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Although widely studied experimentally in the 1990s, the structure and properties of low-dimensional or high-pressure phases of fullerenes have recently been re-examined. Remarkably, recent experiments have shown that transparent, nearly pure amorphous sp3-bonded carbon phases can be obtained by heating a C60 molecular crystal at a high pressure. With the additional aim of testing the ability of three classical carbon potentials reactive empirical bond order, environment-dependent interatomic potential, and reactive force-field to reproduce these results, we investigate the details of the structural transformations undergone by fullerene crystals over a wide range of pressures and temperatures. All the potentials tested show that the initial polymerization of fullerenes is accompanied by negative thermal expansion, albeit in slightly different ranges. However, more significant differences in structural and mechanical properties are observed in the amorphous phases, in particular the sp3 carbon fraction and the existence of layered amorphous carbon. Overall, these results indicate to which extent classical reactive potentials can be used to explore phase transitions over a wide range of pressures and temperatures. [ABSTRACT FROM AUTHOR]

The path to minimal life involves a series of stages that can be understood in terms of incremental, stepwise additions of complexity ranging from simple solutions of organic compounds to systems of encapsulated polymers capable of capturing nutrients and energy to grow and reproduce. This brief review will describe the initial stages that lead to populations of protocells capable of undergoing selection and evolution. The stages incorporate knowledge of chemical and physical properties of organic compounds, self-assembly of membranous compartments, non-enzymatic polymerization of amino acids and nucleotides followed by encapsulation of polymers to produce protocell populations. The results are based on laboratory simulations related to cyclic hydrothermal conditions on the prebiotic Earth. The final portion of the review looks ahead to what remains to be discovered about this process in order to understand the evolutionary path to minimal life.

Polymerization of nucleotides under prebiotic conditions simulating the early Earth has been extensively studied. Several independent methods have been used to verify that RNA-like polymers can be produced by hot wet-dry cycling of nucleotides. However, it has not been shown that these RNA-like polymers are similar to biological RNA with 3'-5' phosphodiester bonds. In the results described here, RNA-like polymers were generated from 5'-monophosphate nucleosides AMP and UMP. To confirm that the polymers resemble biological RNA, ribonuclease A should catalyze hydrolysis of the 3'-5' phosphodiester bonds between pyrimidine nucleotides to each other or to purine nucleotides, but not purine-purine nucleotide bonds. Here we show AFM images of specific polymers produced by hot wet-dry cycling of AMP, UMP and AMP/UMP (1:1) solutions on mica surfaces, before and after exposure to ribonuclease A. AMP polymers were unaffected by ribonuclease A but UMP polymers disappeared. This indicates that a major fraction of the bonds in the UMP polymers is indeed 3'-5' phosphodiester bonds. Some of the polymers generated from the AMP/UMP mixture also showed clear signs of cleavage. Because ribonuclease A recognizes the ester bonds in the polymers, we show for the first time that these prebiotically produced polymers are in fact similar to biological RNA but are likely to be linked by a mixture of 3'-5' and 2'-5' phosphodiester bonds.

The nanocomposites of ferroferric oxide ([Fe.sub.3][O.sub.4]) with polyhydroxyurethane (PHU) were fabricated via a physical mixing approach. This process involved grafting poly(N-vinyl pyrrolidone) (PVPy) chains onto the surfaces of [Fe.sub.3][O.sub.4] nanoparticles via surface-initiated living radical polymerization. The PVPy-grafted [Fe.sub.3][O.sub.4] nanoparticles were directly incorporated into the precursors of PHUs [i.e., bis(cyclic carbonate) and a trifunctional amine] and the mixtures were cured at high temperatures to form organic-inorganic composites. This method ensured that [Fe.sub.3][O.sub.4] nanoparticles were finely dispersed within the PHU matrix through the strong intermolecular hydrogen bonding between PVPy and PHU. Compared to plain PHU network, the nanocomposites had enhanced thermomechanical properties, including higher glass transition temperatures ([T.sub.g]'s) and improved tensile mechanical properties. The inclusion of [Fe.sub.3][O.sub.4] nanoparticles also enhanced the shape memory properties of the PHU networks, improving shape recovery rates, fixity of transient shapes, and recovery of the original shapes. In addition, the nanocomposites demonstrated paramagnetic and photothermal properties and the photothermal behavior enabled a non-contact control of shape recovery. Highlights * Poly(N-vinyl pyrrolidone)-grafted [Fe.sub.3][O.sub.4] nanoparticles were synthesized. * Nanocomposites of PHU with [Fe.sub.3][O.sub.4] were prepared via a physical blending approach. * Incorporation of [Fe.sub.3][O.sub.4] resulted in improved thermomechanical properties. * The nanocomposites had the photothermal properties. KEYWORDS [Fe.sub.3][O.sub.4], nanocomposites, paramagnetic and photothermal properties, polyhydroxyurethane, shape memory properties, 1 | INTRODUCTION Polyurethanes (PUs) were first developed by Otto Bayer in 1939. (1) Over the past decades, PUs have been among the most major synthetic polymers. In general, the [...]

Purpose: Part 2 of this German S3 clinical practice guideline provides recommendations for the process of manufacturing composite restorations. It covers key aspects like caries removal, field isolation, matrix and adhesive techniques, as well as light curing and polishing. The outcomes of interest include survival rates and restoration quality. Materials and Methods: A systematic literature search was conducted by two methodologists using MEDLINE and the Cochrane Library via the OVID platform, including studies up to December 2021. Additionally, the reference lists of relevant manuscripts were manually reviewed. Six PICO questions were developed to guide the search. Consensus-based recommendations were formulated by a panel of dental professionals from 20 national societies and organizations based on the collected evidence and expert opinion. Results: The guideline advocates for one-stage selective caries removal near the pulp and underscores the effectiveness of various isolation techniques, adhesive systems, and the crucial role of light polymerization. The use of anatomically preformed sectional matrices and phosphoric acid etching is recommended to enhance restoration quality. Additionally, polishing composite restorations is advised to improve surface finish. Conclusion: This guideline provides comprehensive recommendations that inform clinicians on optimizing the composite restoration manufacturing processes. The adoption of these best practices can improve the quality and longevity of dental restorations. [ABSTRACT FROM AUTHOR]

Age-related hearing loss (ARHL) is a common sensory impairment with complex underlying mechanisms. In our previous study, we performed a meta-analysis of genome-wide association studies (GWAS) in mice and identified a novel locus on chromosome 18 associated with ARHL specifically linked to a 32 kHz tone burst stimulus. Consequently, we investigated the role of Formin Homology 2 Domain Containing 3 (Fhod3), a newly discovered candidate gene for ARHL based on the GWAS results. We observed Fhod3 expression in auditory hair cells (HCs) primarily localized at the cuticular plate (CP). To understand the functional implications of Fhod3 in the cochlea, we generated Fhod3 overexpression mice (Pax2-Cre+/-; Fhod3Tg/+) (TG) and HC-specific conditional knockout mice (Atoh1-Cre+/-; Fhod3fl/fl) (KO). Audiological assessments in TG mice demonstrated progressive high-frequency hearing loss, characterized by predominant loss of outer hair cells, and a decreased phalloidin intensities of CP. Ultrastructural analysis revealed loss of the shortest row of stereocilia in the basal turn of the cochlea, and alterations in the cuticular plate surrounding stereocilia rootlets. Importantly, the hearing and HC phenotype in TG mice phenocopied that of the KO mice. These findings suggest that balanced expression of Fhod3 is critical for proper CP and stereocilia structure and function. Further investigation of Fhod3 related hearing impairment mechanisms may lend new insight towards the myriad mechanisms underlying ARHL, which in turn could facilitate the development of therapeutic strategies for ARHL.

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 pursuit of developing novel approaches to fully organic and efficient phosphorescent materials is in high demand. The optical activity of such functional, organic phosphorescent/fluorescent materials may exhibit great temperature dependence, allowing their application as advanced, highly sensitive molecular thermometers. In this study, a rational strategy involving host–guest complexation and polymerization of [2.2]paracyclophane (PCP) based molecules with cucurbit[8]uril (CB8) to suppress the molecular motion and promote temperature‐dependent phosphorescence is presented. The rigid cavity of CB8 provides an ideal microenvironment to host PCP molecules 1 and 2, significantly enhancing the photophysical performance after complexation. Co‐polymerizing phosphors 1 and 2 with acrylamide is an efficient method for improving phosphorescence. Incorporating CB8 into the resulting P‐1 and P‐2 polymers enhances phosphorescence performance. Importantly, the obtained materials exhibit a big structure‐dependent spectral shift and change of phosphorescence lifetimes with temperature, allowing novel, phosphorescence‐based, and purely organic optical thermometers to be developed. The practical applications of PCP‐based luminescent materials in temperature sensing via a multi‐parameter approach are showcased, i.e., using fluorescence spectral shift and changes in bandwidth, as well as phosphorescence lifetimes, exhibiting thermal sensitivity of ≈17.7 cm−1 °C−1, 47.8 cm−1 °C, and 5.2% °C−1, respectively. [ABSTRACT FROM AUTHOR]

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A rapid in situ synthesis of electrochromic covalent organic frameworks (EC‐COFs) was proposed by using green electrochemical interface polymerization of N,N,N',N'‐tetrakis(4‐aminophenyl)‐1,4‐benzenediamine (TPDA) and 2,5‐dihydroxyterephthalaldehyde (DHBD). The synthetized TPDA‐DHBD films exhibit stable polymorphic color variations under different applied potentials, which can be attributed to the redox state changes of bis(triphenylamine) and imine electroactive functional groups within the COFs skeleton. TPDA‐DHBD represents markedly different electrochromisms from red to cyan due to the steric hindrance effect caused by the presence of UO22+, demonstrating the unique tunability of COFs materials. This work offers a new feasible idea for rapid EC‐COFs synthesis and tunable EC‐COFs realization. [ABSTRACT FROM AUTHOR]

Non‐activated linear α‐olefins are valuable building blocks for organic transformation or olefin (co)polymerization, but they are recognized as textbook knowledge for non‐homopolymerizable monomers under radical conditions. In this article, we disclose our effort to achieve an unprecedented library of all carbon‐bonded sequence‐regulated polymers via radical isomerization homopolymerization of α‐olefin derivatives. The success of this distinctive polymerization is attributed to the remarkable efficiency and selectivity exhibited during the cyano group migration or hydrogen atom transfer, which is greatly enhanced by the precise engineering of their monomer structures. This polymerization process enables the elongation of polymer chains by five, six, or seven carbon atoms at each propagation step. These polymers, obtained through the cyano group migration or hydrogen atom transfer involved radical isomerization polymerization processes, emerge as promising candidates resembling polyethylene or polyacrylonitrile copolymers. [ABSTRACT FROM AUTHOR]

In this study, two cardanol based epoxidized resins, NC514 with less than two epoxies per molecule and side chain epoxidized cardanol glycidyl ether (SCECGE) with approximately 2.45 epoxies (1.0 phenolic+1.45 aliphatic epoxies) per molecule were methacrylated. The methacrylated versions of cardanol based NC514 (NC514VE) and SCECGE (SCECGEVE) epoxy resins were used as cross‐linker units in vinyl ester formulations with methacrylated lauric acid (MFA) and styrene (ST) as bio‐based and synthetic based reactive diluents respectively, at various concentrations (10–40 wt%). The curing reactions of the resins were studied via FTIR and the extent of polymerization was determined for different cross‐linker units in the presence of ST and MFA. Our mechanical and thermomechanical characterizations showed that VER formulations prepared with cardanol based SCECGEVE cross‐linker unit have significantly improved properties than the samples prepared with commercially available counterpart NC514VE using either reactive diluent. These properties of SCECGEVE were also comparable with to that of methacrylated petroleum‐based diglycidyl ether of bisphenol A vinyl ester (DGEBAVE) formulations unlike NC514VE formulations due to more effective side chain functionalization and cross‐linking. [ABSTRACT FROM AUTHOR]

The construction of poly‐dioxolane (PDOL) solid‐state electrolytes by in situ polymerization is an effective way to achieve high performance lithium‐metal batteries. However, the poor electrochemical stability and safety issues of linear PDOL limit their further application. In this work, a multifunctional crosslinker has been introduced to construct a flame retardant crosslinked quasi solid‐state electrolyte (FCDOL). Due to the synergistic effect of the crosslinked network, the prepared FCDOL achieves excellent room temperature ionic conductivity (0.72 mS cm−1), high Li+ transference number (0.655), wide electrochemical stabilization window (4.8 V vs Li/Li+), and impressive performance when matched with lithium metal anodes (>4000 h plating/stripping) and high‐voltage cathodes, and the corresponding pouch cells can withstand abusive tests such as bending and cutting, encouraging that in situ polymerization of SPEs provides new insights into high‐energy density and high‐safety solid‐state batteries. [ABSTRACT FROM AUTHOR]

The growing demand for energy‐storage devices has raised inevitable concerns regarding the availability of redox‐active inorganic compounds and metals. It is expected that some of the inorganic compounds will be replaced by organic redox polymers, which are produced from abundant sources using environmentally benign processes, and they exhibit inherent advantages, including flexibility, processability, and biocompatibility. Redox polymers contain groups that can be reversibly reduced and oxidized by gaining and releasing electrons, respectively, and constitute an emerging class of functional organic materials. This article begins with a retrospective discussion of polymers and their electron exchange concepts, presenting them as old but new materials. The basics of electrochemical redox couples are briefly reintroduced, and the chemical design strategies for extending them to redox polymers are summarized. Subsequently, the efficient and reversible charge propagation and storage in densely populated redox‐active sites on soft polymer platforms are discussed. The potential to employ redox polymers in rechargeable charge‐storage applications and next‐generation devices is discussed, along with the current challenges and prospects. This outlook suggests fundamental questions and proposes interesting topics for redox polymers to facilitate their development as valuable materials for use in sustainable technologies. [ABSTRACT FROM AUTHOR]

This study aims to synthesize and characterize a sulfated‐starch‐based superabsorbent polymer (S‐SAP). The S‐SAP is prepared by grafting 2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid (AMPS) and acrylic acid (AA) onto sulfated starch, which is subsequently crosslinked using N,N‐methylene‐bis‐acrylamide (MBA) via free radical polymerization with ammonium persulfate as the initiator. The successful grafting of AA and AMPS onto the starch backbone improves the thermal stability and increases the swelling capacity of the polymer. The swelling capacity and reusability of the S‐SAP are compared with those of commercial superabsorbent polymers (C‐SAPs). The swelling capacity of the S‐SAP is higher than those of C‐SAPs, reaching 417 g g−1 in distilled water and 47 g g−1 in a 0.15 M NaCl solution. The water absorption kinetics of the S‐SAP shows a good fit with the pseudo‐second‐order model. The polymer prepared herein has potential applications in horticulture and agriculture. [ABSTRACT FROM AUTHOR]

The issue of non-degradable petroleum-based plastic waste is a global challenge that requires urgent attention due to its harmful impact on humans and the environment. Biomass-based materials have garnered significant attention to address this challenge in recent times. Lignin, with its abundance, low price, and rich aromatic groups, is not only essential biomass but also a crucial material that can be utilized to produce biodegradable polymers. This review paper provides comprehensive knowledge of the synthesis and applications related to lignin, polyester, and lignin–polyester copolymers with a specific focus on organic polymer synthesis techniques and diverse applications. Beginning with lignin, the review explores various extraction methods from raw biomass resources aimed at enhancing its compatibility with polyester matrices. Next, we discuss lignin chemical modification methods that alter its chemical structure and properties, ultimately enhancing its integration with polyesters. Subsequently, the synthesis of polyester is examined, encompassing condensation polymerizations and ring-opening polymerizations. These methods are evaluated for their scalability and capability in producing tailored polymer chains suitable for copolymerization with lignin. The copolymerization strategies involving lignin and polyester are explored in detail, including graft-onto and graft-from approaches. Each method is discussed for its ability to control copolymer composition and properties, which are crucial for achieving desired material characteristics. In terms of applications, the review highlights the wide-ranging utility of lignin–polyester copolymers across industries such as packaging, construction, and separation. These polymers offer improved biodegradability, thermal stability, and mechanical strength compared to conventional polyesters, making them perfect candidates for novel sustainable materials. Overall, this review provides valuable insights into the synthesis methods and applications of lignin, polyester, and lignin–polyester copolymers offering a comprehensive overview of their potential for addressing environmental concerns and expanding the scope of lignin-derived materials in various industrial applications. [ABSTRACT FROM AUTHOR]

Despite decades of research, the fundamental question of structure and morphology of the poly(3,‐4‐ethylenedioxythiophene):poly(styrene sulfonate) complex (PEDT: PSS) electrically conducting polymer remains open. Here, through a systematic study of the polymerization of 3,4‐ethylenedioxythiophene (EDT) on two series of sulfonated polystyrenes, i.e., PS‐co‐SSH and PS‐co‐SSNa, with per cent sulfonation 24 ≲ x ≲ 100, this study shows that the substrate polyelectrolyte not only affords charge compensation and processability, but also templates the morphology of the growing PEDT chain—whether extended, coiled or collapsed. This determines the electrical, electronic and optical properties of the resultant PEDT: PSS interpolyelectrolyte complexes, including their work function. This study calls this the Polyelectrolyte Template model. The PEDT: PSS complex retains memory of its polymerization morphology even after subsequent ion‐exchange, for example, to the same acid form. Electrical conductivity decreases sharply with decreasing x, and depends on whether the polymerization is templated with the H+ or Na+ form of the polyelectrolyte. The work function is less sensitive to x, but exhibits a transition from low to high work function (5.2–5.3 eV) when x exceeds a threshold, which indicates formation of a polar surface driven by molecular‐scale segregation of the PSS counteranion. This surface segregation also affects the ability of these complexes to inject holes into very large‐ionization‐energy semiconductors. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks are a class of crystalline porous polymers formed by linking organic units into periodically aligned skeletons and pores. Here we report a strategy for wiring these frameworks with conducting polymers via wall engineering and polymerization. We anchored each edge site with one pyrrole unit, which is densely packed along the z direction yet protruded from pore walls. This assembly enables the polymerization of pyrrole units to form polypyrrole and creates a new polypyrrole chain conformation. The resultant framework constitutes six single file polypyrrole chains in each pore and develop spatially segregated yet built‐in single molecular wires with exceptional stable polarons. Hall effect measurements revealed that the materials are p‐type semiconductors, increase conductivity by eight orders of magnitude compared to the pristine frameworks, and achieve a carrier mobility as large as 13.2 cm2 V−1 s−1. Our results open an avenue to π electronic frameworks by interlayer molecular wiring with conducting polymers. [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]

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]

The aim of this study was to evaluate the degree of conversion (%), flexural strength (MPa), elastic modulus (GPa), compressive strength (MPa), Knoop microhardness (KHN), post-gel shrinkage (%) and prediction of ideal concentration of cholesteryl methacrylate (CM) in experimental resins. Four formulations were manipulated (F): F1, control group, (0 % CM); F2 (15 % CM); F3 (19.8 % CM) and F4 (30 % CM). Bis-GMA and CM percentages were determined using Statistica™ software. For the degree of conversion test, Raman spectroscopy was used. To testing flexural strength, elastic modulus and compressive strength, a universal testing machine was used. For the Knoop microhardness test five indentations were made in each sample. Post-gel shrinkage was determined using the strain gauge method. Statistica™ software processed all data obtained in this study. Results were submitted to one-way ANOVA and Tukey's post hoc tests (α = 0.05). Better performance was observed for F2 (15 % CM) and F3 (19,8 % CM) for degree of conversion, elastic modulus and post-gel shrinkage. For Knoop microhardness F2 (15 % CM), F3 (19,8 % CM) and F4 (30 % CM) showed higher values than F1 (0 % CM). For flexural strength F1 (0 % CM) and F3 (19,8 %) were similar and F4 showed the lowest values and for compressive strength F1 (0 % CM) showed the highest values. For mixture designs analysis data, concentrations ≤ 25 % of CM would provide better results. Addition of CM at concentrations lower than 30 % contributed to a significant increase in the degree of conversion, microhardness values, elastic modulus and reduction of post-gel shrinkage. • Cholesteryl methacrylate proved to be a promising polymer for improving composites. • An endocyclic double bond can be an additional site for photochemical cycloaddition. • Concentrations ≤ 25 % cholesteryl methacrylate enhance composite resins. • Post-gel shrinkage performed better with 15 %, 19.8 % and 30 % cholesteryl methacrylate. • Knoop microhardness was higher with 15 %, 19.8 %, and 30 % cholesteryl methacrylate. [ABSTRACT FROM AUTHOR]

Hydrogels are promising materials for medical devices interfacing with neural tissues due to their similar mechanical properties. Traditional hydrogel‐based bio‐interfaces lack sufficient electrical conductivity, relying on low ionic conductivity, which limits signal transduction distance. Conducting polymer hydrogels offer enhanced ionic and electronic conductivities and biocompatibility but often face challenges in processability and require aggressive polymerization methods. Herein, we demonstrate in situ enzymatic polymerization of π‐conjugated monomers in a hyaluronan (HA)‐based hydrogel bioink to create cell‐compatible, electrically conductive hydrogel structures. These structures were fabricated using 3D bioprinting of HA‐based bioinks loaded with conjugated monomers, followed by enzymatic polymerization via horseradish peroxidase. This process increased the hydrogels' stiffness from about 0.6 to 1.5 kPa and modified their electroactivity. The components and polymerization process were well‐tolerated by human primary dermal fibroblasts and PC12 cells. This work presents a novel method to fabricate cytocompatible and conductive hydrogels suitable for bioprinting. These hybrid materials combine tissue‐like mechanical properties with mixed ionic and electronic conductivity, providing new ways to use electricity to influence cell behavior in a native‐like microenvironment. [ABSTRACT FROM AUTHOR]

Endo-norbornene derivatives are much cheaper and more accessible. However, it is difficult to prepare endo-polynorbornenes with ultra-high molecular weight (UHMW) by ring opening metathesis polymerization (ROMP) owing to the low activity. The molecular weight of poly(endo-NB-2OH)n could only reach to 309.1 kg mol−1 for 24 h via ROMP. While, UHMW poly(endo-NB-2OH)m was prepared by combining ROMP and acyclic metathesis reaction in much shorter time. The effects of residual monomer, amount of H2SO4, concentration, temperature and reaction time were investigated in depth. The UHMW P(endo-NB-2OH)m (Mn=2645.5 kg mol−1, PDI = 1.74) could be obtained at 80 °C for 5 min with H2SO4/G3 as 10/1 and concentration of 0.1 M. Moreover, UHMW P(endo-NBI-OH)m(Mn=1114.2 kg mol−1, PDI = 1.95) was also successfully prepared by this method. However, the H2SO4/G3 should increase to 30/1, and reacted for 45 min owing to the steric resistance of the cyclic dicarboximide. For P(exo-NBI-OH)n with lower activity, reaction time should prolong to 3 h to obtain UHMW P(exo-NBI-OH)m(Mn=1716.7 kg mol−1, PDI = 1.93). Finally, UHMW P(endo-NB-2alkyne)m, P(endo-NBI-alkyne)m, and P(exo-NBI-alkyne)m were successfully prepared via post-modification. Acyclic metathesis reaction is a robust and universal reaction to prepare other functional UHMW polynorbornenes, especially for the UHMW endo-polynorbornenes, which could not be prepared by ROMP efficiently. [ABSTRACT FROM AUTHOR]

3D nanolithography based on two‐photon polymerization (TPP) allows for the high‐precision fabrication of nearly arbitrary 3D micro/nanostructures, finding extensive applications in areas such as micro‐optics, micro‐mechanics, and biomedicine. However, the large size, complexity of optical systems, and high costs have significantly constrained the widespread adoption of 3D nanolithography technology in both scientific research and industry. In this study, a metasurface is introduced, for the first time, into 3D nanolithography resulting in the construction of a miniaturized and simplified TPP system that achieved efficient multi‐focus parallel processing with high uniformity. A microlens array is fabricated, showcasing the system's application capacity to generate an array of devices with high consistency and quality. It is believed that the utilization of metasurface devices will provide a novel TPP operating platform, enabling richer and more flexible printing functionalities while maintaining system miniaturization and low cost. [ABSTRACT FROM AUTHOR]

Vanillyl alcohol has emerged as a widely used building block for the development of biobased monomers. More specifically, the cationic (photo‐)polymerization of the respective diglycidyl ether (DGEVA) is known to produce materials of outstanding thermomechanical performance. Generally, chain transfer agents (CTAs) are of interest in cationic resins not only because they lead to more homogeneous polymer networks but also because they strikingly improve the polymerization speed. Herein, the aim is to compare the cationic chain‐growth photopolymerization with the thermally initiated anionic step‐growth polymerization, with and without the addition of CTAs. Indeed, CTAs lead to faster polymerization reactions as well as the formation of more homogeneous networks, especially in the case of the thermal anionic step‐growth polymerization. Resulting from curing above the TG of the respective anionic step‐growth polymer, materials with outstanding tensile toughness (>5 MJ cm−3) are obtained that result in the manufacture of potential shape‐memory polymers. [ABSTRACT FROM AUTHOR]

The preparation of so-called hybrid nanomaterials has been widely developed in terms of functional and morphological complexity. However, the specific control of the arrangement of organic and inorganic species, which determines the properties of the final material, still remains a challenge. This article offers a review of the strategies that have been used for the preparation of polymer–inorganic hybrid nanoparticles and nanocapsules via processes involving miniemulsions. Different polymer–inorganic nanostructures are classified into four main groups according to the sequential order followed between the synthesis of the polymer and the inorganic species, and the presence or not of their counterpart precursors. The minimization of the energy of the system governs the self-assembly of the different material components and can be addressed by the miniemulsion formulation to reduce the interfacial tensions between the phases involved. The state of the art in the preparation of hybrid nanoparticles is reviewed, offering insight into the structural possibilities allowed by miniemulsion as a versatile synthetic technique. [ABSTRACT FROM AUTHOR]

We studied the properties of a reaction front that forms in irreversible reaction–diffusion systems with concentration-dependent diffusivities during the synthesis of polymer brushes. A coarse-grained model of the polymerization process during the formation of polymer brushes was designed and investigated for this purpose. In this model, a certain amount of initiator was placed on an impenetrable surface, and the "grafted from" procedure of polymerization was carried out. The system consisted of monomer molecules and growing chains. The obtained brush consisted of linear chains embedded in nodes of a face-centered cubic lattice with excluded volume interactions only. The simulations were carried out for high rafting densities of 0.1, 0.3, and 0.6 and for reaction probabilities of 0.02, 0.002, and 0.0002. Simulations were performed by means of the Monte Carlo method while employing the Dynamic Lattice Liquid model. Some universal behavior was found, i.e., irrespective of reaction rate and grafting density, the width of the reaction front as well as the height of the front show for long times the same scaling with respect to time. During the formation of the polymer layer despite the observed difference in dispersion of chain lengths for different grafting densities and reaction rates at a given layer height, the quality of the polymer layer does not seem to depend on these parameters. [ABSTRACT FROM AUTHOR]

Polyamides' properties are greatly influenced by the polymerization process and the type of feedstock used. The solid forms of nylon salts play a significant role in determining the final characteristics of the material. This study focuses on the long-chain bio-nylon 512. Firstly, we systematically investigated the possible solid forms of the nylon 512 salt, including crystal forms and morphologies, by massive experimental screening, single-crystal X-ray diffraction, Hirshfeld surface analysis, and TG-DSC measurements. The regulation and control of the various solid forms were achieved through solid-state transformations (SSTs) and solution-mediated phase transformations (SMPTs). Our findings shows that the nylon 512 salt exists in two crystal forms (anhydrate and dihydrate) and four morphologies (needle-like, plate-like, rod-like, and massive block crystal). Many factors will influence the formation of these solid forms, such as water activity, temperature, solvent, and ultrasonic physical fields. We can choose the right factors to regulate this as needed. On this basis, we studied the effects of different solid forms (crystal forms and morphologies) on the properties of the resulting polyamides prepared using direct solid-state polymerization (DSSP). The solid form of the salt had many effects on the polymer, including its structure, melting point, and mechanical properties. The polyamide obtained through DSSP of the anhydrate salt exhibited a higher melting point (204.22 °C) and greater elastic modulus (3.366 GPa) compared to that of the dihydrate salt, especially for the anhydrate salt of plate-like crystals. [ABSTRACT FROM AUTHOR]

ABSTRACT Objective Materials and Methods Results Conclusions Clinical Significance This study aimed to evaluate, through a case report combined with in vitro study, whether a new diagnostic white tip for the transillumination technique during resin infiltration influences the procedure and degree of conversion (DC).A clinical case report demonstrated resin infiltration using the transillumination technique with a new white diagnostic tip (Radii Xpert LED diagnostic tip, SDI, Bayswater, VIC, AU) along with a light‐curing device to enhance aesthetic results. An in vitro study assessed the DC of two diagnostic white tips (Radii Xpert LED diagnostic tip [SDI, Bayswater, VIC, AU] and Valo Grand White Light Lens [Ultradent Prod., South Jordan, UT, USA]) compared to that achieved using conventional tips of both light‐curing devices. Statistical analysis was performed using two‐way ANOVA and Tukey's test (α = 0.05).The clinical case achieved complete masking of the white spot lesion. In vitro, the diagnostic white tips exhibited significantly lower DC values compared to conventional tips (p = 0.001), regardless of the light‐curing unit.The diagnostic white tip used in the transillumination technique improves resin infiltration visibility without compromising the degree of conversion.The transillumination technique with the diagnostic white tip enables monitoring of resin infiltration while maintaining effective polymerization. [ABSTRACT FROM AUTHOR]

This study focuses on utilizing montmorillonite (MMT) to induce a multi-micro/nanolayer morphology in PA6/ABS blend polymers by mitigating phase retraction and coalescence. Both untreated and modified MMT were incorporated at weight contents ranging from 1 to 5 wt% to manipulate morphology through selective localization at the interface. The nanocomposites' morphology was analyzed, and the cooperative effects were correlated with their structural, thermal, rheological, and mechanical characteristics. Structural analysis revealed that intercalation resulted in the appearance of novel bands, particularly in CTAB-modified MMT, which adopted a tilted monolayer arrangement. SEM results demonstrated excellent distribution and dispersion of exfoliated modified MMT, effectively suppressing coalescence and promoting a finer multilayer morphology. Compared to nanocomposites based on unmodified MMT, the ones based on CTAB-modified MMT exhibited superior thermal stability. Furthermore, the stiffness of the blend matrix increased with clay content, and the nanocomposites stabilized with modified MMT showed enhanced strain-to-failure properties. [ABSTRACT FROM AUTHOR]

Molecular bottlebrush (MBB) has been considered as an important type of unimolecular nanomaterial for widespread applications ranging from energy to biomedicine, due to its typical one‐dimensional molecular conformation with tunable aspect ratio and chemical composition. In the recently decades, the ring‐opening metathesis polymerization (ROMP) combined with the grafting‐through strategy has emerged as a powerful tool for synthesizing MBBs with various architecture, including (multi)block MBBs, core‐shell MBBs, random MBBs and Janus MBBs et al. In this review, the recent advances on the synthesis of MBBs including the rational preparation of NB terminated macromonomers (MMs) and the grafting‐through ROMP are briefly summarized. Moreover, the emerging progress on the grafting‐through ROMP performed in the aqueous media is also highlighted. [ABSTRACT FROM AUTHOR]

The control of the regioselectivity of metal‐catalyzed α‐olefins polymerization is of everlasting interest. Most nickel and palladium catalysts show high regioselectivity involving 2,1‐insertion of α‐olefins and 1,ω‐enchainment chain‐straightening, especially α‐diimine nickel catalysts. In this contribution, we report extremely rare regioselective chain‐straightening polymerization of α‐olefins through 2,ω‐enchainment using unsymmetrical amine–imine nickel catalysts. The polymerizations of α‐olefins (1‐hexene, 1‐octene, and 1‐decene) were studied in detail, and the effects of catalyst structure, reaction temperature, and monomer concentration on the polymerization activity and the regioselectivity were examined. The unsymmetrical N‐substituents of the amine–imine nickel catalysts play a crucial role in the regioselectivity. High regioselectivity involving 80.4% 1,2‐insertion and 84.5% 2,ω‐enchainment is realized to produce amorphous polyolefins without melting temperatures. [ABSTRACT FROM AUTHOR]

Organic radicals are gaining significant interest in luminescent materials due to their unique properties, which present unprecedented opportunities for innovation across various fields, from display technology to biomedical applications. However, addressing challenges related to stability and low fluorescence efficiency is crucial to unlocking their full potential for practical applications. Polymerization has emerged as an effective strategy to enhance intra‐ and interchain through‐space interactions, enabling the creation of stable luminescent radicals with excellent processing and multifunctional properties. This concept emphasizes the strategic use of polymerization in designing and synthesizing stable main‐chain and side‐chain radical polymers. This approach not only broadens the scope of stable radicals but also improves their luminescence properties as photofunctional materials. [ABSTRACT FROM AUTHOR]

Fluorosilicone rubber is essential for sealing in extreme temperatures and non‐polar environments due to its exceptional adaptability. However, achieving a high yield of fluorosilicone polymers with medium and high fluorine content remains a challenge. Herein, a facile gradient strategy is developed that involves modifying the method of cyclic monomer addition based on the rate of ring‐opening polymerization (ROP), to improve yield and adjust fluorine content precisely. The polymerization process is designed and tailored based on the reaction rates of anionic ring‐opening polymerization (AROP) and cationic ring‐opening polymerization (CROP) via an efficient gradient strategy. The effects of the polymerization process on the viscosity and yield of vinyl fluorosilicone polymers and hydrofluorosilicone polymers are investigated and optimized. Notably, the as‐prepared vinyl‐terminated fluoromethylsilane with 60% fluorine content (FMS‐Vi‐60F) has a high yield (86.6%) and high viscosity (150 000 mPa·s) in a short reaction time, which is superior to previous methods. Clearly, the gradient ring‐opening method developed in this work provides a facile and efficient synthesis for fabricating fluorosilicone polymers with a high yield and tunable fluorine content. [ABSTRACT FROM AUTHOR]

Protein photocatalysts provide a modular platform to access new reaction pathways and affect product outcomes, but their use in polymer synthesis is limited because co‐catalysts and/or co‐reductants are required to complete catalytic cycles. Herein, we report using zinc myoglobin (ZnMb), an inherently photoactive protein, to mediate photoinduced electron/energy transfer (PET) reversible addition‐fragmentation chain transfer (RAFT) polymerizations. Using ZnMb as the sole reagent for catalysis, photomediated polymerizations of N,N‐dimethylacrylamide in PBS were achieved with predictable molecular weights, dispersity values approaching 1.1, and high chain‐end fidelity. We found that initial apparent rate constants of polymerization increased from 4.6×10–5 s−1 for zinc mesoporpyhrin IX (ZnMIX) to 6.5×10–5 s−1 when ZnMIX was incorporated into myoglobin to yield ZnMb, indicating that the protein binding site enhanced catalytic activity. Chain extension reactions comparing ZnMb‐mediated RAFT polymerizations to thermally‐initiated RAFT polymerizations showed minimal differences in block copolymer molecular weights and dispersities. This work enables studies to elucidate how protein modifications (e.g., secondary structure folding, site‐directed mutagenesis, directed evolution) can be used to modulate polymerization outcomes (e.g., selective monomer additions towards sequence control, tacticity control, molar mass distributions). [ABSTRACT FROM AUTHOR]

Protein aggregation, particularly the formation of amyloid fibrils, is associated with numerous human disorders, including Parkinson's disease. This neurodegenerative condition is characterised by the accumulation of α‐Synuclein amyloid fibrils within intraneuronal deposits known as Lewy bodies or neurites. C‐terminally truncated forms of α‐Synuclein are frequently observed in these inclusions in the brains of patients, and their increased aggregation propensity suggests a role in the disease's pathogenesis. This study demonstrates that the small molecule ZPD‐2 acts as a potent inhibitor of both the spontaneous and seeded amyloid polimerisation of C‐terminally truncated α‐Synuclein by interfering with early aggregation intermediates. This dual activity positions this molecule as a promising candidate for therapeutic development in treating synucleinopathies. [ABSTRACT FROM AUTHOR]

Polymerization of benzoxazine at low temperatures is important because the high‐temperature polymerization restricts its utilization in a wide range of applications, though the polybenzoxazines possess excellent properties. The effect of nitro functionality and various substituents on the thermal curing of benzoxazine and the flame‐retardant behavior are mainly focused in this study. In the present work, 2,2′‐methylenebis(4‐nitrophenol) (NBP) was synthesized from 4‐nitrophenol and is used for the synthesis of benzoxazine derivatives with five structurally different aromatic amines. As the synthesized benzoxazine contains nitro‐groups in the phenolic part and various substituted functional groups in different positions of the amine part, the curing temperatures significantly varied among each other. The effect of different substituents on the thermal ring‐opening polymerization (ROP) of benzoxazine was studied with exotherms of the DSC thermogram. The 4‐fluoroaniline and 2‐aminobenzotrifluoride‐based benzoxazines show the highest and lowest curing temperatures of 272 and 189 °C, respectively, which is based on their substituents and their position that can act as an internal catalyst. The resulting polybenzoxazines possess higher char yield (49% ≤ 63%) and higher values of LOI (37 ≤ 43) including excellent flame retardant (UL94‐V0) behaviors suggesting that the polybenzoxazine can be used as coatings for high‐performance industrial applications. [ABSTRACT FROM AUTHOR]

휋‐Conjugated polymers, including those based on acetylenic repeating units, are an exciting class of materials that offer narrow optical band gaps and tunable frontier orbital energies that lead to their use in organic electronics. This work expands the knowledge of structure‐property relationships of acetylenic polymers through the synthesis and characterization of a series of Glaser‐Hay‐coupled model compounds and random copolymers comprised of BF2 formazanate, fluorene, and/or bis(alkoxy)benzene units. The model compounds and copolymers synthesized exhibit redox activity associated with the reversible reduction of the BF2 formazanate units and the irreversible reduction of the fluorene and bis(alkoxy)benzene units. The copolymers exhibit absorption profiles characteristic or intermediate of their respective models and homopolymers, leading to broad absorption of UV–vis light. The alkyne linkages of the model compounds and copolymers are reacted with [Co2(CO)8] to convert the alkyne functional groups into cobalt carbonyl clusters. This transformation leads to blue‐shifted absorption profiles due to a decrease in π‐conjugation, demonstrating the ability to tune the properties of these materials through post‐polymerization functionalization. The redox activity and broad absorption bands of the polymers reported make them excellent candidates for use in photovoltaics and other light‐harvesting applications. [ABSTRACT FROM AUTHOR]

In low‐density polyethylene (LDPE) production, low‐molecular‐weight species are used as chain transfer agents (CTAs). They reduce the degree of polymerization, which has an impact on the polymer properties, such as processability. To specifically adjust the product properties, a detailed understanding of the transfer kinetics to CTAs is indispensable. Thus, the transfer activity of various primary, secondary, and tertiary alcohols as well as diols was investigated experimentally between 120 °C and 250 °C at 2000 bar. The results were evaluated using the Mayo and chain length distribution (CLD) method, and the latter was found to give more reliable results. It was observed that the hydroxy group systematically increases transfer activity compared to alkanes. Additionally, a linear increase of transfer activity with the number of hydrogen atoms is found. [ABSTRACT FROM AUTHOR]

Catalytic ethylene oligomerization is important in the petrochemical industry, as it produces valuable products like linear alpha‐olefins (LAOs) for the synthesis of polymers and specialty chemicals. Catalysts, typically transition metal complexes or metal‐containing materials, play a crucial role in selective oligomerization by providing active sites for ethylene activation and controlling product distribution. Recently, defective metal‐organic frameworks (MOFs) with well‐defined structures and unsaturated active sites have emerged as potential catalysts for ethylene oligomerization. In this study, we employ density functional theory calculations to investigate the energetic selectivity of competing pathways (including dimerization, isomerization and trimerization) during ethylene oligomerization on defective HKUST‐1 supported metal hydrides (H−M–DHKUST‐1, M: Co, Ni, Ru, Rh and Pd). On all the five hydrides, ethylene dimerization is found to be more preferential than trimerization and isomerization. In the microenvironment of defective paddlewheel of HKUST‐1, isomerization is highly unfavorable compared with dimerization because of high energy required for chain walk, and 1‐butene is expected to be the major product on all the five hydrides. Analysis of NBO charges reveals a notable reduction in cationic nature at the metal site on H−Ru–DHKUST‐1, which facilitates β‐hydride elimination for dimerization. The microscopic insights from this computational study might facilitate the rational design of new MOFs and other MOF‐supported catalysts for selective ethylene oligomerization. [ABSTRACT FROM AUTHOR]

The origin of stereocontrol in ring opening polymerization (ROP) of racemic lactide (rac‐LA) promoted by achiral aluminium‐based catalysts has been explained through DFT calculations combined with a molecular descriptor (%VBur) and the activation strain model (ASM‐NEDA) analysis. The proposed chain end control (CEC) model suggests that the ligand framework adopts a chiral configuration mimicking the enantiomorphic site control (ESC) while also incorporating control of the last inserted monomer unit. It is found that the ligand wrapping mode around the aluminium centre is dictated by the monomer configuration (R,R‐LA and S,S‐LA). A good correlation with experimental data is achieved only when accounting for the ligand dynamic features and its steric influences, as highlighted by %VBur steric maps and ASM‐NEDA analysis. Understanding the ESC and CEC interplay is an important target for obtaining stereoselective ROP polymerization for the synthesis of biodegradable materials with tailored properties. [ABSTRACT FROM AUTHOR]

Reconfigurable and tunable holograms hold significant practical value in the fields of anti‐counterfeiting, optical security, and information display due to their ability to reprogram holographic patterns and create variable visual effects. However, current encryption techniques face challenges in achieving rapid encryption/decryption and ensuring consistent methods. In this study, a method for producing a reconfigurable encryption hologram utilizing the deformation and recovery properties of micropillars in response to liquid is demonstrated. Micron‐scale micropillars are fabricated using femtosecond laser two‐photon polymerization. By exploiting the rapid deformation and recovery capabilities of micropillars with specific pitches and aspect ratios in response to liquids, micropillar structures and holograms are combined to construct reconfigurable holograms. The encrypted pattern information in the reconfigurable holograms is only readable following immersion in alcohol and laser irradiation. The proposed method offers a facile, reversible, reusable, and practical solution for information encryption, with significant potential in anti‐counterfeiting and optical security. [ABSTRACT FROM AUTHOR]

Within living organisms, numerous nanomachines are constantly involved in complex polymerization processes, generating a diverse array of biomacromolecules for maintaining biological activities. Transporting artificial polymerizations from lab settings into biological contexts has expanded opportunities for understanding and managing biological events, creating novel cellular compartments, and introducing new functionalities. This review summarizes the recent advancements in artificial polymerizations, including those responding to external stimuli, internal environmental factors, and those that polymerize spontaneously. More importantly, the cutting‐edge biomedical application scenarios of artificial polymerization, notably in safeguarding cells, modulating biological events, improving diagnostic performance, and facilitating therapeutic efficacy are highlighted. Finally, this review outlines the key challenges and technological obstacles that remain for polymerizations in biological organisms, as well as offers insights into potential directions for advancing their practical applications and clinical trials. [ABSTRACT FROM AUTHOR]

This study presents, for the first time, a new method for the synthesis of polymers containing different ratios of oxidized quinoid and reduced benzenoid units in polyaniline (PANi)‐like structure. Copolymers were synthesized by an oxidative copolymerization method of p‐phenylene diamine (p‐PDA) and o‐anisidine (o‐An) in an organic medium using different initial compositions of monomers. The compositions of the copolymer were determined based on 1H NMR spectral data. The thermal stability, electrical conductivity, morphology, and solubility were studied and a comparative analysis with polyaniline and corresponding homopolymers was been carried out. The thermal behavior of copolymers was studied using thermogravimetric analysis and differential scanning calorimetry. It was found that during heating one endothermic process of water evaporation and two exothermic processes occur, which depend on copolymer composition, and only 30% weight loss occurs up to 600 °C. It is shown that room‐temperature conductivity of copolymers doped with hydrochloric and sulfuric acids ranges from 10−5 to 10−3 S cm−1 and increases with increasing concentration of o‐anisidine structural units. The conductivity of iodine‐doped copolymers is of the same order as the conductivity of iodine‐doped PANi in emeraldine and leucoemeraldine forms. The morphology of doped copolymers depends on the co‐monomer ratio and the type of dopants. [ABSTRACT FROM AUTHOR]

Aramid copolymers have garnered significant interest due to their potential applications in extreme environments such as the aerospace, defense, and automotive industries. Recent developments in aramid copolymers have moved beyond their traditional use in high-strength, high-temperature resistant fibers. There is now a demand for new polymers that can easily be processed into thin films for applications such as electrical insulation films and membranes, utilizing the inherent properties of aramid copolymers. In this work, we demonstrate two novel aramid copolymers that are capable of polymerizing in polar organic solvents with a high degree of polymerization, achieved by incorporating flexible bis(4-aminophenoxy) benzene moieties into the chain backbone. The synthesized MBAB-aramid and PBAB-aramid have enabled the fabrication of exceptionally thin, clear films, with an average molecular weight exceeding 150 kDa and a thickness ranging from 3 to 10 μm. The dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA) reveal that the thin films of MBAB-aramid and PBAB-aramid exhibited glass transition temperatures of 270.1 °C and 292.7 °C, respectively, and thermal decomposition temperatures of 449.6 °C and 465.5 °C, respectively. The mechanical tensile analysis of the 5 μm thick films confirmed that the tensile strengths, with elongation at break, are 107.1 MPa (50.7%) for MBAB-aramid and 113.5 MPa (58.4%) for PBAB-aramid, respectively. The thermal and mechanical properties consistently differ between the two polymers, which is attributed to variations in the linearity of the polymer structures and the resulting differences in the density of intermolecular hydrogen bonding and pi-pi interactions. The resulting high-strength, ultra-thin aramid materials offer numerous potential applications in thin films, membranes, and functional coatings across various industries. [ABSTRACT FROM AUTHOR]

Phasins are proteins located on the surface of poly-3-hydroxybutyrate (P3HB) granules that affect the metabolism of the polymer, the size and number of the granules, and some also have stress-protecting and growth-promoting effects. This study evaluated the effect of inactivating two new phasins (PhbP2 or PhbP3) on the cellular growth, production, and molecular mass of P3HB in cultures under low or high oxygen transfer rates (OTR). The results revealed that under high OTRₘₐₓ conditions (between 8.1 and 8.9 mmol L−1 h−1), the absence of phasins PhbP2 and PhbP3 resulted in a strong negative effect on the growth rate; in contrast, the rates of specific oxygen consumption increased in both cases. This behavior was not observed under a low oxygen transfer rate (3.9 ± 0.71 mol L−1 h−1), where cellular growth and oxygen consumption were the same for the different strains evaluated. It was observed that at high OTR, the absence of PhbP3 affected the production of P3HB, decreasing it by 30% at the end of cultivation. In contrast, the molecular weight remained constant over time. In summary, the absence of phasin PhbP3 significantly impacted the growth rate and polymer synthesis, particularly at high maximum oxygen transfer rates (OTRₘₐₓ). [ABSTRACT FROM AUTHOR]

The polypropylene (PP) synthesis process is crucial in the plastics industry, requiring precise control as it directly impacts the catalytic activity and the final product's performance. This study investigates the effects of trace amounts of four different mercaptans on the polymerization of propylene using a fourth-generation Ziegler–Natta (ZN) catalyst. Various concentrations of these mercaptans were tested, and results showed that their presence significantly reduced the melt flow index (MFI) of the final PP. The most notable MFI decrease occurred at 37.17 ppm of propyl mercaptan and 52.60 ppm of butyl mercaptan. Methyl and ethyl mercaptan also reduced the MFI at lower concentrations, indicating that mercaptans act as inhibitors by slowing down the polymerization process and reducing the fluidity of molten PP. The highest MFI increase was observed at lower concentrations of each mercaptan, suggesting that smaller molecular inhibitors require less concentration. This trend was also seen in the catalyst's productivity, where lower concentrations of methyl mercaptan reduced PP production more effectively than higher concentrations of butyl mercaptan. Fourier transform infrared spectroscopy (FTIR) identified interactions between the mercaptans and the ZN catalyst. Computational analysis further supported these findings, providing insights into the molecular interactions and suggesting possible inhibition mechanisms that could impact the final properties of polypropylene. [ABSTRACT FROM AUTHOR]

Synthesis of polyurethane‐type poly[3]rotaxanes is achieved by polyaddition between a cyclodextrin (CD)‐based [3]rotaxane diol and various diisocyanate species, which provide a more defined structure compared to conventional polyrotaxane syntheses. In this study, hydroxyl groups on CDs of [3]rotaxane diol are initially acetylated, and deprotected after the polyaddition to introduce polyurethane backbone structure into polyrotaxane framework. Despite a relatively complicated chemical structure, [3]rotaxane diol monomer is successfully synthesized in a high yield (overall 67%) without any taxing purification process, which is beneficial for practical applications. The polymerization itself proceeds well under a standard polyaddition reaction condition to afford corresponding polyurethanes around 80% yield with Mn > 30 kDa. The poly[3]rotaxanes show different aggregation behavior or optical properties, whether or not acetyl groups are present, and are analyzed by XRD, SEM, and fluorescence measurements. [ABSTRACT FROM AUTHOR]

This work presents a versatile strategy for the synthesis of dual stimuli‐responsive amphiphilic glycomacromolecules with tailored release properties. Amphiphilic precision glycomacromolecules (APGs) derived from tailor‐made building blocks using solid phase polymer synthesis form glycofunctionalized micelles, a versatile class of materials with applications in drug delivery, as antiinfection agents as well as simple cell mimetics. In this work, this concept is extended by integrating cleavable building blocks into APGs now allowing stimuli‐responsive release of glycan ligands or destruction of the micelles. This study incorporates a newly designed acid‐labile building block, 4‐(4‐(((((9H‐fluoren‐9‐yl)methoxy)carbonyl)amino)methyl)‐1,3‐dioxolan‐2‐yl)benzoic acid (DBA), suitable also for other types of solid phase or amide chemistry, and an established UV‐cleavable 2‐nitrobenzyl linker (PL). The results demonstrate that both linkers can be cleaved independently and thus allow dual stimuli‐responsive release from the APG micelles. By choosing the APG design e.g., placing the cleavable linkers between glycomacromolecular blocks presenting different types of carbohydrates, they can tune APG and micellar stability as well as the interaction and cluster formation with a carbohydrate‐recognizing lectin. Such dual‐responsive glycofunctionalized micelles have wide potential for use in drug delivery applications or for the development as anti‐adhesion agents in antiviral and antibacterial treatments. [ABSTRACT FROM AUTHOR]

Biosensors stand at the forefront of innovation in critical fields such as medicine, food safety, and environmental monitoring, offering precise detection of specific biomarkers. Among these, polymer-based biosensors have emerged as powerful tools, evolving from inert materials to intricately tailored structures capable of precise molecular binding. Electrospinning, a prominent fabrication method, offers a cost-effective approach for developing diagnostic kits, pushing the boundaries of biosensors with exceptionally low analyte detection limits. However, the reliance on commercial polymers restricts the versatility of electrospun nanofibers due to the fixed properties and limited functionalization options of off-the-shelf materials. These constraints prevent the tailoring of nanofibers to meet specific or diverse needs, as their molecular structure and surface functionalities are not easily adjustable. A promising solution is integrating Controlled Radical Polymerization (CRP) with electrospinning. CRP provides precise control over polymer properties, enabling the creation of nanofibers with customized functionalities for various applications. This approach combines the benefits of electrospinning, such as high surface area-to-volume ratios, with the advanced capabilities of CRP to enhance the selectivity and sensitivity of biosensors. This review represents recent advancements in biosensors, covering acquisition, characterization, and applications, with a focal point on the role of functional polymers. Exploring biosensor architecture, electrospinning principles, controlled polymer synthesis, CRP techniques, and polymer topologies, the manuscript also discusses challenges and future prospects, including microfluidic integration, multi-detection capabilities, machine learning, and the development of wearable biosensors. [ABSTRACT FROM AUTHOR]