, and EVA exhibit superior resistance to radiation damage. [ABSTRACT FROM AUTHOR]

Stable aqueous dispersions of spin-crossover (SCO) doped [FeII(Htrz)2(trz)](BF4) nanoparticles (NPs) were prepared by using water-soluble polyvinylpyrrolidone (PVP) as protecting polymer. The metal or ligand substitution percentage regulated the ultra-small size and morphology of the NPs. At the same time, the colloidal dispersions showed a complete conversion of the LS state to the HS state of the FeII ion. [ABSTRACT FROM AUTHOR]

Direct oxidation of KA oil (the mixture of cyclohexanone and cyclohexanol) toward ε-caprolactone is in high demand yet hard to implement in need of juggling the activation of both methyne C-H bond of cyclohexanol and α-C-C bond of cyclohexanone. Here we demonstrate that in situ formed Cu1+δ-Oδ-• active site, which originates from relay reaction at Ni(II) and Cu(I) pairs in a metal-organic framework (known as NiCu-MOF-74) with O2 and benzaldehyde (PhCHO), efficiently oxidizes KA oil toward ɛ-caprolactone along with good stability. Mechanism investigation discloses that the auxiliary Ni(II) site first adsorbs O2 for abstracting formyl hydrogen in PhCHO followed by transfer of PhCO· to react with another O2 over the major Cu(I) site, leading to formation of Cu1+δ-Oδ-• and PhCOOH. This major-auxiliary cooperative strategy will be particularly suitable for multivariate MOFs as next generation catalysts towards complex reactions. ε-Caprolactone is a key starting point for the preparation of many polymers, such as polycaprolactone, polyurethane and nylon-6. Here the authors show that a metal-organic framework in conjunction with oxygen and benzaldehyde can facilitate the synthesis of ε-caprolactone from ketone-alcohol oil feedstock in a cascade oxidation. [ABSTRACT FROM AUTHOR]

Corrosion of the rebar in reinforced concrete (RC) structures is a critical concern, compromising their reliability and long‐term operation. Carbon fibre–reinforced polymer (CFRP) tapes are widely used for strengthening RC structures due to their superior properties such as light weight, high strength and ease of application. The study aims to investigate the effectiveness of using CFRP‐bonded tapes as a flexural repair system for RC beams, considering the effect of pre‐repair damage to rebar. The experimental programme consisted of testing two unstrengthened control specimens without damage and two samples with 50% damage to the rebar, strengthened with CFRP materials. To maximize the effectiveness of CFRP materials for strengthening, a comprehensive understanding of their behaviour, particularly during the later stages of loading, is essential. The purpose of this study is to fill this gap of knowledge with the use of innovative remote monitoring techniques: submicron indicators and digital image correlation (DIC). By cross‐verifying results through two independent approaches, any potential biases or errors inherent were mitigated, leading to more robust and reliable outcomes of the experimental research. A comprehensive analysis of the obtained experimental data, also validated through theoretical calculations, has shown that the proposed repair method ensured a 95% recovery of the initial bearing capacity. Also, notable changes in the behaviour of samples were observed with increased strains and deflections compared to control samples. Remarkable possibilities of the DIC method enabled monitoring of the stress–strain state of the full‐scale samples until the destruction stage. The findings of the research are significant in the engineering application, as it deepened the understanding of CFRP strengthening techniques and can potentially broaden the use of CFRP tapes in strengthening corroded RC beams. [ABSTRACT FROM AUTHOR]

Self‐assembly is an effective approach to construct complicated structures. Polyrotaxanes (PRs) as one of the typical polymer types with complex structure, own interlocked structures and dynamic components, in which it results in unique characteristics and functions. Currently, the synthesis of which involves covalent reactions to hinder the development of polyrotaxanes. Herein, we employed supramolecular interactions as well as dynamic covalent bonds to synthesize PRs by sequential self‐assembly. First, we prepared M1 possessing two diamine structures and M2 of a bisammonium salt with two dibenzylammonium (DBA) units modified by two stoppers at its ends, then M1 and M2 self‐assembled into supramolecular polymers stemming from hydrogen bonding of [N+−H ⋅ ⋅ ⋅ O] under high concentrations. After adding 2,6‐pyridinedicarboxaldehyde (M3), the imine bond formation enabled the generation of macrocycles, transforming supramolecular polymers into PRs. Besides, the solution of polyrotaxanes was applied as the adhesive for diverse hard and soft materials. This strategy provides an important approach for synthesizing PRs, accelerating the advances of mechanically interlocked polymers. [ABSTRACT FROM AUTHOR]

To achieve sustainable and energy‐efficient CO2 capture processes, it is imperative to develop membranes that possess both high CO2 permeability and selectivity. One promising approach involves integrating high‐aspect‐ratio nanoscale fillers into polymer matrices. The high‐aspect‐ratio fillers increase surface area and improve interactions between polymer chains and gas molecules passing through the membrane. This study focuses on the integration of cellulose nanocrystals (CNCs) with an impressive aspect ratio of around 12 into rubbery polymers containing polyethylene oxide (PEO), namely PEBAX MH 1657 (poly[ether‐block‐amide] [PEBA]) and polyurethane (PU), to fabricate mixed‐matrix membranes (MMMs). By exploiting the interfacial interactions between the polymer matrix and CNC nanofillers, combined with the surface functionalities of CNC nanofillers, the rapid and selective CO2 transport is facilitated, even at low filler concentrations. This unique feature enables the development of thin‐film composites (TFCs) with a selective layer around 1 μm. Notably, even at a filling ratio as low as 1 weight percent, the resulting membranes exhibit remarkable CO2 permeability (>90 Barrer) and CO2/N2 selectivity (>70). These findings highlight the potential of integrating CNCs into rubbery polymers as a promising strategy for the design and fabrication of highly efficient CO2 capture membranes. [ABSTRACT FROM AUTHOR]

Theoretical analysis of the kinetic scheme describing formation and randomization of a binary copolymer due to end‐group interchange reactions is presented. Compact analytical expressions are obtained for the transient and equilibrium values of the copolymer degree of blockiness and fractions of active end‐groups of different types. The resulting copolymer is described by the first‐order Markov statistics, which can be rather far from the Bernoullian one. Its structure is determined by the composition of the system and a single combination of the rate constants of four elementary reactions. The kinetics includes fast and slow stages with characteristic time periods independent of and proportional to the average polymerization degree, respectively. During the fast stage, the initial polymers disappear, whereas the copolymer degree of blockiness is still very low. The distribution of units in the copolymer is Markovian, only if the initial polymers possess the most probable molar mass distributions. At the slow stage copolymer randomization gradually progresses, whereas the distribution of end groups may change in the opposite direction compared to the fast stage. The results can be used to analyze the experimental data on the chain structure of condensation, metathesis, and dynamic covalent polymers, where interchange reactions play a significant role. [ABSTRACT FROM AUTHOR]

AbstractThis study aims to investigate Polylactic Acid (PLA) and Polycaprolactone (PCL) polymers for microencapsulation of hydrophilic and hydrophobic anti-glaucoma drugs using an emulsion-based solvent evaporation technique. Microparticle size was analysed using optical microscopy, while drug-polymer interactions through Dynamic-Light-Scattering (DLS) and Fourier-Transform-Infra-red/Attenuated-Total-Reflection spectroscopy (FTIR/ATR). In vitro, drug release studies were performed to investigate drug encapsulation and release profiles. Spherical microparticles, with particle size 94 ± 6.9 μm for PCL-based and 100 ± 3.74 μm for PLA-based formulation, were obtained. Drug release studies showed 100% release over about 32 days, with encapsulation efficiency (%EE) and drug loading (%w/w) reaching up to 95 and 2.84% for PLA-based and 97 and 2.91% for PCL-based microparticles, respectively. DLS studies reveal an increase in hydrodynamic radius (RH), which correlates to enhanced drug encapsulation. So, the nature of the drug and polymer significantly impacts drug encapsulation and release, with drug-polymer interactions playing a crucial role alongside experimental parameters. [ABSTRACT FROM AUTHOR]

Poly(2‐(N,N‐dimethylamino)ethyl acrylate) (PDMAEA) is a promising charge‐shifting polycation with the capacity to form a range of morphologically distinct polyelectrolyte assemblies. Nevertheless, the basic character of the monomer and its hydrolytic instability impedes its controlled synthesis to higher molecular weight (MW). Herein, the reversible addition‐fragmentation chain transfer polymerization of DMAEA is reported using a tert‐butanol/V70 initiator/trithiocarbonate‐based chain transfer agent (CTA) polymerization setup. The CTA instability is demonstrated in the presence of the unprotonated tertiary amino group of the DMAEA monomer, which limits the control over the conversion and MW of the polymer. In contrast, the shielding of the amino groups by their protonation leads to polymerization with high conversions and excellent control over MWs of polymer up to 100 000 g mol−1. Hydrolytic degradation study at pH values ranging from 5 to 9 reveals that both basic and protonated PDMAEA undergo a pH‐dependent hydrolysis. The proposed polymerization conditions provide a means of synthesizing PDMAEA with well‐controlled characteristics, which are beneficial for controlling the complexation processes during the formation of various polyelectrolyte assemblies. [ABSTRACT FROM AUTHOR]

Achieving fast Li+ transport kinetics and stable electrode/electrolyte interfaces is of paramount importance, yet extremely challenging for the practical success of solid‐state lithium metal batteries, which requires the rational design of the structure and composition of solid‐state electrolytes. Herein, a composite quasi‐solid‐state electrolyte is fabricated through in situ polymerization of a molecule‐designed polymer chain within the functionalized molecular sieve framework (Al‐MCM41). In this design, the robust Brønsted/Lewis acid–base interactions between Al‐MCM41 and TFSI− facilitate the dissociation of lithium salt, leading to a Li+ transference number as high as 0.81. Meanwhile, the well‐ordered mesopores of Al‐MCM41 act as the “reservoir” of the polymer chain, creating continuous ionic migration pathways to offer an excellent Li+ conductivity of 1.09 × 10−3 S cm−1 at 30 °C. Furthermore, the polymer with fluorinated and nitrided functional groups guarantees a dual‐reinforced anode and cathode interface. Such an integrated electrolyte with simultaneous unimpeded Li+ transport and robust interfaces delivers extraordinary capacity retention of 84.6% over 600 cycles at 5 C when coupled with LiFePO4 cathode and remarkable reversible capacity of 129.0 mAh g−1 after 200 cycles with high‐voltage NCM622 cathode. This work provides a significant avenue for enhancing the practical feasibility of solid‐state lithium metal batteries. [ABSTRACT FROM AUTHOR]

This review introduces solid electrolytes based on sulfide/polymer composites which are used in all‐solid‐state lithium batteries, describing the use of polymers as plasticizer, the lithium‐ion conductive channel, the preparation methods of solid‐state electrolytes (SSEs), including dry methods and wet methods with their advantages and disadvantages. In addition, the physicochemical stability of sulfide/polymer composite based solid‐state electrolytes is analyzed. The sulfide/polymer composite based solid‐state electrolyte can be utilized in lithium metal or lithium sulfur batteries. However, there are still many problems left to be solved in practical applications of these solid‐state electrolytes. In this review, several solutions are explored. Firstly, the ultra‐long life cycle of batteries can be achieved by thinning the composite electrolyte. Secondly, when sulfur is applied as the positive electrode, the thinning electrolyte can reduce polarization and other problems. Finally, an integrated battery is employed to reduce the interface impedance. By addressing these aspects, the review aims to provide valuable insights into the future development of high‐performance solid‐state electrolytes in lithium battery technology. [ABSTRACT FROM AUTHOR]

Smart persistent organic room‐temperature phosphorescence (RTP) materials, capable of responding to microenvironmental changes, are critically important in various optoelectronic applications. However, conventional persistent RTP materials usually have not stretchability and flexibility, limiting some practical applications. This study reports a facile and one‐pot photo‐initiated copolymerization method to prepare photoactivated persistent RTP polymers with multicolored afterglow, excellent stretchability, self‐healable and recyclable properties. Impressively, the polymers can be stretched up to 500% without significant loss in RTP intensity and lifetime, and they possess a self‐healing ability with a healing efficiency of 69.6%. Utilizing these photoactivated and stretchable persistent RTP polymers, dual encryption can be achieved under UV irradiation and stretching conditions, thereby enhancing the security levels of the stored confidential information. Overall, this study represents the first example of self‐healable and recyclable stimuli‐responsive RTP materials, demonstrating their bright future for the flexible and wearable optoelectronics. [ABSTRACT FROM AUTHOR]

Mechanochromic functionality realized via the force‐responsive mechanophores in polymers has great potential for damage sensing and information storage. Mechanophores with the ability to recognize multiple stimuli for tunable chromic characteristics are highly sought after for versatile sensing ability and color programmability. Nevertheless, the majority of mechanophores are based on single‐component chromophores with limited sensitivity, or require additional fabrication technology for multi‐modal chromism. Here, we report a novel multifunctional mechanophore capable of vividly detectable and tunable mechanochromism in polymers. This synergistic optical coupling relies on strategically fusing rhodamine and spiropyran (Rh−SP), and tethering polymer chains on both subunits. The mechanochromic behaviors of the Rh−SP‐linked polymers under sonication and compression are thoroughly evaluated in response to changes in force and the light‐controlled relaxation process. Non‐sequential ring‐opening of the two subunits under force is identified, endowing high‐contrast mechanochromism. Light‐induced differential ring‐closing reactions of the two subunits, together with the acidichromism of the SP moiety, are employed to engineer elastomers with programmable and wide‐spectrum colors. Our work presents an effective strategy for highly appreciable and regulable mechanochromic functionality, and also provides new insights into the rupture mechanisms of π‐fused mechanophores, as well as how the stimuli history controls stress accumulation in polymers. [ABSTRACT FROM AUTHOR]

Integrating multi-stimuli response properties in one molecule is challenging. This study presents two 2D polymers, [(Bpydp)Ln(H2O)(BDC)]·NO3·2H2O (Ln = Eu(1), Tb(2)), exhibiting rapid photo-responsiveness and the ability to detect specific small-molecule amines. In particular, complex 1 combines the functions of inkless printing, amine detection, anti-counterfeiting, and fluorescence recognition. [ABSTRACT FROM AUTHOR]

Enhanced electronic coupling gives rise to many intriguing properties in π–d conjugated metal–organic frameworks (CMOFs). By low-temperature scanning tunneling microscopy and density functional theory calculation, we investigate the electronic coupling in one-dimensional (1D) π–d conjugated FeQDI polymers. Our experiments have resolved the bulk and end states stemming from Fe atoms in different coordination environments and their spatial extension due to π–d conjugation. By fitting the band structure by Wannier functions in an energy range of −0.5 eV to 0 eV, the Fe–Fe, QDI–QDI and Fe–QDI hopping integrals are determined to be 15 meV, 121 meV and 24 meV, respectively. Our work provides experimental and theoretical insights into the electronic coupling in 1D CMOFs. [ABSTRACT FROM AUTHOR]

A novel dithiocarbamate polymer (TTDP) derived from bis(2‐aminothiazole) sulfide was synthesized through a straightforward process. The synthesis involved the initial conversion of 2‐aminothiazole into its bis(sulfide), subsequent reaction with chloroacetyl chloride, and final copolymerization with disodium ethylene bisdithiocarbamate. TTDP boasts a high percentage of functional groups containing sulfur, nitrogen, and oxygen, contributing to its hydrophilicity, strong chelation capacity with metal cations, and compatibility with other polymers. Therefore, it was used as a strong candidate for making membranes in water media. According to this, TTDP was blended in ratios 1, 2, 5, and 10 wt% with polyvinyl chloride (PVC; 15 wt%), 2 wt% of polyethylene glycol 4000 in N,N‐dimethylacetamide as polymeric membranes for water‐based applications. The blended membranes were prepared using the casting and immersion precipitation method. The blended membrane showed high fluxes, up to 1052 L/m2 h for 2 wt% of TTDP (in comparison to the bare membrane's 459 L/m2h). Notably, they demonstrated an excellent protein solution flux of 222–269 L/m2 h at 3 bar with 96%–98% bovine serum albumin rejection. Furthermore, these membranes showed remarkable efficacy in removing cadmium ions (up to 98.96% for 5 and 10 wt% TTDP) and synthetic dye methyl orange (up to 84.03% for 2 wt% TTDP). [ABSTRACT FROM AUTHOR]

The development of non-contact in situ techniques for monitoring cure kinetics has the potential to greatly improve both resin formulation and processing. We have recently shown that low-frequency Raman spectroscopy is a viable method for assessing resin structural cure kinetics and complements the traditional chemical conversion determined from the fingerprint region of the spectrum. In this work, we further evaluate the relationship between structural and chemical conversion by investigating two chemically identical yet rheologically different interpenetrating polymer network resin formulations. Rheological analysis demonstrates a relationship between structural conversion and storage modulus, which is not observed in the chemical conversion data. We show that one can produce master cure kinetics curves with comparable kinetic constants using both the chemical and structural conversion methodologies. Parametric analysis of the structural conversion, chemical conversion, and photorheological conversion was combined with a semi-empirical model for the storage shear modulus as a function of the extent of cure. [ABSTRACT FROM AUTHOR]

Tailored ribbing structures are obtained by large‐scale rolling in polymer PDMS thin‐films by adding carbon nanotubes (CNT) inclusions, which significantly improved the mechanical behavior of systems subjected to dynamic compressive strain rates. A nonlinear explicit dynamic three‐dimensional finite‐element (FE) scheme is used to understand and predict the thermomechanical response of the manufactured ribbed thin‐film structures subjected to dynamic in‐plane compressive loading. Representative volume element (RVE) FE models of the ribbed thin‐films are subjected to strain rates as high as 104 s−1 in both the transverse and parallel ribbing directions. Latin Hypercube Sampling of the microstructural parameters, as informed from experimental observations, provide the microstructurally based RVEs. An interior‐point optimization routine is also employed on a regression model trained from the FE predictions that can be used to design ribbed materials for multifunctional applications. The model verifies that damage can be mitigated in CNT‐PDMS systems subjected to dynamic compressive loading conditions by controlling the ribbing microstructural characteristics, such as the film thickness and the ribbing amplitude and wavelength. This approach provides a framework for designing materials that can be utilized for applications that require high strain rate damage tolerance, drag reduction, antifouling, and superhydrophobicity. [ABSTRACT FROM AUTHOR]

Context: In this work, a new polymeric structure was designed consisting of a nanometric sheet of graphene (G) and a polymethylmethacrylate (PMMA) repeat unit, which was designated as PMMA-G. Three degrees of polymerization of PMMA-G were considered: monomer (PMMA-G1), dimer (PMMA-G2), and trimer (PMMA-G3). The effect of incorporating a nanometric sheet of graphene into the molecular structure of PMMA on the modification of some of its main optical, magnetic, and electrical properties was investigated. Currently, the study presented here is of great relevance since various areas of technology require new materials with specific properties for the development of new devices. The results of our study reveal that the dielectric constant of PMMA is reduced when graphene is incorporated. However, a percentage increase of 14.48% in the refractive index of PMMA when graphene is inserted to form the nanocomposite is observed. It is found that the absolute value of molar magnetic susceptibility of PMMA increases considerably when reinforced with graphene. Finally, when reinforcing PMMA with graphene to obtain the PMMA-G nanocomposite, the electrical resistivity increases by almost an order of magnitude. Methods: We used computational tools under Materials Studio (MS) software. We built a PMMA molecule with three degrees of polymerization, graphene sheet, and polymethylmethacrylate-graphene composite (PMMA-G) was built also with three degrees of polymerization using a concentration of 50% graphene over the PMMA polymer. For each structure, we used computational code DMol3 of MS, which is based on the Density Functional Theory, and the geometry optimization process was carried out to obtain the most stable structures. Finally, using the connectivity indices method together with topological properties of the molecular structures, implemented in Synthia computational code of MS software, we calculated the dielectric constant, magnetic susceptibility, refractive index, and electrical resistivity, for pure PMMA and PMMA-G structures for their three degrees of polymerization. The results were analyzed, and the changes in these properties were discussed in terms of the effect of an electric and magnetic field on the molecular structures of PMMA-G with respect to PMMA. [ABSTRACT FROM AUTHOR]

The Fused Filament Fabrication is an economic 3D printing process to produce lightweight polymersbased structures. Therefore, it is drawing a consistently increasing interest from industry and researchers. Flexural and impact properties are two of the critical performance measures for gauging the integrity of the printed structures. Since 2014, numerous studies have been carried out on this topic, however, their holistic overview with a focus on the flexural and impact properties has been barely presented in the literature. The current article reviews the relationship between the process parameters, both operating and geometrical, and these properties in detail. The cause-effect relationship is thoroughly examined considering material effect. This allows the identification of the complex interactive effects and conducive ranges of the important parameters to effectively control the process for achieving the desired mechanical properties. The review establishes that the crystallinity of post-printed polymers is a crucial factor in controlling the mechanical properties, and filled polymers generally offer better properties than unfilled ones if the right filler given the desired properties is chosen. Topology optimization, recyclability of polymers through FFF, and retention of polymer properties after printing are also discussed as innovative trends. Finally, limitations and research gaps are identified, and the latest ideas are proposed as a way forward for further development of the FFF technology. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the effects of adding cholesteryl methacrylate (CM) monomer to experimental composite resins and evaluate its impact on polymerization shrinkage force (PSF), Knoop microhardness (KHN), sorption and solubility (SS), vulnerability to spontaneous oxidation (VOE), porosity (BES), viscosity (V), and cross-link density (CLD). CM was synthesized, mixed with varying proportions of Bis-GMA, 70 wt% filler particles, and 40 % TEGDMA. The groups tested were: CM0 (60 % Bis-GMA), CM6 (54 % Bis-GMA/6 % CM), CM12 (48 % Bis-GMA/12 % CM), CM18 (42 % Bis-GMA/18 % CM) and CM24 (36 % Bis-GMA/24 % CM). The PSF was evaluated using a universal testing machine. KHN was measured with a 50 g load for 30 s. SS was determined according to ISO 4049:2009. VOE was measured with a three-electrode system in an electrochemical cell. BES images were obtained using an electron microscope to assess porosity. Viscosity was measured through rheological analysis. CLD was estimated from hardness readings before and after ethanol storage. CM6 (0.34 N) and CM12 (0.34 N) exhibited the lowest PSF values compared to CM0 (0.91 N). For KHN, CM6 (32.03) and CM12 (31.03) had higher values than CM0 (25.83) and were similar to CM18 (29.39) and CM24 (28.64). SS showed no significant differences among the groups. VOE indicated low vulnerability across all groups. CM12 had greater porosity compared to CM0 in BES images. CM0 had the lowest viscosity among the groups. No differences in CLD were observed among CM0, CM12, CM18, and CM24 regarding softening effects. Adding CM to Bis-GMA/TEGDMA composite resins can reduce polymerization shrinkage force and increase the initial Knoop microhardness without affecting the other properties studied. • Cholesteryl methacrylate proved to be a promising polymer for improving composites. • An endocyclic double bond can be an additional site for photochemical cycloaddition. • Its endocyclic double bond can form adducts with other monomers. • Concentrations of 6 % and 12 % of cholesteryl methacrylate promoted better performance. • Initial microhardness and polymerization shrinkage force showed improved results. [ABSTRACT FROM AUTHOR]