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We present the results for energy landscapes of hexapeptides obtained using interfaces to the Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) program. We have used basin-hopping global optimization and discrete path sampling to explore the landscapes of hexapeptide monomers, dimers, and oligomers containing 10, 100, and 200 monomers modeled using a residue-level coarse-grained potential, Mpipi, implemented in LAMMPS. We find that the dimers of peptides containing amino acid residues that are better at promoting phase separation, such as tyrosine and arginine, have melting peaks at higher temperature in their heat capacity compared to phenylalanine and lysine, respectively. This observation correlates with previous work on the same uncapped hexapeptide monomers modeled using atomistic potential. For oligomers, we compare the variation in monomer conformations with radial distance and observe trends for selected angles calculated for each monomer. The LAMMPS interfaces to the GMIN and OPTIM programs for landscape exploration offer new opportunities to investigate larger systems and provide access to the coarse-grained potentials implemented within LAMMPS. [ABSTRACT FROM AUTHOR]

We explore the large-scale behavior of a stochastic model for nanoparticle growth in an unusual parameter regime. This model encompasses two types of reactions: nucleation, where n monomers aggregate to form a nanoparticle, and growth, where a nanoparticle increases its size by consuming a monomer. Reverse reactions are disregarded. We delve into a previously unexplored parameter regime. Specifically, we consider a scenario where the growth rate of the first newly formed particle is of the same order of magnitude as the nucleation rate, in contrast to the classical scenario where, in the initial stage, nucleation dominates over growth. In this regime, we investigate the final size distribution as the initial number of monomers tends to infinity through extensive simulation studies utilizing state-of-the-art stochastic simulation methods with an efficient implementation and supported by high-performance computing infrastructure. We observe the emergence of a deterministic limit for the particle's final size density. To scale up the initial number of monomers to approximate the magnitudes encountered in real experiments, we introduce a novel approximation process aimed at faster simulation. Remarkably, this approximating process yields a final size distribution that becomes very close to that of the original process when the available monomers approach infinity. Simulations of the approximating process further support the conjecture of the emergence of a deterministic limit. [ABSTRACT FROM AUTHOR]

An accurate description of the long-range (LR) interaction is essential for understanding the collision between cold or ultracold molecules. However, to our best knowledge, there lacks a general approach to construct the intermolecular potential energy surface (IPES) between two arbitrary molecules and/or atoms in the LR region. In this work, we derived analytical expressions of the LR interaction energy, using the multipole expansion of the electrostatic interaction Hamiltonian and the non-degenerate perturbation theory. To make these formulae practical, we also derived the independent Cartesian components of the electrostatic properties, including the multipole moments and polarizabilities, of the monomer for a given symmetry using the properties of these components and the group-theoretical methods. Based on these newly derived formulae, we developed a FORTRAN program, namely ABLRI, which is capable of calculating the interaction energy between two arbitrary monomers both in their non-degenerate electronic ground states at large separations. To test the reliability of this newly developed program, we constructed IPESs for the electronic ground state of H2O–H2 and O2–H systems in the LR region. The interaction energy computed by our program agreed well with the ab initio calculation, which shows the validity of this program. [ABSTRACT FROM AUTHOR]

We study the dynamics of the end monomers of a real chain confined in a spherical cavity to search for a small target on the cavity surface using Langevin dynamics simulation. The results are compared and contrasted with those of a Rouse chain to understand the influence of excluded volume interactions on the search dynamics, as characterized by the first passage time (FPT). We analyze how the mean FPT depends on the cavity size Rb, the target size a, and the degree of confinement quantified by Rg/Rb, with Rg being the polymer radius of gyration in free space. As a basic finding, the equilibrium distribution of the end monomers of a real chain in a closed spherical cavity differs from that of a Rouse chain at a given Rg/Rb, which leads to the differences between the mean FPTs of real and Rouse chains. Fitting the survival probability S(t) by a multi-exponential form, we show that the S(t) of real chains exhibits multiple characteristic times at large Rg/Rb. Our simulation results indicate that the search dynamics of a real chain exhibit three characteristic regimes as a function of Rg/Rb, including the transition from the Markovian to non-Markovian process at Rg/Rb ≈ 0.39, along with two distinct regimes at 0.39 < Rg/Rb < 1.0 and Rg/Rb > 1.0, respectively, where S(t) exhibits a single characteristic time and multiple characteristic times. [ABSTRACT FROM AUTHOR]

Recent experiments by Brückner et al. [Science 380, 1357 (2023)] have observed an anomalous chain length dependence of the time of near approach of widely separated pairs of genomic elements on transcriptionally active chromosomal DNA. In this paper, I suggest that the anomaly may have its roots in internal friction between neighboring segments on the DNA backbone. The basis for this proposal is a model of chain dynamics formulated in terms of a continuum scaled Brownian walk (sBw) of polymerization index N. The sBw is an extension of the simple Brownian walk model widely used in path integral calculations of polymer properties, differing from it in containing an additional parameter H (the Hurst index) that can be tuned to produce varying degrees of correlation between adjacent monomers. A calculation using the sBw of the mean time τc for chain closure predicts—under the Wilemski–Fixman approximation for diffusion-controlled reactions—that at early times, τc varies as the 2/3 power of N, in close agreement with the findings of the Brückner et al. study. Other scaling relations of that study, including those related to the probability of loop formation and the mean square displacements of terminal monomers, are also satisfactorily accounted for by the model. [ABSTRACT FROM AUTHOR]

Borneol is a natural monoterpene with significant applications in various industries, including medicine and perfumery. It presents several diastereomers with different physical and chemical properties, influenced by their unique structures and interactions with molecular receptors. However, a complete description of its inherent structure and solvent interactions remains elusive. Here, we report a detailed investigation of the gas-phase experimental structures of borneol and isoborneol, along with the description of their microsolvation complexes with the common solvents water and dimethyl sulfoxide. The molecules and complexes were studied using chirped-pulse Fourier transform microwave spectroscopy coupled to a supersonic expansion source. Although three rotamers are potentially populated under the conditions of the supersonic expansion, only one of them was observed for each monomer. The examination of the monohydrated complexes revealed structures stabilized by hydrogen bonds and non-covalent C–H⋯O interactions, with water as the hydrogen bond donor. Interestingly, in the clusters with dimethyl sulfoxide, borneol and isoborneol change their roles acting as donors. We further identified a higher-energy rotamer of the borneol monomer in one of the complexes with dimethyl sulfoxide, while that rotamer was missing in the experiment for the monomer. This observation is not common and highlights a specific position in borneol especially favorable for forming stable complexes, which could have implications in the understanding of the unique physical and chemical properties of the diastereomers. [ABSTRACT FROM AUTHOR]

The electronic and vibrational spectra of the meso-tetrakis(4-sulfonatophenyl)-porphyrins (TSPP) have been studied computationally using the PFD-3B functional with time-dependent density functional theory for the excited states. The calculated UV-vis absorption and emission spectra in aqueous solution are in excellent agreement with the experimental measurements of both H2TSPP−4 (monomer) at high pH and H4TSPP−2 (forming J-aggregate) at low pH. Moreover, our calculations reveal an infrared absorption at 1900 cm−1 in the singlet and triplet excited states that is absent in the ground state, which is chosen as a probe for transient IR absorption spectroscopy to investigate the vibrational dynamics of the excited state. Specifically, the S2 to S1 excited state internal conversion process time, the S1 state vibrational relaxation time, and the lifetime of the S1 excited electronic state are all quantitatively deduced. [ABSTRACT FROM AUTHOR]

The simulation of polymer solutions often requires the development of methods that accurately include hydrodynamic interactions. Resolution on the atomistic scale is too computationally expensive to cover mesoscopic time and length scales on which the interesting polymer phenomena are observed. Therefore, coarse-graining methods have to be applied. In this work, the solvent is simulated using the well-established multi-particle collision dynamics scheme, and for the polymer, different coarse-graining methods are employed and compared against the monomer resolved Kremer–Grest model by their resulting diffusion coefficients. This research builds on previous work [Ruiz-Franco et al., J. Chem. Phys. 151, 074902 (2019)], in which star polymers and linear chains in a solvent were simulated and two different coarse-graining methods were developed, in order to increase computational efficiency. The present work extends this approach to ring polymers and seeks to refine one of the authors' proposed model: the penetrable soft colloid model. It was found that both proposed models are not well suited to ring polymers; however, the introduction of a factor to the PSC model delivers satisfying results for the diffusion behavior by regulating the interaction intensity with the solvent. [ABSTRACT FROM AUTHOR]

Synthetic multiblock copolymers are an interesting class of polymeric chains and have emerged as promising materials to mimic the function of complex biomolecules. In this work, we use Wang–Landau sampling to study sequences of multiblock ( A n B n ) m copolymers on the simple cubic lattice, where n represents the block length and m represents the number of blocks. We first compare to the thermodynamic and structural properties of four sequences previously studied in the continuum [W. Wang et al., J. Chem. Phys. 141, 244907 (2014)] to observe the differences that arise during the collapse process. We then focus on the structural transitions that occur at temperatures below the coil-to-globule transition in the lattice. Moreover, by studying additional sequences, we detail the relationship between the block length, number of blocks, and, thus, overall polymer length with respect to said structural transitions. Finally, we observe how the formation and shape of a ground state core of the more strongly interacting monomer type affect the procession of structural changes that occurs as temperature increases. [ABSTRACT FROM AUTHOR]

The network structure and reactivity of suitable restoration agent consisting of silane coupling agents (SCAs) of the brittle walls of a cultural heritage site located underground in a desert area in Egypt were investigated using 1H pulsed nuclear magnetic resonance (pulse NMR). It should possess both high coagulation strength and ductility to ensure that it can withstand an earthquake; it should also contain ethoxy rather than methoxy groups, which generate toxic methanol. The solidification rate for the SCA or oligomer with ethoxy groups was lower than those with methoxy groups; however, the final polycondensates showed the same relaxation time (hardness). The difference spectrum was developed newly to analyze the network structure combined higher strength and ductility. The distribution of crosslinking degree of such polycondensates was narrow, and the amount of lower crosslinking degree was small. On the other hand, the distribution was wide in the polycondensates with ductility but lower strength. From the compression tests of model sand solidified with the restoration agent for both methoxy and ethoxy types showed the superior properties combined higher strength and ductility. The pulse NMR experiment was useful for estimating the solidification rate and the network structure. [ABSTRACT FROM AUTHOR]

The development of amphiphiles for sustained drug delivery represents a promising approach in biomedical fields. Polymeric self‐assembly with a hydrophobic core offers plenty of opportunities to encapsulate hydrophobic drugs for facilitating targeted delivery to the specific sites of action. Herein, N‐Boc tryptophan has been used to develop a hydrophobic monomer, Boc‐tryptophan‐HEMA (HBT). The HBT monomer has further been grafted on modified alginic acid through the RAFT technique to synthesize a unique amphiphilic copolymer with fluorescence characteristics. The advanced polymer chromatography demonstrates a narrow distribution curve, signifying the living nature of polymerization. The copolymer has exhibited self‐aggregation behavior with two distinct shapes at two different critical aggregation concentrations (CAC). The concentration‐dependent shape variation has been investigated using FESEM and TEM analyses, further supported by a small‐angle x‐ray scattering analysis. The self‐aggregation behavior of the copolymer facilitates the uptake of a model hydrophobic drug (naproxen) and its release in a sustained manner with varied rates at two different concentrations. [ABSTRACT FROM AUTHOR]

Dental caries is the most widespread form of disease, affecting over 90% of the global population. Amalgam fillings, which have been in use for nearly two centuries, will face an European Union ban by 2025. Although photocomposite fillings are a suitable alternative, health concerns persist because of potential substance release into the oral cavity. This study aimed to evaluate the release of photoinitiator substances and monomers from dental materials into various solvents at different temperatures over 30 days. Cylindrical specimens of the composite resins were submerged in different extraction solutions and incubated at 37 and 50°C. The findings demonstrated that both the extraction solvent and extraction temperature significantly influenced the quantity of leachables (p < 0.05). Furthermore, most leachables were released within the initial days, although some monomers continued to elute for over 30 days. The estimated daily intake was calculated for the worst‐case scenario, confirming the biocompatibility of the composite fillings. The weight loss of dental materials ranged up to 3.5% after 30 days, regardless of the extraction conditions and dental material (p > 0.05). In conclusion, this study contributes to filling several research gaps in the field by addressing the biocompatibility of various dental materials through quantitative and qualitative analyses supported by statistical evaluation. [ABSTRACT FROM AUTHOR]

Recently, the important role of sterically bulky aromatic substituents at the axial position of the metal center for synthesizing high‐performance catalysts were recognized. In this study, a series of α‐diimine nickel complexes with bulky N‐ortho‐aryl substituents were designed and synthesized. The as‐synthesized nickel complexes showed high activities (up to 2.3×107 g ⋅ mol−1 ⋅ h−1) and superior thermostability, giving access to moderately branched polyethylenes (35–86/1000 C) with high molecular weights (up to 197.5×104 g ⋅ mol−1). The polyethylene materials generated by these nickel complexes at 80 °C exhibited outstanding tensile mechanical. In addition, these nickel complexes could also catalyze the copolymerization of ethylene and polar monomer with modest activity (such as undecenoic acid, 10‐undecen‐1‐ol and 6‐chlorohex‐1‐ene), yielding functionalized polyolefin with adjustable molecular weights (6.8–222.9×104 g ⋅ mol−1) and incorporation ratios (0.2–4.3 mol %). [ABSTRACT FROM AUTHOR]

Rose bengal (RB) is a widely used photosensitizer for determining quantum yields of singlet oxygen generation. While it is known to aggregate in polar environments at concentrations above 2 μM, the relationship between RB concentration and singlet oxygen photogeneration remains unclear. This study investigates the shift from monomeric to dimeric RB with increasing concentration and its impact on singlet oxygen generation in D2O‐based solutions and DMPC liposomes. Absorbance maxima for RB were observed at 514 nm (dimer) and 549 nm (monomer), with ionic environments influencing aggregation rates. Singlet oxygen phosphorescence showed non‐linear dependency above 2 μM, indicating the effects of aggregation. Results suggest that RB concentrations should be kept at 1 μM or lower in photochemical studies to avoid aggregation‐related discrepancies in singlet oxygen yield determination. These findings highlight the importance of considering RB aggregation in photochemical research and medical applications. [ABSTRACT FROM AUTHOR]

Existing adsorption materials with drawbacks in the weak organic solvents/oil retention ability, slow adsorption speed and low adsorption capacity for alkanes still hardly meet demands of the application field, especially in emergencies. The copolymerization of the long‐chain alkenes, 1‐octene, with isoprene was designed in this paper to synthesize an adsorption resin (PIOT), instead of acrylate monomers reported in the literature. And trimethylolpropane triacrylate was designed as a crosslinking agent. Results show that the PIOT grows in the form of powders, which are the loose accumulation of nanoflakes with a diameter of about 47.89 ± 11.06 nm. In view of the chain structure and morphology of the PIOT, it can quickly reach the maximum adsorption within 10 s along with a high adsorption capacity for various solvents and kerosene. Even for hexane, the adsorption capacity of the PIOT increases by 345.2% compared with the reported adsorption resin. The oil retention rate of PIOT can be maintained at 86 ± 6% after centrifugation at 1000–3000 rpm for 5–25 min. Compared with commercial activated carbon, the PIOT has outstanding advantages in recycling property and oil retention rate and compared with the reported acrylate adsorption resin, the PIOT has made a great breakthrough in adsorption capacity for alkanes. [ABSTRACT FROM AUTHOR]

Solvatochromism plays a pivotal role in various scientific and technological fields including those that explore molecular interactions, sensing technologies, and organic electronics. Notably, despite their ease of manipulation, direct visualization, and potential for single particle‐based sensing, micro‐sized solid particles have been the focus of a surprisingly low number of solvatochromism investigations. In this study, polydiacetylene (PDA) particles are synthesized and their solvatochromism is investigated at the single particle level using optical laser tweezers‐based methods. The findings reveal that unpolymerized monomers within PDA particles at the water/n‐decane interface undergo dissolution in the n‐decane phase to form internal voids in the particles. This phenomenon leads to structural deformation of the PDA which triggers a solvatochromic response. Studies that integrate this phenomenon with established particle‐based methodologies should provide deeper insights into diverse chromism behaviors and potential applications of solvatochromic materials. [ABSTRACT FROM AUTHOR]

Polymeric carbon nitride (CN) has emerged as a promising photoanodic material in water‐splitting photoelectrochemical cells (PEC). However, the current deposition methods of CN layers on substrates usually include a long heating process at 500−550 °C, which might cause sublimation or decomposition of the CN monomers and destruction of the substrate, leading to a nonuniform CN film. Herein, a simple, fast, and scalable energy‐economic procedure to synthesize homogenous CN films is introduced. The predesigned CN monomers film is subjected for several minutes to higher temperatures than the standard calcination procedure. The short heating process allows the formation of a uniform CN layer, with excellent contact with the substrate and good activity as a photoanode in PEC. The optimal CN photoanode reaches photocurrent densities of ≈200 μA cm−2 at 1.23 versus reversible hydrogen electrode in neutral and acidic solutions and 120 μA cm−2 in a basic solution. [ABSTRACT FROM AUTHOR]

Alginate is a brown seaweed-based linear polysaccharide of D – mannuronic acid and L – guluronic acid residues. Hydrolysis products of the polysaccharide, specifically oligosaccharides, have been receiving increasing interest, due to their significant bioactivity and potential utilisation routes. The bioactivity of alginate oligosaccharides is closely linked to structural characteristics, namely: molecular weight, degree of polymerisation, and ratio of the monomers (the M/G ratio). Hence, potential applications (such as utilisation as a biostimulant fertilizer) depend on these parameters. This review focuses on recent advances in producing alginate oligosaccharides using chemical or enzymatic methods. The literature survey includes utilisation of these methods at both laboratory and industrial scale. For the chemical methods, we assessed the standard laboratory scale procedures of alginate oligosaccharide production, the potential of scaling up to an industrial level, and the subsequent challenges. For the enzymatic route, we provide an overview of alginate lyases and the application perspectives of enzymatic hydrolysis of alginate. [ABSTRACT FROM AUTHOR]

A series of novel side-chain liquid crystalline (SCLC) copolymers were synthesized by attaching two distinct mesogenic units, namely a chiral cholesteryl-based monomer (M1) and an achiral biphenyl-based monomer (M2), to a poly(3-mercaptopropylmethylsiloxane) (PMMS) backbone via thiol-ene click chemistry. The influence of side chain composition on the self-assembly behavior and phase structures of these SCLC copolymers was systematically investigated using different instrument. Results indicate that three distinct liquid crystalline phases and four unique molecular configurations were identified within the polymer series, with the emergence of the liquid crystalline phase being a synergistic outcome of the two distinct side chains. This study underscores the critical influence of side chain dimensions, rigidity, and spatial volume on the self-assembly structures and phase characteristics of liquid crystalline polymers, providing valuable insights for the rational design and development of advanced functional materials with tailored properties. [ABSTRACT FROM AUTHOR]

The preparation of three metal (Ag(I) and Hg(II)) complexes based on bis‐carbene ligands and correlative three precursors H2Ln·(PF6)2 (n = 1–3) were reported. In each cationic moiety of complexes 1 and 2 and the monomer of complex 3, two Ag+ (or Hg2+) ions and two Ln (n = 1–3) formed one 36‐membered macrometallocycle. There existed π–π interactions between two naphthalenes in each cationic moiety of 1 and 2. The monomers of 3 were connected together through HgO bonds to form 1D chain. In the crystal packings of 1–3, two‐dimensional and three‐dimensional supramolecular structures were formed through CH˙˙˙π contacts and CH˙˙˙F H bonds. Additionally, the recognition capacity of 1 for H2PO4− was studied via fluorescence spectra, UV/Vis spectra, HRMS, 1H NMR titrations, and infrared (IR) spectra. [ABSTRACT FROM AUTHOR]

A new cadmium complex with a flexible imidazolinethione ligand has been successfully synthesized. The ligand acts as a bidentate chelating molecule, resulting in the structure being a monomer. In this monomer, cadmium has an octahedral geometry coordinated by four sulfur atoms from two mbit ligands where mbit = 3,3'-methylenebis(1-methyl-1,3-dihydro-2H-imidazole-2-thione) and two oxygen atoms from the DMF molecules. The $ \textrm{ClO}_4^ - $ ClO 4 − anions are uncoordinated and neutralize the positive charge of the cationic complex. The title complex has a good capacity for adsorbing several organic dyes from pollutant solutions. [ABSTRACT FROM AUTHOR]

Polyvinyl chloride (PVC) is the world's third-most widely manufactured thermoplastic, but has the lowest recycling rate. The development of PVC-like plastics that can be depolymerized back to monomer contributes to a circular plastic economy, but has not been accessed. Here, we develop a series of chemically recyclable plastics from the reversible copolymerization of cyclic anhydride with chloral. The copolymerization is highly efficient through the anionic or cationic mechanism under mild conditions, yielding polyesters with tunable structure and properties from multiple commercial monomers. Notably, these polyesters manifest mechanical properties comparable to PVC and polystyrene. Meanwhile, such polyesters are flame-retardant like PVC due to high chloride content. Of significance, these polyesters can be depolymerized back to starting monomers at high temperatures owing to the reversibility of the copolymerization, leading to a circular economy. Overall, the readily available monomers, simple synthesis, advantageous performance, and practical recyclability make the polymers promising for applications. The development of PVC-like plastics that can be depolymerized back to monomer contributes to a circular plastic economy but remains understudied. Here, the authors develop a series of chemically recyclable plastics from the reversible copolymerization of cyclic anhydride with chloral. [ABSTRACT FROM AUTHOR]

In this study, a pullulan hydrogel is grafted by poly(N-vinylimidazole) (PNVI) in a heterogeneous acidic medium under a nitrogen atmosphere for Methyl Orange (MO) and Acid Green 25 (AG25) dye removal application. The effect of monomer concentration as a significant parameter for grafting yield is investigated thoroughly, and it is demonstrated that 189% grafting yield of PNVI grafted onto epichlorohydrin crosslinked pullulan (pullulan-ECH-graft-PNVI) can be obtained under proper conditions. Equilibrium water absorption capacity values reveal the pH-responsivity of pullulan-ECH-graft-PNVI hydrogels (6000%) as compared to the epichlorohydrin crosslinked pullulan (pullulan-ECH) hydrogel (1000%) counterpart. Further characterization of the samples was performed by Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), and X-ray diffraction (XRD). Adsorption of MO and AG25 on pullulan-ECH-graft-PNVI samples was studied at various pH, dye concentration, and time. The optimal adsorption pH value was measured at pH 3.0 with an adsorption capacity of 36.6 mg MO/g adsorbent and 5.72 mg AG25/g adsorbent. Isotherms and kinetic studies describe the adsorption profiles of the samples. The adsorption trends of the samples best fit the Freundlich model, which supports heterolayer dye adsorption and surface heterogeneity. Adsorption kinetic results indicate a pseudo-second-order kinetic model, which shows chemisorption. [ABSTRACT FROM AUTHOR]

The production of organic silicon (Si) monomer from metallurgical-grade silicon (MG–Si) is hindered by CaSi2, leading to a decreased yield of (CH3)2SiCl2. Therefore, strict control of CaSi2 content is essential. However, the existing MG–Si oxidation refining process fails to prevent the precipitation of FeSi2 and the reduction of Si8Al6Fe4Ca content, while simultaneously decreasing CaSi2 content. To address this issue, a novel method of adjusting aluminum (Al) content in MG–Si to reduce CaSi2 content and increase Si2Al2Ca or Si8Al6Fe4Ca content was proposed. The results indicated that the impurity ratio in MG–Si directly influenced the type of precipitating intermetallics. Specifically, when m(Al/Ca) < 1.35, CaSi2, FeSi2, and Si2Al2Ca were present. When 1.35 < m(Al/Ca) < 1.35 + 0.48 m(Fe/Ca), FeSi2, Si2Al2Ca, and Si8Al6Fe4Ca were encountered. Additionally, when the Al content m(Al/Ca) > 1.35 + 0.48 m(Fe/Ca), only Si2Al2Ca and Si8Al6Fe4Ca were observed. Upon adjusting the Al content in high-Ca MG–Si to m(Al/Ca) > 1.35, CaSi2 was effectively eliminated. Furthermore, within the experimental range, the average content of Si8Al6Fe4Ca precipitates increased from 12.84 to 37.94 wt pct after adjusting the Al content in the melt, representing a maximum increase of ~ 2.95 times. This study successfully elucidated the regulation of calcium (Ca)-containing intermetallics in high-Ca MG–Si, paving the way for the production of high-quality MG–Si raw materials for silicone monomer synthesis. [ABSTRACT FROM AUTHOR]

As in natural cytoskeletons, the cooperative assembly of fibrillar networks can be hosted inside compartments to engineer biomimetic functions, such as mechanical actuation, transport, and reaction templating. Coacervates impose an optimal liquid-liquid phase separation within the aqueous continuum, functioning as membrane-less compartments that can organise such self-assembling processes as well as the exchange of information with their environment. Furthermore, biological fibrillation can often be controlled or assisted by intracellular compartments. Thus, the reconstitution of analogues of natural filaments in simplified artificial compartments, such as coacervates, offer a suitable model to unravel, mimic, and potentially exploit cellular functions. This perspective summarises the latest developments towards assembling fibrillar networks under confinement inside coacervates and related compartments, including a selection of examples ranging from biological to fully synthetic monomers. Comparative analysis between coacervates, lipid vesicles, and droplet emulsions showcases the interplay between supramolecular fibres and the boundaries of the corresponding compartment. Combining inspiration from natural systems and the custom properties of tailored synthetic fibrillators, rational monomer and compartment design will contribute towards engineering increasingly complex and more realistic artificial protocells. The bottom-up reconstitution of natural filaments within simplified artificial cellular compartments, such as coacervates, offer a model to study, mimic, and potentially exploit cellular functions. Here, the authors summarize the latest developments towards assembling confined fibrillar networks inside coacervates and related compartments, including a selection of examples ranging from biological to fully synthetic building blocks. [ABSTRACT FROM AUTHOR]

Alkaline‐stable, highly conductive anion exchange membranes (AEMs) are attentively expected solid polymer electrolytes that contribute to achieving high performance and durability for anion exchange membrane water electrolyzers (AEMWEs). The technical challenges of AEMs mainly stem from the degradation of the polymer backbones, side chains, and anchoring cationic groups. Herein, new and stable AEMs (QTAF) are designed using 3,3′′‐dichloro‐2′,5′‐bis(trifluoromethyl)‐1,1′:4′,1′′‐terphenyl (TFP) monomers as the hydrophobic component incorporated into the polyphenylene backbone and 3,3′‐(2,7‐dichloro‐9H‐fluorene‐9,9‐diyl)bis(N,N‐dimethylpropane‐1‐amine) (AF) monomers as the hydrophilic component. After tuning the copolymer composition, the highest hydroxide ion conductivity (168.7 mS cm−1 at 80 °C) is achieved with the QTAF‐3.0 membrane. The QTAF‐3.0 membrane survives in harsh alkaline conditions (8 M KOH solution, 80 °C), with high conductivity (75.8 mS cm−1) after 810 h. A water electrolysis cell with QTAF‐3.0 membrane and non‐noble Ni0.8Co0.2O anode catalyst operates stably at a constant current density (1.0 A cm−2) for 1000 h with a negligible voltage increase rate of 1.1 µV h−1 after the initial voltage increase. The water electrolysis performance of the post‐tested QTAF‐3.0 cell is 1.83 V, only a 6.4% increase from the initial performance at 2.0 A cm−2, suggesting the high potential of the QTAF‐3.0 membrane for practical AEMWE applications. [ABSTRACT FROM AUTHOR]

This theoretical study reveals the origin of regioselectivity of a polar vinyl monomer (PVM) in the copolymerization of different PVMs with ethylene by the DBB–Ipty α-diimine Pd(II) complex with a bulky dibenzobarrelene (DBB) backbone and bulky axial pentiptycenyl (Ipty) substituents. DFT calculations were employed to investigate the regioselectivity of the insertion of three acrylate monomers (CH2＝CHCOOR: R = H, AA; R = Me, MA; and R = tBu, tBA) catalyzed by the DBB–Ipty Pd(II) complex. The results indicate that with the increase of the size of the monomer substituents (AA < MA < tBA), greater repulsion occurs between the monomer and the catalyst, leading to a gradual preference for 1,2-insertion. By stepwise regression analysis, a multivariate linear regression (MLR) model on the factors affecting regioselectivity was constructed. Coefficient analysis of the MLR equation reveals that the buried volume (%Vbur) of the monomer and the NBO charge on the vinyl C1 atom (NBOC1) significantly affect the regioselectivity of monomer insertion. Specifically, the bigger %Vbur tends to 1,2-insertion of the PVM, while the higher NBOC1 is apt to 2,1-insertion. Through the contribution values of the coefficients in the equation, we can derive that steric hindrance is the primary factor of regioselectivity, while the electronic effect plays a secondary role. [ABSTRACT FROM AUTHOR]

Compared to imine covalent organic frameworks (COFs), the superior stability of amine‐linked COFs renders them more suitable for long‐term harsh real‐world environments. Their numerous amine sites can serve as functional groups or be subjected to post‐modification to further enhance the performance of the material. However, the assortment and abundance of amine‐linked COFs via currently lacking due to restricted monomer varieties and synthetic methods. Herein, this study presents an innovative approach for synthesizing quinone‐amine‐linked COFs by directly combining 2,5‐dihydroxy‐1,4‐benzoquinone (DHBQ) with various amine monomers and introduce a novel photocatalyst, DHBQ‐TAPP‐COF, specifically tailored to efficiently reduce uranium in harsh environments. DHBQ‐TAPP‐COF features a unique donor–acceptor structure, with the DHBQ units serving as acceptors because they contain abundant oxygen atoms that facilitate metal ion coordination, thereby enhancing charge carrier separation, carrier utilization, and uranium reduction efficiency. The quinone‐amine linkages offer improved stability, extended π‐conjugation, heightened local polarity, and conductivity, which enable efficient carrier transfer within the material and thus enhance the overall performance of the uranium photocatalyst. The proposed photocatalyst can efficiently reduce U(VI) without sacrificial agents or decomposition to precipitate UO2 at a recovery rate exceeding 98%. This catalyst provides an efficient and convenient strategy for the stable and high‐performance photocatalytic reduction of uranium. [ABSTRACT FROM AUTHOR]

Amino‐acid‐derived polyzwitterions and polybetaines (PBs) are two promising alternatives to non‐ionic polymers, for example, to increase tumor permeability. In this study, amino‐acid‐derived polyzwitterions are synthesized and a strategy to quarternize the amine in the side chain functional group is developed to combine the advantages of both types. The functional monomer is polymerized via reversible addition−fragmentation chain‐transfer polymerization for which a kinetic study is performed. Further, the impact of the permanent positive charge on amino‐acid‐derived polyzwitterions is studied based on two zwitterionic polymers obtained via post‐polymerization modification (PPM) of Poly(N‐acryloxysuccinimide) to allow good comparison between methylated and non‐methylated polymers. Circular dichroism shows that the stereocenter remains intact during PPM. pH titration and ζ‐potential measurements show that the methylated polymer has a negative ζ‐potential over the measured pH range and, therefore, the polymer remains zwitterionic over a broader pH range than its non‐methylated equivalent. Both polymers are well tolerated by mammalian cells up to concentrations of 1 mg mL−1. The study introduces a path to a new polymer class that combines the advantages of both PBs and amino‐acid‐derived polyzwitterions and highlights the impact a permanent charge has on the physiochemical properties. [ABSTRACT FROM AUTHOR]

Photomediated reversible addition fragmentation chain transfer (RAFT) step‐growth polymerization is performed using a trithiocarbonate‐based chain transfer agent (CTA) and acrylate‐based monomers both with and without a photocatalyst. The versatility of photo‐mediated RAFT step‐growth is demonstrated by one‐pot synthesis of a graft copolymer via sequential monomer addition. Furthermore, oxygen‐tolerant photo‐mediated RAFT step‐growth is demonstrated, facilitated by the appropriate selection of photocatalyst and solvent pair (zinc tetraphenyl porphyrin [ZnTPP] and dimethyl sulfoxide [DMSO]), enabling ultralow volume polymerization under open‐air conditions. [ABSTRACT FROM AUTHOR]

Amino acid‐based poly(ester urea)s are an attractive class of polymers that are of interest for a variety of biomedical applications. Generally, amino acid‐based poly(ester urea)s are prepared by polymerization of diamines, which are obtained from the corresponding amino acids and aliphatic diols. This article presents an alternative synthetic strategy that uses diamine monomers obtained from aromatic, 4‐hydroxycinnamic acid‐derived diols. A library of structurally related diamine monomers has been prepared by coupling l‐leucine to 4‐hydroxycinnamic acid‐based diols that incorporate alkyl spacers of different lengths. The exploration of 4‐hydroxycinnamic acid as a building block is interesting as it can be obtained from various biological resources, such as for example lignin, and thus provides an opportunity to take advantage of (under‐utilized) bio‐based renewables for the design of new polymer materials. These diamine monomers can be copolymerized in a solvent‐free, one‐pot, two‐step process using dimethyl carbonate as an environmentally sustainable reagent to afford amino acid‐based aromatic poly(ester urea) homo‐ and copolymers with thermal properties that can be tuned by varying the chemical structure of the diamine monomer, or via copolymerization of two different monomers. [ABSTRACT FROM AUTHOR]

The catalytic pyrolysis of guaiacol-based lignin monomers, vanillin, syringol, and eugenol over commercial HZSM-5 has been investigated using operando Photoelectron Photoion Coincidence (PEPICO) spectroscopy to unveil the reaction mechanism by detecting reactive intermediates, such as quinone methides and ketenes, and products. Vanillin shares the decomposition mechanism with guaiacol due to prompt and efficient decarbonylation, which allows us to control this reaction leading to a phenol selectivity increase by switching to a faujasite catalyst and decreasing the Si/Al ratio. Syringol first demethylates to 3-methoxycatechol, which mainly dehydroxylates to o- and m-guaiacol. Ketene formation channels over HZSM-5 are less important here than for guaiacol or vanillin, but product distribution remains similar. C3 addition to guaiacol yields eugenol, which shows a more complex product distribution upon catalytic pyrolysis. By analogies to monomers with simplified functionalization, namely allylbenzene, 4-allylcatechol, and 4-methylcatechol, the eugenol chemistry could be fully resolved. Previously postulated reactive semi-quinone intermediates are detected spectroscopically, and their involvement opens alternative pathways to condensation and phenol formation. Allyl groups, produced by dehydroxylation of the β-O-4 bond, may not only decompose via C1/C2/C3 loss, but also cyclize to indene and its derivatives over HZSM-5. This comparably high reactivity leads to an unselective branching of the chemistry and to a complex product distribution, which is difficult to control. Indenes and naphthalenes are also prototypical coke precursors efficiently deactivating the catalyst. We rely on these mechanistic insights to discuss strategies to fine-tune process conditions to increase the selectivities of desired products by enhancing either vanillin and guaiacol or supressing eugenol yields from native lignin. [ABSTRACT FROM AUTHOR]

TBRT and ATRP are orthogonal initiation chemistries used in vinyl polymerisations. Here, we present the first combination of these techniques to readily create high molecular weight branched polyester macroinitiators capable of forming star copolymers from a range of methacrylate monomers. [ABSTRACT FROM AUTHOR]

Plastics redesign for circularity has primarily focused on monomer chemistries enabling faster deconstruction rates concomitant with high monomer yields. Yet, during deconstruction, polymer chains interact with their reaction medium, which remains underexplored in polymer reactivity. Here, we show that, when plastics are deconstructed in reaction media that promote swelling, initial rates are accelerated by over sixfold beyond those in small-molecule analogs. This unexpected acceleration is primarily tied to mechanochemical activation of strained polymer chains; however, changes in the activity of water under polymer confinement and bond activation in solvent-separated ion pairs are also important. Together, deconstruction times can be shortened by seven times by codesigning plastics and their deconstruction processes. [ABSTRACT FROM AUTHOR]

In this study, we designed and synthesized a series of norbornene‐furan functionalized benzoxazine monomers (HPAP‐fa, HPAMP‐fa, and HPTM‐fa) by regulating the bridge length in benzoxazine structure in order to improve the comprehensive performance of norbornene‐furan functionalized benzoxazine system. This research systematically examined the impact of flexible segments on the structural information, polymerization behaviors, thermal stability, and flame retardancy of resulting polybenzoxazines. Initially, the structural characteristics of benzoxazine were confirmed through nuclear magnetic resonance, Fourier‐transform infrared (FT‐IR), and HR‐MS. Subsequently, the polymerization mechanisms of each benzoxazine monomer were investigated utilizing differential scanning calorimeter and in situ FT‐IR analyses. Finally, the thermal stability and flame‐retardant properties were investigated by TGA and micro‐combustion calorimetry measurements. Consequently, HPAP‐fa exhibited the lowest polymerization temperature and the corresponding poly(HPAP‐fa) showed very high thermal stability (Td5 of 392°C and Td10 of 437°C) as well as excellent flame retardancy (HRC of 83.7 J g−1 K−1), which shows a significant improvement compared to poly(HPTM‐fa). As a result, the modulation of bridge segments within the monomer represents a viable approach towards enhancing the holistic efficacy of norbornene‐furan functionalized benzoxazine systems. [ABSTRACT FROM AUTHOR]

The development of epoxy resins is mainly dependent on non-renewable petroleum resources, commonly diglycidyl ether bisphenol A (DGEBA)-type epoxy monomers. Most raw materials of these thermoset resins are toxic to the health of human beings. To alleviate concerns about the environment and health, the design and synthesis of bio-based epoxy resins using biomass as raw materials have been widely studied in recent decades to replace petroleum-based epoxy resins. With the improvement in the requirements for the performance of bio-based epoxy resins, the design of bio-based epoxy resins with unique functions has attracted a lot of attention, and bio-based epoxy resins with flame-retardant, recyclable/degradable/reprocessable, antibacterial, and other functional bio-based epoxy resins have been developed to expand the applications of epoxy resins and improve their competitiveness. This review summarizes the research progress of functional bio-based epoxy resins in recent years. First, bio-based epoxy resins were classified according to their unique function, and synthesis strategies of functional bio-based epoxy resins were discussed, then the relationship between structure and performance was revealed to guide the synthesis of functional bio-based epoxy resins and stimulate the development of more types of functional bio-based epoxy resins. Finally, the challenges and opportunities in the development of functional bio-based epoxy resins are presented. [ABSTRACT FROM AUTHOR]

Glycolysis of poly(ethylene terephthalate) (PET) is a prospective way for degradation of PET to its monomer bis(hydroxyethyl) terephthalate (BHET), providing the possibility for a permanent loop recycling. However, most reported glycolysis catalysts are homogeneous, making the catalyst difficult to recover and contaminating the products. Herein, we reported on the Pd-Cu/γ-Al2O3 catalyst and applied it in the glycolysis of PET as catalyst. The formed structure gave Pd-Cu/γ-Al2O3 a high active surface area, which enabled these micro-particles to work more efficiently. The PET conversion and BHET yield reached 99% and 86%, respectively, in the presence of 5 wt% of Pd-Cu/γ-Al2O3 catalyst within 80 min at 160 °C. After the reaction, the catalyst can be quickly separated by filtration, so it can be easily reused without significant loss of reactivity at least five times. Therefore, the Pd-Cu/γ-Al2O3 catalyst may contribute to an economically and environmentally improved large-scale recycling of PET fiber waste. [ABSTRACT FROM AUTHOR]

Selective polymerization with heterogeneous catalysts from mixed monomers remains a challenge in polymer synthesis. Herein, we describe that nano-sized zinc glutarate (ZnGA) can serve as a catalyst for the selective copolymerization of phthalic anhydride (PA), propylene oxide (PO) and lactide (LA). It was found that the ring-opening copolymerization (ROCOP) of PA with PO occurs firstly in the multicomponent polymerization. After the complete consumption of PA, the ring-opening polymerization (ROP) of LA turns into the formation of block polyester. In the process, the formation of zinc–alkoxide bonds on the surface of ZnGA accounts for the selective copolymerization from ROCOP to ROP. These results facilitate the understanding of the heterogeneous catalytic process and offer a new platform for selective polymerization from monomer mixtures. [ABSTRACT FROM AUTHOR]

Ethylene-propylene-diene monomer (EPDM) is a key engineering material; its mechanical characterization is important for the safe use of the material. In this paper, the coupled effects of thermal degradation temperature and time on the tensile mechanical behavior of EPDM rubber were investigated. The tensile stress-strain curves of the aged and unaged EPDM rubber show strong nonlinearity, demonstrating especially rapid stiffening as the strain increases under small deformation. The popular Mooney–Rivlin and Ogden (N = 3) models were chosen to fit the test data, and the results indicate that neither of the classical models can accurately describe the tensile mechanical behavior of this rubber. Six hyperelastic constitutive models, which are excellent for rubber with highly nonlinearity, were employed, and their abilities to reproduce the stress-strain curve of the unaged EPDM were assessed. Finally, the Davis–De–Thomas model was found to be an appropriate hyperelastic model for EPDM rubber. A Dakin-type kinetic relationship was employed to describe the relationships between the model parameters and aging temperature and time, and, combined with the Arrhenius law, a thermal aging constitutive model for EPDM rubber was established. The ability of the proposed model was checked by independent testing data. In the moderate strain range of 200%, the errors remained below 10%. The maximum errors of the prediction results at 85 °C for 4 days and 100 °C for 2 and 4 days were computed to be 17.06%, 17.51% and 19.77%, respectively. This work develops a theoretical approach to predicting the mechanical behavior of rubber material that has suffered thermal aging; this approach is helpful in determining the safe long-term use of the material. [ABSTRACT FROM AUTHOR]

5,18‐Dimesitylorangarin and its BF2 complex were synthesized by double SNAr reaction of 3,5‐dibromo‐BODIPY with 2‐pyrrolydipyrrin as the first examples of meso‐aryl‐substituted orangarin. These orangarins, delineated as [20]pentaphyrin(1.0.1.0.0), are strongly antiaromatic but rather stable. The free base orangarin was coupled by oxidation with MnO2 to give a 11,11′‐linked dimer, a cyclooctatetraene(COT)‐centered trimer, and a spiro‐trimer. Fused COT‐centered 3H‐orangarin dimer was oxidized to the corresponding 2H‐orangarin dimer, which was further coupled to give a triply COT‐centered 2H‐orangarin tetramer. 3H‐Orangarin oligomers are all antiaromatic as evinced by extremely low‐field‐shifted 1H NMR signals of the inner NH and ill‐defined absorption spectra with broad tails. In contrast, COT‐centered 2H‐orangarin dimer and tetramer show moderately low‐field‐shifted NH signals and intense NIR absorbance over 900 nm, suggesting effective π‐conjugation through the COT bridge and almost non‐antiaromatic character. These orangarin oligomers exhibit many reversible redox potentials owing to the intramolecular electronic interactions. Regardless of the different aromatic characters, all the orangarin monomers and oligomers exhibit very rapid excited‐state decays. [ABSTRACT FROM AUTHOR]

This study presents the preparation of a long‐chain amine solution, employing the concept of urea‐formaldehyde synthesis. We also investigate the performance shifts in the cured product post‐urea addition. The Urea‐F curing agent is prepared by reacting EDA/DETA/TETA/TEPA, formaldehyde, and urea, and crosslinked with bisphenol A epoxy resin (E51). The crosslinking agent solves the problem of urea not being suitable for curing epoxy resin, and it improves the problem of low mechanical strength of traditional amine crosslinked epoxy resin cured materials. The cured product underwent evaluation through acid and alkali resistance solution measurement and mechanical and thermal tests. The results show enhanced heat resistance in the cured product, with its maximum thermal decomposition rate exceeding 350°C. The cured products have better mechanical properties than the amine monomers, with enhanced bending strength and superior acid–base solution resistance. The scanning electron microscopy micrograph indicates that the cured product fractures have a tight internal structure. [ABSTRACT FROM AUTHOR]

The development of innovative synthetic strategies to create functional polycaprolactones is highly demanded for advanced material applications. In this contribution, we reported a facile synthetic strategy to prepare a class of CL‐based monomers (R‐TO) derived from epoxides. They readily polymerize via well‐controlled ring‐opening polymerization (ROP) to afford a series of polyesters P(R‐TO) with high molecular weight (Mn up to 350 kDa). Sequential addition copolymerization of MTO and L‐lactide (L‐LA) allowed to access of a series of ABA triblock copolymers with composition‐dependent mechanical properties. Notably, P(L‐LA)100‐b‐P(MTO)500‐b‐P(L‐LA)100 containing the amorphous P(MTO) segment as a soft midblock and crystalline P(L‐LA) domain as hard end block behaved as an excellent thermoplastic elastomer (TPE) with high elongation at break (1438±204 %), tensile strength (23.5±1.7 MPa), and outstanding elastic recovery (>88 %). [ABSTRACT FROM AUTHOR]

Epidermal patches utilized for the transduction of biopotentials and biomechanical signals are pivotal in wearable health monitoring. However, the shortcomings, such as inferior conformal ability, deficient adhesion, and motion artifacts, severely impede the bioelectrodes from perceiving stable and superior‐quality physiological signals. Herein, a polymer epidermal patch possessing a spontaneous Janus structure is facilely prepared through itaconic acylhydrazine (IAH) induced gradient polymerization. The solubility discrepancy of the monomers in IAH authorized the Janus structure with distinct adhesion properties on each side. Moreover, the hydrogen bond network constructed by IAH confers the polymer with a high degree of skin compliance, enabling dynamic and stable mechanical properties to withstand complex monitoring environments. By integrating skin‐like softness (Young's modulus ≈0.16 MPa), robust adhesion (35 kPa), and high signal‐to‐noise ratio (32 dB), this epidermal patch displays exceptional elasticity within the physiological activity spectrum, provides swift electrical and mechanical self‐recovery capabilities, and resists interference in dynamic signal monitoring (deformation, compression, humidity, etc.). By demonstrating multifaceted applications for Electrocardiogram recording under diverse disturbances, the epidermal patch profiles a promising noninvasive, enduring wearable bioelectronic interface with immunity to interference. [ABSTRACT FROM AUTHOR]

During the construction of supramolecular polymers of smaller nanoparticles/nanoclusters bearing hierarchy and homochirality, the mechanism understanding via intuitive visualization and precise cross-scale chirality modulation is still challenging. For this goal, a cooperative self-assembly strategy is here proposed by using ionic complexes with uniform chemical composition comprising polyanionic nanocluster cores and surrounded chiral cationic organic components as monomers for supramolecular polymerization. The single helical polymer chains bearing a core-shell structure at utmost length over 20 μm are demonstrated showing comparable flexibility resembling covalent polymers. A nucleation-elongation growth mechanism that is not dealt with in nanoparticle systems is confirmed to be accompanied by strict chiral self-sorting. A permeable membrane prepared by simple suction of such supramolecular polymers displays high enantioselectivity (e.e. 98% after four runs) for separating histidine derivatives, which discloses a benefiting helical chain structure-induced functionalization for macroscopic supramolecular materials in highly efficient racemate separation. Understanding the mechanism for supramolecular polymer assembly from nanoclusters bearing hierarchy and homochirality is challenging. Here, the authors report a cooperative self-assembly strategy using ionic complexes with chiral surfactants through a nucleation-elongation growth mechanism with chiral self-sorting and prepare a permeable membrane for the separation of histidine derivatives. [ABSTRACT FROM AUTHOR]

While a large number of chemically recyclable thermoplastics have been developed in recent years, technologically important thermoplastic elastomers (TPEs) that are not only bio-based and fully recyclable but also exhibit mechanical properties that can rival or even exceed those petroleum-based, non-recyclable polyolefin TPEs are critically lacking. The key challenge in developing chemically circular, bio-based, high-performance TPEs rests on the complexity of TPE's block copolymer (BCP) structure involving block segments of different suitable monomers required to induce self-assembled morphologies responsible for performance as well as the control and monomer compatibility in their synthesis and the selectivity in their depolymerization. Here we demonstrate the utilization of bio-sourced δ-valerolactone (δVL) and its simple α-alkyl-substituted derivatives to produce all δVL-based polyester tri-BCP TPEs, which exhibit not only complete (closed-loop) chemical recyclability but also excellent toughness that is 2.5–3.8 times higher than commercial polyolefin-based TPEs. The visualized cylindrical morphology formed via crystallization-driven self-assembly in the new all δVL tri-BCP is postulated to contribute to the excellent TPE property. While a large number of chemically recyclable thermoplastics have been developed in recent years, technologically bio-based and fully recyclable thermoplastic elastomers (TPEs) with excellent mechanical properties are lacking. Here the authors demonstrate an all δvalerolactone-based polyester tri-BCP TPEs, which exhibit not only closed-loop chemical recyclability but also exceptional toughness. [ABSTRACT FROM AUTHOR]

Recent progress regarding the copolymerization of norbornene with various polar α‐olefins catalyzed by nickel and palladium catalysts is reviewed here with special attention paid to the diverse catalyst frameworks, polar monomer scopes as well as polymer microstructures. Both the influences of steric effect and electron property of ligand substituents and the type of polar monomers on the catalytic behaviors (activity, stability, polarity tolerance, etc.) and the polymer microstructures (molecular weight and distribution, comonomer contents, etc.) have been summarized. The introduction of noncyclic‐olefins, such as polar vinyl monomers, polar higher α‐olefins, and polar styrenes, into rigid cyclic‐based polynorbornene chain resulted in significant modifications on the polarity, compatibility, thermostability, processibility, transparency, and many other properties of the material, which has also been discussed in the review. The contents of this review have been classified according to the type of polar monomers involved in the norbornene copolymerization, and each section included nickel and palladium catalysts bearing different ligand structures, which will be meaningful for the development of new types of catalysts and new families of norbornene‐based cyclic olefin copolymer materials in the future. [ABSTRACT FROM AUTHOR]

Nature uses complex self‐assembly pathways to access distinct functional non‐equilibrium self‐assemblies. This remarkable ability to steer same set of biomolecules into different self‐assembly states is done by avoiding thermodynamic pit. In synthetic systems, on demand control over 'Pathway Complexity' to access self‐assemblies different from equilibrium structures remains challenging. Here we show versatile non‐equilibrium assemblies of the same monomer via alternate assembly pathways. The assemblies nucleate using non‐classical or classical nucleation routes into distinct metastable (transient hydrogels), kinetic (stable hydrogels) and thermodynamic structures [(poly)‐crystals and 2D sheets]. Initial chemical and thermal inputs force the monomers to follow different assembly pathways and form soft‐materials with distinct molecular arrangements than at equilibrium. In many cases, equilibrium structures act as thermodynamic sink which consume monomers from metastable structures giving transiently formed materials. This dynamics can be tuned chemically or thermally to slow down the dissolution of transient hydrogel, or skip the intermediate hydrogel altogether to reach final equilibrium assemblies. If required this metastable state can be kinetically trapped to give strong hydrogel stable over days. This method to control different self‐assembly states can find potential use in similar biomimetic systems to access new materials for various applications. [ABSTRACT FROM AUTHOR]

The investigation of impact of through‐space/through‐bond electronic interaction among chromophores on photoexcited‐state properties has immense potential owing to the distinct emergent photophysical pathways. Herein, the photoexcited‐state dynamics of homo‐sorted π‐stacked aggregates of a naphthalenemonoimide and perylene‐based acceptor‐donor (NI‐Pe) system and a fork‐shaped acceptor‐bisdonor (NI‐Pe2) system possessing integrally stacked peri‐substituted donors was examined. Femtosecond transient absorption (fsTA) spectra of NI‐Pe monomer recorded in chloroform displayed spectroscopic signatures of the singlet state of Pe; 1Pe*, the charge‐separated state; NI−⋅‐Pe+⋅, and the triplet state of Pe; 3Pe*. The examination of ultrafast excited‐state processes of NI‐Pe aggregate in chloroform revealed faster charge recombination (τCRa ${{\tau }_{CR}^{a}}$ =1.75 ns) than the corresponding monomer (τCRm ${{\tau }_{CR}^{m}}$ =2.46 ns) which was followed by observation of a broad structureless band attributed to an excimer‐like state. The fork‐shaped NI‐Pe2 displayed characteristic spectroscopic features of the NI radical anion (λmax~450 nm) and perylene dimer radical cation (λmax~520 nm) upon photoexcitation in non‐polar toluene solvent in the nanosecond transient absorption (nsTA) spectroscopy. The investigation highlights the significance of intrinsic close‐stacked arrangement of donors in ensuring a long‐lived photoinduced charge‐separated state (τCR ${{\tau }_{CR}}$ =1.35 μs) in non‐polar solvents via delocalization of radical cation between the donors. [ABSTRACT FROM AUTHOR]

AbstractPoly(acrylonitrile-co-styrene) microspheres are utilized in several applications due to their superior mechanical properties, excellent chemical stability, and tunable surface modification. In this work, poly(acrylonitrile-co-styrene) microspheres were synthesized in ethyl acetate usingreflux precipitation polymerization. The average particle size and morphology of microspheres were carefully measured to investigate the responding influencing factors. In the growth process of these microspheres, the average particle size of poly(AN-co-St) microspheres changed a little after 180 min. However, the yield of the microspheres continued to increase until 420 min. The properties of the solvents had a significant impact on both the average particle size and the morphology of the poly(AN-co-St) microspheres. The concentrations of the initiator and the cross-linker have minimal effect on the average particle size of poly(AN-co-St) microspheres. By controlling the monomer content at 25 wt%, the yield of these microspheres could reach 82%. The method is straightforward to operate andthe prepared microspheres exhibithigh sphericity and uniformity. As a result, it shows great promise for thepreparation of submicron poly(AN-co-St) microspheres. [ABSTRACT FROM AUTHOR]

Visible light‐induced polymerization, as a promising and green strategy, is showing great potential in preparing value‐added polymers. Herein, a visible light photoredox catalysis method is reported to afford a library of polyamide with high yields (up to 99%) and high molecular weights (Mws) (up to 71 000 g mol−1). Dithioacids and diamines as the monomers, and 9‐mesityl‐10‐methylacridinium tetrafluoroborate (Mes‐Acr‐MeBF4) as the organic photoredox catalyst give the polyamides with structural diversity in air under mild conditions without extra metal, base, or additives. [ABSTRACT FROM AUTHOR]