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Reliable thermodynamic and kinetic properties of free radical polymerization reactions are essential for synthesizing both primary polymeric materials and specialty polymers. The computational generation of these data from quantum chemistry requires a time-efficient method capable of capturing the essential physics. One such method, fixed-node diffusion Monte Carlo (FN-DMC) (using single Slater–Jastrow trial wavefunctions), has demonstrated the capability to recover 90%–95% of missing dynamic correlation energy for typical systems. In this study, methyl radical addition to ethylene serves as a simple model to test FN-DMC's ability to calculate enthalpies of reaction and activation energies with different time steps, antisymmetric trial wavefunctions, basis set sizes, and effective core potentials. The FN-DMC computational protocol thus defined for methyl radical addition to ethylene is subsequently benchmarked against Weizmann-1 and experimental reaction enthalpies from Lin et al.'s test set of 21 radical addition and 28 hydrogen abstraction enthalpies. Our findings reveal that FN-DMC consistently generates reaction enthalpies with chemical accuracy, exhibiting mean absolute deviation of 3.5(7) and 1.4(8) kJ/mol from the Weizmann-1 reference for radical addition and hydrogen abstraction reactions, respectively. Given its favorable computational scaling and high degree of parallelizability, we, therefore, recommend more comprehensive testing of FN-DMC with effective core potentials to address more extensive and intricate polymerization reactions and reactions with other radicals. [ABSTRACT FROM AUTHOR]

We present an approximate analytical approach to the adsorption problem of ABA triblock copolymers confined between two parallel plates in a θ solvent and give the expression of the propagator q(x, t) as a piece-wise function by solving the modified diffusion equation. In this way, the role of separation between the two plates, adsorption energy and block lengths on segment concentration profile, chain conformations, and interaction potential is then investigated, which agrees well with the numerical results. It is demonstrated that there are parallels between lengthening adsorbing A blocks and increasing surface affinity: strong adsorption and long adsorbing blocks favor the formation of loops and bridges, whereas more tails and free chains exist in the case of weak adsorption and short A blocks at large separations. For moderate and strong adsorptions, the bridging fraction begins to plummet at a separation larger than the end-to-end distance of non-adsorbing B block RB and becomes negligible at above 2RB owing to the entropy effect. The depth of the potential well in the interaction potential profile depends on the adsorption energy and A block length, while the location of the potential minimum corresponds to the onset of the sharp decrease in bridges. [ABSTRACT FROM AUTHOR]

Polymeric surfactants are amphiphilic molecules with two or more different types of monomers. If one type of monomer interacts favorably with a liquid, and another type of monomer interacts favorably with another, immiscible liquid, then polymeric surfactants adsorb at the interface between the two liquids and reduce the interfacial tension. The effects of polymer architecture on the structural and thermodynamic properties of the liquid–liquid interface are studied using molecular simulations. The interface is modeled with a non-additive binary Lennard-Jones fluid in the two-phase region of the phase diagram. Block and gradient copolymer surfactants are represented with coarse-grained, bead-spring models, where each component of the polymer favors one or the other liquid. Gradient copolymers have a greater concentration at the interface than do block copolymers because the gradient copolymers adopt conformations partially aligned with the interface. The interfacial tension is determined as a function of the surface excess of polymeric surfactant. Gradient copolymers are more potent surfactants than block copolymers because the gradient copolymers cross the dividing surface multiple times, effectively acting as multiple individual surfactants. For a given surface excess, the interfacial tension decreases monotonically when changing from a block to a gradient architecture. The coarse-grained simulations are complemented by all-atom simulations of acrylic-acid/styrene copolymers at the chloroform-water interface, which have been studied in experiments. The agreement between the simulations (both coarse-grained and atomistic) and experiments is shown to be excellent, and the molecular-scale structures identified in the simulations help explain the variation of surfactancy with copolymer architecture. [ABSTRACT FROM AUTHOR]

Block copolymers at homopolymer interfaces are poised to play a critical role in the compatibilization of mixed plastic waste, an area of growing importance as the rate of plastic accumulation rapidly increases. Using molecular dynamics simulations of Kremer–Grest polymer chains, we have investigated how the number of blocks and block degree of polymerization in a linear multiblock copolymer impacts the interface thermodynamics of strongly segregated homopolymer blends, which is key to effective compatibilization. The second virial coefficient reveals that interface thermodynamics are more sensitive to block degree of polymerization than to the number of blocks. Moreover, we identify a strong correlation between surface pressure (reduction of interfacial tension) and the spatial uniformity of block junctions on the interface, yielding a morphological framework for interpreting the role of compatibilizer architecture (number of blocks) and block degree of polymerization. These results imply that, especially at high interfacial loading, the choice of architecture of a linear multiblock copolymer compatibilizing surfactant does not greatly affect the modification of interfacial tension. [ABSTRACT FROM AUTHOR]

The domain reversal dynamics of the pristine and 10 wt. % BiFeO3 nanoparticle-embedded P(VDF-TrFE) (polyvinylidene fluoride-trifluoroethylene) flexible ferroelectric membranes were investigated. A scaling relation of A∝fαE0β relevant to the domain reversal dynamics was eventually determined. The pristine P(VDF-TrFE) flexible membrane takes the form of A∝f0.04077E00.39748 in stage III of high electric fields. Nevertheless, for BiFeO3-embedded P(VDF-TrFE) [BFO/P(VDF-TrFE)] flexible membranes, the relations are developed as A∝f−0.3326E02.74911 in the low electric fields of stage I and as A∝f0.04309E01.04872 in stage III separately. The negative α indicates that more and more domain reversal lags behind the alternating periodic electric field in stage I. Instead, in stage III, the positive α indicates that most domain reversals can occur anytime whatever the alternating speed of electric fields is. Analogously, the positive β indicates that at any selected frequency, domains can flip at an external electric field. Abnormally, for the pristine P(VDF-TrFE) membrane, the scaling relation in the first E0 stage is broken, reflecting only dielectric contributions this time. The dynamic scaling data are significant for the micromechanism accomplishments of copolymers and for the designs of flexible electric devices. [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]

To solve problems such as inadequate proppant carrying capacity, a complex viscosity changing process, and limited environmental friendliness associated with traditional slick water fracturing fluids, a variable viscosity friction reducer called Jianghan friction reducer (JHFR) with low damage, high drag reduction, and strong proppant‐carrying capacity is prepared by inverse emulsion polymerization. The properties of JHFR are investigated by viscometer, JHFR‐II high‐temperature and high‐pressure slick water drag reduction rate tester, surface tension meter, and JHCQ Core dynamic damage evaluation device. The result shows that the dissolution time of JHFR is less than 120 s. The drag reduction of 0.08 wt% JHFR (4.83 mPa s) is 80.3%. When the concentration of JHFR increases from 0.08 to 0.8 wt %, the viscosity of the JHFR increases from 4.83to 97.41 mPa s. After sheared at 90°C and 170 s−1 for 60 min, the viscosity of 0.8 wt% JHFR still maintains 51 mPa s. The damage rate of JHFR to core matrix permeability is lower than 30%. JHFR also shows the advantages of easy breakage and low residue. It provides guidance for the design and selection of fracturing fluid for unconventional oil and gas reservoir development. [ABSTRACT FROM AUTHOR]

Ultrafiltration (UF) membranes with excellent dye removal and antibacterial activity are highly desired in dye wastewater treatment, and more importantly environmental protection puts high demands on polymeric membrane materials. In this work, three methacrylate copolymers containing quaternary ammonium salt were synthesized to cast UF membranes. The physicochemical property, structural evolution, dye separation, and antibacterial activity of as‐prepared membranes were systematically investigated. With increased content of the hydrophilic monomer allyl polypropylene glycol (APPG) in the feed, the wettability and positive charge of the resultant membranes were enhanced. Remarkably, the supporting layer of membranes changed from finger‐like pore structure to sponge‐like pore structure by increasing APPG content, and the sponge‐like membranes showed higher retention rates for dyes (99.78% for victoria blue B, 90.49% for methylene blue, and 97.43% for methyl blue) compared with the finger‐like membranes. Besides, the sponge‐like membranes exhibited high rejection for vctoria blue B (>99%) in dye/salt mixture and simultaneously low rejection for salts (<10%), indicating effective selective separation to dye/salt mixture, and also achieved easy regeneration. It was also found that increased hydrophilicity and positive charge endowed membranes with better antibacterial activity. This work will provide an alternative for dye/salt selective separation in dye effluent treatment. [ABSTRACT FROM AUTHOR]

The application and promotion of biodegradable plastics are hindered by the imbalance between their mechanical and degradation performance imbalance, as well as high costs. Herein, a series of poly(ethylene adipate‐co‐terephthalate) (PEAT) copolyesters with excellent mechanical and degradation properties are synthesized by one‐step melt polycondensation. The influence of the proportion of aliphatic groups in the molecular chain on the structure and properties, especially the degradation performance, of the copolyesters was studied. The molecular chain flexibility and degradability of PEAT increases with increasing of adipic acid content and decreasing of ET fragment length (LET). The comprehensive mechanical properties of PEAT60 can be comparable to traditional packaging material poly(butylene adipateco‐terephthalate) (PBAT). The degradation performance of PEAT can be adjusted the molecular chain structure. PEAT with LET < 3 exhibit degradation performance, and PEAT with LET < 2.2 exhibit significant degradation acceleration. The excellent mechanical and degradable properties of PEAT copolyester make it expected to be used in degradable packaging and other fields to help solve plastic pollution, while its lower cost will aid in the promotion of degradable materials. [ABSTRACT FROM AUTHOR]

Phase change materials (PCM) often encounter severe problems of leakage and shape collapse concerns. Chemical modification methods, utilizing chemical bonds to bind phase change molecular chains, have the potential to address the above‐mentioned problems radically. However, this approach often entails the use of expensive raw materials and complex processes. Therefore, a simple one‐pot preparation method had been reported using earth‐abundant and inexpensive octadecyl methacrylate (OMA) and 1,6‐hexanediol diacrylate (HD) as raw materials to prepare PCM with a molecular structure of cross‐linked polymer main chains and phase change side chains through free radical polymerization. Owing to the three‐dimensional polymer main chain structure, it exhibited excellent leakage‐proof performance, maintaining its form‐stable nature at 70°C with no obvious leakage observed during the phase change process, confirming it to be an excellent intrinsic solid–solid PCM (SSPCM). Additionally, the introduction of the cross linking segment significantly improves its thermal stability, and the 50% degradation temperature increased significantly from 228.8 to 355.9°C. Moreover, the latent heat increased with the decrease of the crosslinking density until the molar ratio of HD/OMA was reduced to 1/40 and then tended to reach constant. At the optimal ratio the latent heat of SSPCM can reach 88.23 J g−1. Excessive crosslinking density will affect the stacking tightness of molecular chains during the crystallization process, thereby reducing the latent heat. [ABSTRACT FROM AUTHOR]

A series of triphenol‐diamine‐type hyperbranched benzoxazines are synthesized by using polyformaldehyde, 1,1,1‐tri(4‐hydroxyphenyl) ethane, and primary amines such as p‐phenylenediamine, 4,4′‐diaminodiphenylmethane, polyetheramine, and bifuranocyclic diamine via Mannich condensation. Then, copolymers with bifunctional benzoxazine (BA‐a) are prepared to obtain superior properties. The polymerization behavior of the copolymers examined using a differential scanning calorimeter and a Fourier transform infrared indicates that the introduction of hyperbranched benzoxazines facilitates the benzoxazine curing reaction, decreasing the onset and peak temperatures of the curing process. Thermogravimetric analysis results suggest the cured hyperbranched benzoxazine demonstrates good thermal stability and can improve the heat resistance of benzoxazine. In addition, dynamic mechanical analysis suggests the glass transition temperature of the copolymers with BA‐a was increased after copolymerization, thus making all the copolymers obtain higher service temperatures. The test results from the universal testing machine and the fracture morphologies of copolymers indicate the hyperbranched benzoxazines with branched structures cause dendritic folds to appear on the surface of copolymers upon polymerization, preventing rapid cracking and spreading of the thermoset resin by dissipating more impact energy through this irregular dendritic appearance, thus obtaining strength and toughness superior to that of BA‐a resins. [ABSTRACT FROM AUTHOR]

Alternating‐rich copolymer of vinylboronic acid pinacol ester (VBpin) and maleic anhydride (MAH) was found to catalyze direct dehydrative esterification of carboxylic acid and alcohol. The key to the catalytic function is the activation of the MAH unit by the neighboring Lewis acidic boron directly connected to the backbone through the formation of five‐membered ring. The effects of the side‐chain cooperation were clarified through comparisons with the polymers having similar structures and a conventional titanium catalyst as well as the analyses of reactions with carboxylic acid or alcohol. The catalytic activity was enhanced as the molecular weight was higher, which is owing to the structural feature that boron is directly attached to the backbone. The cooperative catalysis is of interest because of its conceptual similarity with enzyme. [ABSTRACT FROM AUTHOR]

Allyl ether naphthol resin (ANPF) was synthesized by introducing 1,5‐dihydroxynaphthalene and 2,7‐dihydroxynaphthalene into phenolic resin and was copolymerized with 4,4′‐bismaleimidodiphenylmethane resin (BDM) to obtain allyl ether naphthol‐modified bismaleimide resins (15‐ANPF‐BDM and 27‐ANPF‐BDM). The resulting thermal stability and glass transition temperature (Tg) were explored by thermogravimetric and dynamic mechanical analyses. The char yield of 15‐ANPF‐BDM at a temperature of 800°C was 46.0%. Additionally, the Tg of 15‐ANPF‐BDM was measured as 311°C, which is an increase of 44°C compared to that of c. The mechanical properties of the ANPF‐BDM/quartz fiber (Qf) composites were also investigated. The results reveal that ANPF‐BDM/Qf composites exhibit similar mechanical strength to APF‐BDM/Qf composites at room temperature. In addition, the mechanical properties of the ANPF‐BDM/ Qf composites demonstrated significant improvement in mechanical properties retained significantly improved at 200°C, with a 68% flexural strength retention and a 96% interlaminar shear retention of 15‐ANPF‐BDM/Qf composites. Thus, ANPF‐BDM/Qf composites exhibit outstanding mechanical properties at 200°C. [ABSTRACT FROM AUTHOR]

To maintain performance of an aqueous-based drilling muds (ABDMs), it was imperative to understand the decay mechanism of the incorporated synthetic polymers, when exposed to the elevated temperatures. The understanding of the decay mechanism could provide a polymer replenishment strategy for the fluid to retain a specific rheology and filtrate control performance. In this context, thermal-degradation of various acrylamide co-polymers was investigated in different monovalent brines. The acrylamide co-polymers were custom synthesized, and their molecular weight and % sulfonic substitution was verified using the capillary viscometer and nuclear magnetic resonance spectroscopy techniques respectively. The co-polymer thermal degradation mechanism (i.e., polymer hydrolysis) in various monovalent brines (KCl, NaCl and NaBr) was quantified by novel titration for temperature range {121 °C, 177 °C}. The degradation response of the co-polymers was then correlated with their rheology and HPHT (high-pressure-high-temperature) filtrate performance; for instance, the titration studies showed that co-polymer degradation was 12–15% and 44–47% after sixteen hours aging at 121 °C and 177 °C respectively; correspondingly the co-polymer performance in ABDM, exhibited HPHT filtrate of 12–18 mL and 38–40 mL at those respective temperatures after sixteen hours of aging. The quantified understanding of the co-polymer thermal degradation was used to device a new approach for co-polymer replenishment strategy; it was illustrated that a 7% replenishment of the co-polymer for every eight hours, at 121 °C, enabled sustained HPHT filtrate of 12–18 mL for the studied evaluation period of thirty-two hours. The replenishment approach presented in the study would provide a valuable tool for drilling automation to ensure sustained fluid performance. [ABSTRACT FROM AUTHOR]

Circularly polarized luminesce (CPL) materials are crucial for various applications, including display devices and bionics. However, existing CPL materials face difficulties in simultaneously meeting large luminescence asymmetry factors (glum), high photoluminescence quantum yields (PQY), and long lifetime. Here, a simple strategy to prepare a series of high‐performance CPL liquid crystal copolymers is constructed by triplet–singlet Förster‐resonance energy transfer (TS‐FRET). A series of chiral liquid crystal copolymers are successfully synthesized by copolymerizing phosphorescent donor bearing chiral cholesterol mesogen with fluorescence acceptor bearing naphthalimide chromophore. The introduction of the naphthalimide component promotes the formation of twist grain boundary smectic‐A phase (TGBA*) and behaves distinctive selective reflective effect. An effective TS‐FRET process occurs in the two components of copolymers, and dual emission characteristics of thermally activated delayed fluorescence and room‐temperature phosphorescence are observed in the copolymer films. When the naphthalimide content of copolymer is 10%, the luminescence lifetime can achieve 83.0 ms. As the naphthalimide content increases, the glum initially increases and subsequently decreases, reaching a maximum of −1.15. In addition, the copolymer films possess enhanced photoluminescence quantum yield by TS‐FRET with a maximum value of 68%. The application of copolymers in information security is also explored. [ABSTRACT FROM AUTHOR]

Fabrication of chiral hydrogels from thermoresponsive helical dendronized phenylacetylene copolymers (PPAs) carrying three‐fold dendritic oligoethylene glycols (OEGs) is reported. Three different temperatures, i.e. below or above cloud point temperatures (Tcps) of the copolymers, and under freezing condition, were utilized, affording thermoresponsive hydrogels with different morphologies and mechanical properties. At room temperature, transparent hydrogels were obtained through crosslinking among different copolymer chains. Differently, opaque hydrogels with much improved mechanical properties were formed at elevated temperatures through crosslinking from the thermally dehydrated and collapsed copolymer aggregates, leading to heterogeneity for the hydrogels with highly porous morphology. While crosslinking at freezing temperature synergistically through ice templating, these amphiphilic dendronized copolymers formed hydrogels with highly porous lamellar structures, which exhibited remarkable compressible properties as human articular cartilage with excellent fatigue resistance. Amphiphilicity of the dendronized copolymers played a pivotal role in modulating the network formation during the gelation, as well as morphology and mechanical performance of the resulting hydrogels. Through crosslinking, these dendronized copolymers featured with typical dynamic helical conformations were transformed into hydrogels with unprecedently stabilized helicities due to the restrained chain mobilities in the three‐dimensional networks. [ABSTRACT FROM AUTHOR]

Amphiphilic molecules can self-assemble into a wide range of morphologies, making them a promising candidate for drug delivery. Poly-(lactic-co-glycolic acid)–poly-(ethylene glycol) methyl ether (PLGA-MPEG), which is an amphiphilic copolymer, is a broadly used biodegradable drug carrier for drug delivery systems. In this study, computational molecular dynamics (MD) simulations were used to tailor polymeric nanoparticles with improved drug delivery efficacy. To optimize drug loading, customized copolymers with varying lactic acid to glycolic acid ratios, as well as the length of the MPEG chain, were considered. These simulations were carried out with varying amounts of the drug and copolymers. Our findings suggest the optimized conditions under which gemcitabine (GEM) was efficiently encapsulated in polymeric nanoparticles. The simulations reveal that varying the proportions of lactic and glycolic acid and MPEG chain lengths in copolymers can improve drug encapsulation efficiency. Increasing the glycolic content of the copolymers resulted in better GEM encapsulation, which corresponded to a higher binding energy. The strong interaction energy between GEM and the glycolic acid-rich copolymer suggested that the drug might have a slow-release profile. GEM and PLGGA-MPEGn have a higher average number of hydrogen bonds than that with PLGA-MPEGn and PLLGA-MPEGn. This indicates that the copolymer's flexibility increased as the concentration of glycolic acid in the copolymer increased, promoting the better formation of polymeric nanoparticles. This study has the potential to pave the way for the fabrication of polymeric nanocarriers capable of efficiently encapsulating drugs. [ABSTRACT FROM AUTHOR]

The intricate interplay between chemical composition and the incorporation of functional fillers plays a pivotal role in shaping the structural attributes and separation efficacy of mixed matrix ultrafiltration membranes. In this work, we report the utilization of a novel organic filler of hydrophilic modified polyimide particles (PI‐SO3) for the first time in the preparation of mixed matrix ultrafiltration membranes. A series of ultrafiltration membranes were fabricated using polysulfone as the matrix material and PI‐SO3 as the additive. The addition of PI‐SO3 to the mixed matrix membrane effectively enhanced both water flux and antifouling ability. The ultrafiltration membrane with 0.2% particle content exhibited the highest pure water flux at 535.5 L h−1 m−2, owing to the synergistic regulation of pore structures and surface hydrophilicity. The ultrafiltration membrane with 0.5% PI‐SO3 particles demonstrated the highest flux recovery rate at 76.8%, attributed to the superior hydrophilicity displayed by the added particles within the ultrafiltration membrane. The increased particles content correlated with improved hydrophilicity on the membrane surface, resulting in enhanced antifouling performance. The hydrophilic modified particles effectively regulated pore structures, surface hydrophilicity, and surface charge, ultimately enhancing the performance of mixed matrix ultrafiltration membranes for wastewater purification. Therefore, the use of modified polyimide particles as fillers introduces an innovative method to economically enhance ultrafiltration membranes, providing a potential solution to mitigate the economic costs associated with trade‐off effects during the modification process. [ABSTRACT FROM AUTHOR]

The introduction of reactive groups into thermoplastic tougheners can overcome the phase separation problem between conventional thermoplastic resins and thermosetting resins, thereby improving the compatibility between the two phases and significantly enhancing the materials' toughness. In this study, a series of polyaryletherketone (RPEK‐C) copolymers with a molecular backbone containing reactive propenyl and controllable groups are prepared. Through blending different amounts and different reaction group contents of thermoplastic resins into the N,N'‐（4,4'‐methylenediphenyl) dimaleimide(BDM)/2,2′‐diallylbisphenol A (DABPA) system, all of them show a homogeneous phase instead of separation phase after curing, and the impact toughness is improved to different degrees. When RPEK‐C‐10 with 7.5 phr is added, the impact strength of the toughened BDM/DABPA can be increased up to 172.5%. Compared with the nonactive PEK‐C, active groups of RPEK‐C can react with BDM, playing a role in "anchoring" the thermoplastic molecular chains. The toughening mechanism of BDM/DABPA with RPEK‐C participating is discussed. This study shows that polyaryletherketones with functional active group have great potential application in high‐end toughening fields. [ABSTRACT FROM AUTHOR]

A new type polymeric adsorbent, poly(allylphenol‐co‐hydroxyethyl methacrylate‐co‐vinyl imidazole) (PAHV), is synthesized in this study. 2‐Hydroxyethyl methacrylate is used as complementary monomers along with 1‐vinyl imidazole and allylphenol monomers. The photopolymerization method is preferred as a synthesis method and benzophenone is used as the photoinitiator. The effectiveness of the PAHV against bacterial species such as Escherichia coli and Staphylococcus aureus is investigated by the Clinical and Laboratory Standards Institute (CLSI) disk diffusion method. The inhibition areas of PA1H1V3 and PA1H1V1 derivatives against E. coli and S. aureus are measured as 25 mm ± 0.25 mm and 7 mm ± 0.1 mm; 20 mm ± 0.25 mm, and 5 mm ± 0.1 mm, respectively. Sorption efficiencies (%) at pH = 6 (selected optimum pH) for 100 μg/L Cd and Cr of the PA1H1V1, PA1H3V1, and PA1H1V3 derivatives are found to be 69.0 ± 2.7 and 58.3 ± 6.7, 66.8 ± 6.2 and 75.8 ± 5.5, and 97.2 ± 3.7 and 97.7 ± 3.2 (n = 3), respectively. Adsorption studies revealed that the PA1H1V3 polymer can be used as an alternative for the sorption of cadmium and chromium. The pseudo‐second‐order model and Langmuir isotherm model fits for both adsorption processes. The adsorption capacities obtained from the Langmuir isotherm model for chromium and cadmium sorption are 52.63 and 68.49 μg g−1, respectively. [ABSTRACT FROM AUTHOR]

Statistical copolymers are commercially important because their properties can be tuned by comonomer selection and composition. Rubbery‐state styrene (S)/n‐butyl acrylate (nBA) copolymers have previously been reported to exhibit facile, autonomous self‐healing over a narrow composition band (47/53 to 53/47 mol%). The need for a narrow composition band is explained by alternating comonomer sequences that accommodate interchain secondary bonding. It is hypothesized that copolymers that achieve interchain secondary bonding without alternating sequences can exhibit facile self‐healing over a broad composition range. 2‐ethylhexyl acrylate (EHA) is identified as yielding sequence‐independent secondary bonding interactions. For these interactions it is tested experimentally by glass transition breadth in rubbery‐state S/EHA copolymers, with S/n‐hexyl acrylate (nHA) and S/nBA copolymers as controls. The n‐alkyl acrylate random copolymers exhibit enhanced glass transition breadths over narrow composition bands that correspond to autonomous self‐healing. In contrast, S/EHA copolymers exhibit much greater glass transition breadths than S/nHA and S/nBA copolymers at all compositions tested as well as self‐healing of damage over a broad composition range with full tensile‐property recovery, often in 3–10 h. Characterization of glass transition breadth may serve as a simple screening tool for identifying copolymers that exhibit broad‐composition‐range, facile, autonomous self‐healing and contribute to polymer resilience and sustainability. [ABSTRACT FROM AUTHOR]

The self‐assembly and dynamics of amphiphilic diblock copolymers composed of densely grafted poly(oligo ethylene glycol methacrylate) (POEGMA) and poly(lauryl methacrylate) (PLMA) by means of calorimetry, small‐angle X‐ray scattering (SAXS), and dielectric spectroscopy are investigated. It is reported that the inherent immiscibility between the parent homopolymers, combined with the increased molar mass, results in strong segregation, maintained up to elevated temperatures (i.e., T = 423 K). SAXS reveals that well‐separated POEGMA and PLMA domains self‐assemble into spheres with bicontinuous cubic packing and in lamellar nanostructure in copolymers with respective compositions of 16 and 52 wt.% PLMA. This strong segregation enables the weak crystallization/melting of the short ethylene glycol chains. Additionally, molecular dynamics are investigated through isothermal dielectric and calorimetry measurements. The segmental dynamics (i.e., Tg‐related) of POEGMA and PLMA closely resemble that found in respective homopolymers, implying heterogeneous dynamics. In the glassy state, the local motions of the POEGMA side chains predominantly govern the observed secondary processes in the copolymers. The results on the heterogeneous dynamics in the current amphiphilic diblock copolymers with the densely grafted architecture are compared and contrasted with copolymers having a bottle–brush architecture lacking the amphiphilic nature. [ABSTRACT FROM AUTHOR]

This work presents new anisotropic growth‐directing copolymers suitable for the seed‐mediated growth of gold nanorods (GNRs). Copolymers with different architectures are studied. They all contain dimethylaminomethyl methacrylate (DMAEMA) functionalized with 1‐bromohexadecane (BHD) as the vital component. For the synthesis of the different copolymers, the photo‐iniferter reversible addition–fragmentation chain transfer (photoRAFT) polymerization is used, where DMAEMA is combined with a lower critical solution temperature (LCST) polymer block for better solubility after the functionalization. The results show that the presented copolymers can induce anisotropic growth of gold nanoparticles. Additionally, the influence of the LCST of the water‐soluble block and the temperature of the growth solution on the GNR synthesis are investigated. Furthermore, the plasmonic behavior of the resulting GNRs solution is investigated at temperatures around the LCST of the copolymer. [ABSTRACT FROM AUTHOR]

The memory of crystalline phase in the melt of isotactic polypropylene (iPP) in regiodefective samples of iPP characterized by different concentrations regiodefects, constituted by secondary 2,1 propene units, is studied. The self‐nucleation (SN) experiments have demonstrated that the presence of 2,1 regiodefects produces a strong memory of the crystalline phase in the melt that persists up to temperatures much higher than the melting temperature. The extension of the heterogeneous melt (domain II) containing self‐nuclei increases with increasing the concentration of regiodefects. The higher the concentration of regiodefects the higher the temperature at which the self‐nuclei are dissolved and the homogeneous melt is achieved. This demonstrates that a strong memory of the crystalline phase of iPP in the melt exists not only in copolymers with noncrystallizable bulky comonomeric units rejected from the crystals but even when small defects are largely included in the crystals. [ABSTRACT FROM AUTHOR]

The aim of this work was the characterization of polymer microspheres obtained by the suspension polymerization of divinylbenzene (DVB) and glycidyl methacrylate (GMA), depending on the pore-forming diluents and molar ratio of monomers. The assessed properties included the chemical and porous structure, thermal stability, and sorption capacity of the obtained polymers towards methylene blue. The abovementioned characteristic was carried out for two series of copolymers with molar ratios of monomers of 1:2, 1:1 and 2:1, synthetized with toluene and a mixture of decanol and benzyl alcohol. The structure of the polymers was confirmed by FTIR and elemental analysis. The results of TGA demonstrated the main influence on thermal stability was the composition of polymers, whereas the impact of porogens was negligible. The SBET varied in the range of 12–534 m2g−1 for polymers obtained with toluene and 0–396 m2g−1 with the mixture of alcohols. Toluene enhanced the formation of micro- and mesopores, while the mixture of alcohols enhanced the creation of meso- and macropores. For the polymers prepared with toluene, their effectiveness in water purification decreases in the following order: DVB-GMA 2:1 > DVB-GMA 1:1 > DVB-GMA 1:2, according to the decreasing values of porous structure parameters. In the case of a series obtained with a mixture of alcohols, such correlation was not observed. [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]

An integrated visual energy system consisting of conjugated polymer electrodes is promising for combining electrochromism with energy storage. In this work, we obtained copolymer bifunctional electrodes poly(3,6-dimethoxythieno[3,2-b]thiophene-co-2,3-dihydrothieno[3,4-b][1,4]dioxin-3-ylmethanol)(P(TT-OMe-co-EDTM)) by one-step electrochemical copolymerization, which exhibits favorable electrochromic and capacitive energy storage properties. Because of the synergistic effect of PTT-OMe and PEDTM, the prepared copolymers show better flexibility. Moreover, the morphology and electrochemical properties of the copolymers could be adjusted by depositing different molar ratios of 3,6-dimethoxythieno[3,2-b]thiophene (TT-OMe) and 2,3-dihydrothieno[3,4-b][1,4] dioxin-3-ylmethanol (EDTM). The P(TT-OMe-co-EDTM) electrodes realized a high specific capacitance (190 F/g at 5 mV/s) and recognizable color conversion. This work provides a novel and simple way to synergistically improve electrochromic and energy storage properties and develop thiophene-based conducting polymers for electrochromic energy storage devices. [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]

Polymer networks remain an essential class of soft materials. Despite their use in everyday materials, connecting the molecular structure of the network to its macroscopic properties remains an active area of research. Much current research is enabled by advances in modern polymer chemistry providing an unprecedented level of control over macromolecular structure. At the same time, renewed interest in self‐healing, dynamic, and/or adaptable materials continues to drive substantial interest in polymer network design. As part of a special issue focused on research performed in the Polymer Science and Engineering Department at the University of Massachusetts, Amherst, this review highlights connections between macromolecular structure of networks and observed mechanical properties as investigated by the Tew research group. [ABSTRACT FROM AUTHOR]

Formulating polymer blends is of vital scientific and industrial interest because of their low cost and the possibility of producing new materials with tailored properties. In this research, polypropylene (PP)/acrylonitrile–butadiene–styrene (ABS) polymer blends were prepared using styrene-ethylene-butylene-styrene (SEBS) and styrene-ethylene-propylene (SEP) copolymers. The polymer blends were extruded and injection molded to evaluate the mechanical, rheological, thermal, and thermomechanical properties, infrared spectroscopy, and morphology. Incorporating SEBS and SEP copolymers into the PP/ABS blend increased the torque and reduced the melt flow index, indicating higher viscosity than the PP/ABS base system. As a result, improved compatibility of PP/ABS/SEBS and PP/ABS/SEP blends was achieved, thereby improving the mechanical properties of PP/ABS. However, the SEBS copolymer was more effective. Compared to neat PP, the PP/ABS/SEBS blend with 15% SEBS showed increases in impact strength, elongation at break, and heat deflection temperature (HDT) of 87%, 107%, and 7%, respectively. In addition, the elastic modulus and Shore D hardness were in line with neat PP, and thermal stability measured through thermogravimetry exceeded that of PP by 8 °C. Evidence of fractured ABS particles in the PP matrix was seen in the scanning electron microscopy (SEM) morphology, suggesting that SEBS migrated to the interface. SEBS also remained dispersed in the PP matrix, as confirmed by selective phase extraction, which favored a synergic effect of properties in the PP/ABS/SEBS blend (70/15/15%). This blend offered potential for applications such as toys, furniture accessories, packaging, and housewares. [ABSTRACT FROM AUTHOR]

Appropriate mechanical properties is one of the prerequisites for the applications of hydrogels, where cross‐linker is a crucial component in manipulating such mechanical property. Herein, acryloyl‐functionalized polyethyleneimine (APEI) was innovatively used as novel functional cross‐links to optimize the mechanical properties of polyacrylamide (PAM) hydrogels. APEI cross‐links were synthesized by simply adding acryloyl chloride into polyethyleneimine in aqueous solution. The chemical structures of APEI were confirmed by Fourier transform infrared and nuclear magnetic resonance spectra. APEI possessed massive highly acryloyl functional groups that can serve as multifunctional cross‐linking centers for the polymerization of monomers via covalent bonding interactions. These covalent bonds are favorable for constructing a firm 3D cross‐linked networks for hydrogels to withstand deformations, endowing hydrogels with the improved mechanical properties. The tensile strength with an elongation at break for the hydrogels can reach 234 kPa and 18.4‐fold, respectively. In addition, even the hydrogels can bear cyclic mechanical loads and deformations for 50 cycles at 5‐fold stain, indicating a good fatigue resistance. The deformability of APEI cross‐links clusters under stretching was responsible for the stretchability of PAM/APEI hydrogels. This work provides a simple strategy to enhance the mechanical properties of hydrogels via the development of novel APEI chemical cross‐linker. [ABSTRACT FROM AUTHOR]

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

Organic electrochemical transistors (OECTs) are of great interest in low‐power bioelectronics and neuromorphic computing, as they utilize organic mixed ionic‐electronic conductors (OMIECs) to transduce ionic signals into electrical signals. However, the poor environmental stability of OMIEC materials significantly restricts the practical application of OECTs. Therefore, the non‐fused planar naphthalenediimide (NDI)‐dialkoxybithiazole (2Tz) copolymers are fine‐tuned through varying ethylene glycol (EG) side chain lengths from tri(ethylene glycol) to hexa(ethylene glycol) (namely P‐XO, X = 3–6) to achieve OECTs with high‐stability and low threshold voltage. As a result, the NDI‐2Tz copolymers exhibit ambipolarity, rapid response (<10 ms), and ultra‐high n‐type stability. Notably, the P‐6O copolymers display a threshold voltage as low as 0.27 V. They can operate in n‐type mode in an aqueous solution for over 60 h, maintaining an on‐off ratio of over 105. This work sheds light on the design of exceptional n‐type/ambipolar materials for OECTs. It demonstrates the potential of incorporating these ambipolar polymers into water‐operational integrated circuits for long‐term biosensing systems and energy‐efficient brain‐inspired computing. [ABSTRACT FROM AUTHOR]

The inherent brittleness and high cost of polylactic acid (PLA) hinder its further application. Developing low‐cost, flexible, and biodegradable gelatin (GEL)‐modified PLA is a way to broaden the application prospects of PLA applications. Acetyl tributyl citrate (ATBC) was added to overcome the process difficulty of PLA/GEL melt blending and toughening the blends. Maleic anhydride (MAH) grafted PLA (PLA‐g‐MAH) was prepared to improve the compatibility of the PLA/GEL/ATBC. Because of the interface, physical and chemical interaction induced by PLA‐g‐MAH, the compatibility among PLA, GEL, and ATBC was enhanced, which significantly improved the plasticizing efficiency of ATBC. Results showed that the elongation at break of the blends can be improved by 491%, 68 times higher than that of pristine PLA. Moreover, the modified blends did not break under the conditions of notch impact, which exhibited excellent toughness. The blends possessed a high degradation rate owing to the hydrophilic gelatin and PLA‐g‐MAH, significantly accelerated the degradation process of PLA. The prepared PLA/GEL/ATBC/PLA‐g‐MAH biomass blended plastics exhibited good comprehensive performance, with true sustainability and environmental friendliness. [ABSTRACT FROM AUTHOR]

The ordered mesostructures formed by block copolymers on the nanoscale via the self-assembly have attracted a lot of attention of high-performance material science due to its important, potential applications, especially the single gyroid network, single diamond network, and the single plumber′s nightmare (SPN) network. These three networks are very important in the fields of three-dimensional photonic crystals. Whereas single gyroid and single diamond have been stabilized in block copolymers by adjusting the chain architectures, blending, and using multicomponent systems, so far, no effective way has been found to stabilize the SPN network. Considering such situations, by designing B1A1B2A2C3B3, B1A1B2A2C3, B1A1C2B2A2C3, B1A1C2A2C3, and B1C1A1C2A2C3 multiblock copolymers and based on the simple cubic spheres to generate the unstable states via the rapid-component change of blocks, C, from B to A, the nonequilibrium kinetics of structural evolution starting from these unstable states and the corresponding mechanism as well as the effects from the number, position, and size of blocks, C, are explored. The exploration indicates that the metastable SPN network can be reached by the nonequilibrium kinetics of structural evolution after the rapid-component change of blocks, C, within a relatively wide range of volume-fraction A, which is mainly because that the symmetry of simple cubic spheres is the same as that of SPN (No.221 space group）. [ABSTRACT FROM AUTHOR]

Currently, the copolymer of dopamine (DA) and pyrrole (PY) via chemical and electrochemical oxidation usually requires additional oxidants, and lacks flexibility in regulating the size and morphology, thereby limiting the broad applications of DA‐PY copolymer in biomedicine. Herein, the semiquinone radicals produced by the self‐oxidation of DA is ingeniously utilized as the oxidant to initiate the following copolymerization with PY, and a series of quinone‐rich polydopamine‐pyrrole copolymers (PDAm‐nPY) with significantly enhanced absorption in near‐infrared (NIR) region without any additional oxidant assistance is obtained. Moreover, the morphology and size of PDAm‐nPY can be regulated by changing the concentration of DA and PY, thereby optimizing nanoscale PDA0.05‐0.15PY particles (≈ 150 nm) with excellent NIR absorption and surface modification activity are successfully synthesized. Such PDA0.05‐0.15PY particles show effective photoacoustic (PA) imaging and photothermal therapy (PTT) against 4T1 tumors in vivo. Furthermore, other catechol derivatives can also copolymerize with PY under the same conditions. This work by fully utilizing the semiquinone radical active intermediates produced through the self‐oxidation of DA reduces the dependence on external oxidants in the synthesis of composite materials and predigests the preparation procedure, which provides a novel, simple, and green strategy for the synthesis of other newly catechol‐based functional copolymers. [ABSTRACT FROM AUTHOR]

The aqueous solution of binary mixtures of amphiphilic copolymers is a potential platform for fabricating mixed polymeric micelles for pharmaceutical applications, particularly in developing drug delivery depots for a poorly water-soluble compound. This study fabricated and investigated binary mixtures of poloxamer 403 (P403) and poloxamer 407 (P407) at varying P403:P407 molar ratios to develop a vehicle for the poorly water-soluble compound, using ibuprofen as a model drug. The cooperative formation of mixed micelles was obtained, and the solubility of ibuprofen in the binary mixtures was enhanced compared to the solubility in pure water and an aqueous single P407 solution. The binary mixture with the P403:P407 molar ratio of 0.75:0.25 at a total polymer concentration of 19% w/v exhibited the temperature dependence of micellization and sol-to-gel characteristics of the thermosensitive mixed micellar gels. It possessed suitable micellization and gelation characteristics for in situ gelling systems. The release of ibuprofen from the thermosensitive mixed micellar depots was sustained through a diffusion-controlled mechanism. The findings can aid in formulating binary mixtures of P403 and P407 to achieve the desired properties of mixed micelles and micellar gels. [ABSTRACT FROM AUTHOR]

In this study, the structural attributes of nanoparticles obtained by a renewable and non-immunogenic "inulinated" analog of the "pegylated" PLA (PEG-PLA) were examined, together with the potential of these novel nanocarriers in delivering poorly water-soluble drugs. Characterization of INU-PLA assemblies, encompassing critical aggregation concentration (CAC), NMR, DLS, LDE, and SEM analyses, was conducted to elucidate the core/shell architecture of the carriers and in vitro cyto- and hemo-compatibility were assayed. The entrapment and in vitro delivery of sorafenib tosylate (ST) were also studied. INU-PLA copolymers exhibit distinctive features: (1) Crew-cut aggregates are formed with coronas of 2–4 nm; (2) a threshold surface density of 1 INU/nm2 triggers a configuration change; (3) INU surface density influences PLA core dynamics, with hydrophilic segment stretching affecting PLA distribution towards the interface. INU-PLA2NPs demonstrated an outstanding loading of ST and excellent biological profile, with effective internalization and ST delivery to HepG2 cells, yielding a comparable IC50. [ABSTRACT FROM AUTHOR]

With the gradual miniaturization of electronic devices and the increasing interest in wearable devices, flexible microelectronics is being actively studied. Owing to the limitations of existing battery systems corresponding to miniaturization, there is a need for flexible alternative power sources. Accordingly, energy harvesting from surrounding environmental systems using fluorinated polymers with piezoelectric properties has received significant attention. Among them, polyvinylidene fluoride (PVDF) and PVDF co-polymers have been researched as representative organo-piezoelectric materials because of their excellent piezoelectric properties, mechanical flexibility, thermal stability, and light weight. Electrospinning is an effective method for fabricating nanofibrous meshes with superior surface-to-volume ratios from polymer solutions. During electrospinning, the polymer solution is subjected to mechanical stretching and in situ poling, corresponding to an external strong electric field. Consequently, the fraction of the piezoelectric β-phase in PVDF can be improved by the electrospinning process, and enhanced harvesting output can be realized. An overview of electrospun piezoelectric fibrous meshes composed of PVDF or PVDF co-polymers to be utilized is presented, and the recent progress in enhancement methods for harvesting output, such as fiber alignment, doping with various nanofillers, and coaxial fibers, is discussed. Additionally, other applications of these meshes as sensors are reviewed. [ABSTRACT FROM AUTHOR]

The hydrosilylation reaction is a suitable route to prepare efficient, transparent, and low‐viscose silicone surfactants with low surface tension. Initial materials, the catalyst used, and experimental conditions are highly effective variables to achieve the maximum efficiency of the reaction, reduce the consumption of the catalyst, and prevent side reactions. To draw a comprehensive conclusion on the effect of these variables, a series of trimethylsiloxy‐terminated poly (methylhydro‐dimethyl)siloxanes copolymer (abbreviated as RSiH with different preceding numbers) and two unsaturated polyethylene glycols (UPEG200 and UPEG400) were selected, and the reactions in the presence of two platinum‐based catalysts, namely, hexachloroplatinic acid and ammonium hexachloroplatinate, were statistically studied by Design of Experiment. After initial pre‐investigations, the amounts of reactant and catalyst were subjected to analysis of variance using response surface methodology (RSM). Based on the results, low‐viscose and low‐surface tension silicone surfactants were obtained using UPEG400, RSiH105, and (NH4)2PtCl6 as catalysts, at temperatures over 170 °C. The best results were obtained with a relatively low concentration of the catalyst between 2.57 × 10−6 and 2.72 × 10−6 equivalent catalyst per UPEG. The relative equivalent ratio of [UPEG]/[RSiH] at the optimum condition was 1.6, which provided a surface tension below 21 mN/m together with a minimum amount of unreacted RSiH (less than 3%). The silicone surfactant was characterized as a pure product by a series of spectroscopic methods, such as FT‐IR and 1H NMR spectroscopies, as well as bromine number index. These excellent properties make this compound a new alternative in various industries. [ABSTRACT FROM AUTHOR]

Amphiphilic block copolymers are characterized by the presence of distinct hydrophilic and hydrophobic regions, which are usually arranged in alternating blocks. This unique structure allows these copolymers to self‐assemble into well‐defined nanostructures that exhibit remarkable resistance to enzymatic hydrolysis, high biocompatibility and the ability to be customized with specific structures. These properties make them highly desirable in various applications. Self‐assembled amphiphilic polypeptoids are currently under development as a promising class of pharmaceutical agents. However, the utilization of these peptides as drug carriers for efficient delivery presents a number of challenges. These challenges include less‐than‐optimal loading efficacy and restricted biocompatibility. Herein, a series of stable amphiphilic block copolypeptoids (PNEG‐b‐PNBG and PNEG‐b‐PNHG) were designed and synthesized by controlled ring‐opening polymerization. PNEG chain segments provide hydrophilicity, while PNBG and PNHG chain segments provide hydrophobicity. The hydrophobic molecular chains aggregate in aqueous solutions, resulting in the formation of nano‐assemblies. The self‐assembled amphiphilic block polypeptoid copolymers were investigated. The morphologies of copolymers take the form of micelles from tens of nanometers to a few hundred nanometers. The properties of amphiphilic block copolypeptoids used as drug carriers were further investigated by conducting drug release and cytotoxicity tests. The results indicate that the cumulative release efficiency of self‐assembled polypeptoid copolymers can reach up to about 91%. And they have good biocompatibility and can be expected to be safe materials for efficient drug delivery. This work could provide a facile method for the preparation of amphiphilic block peptoid copolymers for biopharmaceutical applications. © 2024 Society of Industrial Chemistry. [ABSTRACT FROM AUTHOR]

Most triblock copolymer-based physical hydrogels form three-dimensional networks through micellar packing, and formation of polymer loops represents a topological defect that diminishes hydrogel elasticity. This effect can be mitigated by maximizing the fraction of elastically effective bridges in the hydrogel network. Herein, we report hydrogels constructed by complexing oppositely charged multiblock copolymers designed with a sequence pattern that maximizes the entropic and enthalpic penalty of micellization. These copolymers self-assemble into branched and bridge-rich network units (netmers), instead of forming sparsely interlinked micelles. We find that the storage modulus of the netmer-based hydrogel is 11.5 times higher than that of the micelle-based hydrogel. Complementary coarse grained molecular dynamics simulations reveal that in the netmer-based hydrogels, the numbers of charge-complexed nodes and mechanically reinforcing bridges increase substantially relative to micelle-based hydrogels. In the formation of physical hydrogels from triblock copolymers, formation of polymer loops can result in topological defects. Here, the authors report the development of hydrogels from oppositely charged copolymers which assembled to form branched and bridge-rich networks. [ABSTRACT FROM AUTHOR]

In this study, a series of poly(butylene succinate)-based copolymers containing various quantities of dimethyl 2,6-naphthalene dicarboxylate (NDC) were synthesized via melt polymerization. The thermal stabilities of the copolymers were maintained, while a slight increment in the stability was observed as the NDC content increased. The results of differential scanning calorimetry and wide-angle X-ray diffraction demonstrated a reduction in the crystallizability of the copolymers with increasing NDC concentration. Unexpectedly, the tensile tests showed significant enhancement of the elongation rate from 122.5 to 2645.0% as the NDC content increased from 0 to 32 mol%. Samples with 28, 30, and 32 mol% NDC showed remarkable abilities with recovery rates above 90% after three test cycles. Moreover, apparent cut mark repairing behaviors were observed under 70 °C heating in samples containing 25, 28, and 30 mol% NDC. These results indicate the potential of the copolymers for self-healing and highly stretchable shape memory wound dressing material applications. [ABSTRACT FROM AUTHOR]

Polypropylene (PP) has recently been actively investigated as a potential power cable insulation substitute for crosslinked polyethylene (XLPE). This is mainly due to PP's higher thermal withstand capability over XLPE. Notably, PP has much higher stiffness than XLPE and therefore needs to be modified with tougher materials to reduce its overall stiffness while maintaining its desirable dielectric properties. To date, many investigations have been conducted on the mechanical and dielectric effects of PP blended with various copolymers. Nevertheless, systematic investigations on the dielectric effects of PP blended with ethylene‐based copolymers having different ethylene contents are less explored. The current work therefore reports on the impact of different ethylene contents of ethylene‐based copolymers on the breakdown performances of PP. The findings reveal that PP blended with a copolymer having a low ethylene content (68.7 wt%) results in at least 11% higher breakdown performance than PP containing a copolymer having a high ethylene content (77.0 wt%). Specifically, PP containing 10 wt% of copolymers having 68.7 wt% of ethylene content results in comparable breakdown performance to XLPE (325 kV mm−1). These results suggest that ethylene‐based copolymers with an appropriately low ethylene content can be blended with PP to achieve desirable breakdown properties. Highlights: PP is blended with copolymers of varying amounts and ethylene contents.PP blended with low amounts of copolymers has good breakdown strength.PP blended with low ethylene level copolymers has favorable breakdown strength.PP blended with copolymers of low ethylene contents is desirable.The breakdown mechanisms are related with the structure and permittivity. [ABSTRACT FROM AUTHOR]

Luminescent Ag nanoclusters (Ag NCs) are a promising probe material for sensing and bioimaging applications. However, the intrinsic obstacle of poor water stability and photostability greatly restrict their practical application in biological systems. Herein, we report the intracellular hypochlorite (ClO−) detection with amphiphilic copolymer-modified luminescent Ag NCs with good biocompatibility and photostability. The Ag NCs were synthesized by using chemically inert hydrophobic ligands and then modified with an amphiphilic (1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(poly(ethylene glycol))-2000]) (DSPE-PEG-2000) and sodium dodecyl sulfonate (SDS) for phase transfer. It was found that the approach of the removal of organic solvents during the phase transfer has remarkable influences on the properties of the Ag NCs, including their size, luminescence property, and aqueous stability. Furthermore, the silver core of Ag NCs could be oxidatively damaged by ClO−, thereby causing photoluminescence (PL) quenching. The ClO−-induced PL quenching was specific over the other common reactive oxygen species (ROS) as well as some common interferences. Finally, they have been successfully applied as a fluorescent nanoprobe for detecting exogenous and endogenous ClO− in living cells. [ABSTRACT FROM AUTHOR]

Over a decade, single‐junction perovskite solar cells (PSCs) have achieved a remarkable power conversion efficiency of 26.4%. However, the pressing challenge remains to address their long‐term stability for large‐scale industrial production. A significant factor contributing to this instability is the use of doped hole‐transporting materials (HTMs), which often introduce moisture into contact with the perovskite film, leading to its degradation. To address this issue, research has focused on developing novel and stable "dopant‐free" HTMs. These materials possess inherent conductivity and can function without the need for additional dopants. These HTMs, constructed with donors and acceptors, have properties like film‐forming abilities, tunable molecular weights, unique stacking, and high hole mobility. Among the classic donor units, benzodithiophene (BDT) has emerged as a widely utilized component for the synthesis of molecules and polymers for photovoltaic applications. To stimulate further research and optimization of these materials, this overview presents a comprehensive examination of various BDT‐based dopant‐free polymeric HTMs with different acceptor units within the field of PSCs. It provides a concise historical overview, followed by an in‐depth classification and examination of polymeric structures. The exploration delves into their constituent building blocks, aiming to uncover the relationships between structure and activity wherever feasible. [ABSTRACT FROM AUTHOR]

The extent to which electrophores covalently bridged by a saturated linker are electrochemically independent was investigated considering the charge/spin duality of the electron and functionality of the electrophore as a spin carrier upon reduction. By combining computational modeling with electrochemical experiments, we investigated the mechanism by which tethered electrophores react together within 4,4′‐oligo[n]methylene‐bipyridinium assemblies (with n=2 to 5). We show that native dicationic electrophores (redox state Z=+2) are folded prior to electron injection into the system, allowing the emergence of supra‐molecular orbitals (supra‐MOs) likely to support the process of the reductive σ bond formation giving cyclomers. Indeed, for Z=+2, London Dispersion (LD) forces contribute to flatten the potential energy surface such that all‐trans and folded conformers are approximately isoenergetic. Then, upon one‐electron injection, for radical cations (Z=+1), LD forces significantly stabilize the folded conformers, except for the ethylene derivative deprived of supra‐MOs. For radical cations equipped with supra‐MOs, the unpaired electron is delocalized over both heterocycles through space. Cyclomer completion (Z=0) upon the second electron transfer occurs according to the inversion of redox potentials. This mechanism explains why intramolecular reactivity is favored and why pyridinium electrophores are not independent. [ABSTRACT FROM AUTHOR]

Self‐assembly behaviors of special topological polymers such as 8‐figure shaped cyclic polymer are interesting, but are rarely reported so far due to the limited availability. In this work, mikto 8‐figure shaped cyclic copolymers are synthesized with cinnamic acid dimer junctions, in which both rings possess diblock PSx‐b‐PEGy structures. Their self‐assembly in water is investigated in comparison with their corresponding linear precursors. According to scanning electron microscopic (SEM) and transmission electron microscopic (TEM) observation, both of the mikto 8‐figure shaped cyclic polymers and their corresponding linear precursors can form vesicles. But those formed from the former have very smooth surfaces, while those from the linear precursors have rugous surfaces. TEM observation shows that the linear precursors form loose vesicles. The size of micelles formed from 8‐shaped cyclic copolymers is much smaller than that formed from the linear precursors. The topological structure exerts a significant influence on the solution aggregation behavior and provides broad ideas for the construction of precision solution aggregates. [ABSTRACT FROM AUTHOR]

Synthetic polymers are of paramount importance in modern life ‐ an incredibly wide range of polymeric materials possessing an impressive variety of properties have been developed to date. The recent emergence of artificial intelligence and automation presents a great opportunity to significantly speed up discovery and development of the next generation of advanced polymeric materials. We have focused on the high‐throughput automated synthesis of multiblock copolymers that comprise three or more distinct polymer segments of different monomer composition bonded in linear sequence. The present work has exploited automation to prepare high molar mass multiblock copolymers (typically>100,000 g mol−1) using reversible addition‐fragmentation chain transfer (RAFT) polymerization in aqueous emulsion. A variety of original multiblock copolymers have been synthesised via a Chemspeed robot, exemplified by a multiblock copolymer comprising thirteen constituent blocks. Moreover, libraries of copolymers of randomized monomer compositions (acrylates, acrylamides, methacrylates, and styrenes), block orders, and block lengths were also generated, thereby demonstrating the robustness of our synthetic approach. One multiblock copolymer contained all four monomer families listed in the pool, which is unprecedented in the literature. The present work demonstrates that automation has the power to render complex and laborious syntheses of such unprecedented materials not just possible, but facile and straightforward, thus representing the way forward to the next generation of complex macromolecular architectures. [ABSTRACT FROM AUTHOR]

A pioneering approach in the domain of transdermal drug delivery systems (TDDS) is introduced by using microneedles (MNs) fabricated from an amorphous solid dispersion comprising only a model drug and an amphiphilic block copolymer to form a drug nanoformulation upon MN dissolution. To maximize drug loading and ensure consistent release, a minimalist formulation that achieves 40 wt% drug loading, which is a significant improvement over existing methods, is developed. Using scanning electron microscopy, the morphology of MNs is examined across a spectrum of drug loading ratios, demonstrating the consistency in structure and integrity. Mechanical testing confirms the MNs' proficiency in effective skin penetration. A comparative study on the formation of polymeric micelles underscores the innovative concept of a “nano‐in‐micro drug delivery system”. The results demonstrate that MNs manufactured from an amorphous solid dispersion of drug and amphiphilic block copolymer with ultra‐high loading enhance the availability and release dynamics of hydrophobic drugs, positioning them as a tool for enhancing TDDS. This study sets a new benchmark in the utilization of polymer‐drug nanoformulations for transdermal applications and underscores the capacity for high drug loading and the creation of adaptable drug delivery mechanisms for the studied amphiphilic block copolymer. [ABSTRACT FROM AUTHOR]