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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]

This study investigates the behavior of two different mixtures of monomers of polyvinylpyrrolidone (PVP)-based battery binders, polyvinylpyrrolidone:polyvinylidene difluoride (PVP:PVDF) and polyvinylpyrrolidone:polyacrylic acid (PVP:PAA), at graphene and graphite interfaces using classical molecular dynamics simulations. The aim is to identify the best performing monomer binder blend and carbon-based material for the design of battery-optimized energy devices. The PVP:PAA monomer binder blend and graphite are found to have the best interaction energies, densification upon adsorption, and more ordered structure. The adsorption of both monomer binder blends is strongly guided by the higher affinity of PVP and PAA monomeric molecules for the surfaces compared to PVDF. The structure of adsorbed layers of PVP:PVDF monomer binder blend on graphene and graphite develops more quickly than PVP:PAA, indicating faster kinetics. This study complements a previous density functional theory study recently reported by our group and contributes to a better understanding of the nanoscopic features of relevant interfacial regions involving mixtures of monomers of PVP-based battery binders and different carbon-based materials. The effect of a blend of commonly used monomer binders on carbon-based materials is essential for obtaining tightly bound anode and cathode active materials in lithium-ion batteries, which is crucial for designing battery-optimized energy devices. [ABSTRACT FROM AUTHOR]

This note advertises a simple necessary condition for optimality that any list N ↦ vx(N) of computer-generated putative lowest average pair energies vx(N) of clusters that consist of N monomers has to satisfy whenever the monomers interact with each other through pair forces satisfying Newton's "action equals re-action." These can be quite complicated, as, for instance, in the TIP5P model with five-site potential for a rigid tetrahedral-shaped H2O monomer of water, or as simple as the Lennard-Jones single-site potential for the center of an atomic monomer (which is also used for one site of the H2O monomer in the TIP5P model, which in addition has four peripheral sites with Coulomb potentials). The empirical usefulness of the necessary condition is demonstrated by testing a list of publicly available Lennard-Jones cluster data that have been pooled from 17 sources, covering the interval 2 ≤ N ≤ 1610 without gaps. The data point for N = 447 failed this test, meaning the listed 447-particle Lennard-Jones cluster energy was not optimal. To implement this test for optimality in search algorithms for putatively optimal configurations is an easy task. Publishing only the data that pass the test would increase the odds that these are actually optimal, without guaranteeing it, though. [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]

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]

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]

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]

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]

Transport of monomer from droplets to growing latex particles in emulsion polymerization in general is assumed to proceed via diffusion through the aqueous phase. Especially in miniemulsion polymerizations the direct transfer of very hydrophobic species from droplet to droplet is assumed to also proceed via collisions. Amongst the hydrophobic species where this is shown to play a role are monomers, initiators, inhibitors and (catalytic) chain transfer agents. It is well known that the reactor geometry and the stirring speed can have a profound effect on emulsion polymerizations. The 1972 paper of Nomura on the effect of stirring on emulsion polymerization is cited more than 100 times and until today keeps scientists intrigued. Diffusion limitations of monomer going from the droplet into the aqueous phase can occur for very hydrophobic monomers. The alternative route of transport via collisions is often not considered. In this perspective, paper will discuss the evidence for collision based transfer in miniemulsion polymerization and also consider whether collision based monomer transport can play a role in regular emulsion polymerizations. [ABSTRACT FROM AUTHOR]

Supramolecular assemblies with chirality inversion were developed using a co-assembly system comprising solvent monomers and a pyridine-cholesterol gelator. The polarity-dependent chiralities were captured in situ through photopolymerization, enabling the formation of multi-color circularly polarized luminescence films. [ABSTRACT FROM AUTHOR]

The degradation and recycling of waste epoxy resins is an urgent environmental problem, encouraging the use of degradable thermosetting epoxies. In this study, a high-performance thermosetting epoxy resin material that can be easily degraded and recycled was prepared using a low-viscosity and high-activity epoxy monomer, tetrahydrophthalic acid diglycidyl ester. Owing to the breakable ester bond in this epoxy monomer, the thermosetting three-dimensional epoxy cross-linked structure can be rapidly degraded using ethylene glycol at atmospheric pressure. After further depolymerization of the epoxy resin/glycol solution with NaOH, sodium cyclohexene-2-carboxylate was obtained. The sodium salt was acidified, epoxidized, and then re-prepared to obtain the epoxy monomer diglycidyl tetrahydrophthalate. The recycled epoxy monomer possesses the same thermal and mechanical properties as the original epoxy monomer, thus realizing the economic and environmentally friendly degradation and recycling of the thermosetting epoxy resin under mild conditions, and this recycling method is applicable to epoxy systems with ester bonding in the cured material. [ABSTRACT FROM AUTHOR]

This study innovatively employed solid-state fermentation (SSF) to evaluate chitinase induction in Trichoderma harzianum. Solid-state fermentation minimizes water usage, a crucial global resource, and was applied using shrimp waste chitin and a mixture of commercial chitin with wheat bran as substrates. Shrimp waste and wheat bran were pretreated and characterized for SSF, and the fungus's utilization of the substrates was assessed using spectrophotometric and microscopic methods. The resulting enzymes' ability to produce chitooligosaccharides (COS) mixtures was studied. Wheat bran/commercial chitin demonstrated superior performance, with a 1.8-fold increase in chitinase activity (76.3 U/mg protein) compared to shrimp waste chitin (41.8 U/mg protein). Additionally, the COS mixture obtained from wheat bran/commercial chitin showed a higher concentration of reducing sugars, reaching 87.85 mM, compared to shrimp waste chitin (14.87 mM). The COS profile from wheat bran/commercial chitin included monomers to heptamers, while the profile from shrimp waste chitin was predominantly composed of monomers. These results highlight the advantages of SSF for chitinase induction and COS production in T. harzianum, offering potential applications as dietary fiber, antioxidants, and antimicrobial agents. The findings contribute to by-product valorization, waste reduction, and the sustainable generation of valuable products through SSF-based enzyme production. [ABSTRACT FROM AUTHOR]

The new methacrylic azomethine-containing monomers with side chain quinoline moiety were synthesized by reaction of their corresponding alcohols with methacryloyl chloride. The polymers based on new monomers were synthesized by free radical polymerization. Polymers were characterized by 1HNMR spectroscopy, and the results of their photochemical and optical activities are presented. [ABSTRACT FROM AUTHOR]

Background: Genotyping and amyloid fibril detection in tissues are generally considered the diagnostic gold standard in transthyretin-related amyloidosis. Patients carry less stable TTR homotetramers prone to dissociation into non-native monomers, which rapidly self-assemble into oligomers and, ultimately, amyloid fibrils. Thus, the initial event of the amyloid cascade produces the smallest transthyretin species: the monomers. This creates engineering opportunities for diagnosis that remain unexplored. Methods: We hypothesise that molecular sieving represents a promising method for isolating and concentrating trace TTR monomers from the tetramers present in plasma samples. Subsequently, immunodetection can be utilised to distinguish monomeric TTR from other low molecular weight proteins within the adsorbed fraction. A two-step assay was devised (ImmunoSieve assay), combining molecular sieving and immunodetection for sensing monomeric transthyretin. This assay was employed to analyse plasma microsamples from 10 individuals, including 5 pre-symptomatic carriers of TTR-V30M, the most prevalent amyloidosis-associated TTR variant worldwide, and 5 healthy controls. Results: The ImmunoSieve assay enable sensitive detection of monomeric transthyretin in plasma microsamples. Moreover, the circulating monomeric TTR levels were significantly higher in carriers of amyloidogenic TTR mutation. Conclusions: Monomeric TTR can function as a biomarker for evaluating disease progression and assessing responses to therapies targeted at stabilising native TTR. [ABSTRACT FROM AUTHOR]

The three-dimensional imprinted polymeric network was synthesized via a bulk polymerization reaction in the presence of a flavonoid as a template. In this reaction, methacrylic acid (MAA) and acrylic acid (AA), tetrahydrofuran and trimethylolpropanetrimethacrylate, were used as functional monomers, porogen, and cross-linker, respectively. In this study, two kinds of molecularly imprinted polymers (MIPs) with different ratios of 1:8:40 and 1:20:80 (template: functional monomer: cross-linker) were synthesized and compared together. The related binding capacities were calculated as equal to 392.08 mg/g and 609.00 mg/g, respectively, by UV-spectrometer. The synthesized polymers have been evaluated via field emission scan electron microscopy, transmission electron microscopy, and Brunauer–Emmett–Teller techniques. High selectivity and the proper specific surface area as equal to 167.00 m2/g in MIPs-based methacrylic acid (MIPs-MAA) and 434 m2/g in MIPs-based acrylic acid (MIPs-AA) comparatively to non-imprinted molecular polymers are the privileged characteristics in this research. The MIPs provided are a good candidate for the separation of flavonoids with the solid phase extraction method. [ABSTRACT FROM AUTHOR]

The photochemical and photophysical properties of near-infrared (NIR) dyes are significantly influenced by their aggregation state and mesoscopic morphology. However, beyond chemical synthesis, the regulation mechanisms for the properties of NIR dyes, particularly with respect to photothermal properties of the aggregates, are not yet fully understood. Here, we investigate the photothermal behaviors of croconaine-based (CroA) NIR dyes containing dipeptide or amino acids moieties. The introduction of hydrogen bonding promotes π–π stacking of croconaine center, which can efficiently regulate aggregation states and assembly structures in isopropanol. Under laser irradiation, CroA aggregates undergo aggregation-dissociation transition, the in-situ monomer generation process regulates two parameters of photothermal performance: heating rates and plateau photothermal temperatures. This study reveals the regulation effect of non-covalent bonding interactions on CroA aggregates, highlighting supramolecular assembly strategy not only facilitates to construct of photothermal nanomaterials with well-defined structures, but also provides an alternative and effective method for regulating photothermal performance of NIR dyes. [ABSTRACT FROM AUTHOR]

Concerns are constantly growing about our dependance on plastics derived from fossil feedstock, leading to the development of bio-based alternatives. The bio-based polyester poly(ethylene furanoate) (PEF) has attracted increasing attention from the scientific community due to its potential to replace mass-produced poly(ethylene terephtalate) (PET), mainly used in the packaging, film and fibre sectors. PEF can be 100% bio-based since both its monomers can be produced from biological resources, and exhibits superior properties compared to PET, such as its mechanical and gas barrier properties. As PEF gets closer to being produced at a large scale and entering the plastic market, its end-of-life management should be carefully studied in order to mitigate its environmental footprint. This review focusses on the state-of-the art of the main scenarios related to polymers waste, including mechanical and chemical recycling, composting and incineration. [ABSTRACT FROM AUTHOR]

Polyimides are used in various applications, including fuel cells, membranes, and microelectronics, due to their outstanding tensile properties, great thermal stability, low dielectric constant, and chemical inertness. Applications requiring even lower dielectric constants include interlayer dielectrics and tape‐automated bonding. In this study, a covalent organic framework (COF‐1) was synthesized and dispersed in various percentages into a solution of terpoly(amide acid) (TPAA) to produce COF‐1/terpolyimide composites. 3,3′,4,4′‐Oxydiphthalic dianhydride (ODPA), 3,3′,4,4′‐biphenyltetracarboxylicdianhydride (BPDA), and 4,4′‐(hexafluoroisopropylidene)diphthalic anhydride (6FDA) were reacted with 4,4′‐(hexafluoroisopropylidene)bis[(4‐aminophenoxy)benzene] (HFBAPP) or 4,4′‐(hexafluoroisopropylidene) dianiline (6FpDA) to form terpoly(amide acid). In this case, monomers with fluorinated substituents (HFBAPP, 6FpDA, and 6FDA) were utilized to improve free volume. Pores of COF‐1 and gaps between polyimide chains and COF‐1 can be filled with air with a dielectric constant (κ) ~1, lowering the κ value of terpolyimide composites. The κ value of COF‐1/terpolyimide composites decreased as COF‐1 content increased, reaching a minimum of 1.96. Tensile properties decreased slightly with increasing COF‐1 levels. The terpolyimides and their composites were thermally stable up to approximately 520°C. As a result, these polymer composites look promising for use as insulators in microelectronic applications. Highlights: Terpolyimide is prepared using fluorinated monomers to improve bulk volume.Incorporated COF‐1 into terpoly(amide acid) to introduce pores/voids and reduce dielectric constant.Developed COF‐1/terpolyimide composites with a low dielectric constant of 1.96.Optimized COF‐1/terpolyimide composites for microelectronic applications. [ABSTRACT FROM AUTHOR]

The ability to revert polymers to their original monomers represents a crucial chemical recycling technique, promoting sustainability and offering the chance to convert used materials into valuable products. In recent years, numerous studies have explored the use of polymers synthesized via reversible deactivation radical polymerization (RDRP) techniques to facilitate efficient depolymerization reactions. Herein, we report the use of a photocatalyst, zinc tetraphenylporphyrin (ZnTPP), along with light irradiation to accelerate depolymerization of polymers prepared by reversible addition‐fragmentation chain transfer (RAFT) polymerization. We explore various parameters affecting depolymerization efficiency, including solvents, reaction temperature (80, 100, and 120°C), the presence of photocatalysts (ZnTPP and Eosin Y), and the type of RAFT end‐groups, namely trithiocarbonate, dithiobenzoate, and 1H‐pyrazole‐1‐carbodithioate. For instance, when PMMA was diluted to 25 mM in 1,4‐dioxane and heated to 120°C under green light irradiation in the presence of ZnTPP (200 ppm), rapid depolymerization exceeding 70% occurred within 1 h. Without ZnTPP, under similar conditions, the reaction required over 8 h to achieve a slightly lower yield. Furthermore, this method confers moderate oxygen tolerance to the system, enabling depolymerization to proceed without the need of deoxygenation, albeit at a lower rate and consequently lesser monomer recovery (31%). [ABSTRACT FROM AUTHOR]

Often the errors in the measurement of copolymerizations are not accurately determined or included in the calculation of reactivity ratios. Some knowledge of the errors in the initial monomer ratio, conversion, and copolymer composition is however essential to obtain reliable (unbiased) reactivity ratios with a realistic uncertainty. It is shown that the errors serve a trifold purpose; they can serve as weighing factors in the fit, they can be compared with the fit residues to decide whether the chosen model is adequate for the data and they can be used to construct a realistic joint confidence interval for the reactivity ratios. The best approach is to have an estimate of the individual errors in the copolymer composition, either from a thorough error propagation exercise or from replicate measurements. With these errors, the χ2‐joint confidence intervals can then be constructed which gives a realistic estimate of the errors in the reactivity ratios. Utilizing the Errors in Variables Method (EVM) is correct and useful, but only if the individual errors in all the variables in each experiment are more or less known. [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 application of supramolecular assembly (SA) with room temperature phosphorescence (RTP) in aqueous phase has the potential to revolutionize numerous fields. However, using simple molecules with crystalline RTP to construct SA with aqueous phase RTP is hardly possible from the standpoint of forces. The reason lies in that the transition from crystal to SA involves a structure transformation from highly stable to more dynamic state, leading to increased non‐radiative deactivation pathways and silent RTP signal. Here, with the benefit of the confinement from the layered double hydroxide (LDH), various simple molecules (benzene derivatives) can successfully form metastable SA with aqueous phase RTP. The maximum of RTP lifetime and efficiency can reach 654.87 ms and 5.02 %, respectively. Mechanistic studies reveal the LDH energy trap can strengthen the intermolecular interaction, providing the prerequisite for the existence of metastable SA and appearance of aqueous phase RTP. The universality of this strategy will usher exploration into other multifunctional monomer, facilitating the development of SAs with aqueous phase RTP. [ABSTRACT FROM AUTHOR]

This study presents a novel approach to fabricate 3D‐printed phosphorous‐based acrylate monomers using stereolithographic 3D printing technology, aiming to create demonstrators with exceptional shape‐memory characteristics and robust flame retardant properties. The synthesized materials combine the advantages of 3D printing precision with the intrinsic flame retardancy of phosphorous‐based monomers, offering a versatile solution for applications requiring both shape memory functionality and fire resistance. The limiting oxygen index (LOI) value of the intrinsically flame‐retardant shape‐memory polymer (IFR‐SMP) can reach 34%, and the vertical combustion rating after UL 94 can obtain V‐0. The mechanism of the IFR‐SMP flame retardant mainly includes terminating a free‐radical chain reaction and gas phase dilution, which indicates that the gas‐phase mechanism plays an important role in the flame retardancy. This work advances the frontiers of 3D printing technology by demonstrating the synergistic potential of shape memory and flame retardancy within a single material system, providing a pathway toward the development of innovative and resilient materials for the future. [ABSTRACT FROM AUTHOR]

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

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]

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

Since 5-(hydroxymethyl)furfural (HMF) has been labelled as the "sleeping giant" of the bio-based platform-chemical realm, numerous investigations have been devoted to the exploitation of this versatile molecule and its endless chemical transformations into novel monomers for producing bio-based polymers. However, beyond 2,5-furandicarboxylic acid (2,5-FDCA), little attention has been devoted to key aspects that deserve being addressed before bringing forward other HMF-derivatives into the bio-based plastic market, i.e., procedures, scaling-up of the syntheses, products' purification, physical–thermal properties, and above all green metrics (sustainability/greenness of procedures). This critical review focuses on the most investigated derivatives of HMF beyond 2,5-FDCA, assessing their exploitation as monomers for bio-based polymers. HMF-derived compounds have been classified according to their functionalities, i.e., aldehyde-, diol-, polyol-, amine-, acid-, ester-, carbonate-, acrylate-, and epoxy-based monomers. The related synthetic approaches are discussed, evaluating the sustainability of the procedures reported so far, based on green metrics such as the environmental factor (E-factor) and the process mass intensity (PMI). For each family of HMF derivatives, their use as monomers for the synthesis of bio-based polymers has been addressed, taking into consideration the efficiency of the polymerisation reactions, the physical–chemical and thermal properties of the resulting bio-based polymers, as well as their biodegradability if applicable. The overall picture that emerges is that much has been achieved for the synthesis of furan monomers; however, many obstacles still need to be overcome prior to massively introducing these compounds into the bio-based plastic market. Hopefully, the data reported in this review will shed light on the goals achieved so far, and on some critical issues that must still be tackled in the short- or medium-term for a more sustainable and however efficient industrial process. [ABSTRACT FROM AUTHOR]

Bispecific antibodies (bsAbs) hold promises for enhanced therapeutic potential surpassing that of their parental monoclonal antibodies. However, bsAbs pose great challenges in their manufacturing, and one of the common reasons is their susceptibility to aggregation. Building on previous studies demonstrating the functionality and potential manufacturability of Fab-scFv format bsAb, this investigation delved into the impact of environmental factors—such as pH, buffer types, ionic strength, protein concentrations, and temperatures—on its stability and the reversal of its self-associated aggregates. Mildly acidic, low-salt conditions were found optimal, ensuring bsAb stability for 30 days even at elevated temperature of 40 °C. Furthermore, these conditions facilitated the reversal of its self-associated aggregates to monomers during the initial 7-day incubation period. Our findings underscore the robustness and resilience of Fab-scFv format bsAb, further confirming its potential manufacturability despite its current absence as commercial products. [ABSTRACT FROM AUTHOR]

Members of the SLC25 mitochondrial carrier family link cytosolic and mitochondrial metabolism and support cellular maintenance and growth by transporting compounds across the mitochondrial inner membrane. Their monomeric or dimeric state and kinetic mechanism have been a matter of long-standing debate. It is believed by some that they exist as homodimers and transport substrates with a sequential kinetic mechanism, forming a ternary complex where both exchanged substrates are bound simultaneously. Some studies, in contrast, have provided evidence indicating that the mitochondrial ADP/ATP carrier (SLC25A4) functions as a monomer, has a single substrate binding site, and operates with a ping-pong kinetic mechanism, whereby ADP is imported before ATP is exported. Here we reanalyze the oligomeric state and kinetic properties of the human mitochondrial citrate carrier (SLC25A1), dicarboxylate carrier (SLC25A10), oxoglutarate carrier (SLC25A11), and aspartate/glutamate carrier (SLC25A13), all previously reported to be dimers with a sequential kinetic mechanism. We demonstrate that they are monomers, except for dimeric SLC25A13, and operate with a ping-pong kinetic mechanism in which the substrate import and export steps occur consecutively. These observations are consistent with a common transport mechanism, based on a functional monomer, in which a single central substrate-binding site is alternately accessible. Synopsis: The human mitochondrial oxoglutarate carrier (OGC), citrate carrier (CIC), dicarboxylate carrier (DIC) and aspartate/glutamate carrier (AGC2) of the SLC25 family were all thought to be homodimers, operating with a sequential mechanism in which the two exchanged substrates bind at the same time to the transporter. This study shows that they are monomers, except for the dimeric aspartate/glutamate carrier (AGC2), and that they import one substrate first before the other is exported. The human mitochondrial citrate, dicarboxylate and oxoglutarate carriers are structural monomers. In contrast to these carriers, the mitochondrial aspartate/glutamate carrier is a structural dimer. They all operate with a ping-pong kinetic mechanism, where one substrate is imported first, before the the counter-substrate is exported. These kinetic and structural observations are consistent with an alternating access mechanism for mitochondrial carriers using a single substrate-binding site. The oxoglutarate, citrate and dicarboxylate carriers are monomeric in contrast to the dimeric aspartate/glutamate carrier, but all operate with a ping-pong kinetic mechanism. [ABSTRACT FROM AUTHOR]

This study focuses on the development of regiospecific hydroarylation polyaddition of naphthalene‐ and carbazole‐based monomers with diynes under mild reaction conditions at room temperature. A 1‐pyrazole substituent serves as an appropriate directing group for a Co‐catalyst to efficiently activate the C–H bonds of generally inactive six‐membered aromatic hydrocarbons. The 1‐pyrazole groups in 2,6‐di(1‐pyrazolyl)naphthalene adopt planar conformations and act as directing groups, resulting in a smooth hydroarylation reaction. In contrast, the reaction with 1,5‐di(1‐pyrazolyl)naphthalene do not proceed. The polyaddition reaction of 2,6‐di(1‐pyrazolyl)naphthalene selectively proceeds at 3,7‐positions under mild reaction conditions at 30 °C, and yields corresponding poly(arylenevinylene) (PAV) with high molecular weight. This molecular design is also applicable to the hydroarylation polyaddition of carbazole; the polyaddition reaction of 9‐(2‐ethylhexyl)‐3,6‐di(1‐pyrazolyl)carbazole selectively occurred at 2,7‐positions. The optical and electronic properties of the synthesized compounds are evaluated. The obtained PAVs serve as an emitting material in organic light‐emitting diode (OLED). This study aims to develop a Co‐catalyzed hydroarylation polyaddition via C–H activation of generally inactive polyaromatic hydrocarbons (PAHs) under mild conditions. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: The aggregation of α‐synuclein (α‐syn) is strongly influenced by membrane interfaces, but the mechanism of transition from monomers to oligomers at early aggregation stage is not clear. Here, we investigate the adsorption and structure changes of α‐syn on oppositely charged aromatic interfaces through in‐situ surface‐enhanced infrared absorption (SEIRA) spectroscopy and nano‐IR technique. The results show that the synergy of electrostatic and hydrophobic interactions leads to a "fast‐slow" two‐step aggregation pathway on negatively charged interface. Surface adsorption induces the formation of an extended helix structure and subsequently partial helix unwinding in NAC region, which enables the hydrophobic stacking between nearby NAC regions. Stable antiparallel β‐sheet rich aggregates are gradually emerging as further interactions of monomers with the fast formed "first layer". Monomers electrostatically adsorb on positively charged interface by C‐terminus with NAC region and N‐terminus stretched in solvent, which serve as an aggregation core and induce further adsorption and gradual formation of aggregates with C‐terminus exposure. Our results demonstrate the modulation of surface charge and synergy of electrostatic and hydrophobic interactions on the interaction modes and aggregation pathways, which provide insights into dynamic conformation changes of α‐syn at early aggregation stage and imply the important role of spatial‐temporal heterogeneity of membranes in α‐synucleinopathies. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Although various routes have been reported for haloazidation, unavoidable problems exist, such as environmentally unfriendly monomer halogen, the need for in situ generation of unstable halogen azides (XN3), applicability to one type of haloazidation and inability to precisely control selectivity. Herein, we developed a universal strategy for haloazidation of alkenes through controlling the reactivity of IBA‐N3 by switching halogen salts, allowing for the synthesis of a diversity of halogen azide products. Mechanistic studies have shown that by tuning the reactivity of IBA‐N3 via switching halogen salts, different intermediates can be controllably produced to achieve regioselectivity and chemoselectivity in the haloazidation of alkenes. [ABSTRACT FROM AUTHOR]

Imine-linked covalent organic frameworks (COFs) are highly ordered polymer networks that are more chemically stable compared to their boron-linked counterparts making them more attractive for a variety of applications, including as energy storage devices, proton-conductive membranes, and catalytic supports. Furthermore, these imines linked COFs may be synthesized using a diverse spectrum of monomers, providing tremendous design freedom and versatility. We report a general method for synthesizing Imine linked COFs based on the Schiff-base condensation reaction of anilines. The synthesis of 4,4′,4′′-(benzene-1,3,5-triyltris(ethyne-2,1-diyl) trianiline, 4,4′-dicarbaldehyde, 4,4′-(ethyne-1,2-diyl) dibenzaldehyde (BPDA), and terephthalaldehyde (PDA) monomers produced by multistep coupling processes. [ABSTRACT FROM AUTHOR]

Immunoglobulin A (IgA) plays a crucial role in the human immune system, particularly in mucosal immunity. IgA antibodies that target the mucosal surface are made up of two to five IgA monomers linked together by the joining chain, forming polymeric molecules. These IgA polymers are transported across mucosal epithelial cells by the polymeric immunoglobulin receptor pIgR, resulting in the formation of secretory IgA (SIgA). This review aims to explore recent advancements in our molecular understanding of IgA, with a specific focus on SIgA, and the interaction between IgA and pathogen molecules. [ABSTRACT FROM AUTHOR]

Considering the dilemma of obtaining economic and high-performance composites based on non-polar and main-chain-saturated ethylene propylene diene monomer rubber (EPDM), we proposed an effective and universal filler modification and nanocomposite preparation method. Specifically, the montmorillonite (MMT) surface was coated with polydopamine (PDA) to obtain DMMT, which was confirmed by XRD, XPS, FTIR, and TGA. After compounding DMMT gel with the solid EPDM via the gel compounding method, a silane coupling agent, vinyltrimethoxysilane, was introduced to construct covalent interactions between rubber and filler. Compared with the unmodified MMT filler EPDM, the EPDM/DMMT nanocomposite showed much fewer filler aggregates in the matrix. The highest tensile strength of the composites reached 6.5 MPa with 10 phr DMMT, almost 200% higher than that of pure EPDM. [ABSTRACT FROM AUTHOR]

The direct acrylation of soybean oil was investigated by the activation of soybean oil's (SO's) internal fatty unsaturation with acidic catalysts. The effect of the catalyst and the reactant ratio with respect to the unsaturation and reaction time on the direct acrylation process were explored. ASO (acrylated soybean oil) with acrylation degrees (the number of acrylate molecules introduced in a triglyceride molecule) between 1.6 and 2.55 were obtained. The effect of the ASO acrylation degree on copolymerization processes was investigated. The resulting monomers were successfully copolymerized with meth(acrylate) monomers by the miniemulsion polymerization process, favoring the droplet nucleation mechanism and showing conversions higher than 97%. The acrylic–ASO copolymers presented lower Tg and higher hydrophobicity and oleophobicity than the acrylic copolymer. [ABSTRACT FROM AUTHOR]

Molecularly imprinted polymers (MIPs) are a growing highlight in polymer chemistry. They are chemically and thermally stable, may be used in a variety of environments, and fulfill a wide range of applications. Computer-aided studies of MIPs often involve the use of computational techniques to design, analyze, and optimize the production of MIPs. Limited information is available on the computational study of interactions between the epinephrine (EPI) MIP and its target molecule. A rational design for EPI-MIP preparation was performed in this study. First, density functional theory (DFT) and molecular dynamic (MD) simulation were used for the screening of functional monomers suitable for the design of MIPs of EPI in the presence of a crosslinker and a solvent environment. Among the tested functional monomers, acrylic acid (AA) was the most appropriate monomer for EPI-MIP formulation. The trends observed for five out of six DFT functionals assessed confirmed AA as the suitable monomer. The theoretical optimal molar ratio was 1:4 EPI:AA in the presence of ethylene glycol dimethacrylate (EGDMA) and acetonitrile. The effect of temperature was analyzed at this ratio of EPI:AA on mean square displacement, X-ray diffraction, density distribution, specific volume, radius of gyration, and equilibrium energies. The stability observed for all these parameters is much better, ranging from 338 to 353 K. This temperature may determine the processing and operating temperature range of EPI-MIP development using AA as a functional monomer. For cost-effectiveness and to reduce time used to prepare MIPs in the laboratory, these results could serve as a useful template for designing and developing EPI-MIPs. [ABSTRACT FROM AUTHOR]

Polypyrrole (PPy) has attracted widespread attention due to its excellent environmental stability, high conductivity, simple synthesis, good biocompatibility, and reversible redox properties. PPy derivatives not only inherit the advantages of polypyrrole, but also have some unique properties. The side and N-site substitution of PPy can not only yield polymers with good solubility, but it also endows polymers with special functionalities by controlling the introduced functional groups. The performance of copolymers can also be adjusted by the type of monomer or polymerization ratio. In this review, an overview of the different types, main preparation methods, and the application prospects of PPy derivatives reported to date are summarized and presented. The current challenges and future opportunities in this research area are also prospected. [ABSTRACT FROM AUTHOR]

Tandem repeat (TR) proteins are abundant in nature and show diverse biochemical and mechanical properties. However, these proteins can be difficult to synthesize in a precise way because of their repetitive nature. Using a supramolecular polymerization scheme known as hybridization chain reaction, we show how to generate the DNA sequences encoding such TR proteins. The polymerization mechanism allows for identical "monomers" to selectively create TR proteins of different molecular weight. We demonstrate this strategy with examples from elastin‐like polypeptides (ELPs) and mussel foot proteins (mfps). Moreover, the scheme can be adapted to create protein libraries through the use of multiple DNA hairpin "monomers." [ABSTRACT FROM AUTHOR]

The present work focuses on comparing the performance of novel cationic graft copolymer polyvinylpyrrolidone-graft-poly(acrylamide-co-diallyldimethylammonium chloride) (PVP-g-p(AM-co-DADMAC)) synthesized via microwave-assisted technique, with varying amounts of monomers acrylamide (AM) and diallyldimethylammonium chloride (DADMAC) as a flocculant for sugarcane juice. The intended grafting was supported by extensive characterization of the material by various physicochemical methods. As compared to only AM or DADMAC grafted onto PVP, grafted copolymer with highest DADMAC-to-AM ratio was found to be more effective in removing colloids from fresh unaltered cane juice. The mode of action of the synthesized flocculant was explained by synergistic bridging and charge neutralization mechanism. The best grade of PVP-g-p(AM-co-DADMAC) at an optimum dose of only four ppm (within US FDA approved limit) showed a good reduction in the zeta potential (− 7.8 to − 2.9 mV) of the juice along with the formation of large-size floc (618 nm) without affecting the percentage of natural sugar content (degree brix- °bx). [ABSTRACT FROM AUTHOR]

Polylactic acid (PLA), a highly promising biodegradable biopolymer, has been extensively studied over the last two decades. The thermoplastic polyester PLA is bio-based, compostable, and eco-friendly. Its monomer, lactic acid, is fermented from renewable plant sources like starch and sugar. Therefore, PLA is regarded as a desirable substitute for conventional petroleum-based polymers. Because of its biocompatible and biodegradable properties, U.S. FDA (Food and Drug Administration) has approved PLA as a biomedical material. PLA has excellent mechanical, physical, structural, and thermal properties, making it suitable for various applications. However, PLA has limitations such as low impact toughness, hydrophobicity, and slow degradation rate at ambient temperatures. This can be improved by different modification methods, such as copolymerization, making composites or blends of PLA with other biodegradable polymers, or incorporating additives. This review presents information about the various methods of synthesis of PLA, its properties, and the environmental degradation of PLA. In addition, the different processing techniques of PLA are also reviewed. Lastly, the applications of PLA in sectors such as packaging, biomedical, agricultural, automotive, and textile are also discussed. [ABSTRACT FROM AUTHOR]