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In this study, we present a novel orientation discretization approach based on the rhombic triacontahedron for Monte Carlo simulations of semiflexible polymer chains, aiming at enhancing structural analysis through rheo-small-angle scattering (rheo-SAS). Our approach provides a more accurate representation of the geometric features of semiflexible chains under deformation, surpassing the capabilities of traditional lattice structures. Validation against the Kratky–Porod chain system demonstrated superior consistency, underscoring its potential to significantly improve the precision of uncovering geometric details from rheo-SAS data. This approach opens new avenues for investigating the conformations of semiflexible polymers and mechanically induced phase transitions in more complex polymer structures, offering deeper insights into their behavior under various conditions. [ABSTRACT FROM AUTHOR]

Unlike one-dimensional polymers, the theoretical framework on the behaviors of two-dimensional (2D) polymers is far from completeness. In this study, we model single-layer flexible 2D polymers of different sizes and examine their scaling behaviors in solution, represented by Rg ∼ Lν, where Rg is the radius of gyration and L is the side length of a 2D polymer. We find that the scaling exponent ν is 0.96 for a good solvent and 0.64 for under poor solvent condition. Interestingly, we observe a previously unnoticed phenomenon: under intermediate solvent conditions, the 2D polymer folds to maintain a flat structure, and as L becomes larger, multiple folded structures emerge. We introduce a shape parameter Q to diagram the relationship of folded structures with the polymer size and solvent condition. Theoretically, we explain the folding transitions by the competition between bending and solvophobic free energies. [ABSTRACT FROM AUTHOR]

We employ polymer integral equation theory to study a simplified model of semiflexible polymerized ionic liquids (PolyILs) that interact via hard core repulsions and short range screened Coulomb interactions. The multi-scale structure in real and Fourier space of PolyILs (ions chosen to mimic Li, Na, K, Br, PF6, and TFSI) are determined as a function of melt density, Coulomb interaction strength, and ion size. Comparisons with a homopolymer melt, a neutral polymer–solvent-like athermal mixture, and an atomic ionic liquid are carried out to elucidate the distinct manner that ions mediate changes of polymer packing, the role of excluded volume effects, and the influence of chain connectivity, respectively. The effect of Coulomb strength depends in a rich manner on ion size and density, reflecting the interplay of steric packing, ion adsorption, and charge layering. Ion-mediated bridging of monomers is found, which intensifies for larger ions. Intermediate range charge layering correlations are characterized by a many-body screening length that grows with PolyIL density, cooling, and Coulomb strength, in disagreement with Debye–Hückel theory, but in accord with experiments. Qualitative differences in the collective structure, including an ion-size-dependent bifurcation of the polymer structure factor peak and pair correlation function, are predicted. The monomer cage order parameter increases significantly, but its collective ion counterpart decreases, as ions become smaller. Such behaviors allow one to categorize PolyILs into two broad classes of small and large ions. Dynamical implications of the predicted structural results are qualitatively discussed. [ABSTRACT FROM AUTHOR]

Designing homogeneous networks is considered one typical strategy for solving the problem of strength and toughness conflict of polymer network materials. Experimentalists have proposed the hypothesis of obtaining a structurally homogeneous hydrogel by crosslinking tetra-armed polymers, whose homogeneity was claimed to be verified by scattering characterization and other methods. Nevertheless, it is highly desirable to further evaluate this issue from other perspectives. In this study, a coarse-grained molecular dynamics simulation coupled with a stochastic reaction model is applied to reveal the topological structure of a polymer network synthesized by tetra-armed monomers as precursors. Two different scenarios, distinguished by whether internal cross-linking is allowed, are considered. We introduce the Dijkstra algorithm from graph theory to precisely characterize the network structure. The microscopic features of the network structure, e.g., loop size, dispersity, and size distribution, are obtained via the Dijkstra algorithm. By comparing the two reaction scenarios, Scenario II exhibits an overall more idealized structure. Our results demonstrate the feasibility of the Dijkstra algorithm for precisely characterizing the polymer network structure. We expect this work will provide a new insight for the evaluation and description of gel networks and further help to reveal the dynamic process of network formation. [ABSTRACT FROM AUTHOR]

Loop formation in complex environments is crucially important to many biological processes in life. In the present work, we adopt three-dimensional Langevin dynamics simulations to investigate passive and active polymer looping kinetics in crowded media featuring polymer–crowder attraction. We find polymers undergo a remarkable coil–globule–coil transition, highlighted by a marked change in the Flory scaling exponent of the gyration radius. Meanwhile, looping time as a function of the crowder's volume fraction demonstrates an apparent non-monotonic alteration. A small number of crowders induce a compact structure, which largely facilitates the looping process. While a large number of crowders heavily impede end-to-end diffusion, looping kinetics is greatly inhibited. For a self-propelled chain, we find that the attractive crowding triggers an unusual activity effect on looping kinetics. Once a globular state is formed, activity takes an effort to open the chain from the compact structure, leading to an unexpected activity-induced inhibition of looping. If the chain maintains a coil state, the dominant role of activity is to enhance diffusivity and, thus, speed up looping kinetics. The novel conformational change and looping kinetics of both passive and active polymers in the presence of attractive crowding highlight a rather distinct scenario that has no analogy in a repulsive crowding counterpart. The underlying mechanism enriches our understanding of the crucial role of attractive interactions in modulating polymer structure and dynamics. [ABSTRACT FROM AUTHOR]

We propose a method to build full-atomistic (FA) amorphous polymer structures using reverse-mapping from coarse-grained (CG) models. In this method, three models with different resolutions are utilized, namely the CG1, CG2, and FA models. It is assumed that the CG1 model is more abstract than the CG2 model. The CG1 is utilized to equilibrate the system, and then sequential reverse-mapping procedures from the CG1 to the CG2 models and from the CG2 to the FA models are conducted. A mapping relation between the CG1 and the FA models is necessary to generate a polymer structure with a given density and radius of chains. Actually, we have used the Kremer–Grest (KG) model as the CG1 and the monomer-level CG model as the CG2 model. Utilizing the mapping relation, we have developed a scheme that constructs an FA polymer model from the KG model. In the scheme, the KG model, the monomer level CG model, and the FA model are successively constructed. The scheme is applied to polyethylene (PE), cis 1,4-polybutadiene (PB), and poly(methyl methacrylate) (PMMA). As a validation, the structures of PE and PB constructed by the scheme were carefully checked through comparison with those obtained using long-time FA molecular dynamics (MD) simulations. We found that both short- and long-range chain structures constructed by the scheme reproduced those obtained by the FA MD simulations. Then, as an interesting application, the scheme is applied to generate an entangled PMMA structure. The results showed that the scheme provides an efficient and easy way to construct amorphous structures of FA polymers. [ABSTRACT FROM AUTHOR]

Understanding the mechanisms underlying living anionic polymerization is essential for advancing efficient and sustainable elastomer production technologies. This study investigates the introduction of a functional styrene derivative at the initiation of a styrene‐butadiene polymer chain with high efficiency. Butyllithium is the most widely used initiator in anionic polymerization due to its high reactivity, availability, and ability to provide precise control over polymer molecular weight and structure. Modified initiators, formed from N‐(dimethyl(vinylbenzyl)silyl)‐N,N‐bis(trimethylsilyl)amine and isomers of butyllithium (n‐, sec‐, and tert‐), increase initiation efficiency and reduce oligomer formation. The developed procedure demonstrates the effective use of a functional styrene derivative as an alpha chain‐end modifier. The formation of a unimeric structure improves from 15.6% to 88.3%, significantly increasing the yield of alpha functionalization. Direct transfer of the functional styrene derivative to the alpha position expands the potential for functionalization in anionic polymerization. The activity of the preinitiators is evaluated in styrene‐butadiene anionic copolymerization. The functional initiators are terminated and characterized by high‐performance liquid chromatography coupled with gel permeation chromatography to assess the degree of polymerization. This method enables quantitative analysis of oligomer formation. The synthesized copolymers are further characterized by their molar masses, microstructure, Mooney viscosity, and glass transition temperature. [ABSTRACT FROM AUTHOR]

[Display omitted] • Thermoresponsive nanocontainers are synthesized from ionic complexes of polybases. • The complexes can be readily (re)formed by simple mixing of the components. • Resulting comb-like complexes with wedge-shaped ligands exhibit multiscale ordering. • Ligand type controls shape and thermal stability of nanocontainers. • Coarse-grain simulation explores the routes of vesicle and nanocylinders formation. Multi-responsive polymeric nanocontainers attract significant attention for their potential applications in biotechnology, drug delivery, catalysis, and other fields. By incorporating a liquid-crystalline (LC) mesogenic ligand with an alkyl tail length ranging from 8–12 carbons, ionically linked to the polymer backbone, we generate vesicles with walls significantly thinner than those of conventional polymersomes, approaching the thickness of a lipid bilayer. These LC vesicles, ranging in size from 50–120 nm, are designed to be mechanically robust due to the alignment of the hydrophilic polymer backbone within the plane of the vesicle wall. Additionally, incorporating a temperature-sensitive block into the polymer structure imparts thermoresponsiveness to the nanocontainers, enhancing their functionality and adaptability for various applications. Ionic complexes of hydrophilic polybases, specifically poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) and PDMAEMA- b -PNIPAM (poly(N -isopropylacrylamide)) block copolymers, with amphiphilic wedge-shaped mesogens bearing a sulfonic acid group at the focal point were synthesized. The designed nanocontainers, in the form of either vesicles or nanotubes, exhibit a well-defined wall thickness of 5 nm, dictated by the organization of a smectic LC phase. The constructed coarse-grained models elucidate the mechanism of self-assembly, demonstrating that the balance between the hydrophilicity of the main polymer chain and the hydrophobicity of the wedge-shaped pendant groups determines both the internal and external structure of the vesicles. [ABSTRACT FROM AUTHOR]

Polymer structures are essential in biomedical applications due to their biocompatibility, biodegradability, and ability to form intricate structures on micro‐ to nanometer scales. This review, emphasizing electrospinning and phase inversion techniques, examines the fabrication strategies and chemical design of polymer structures for biomedical use. Electrospinning, particularly needleless electrospinning, produces nanofibres with high porosity and flexibility and is widely applied in tissue engineering and drug delivery. Phase inversion, including thermal, nonsolvent‐, vapor‐ and evaporation‐induced phase separation, allows precise control over polymer properties but faces challenges in terms of cooling rates and solvent characteristics. Chemical design through doping, functionalization, cross‐linking and copolymerization enhances the biocompatibility, biodegradability and mechanical properties of polymers, facilitating advanced applications in drug delivery, tissue scaffolding and biosensors. Advanced functional polymers are revolutionizing biomedical fields, offering innovative solutions for therapeutic medicine delivery, disease detection, diagnostics, and regenerative medicine. Despite remarkable progress, challenges, such as scalability, cost‐effectiveness, and environmental impact, persist. This review underscores the transformative potential of advanced polymer materials in medical treatments and advocates for continuous research and interdisciplinary collaboration to overcome existing challenges and fully exploit the capabilities of these materials in improving patient care and medical outcomes. Future perspectives highlight enhancing precision control mechanisms, integrating phase inversion with other techniques and developing large‐scale production methods to advance the field further. [ABSTRACT FROM AUTHOR]

The present study investigates the usability of lignocellulosic kapok fibers as a reinforcement for lightweight composites. Kapok fibers are modified by dewaxing followed by a silane coupling agent at different concentrations. The crystallographic structure and the alignment of silane linkage polymer chains on fiber structure are examined using X‐ray Diffraction (XRD). The linkage of chemical bonds (SiOC And SiOSi) between the polymer structure of the fiber and silane coupling agent is confirmed from FTIR spectroscopy. Additionally, the small angle X‐ray scattering (SAXS) study is done considering kapok fiber as a nonideal two‐phase system and the study investigates the modification occurring within the macromolecular structure of the kapok fiber. Following the grafting of silanes onto the fiber, silane‐modified kapok fiber‐reinforced epoxy composites are fabricated using the hand lay‐up technique. The chemical treatments on the fiber, enhanced flexural, tensile and impact strength of the composites by 132%, 102%, and 146% respectively. [ABSTRACT FROM AUTHOR]

Highly filled polymer fibers offer huge promise for radiation protection safety and wear comfort of personal protective equipment (PPE) in radiation environments. However, it usually sacrifices mechanical properties that directly related to practical usability. Here, as high as 75 wt% PbWO4 (PWO) particles have been filled in polyvinyl alcohol (PVA) fiber via tailoring their size and shape for enhanced γ‐rays shielding and good mechanical properties. Clearly shown that 0 dimensional (0‐D) PWO exhibits better dispersion and compatibility between the interfaces than 1‐D PWO in highly filled PVA fibers. In addition, 70 wt% 0‐D PWO/PVA fibers display better mechanical properties than 70 wt% 1‐D PWO/PVA fibers. Note that 75 wt% 0‐D PWO/PVA fibers show 1.02 cN/dtex of tensile strength. However, 75 wt% 1‐D PWO/PVA fibers fail to be fabricated smoothly. Importantly, the overlapped fabrics with 75 wt% 0‐D PWO/PVA fibers display 43.05% of γ‐ray shielding (105 keV) meanwhile it offers good air and water vapor permeability for wear comfort. The superior γ‐ray shielding ascribes the polymer fibers with the higher filling in comparison with its counterpart, which provides a practical means to design radiation protection safety and wear comfort of articles. Highlights: This work breaks the upper limit of filling in polymer fibersFiller structure can weigh the integrated properties of polymer fibers.0‐D PWO particles promote interfacial compatibility in highly filled fibers.Radiation protection safety and wear comfort of articles tend to be designed. [ABSTRACT FROM AUTHOR]

Carbon dioxide (CO2) serves as a cheap, abundant, and renewable C1 building block for the synthesis of organic compounds and polymers. Selective and efficient CO2 fixation processes are still challenging because of the kinetic and thermodynamic stability of CO2. Among various CO2 fixation processes, the ring-opening copolymerization (ROCOP) of epoxides and CO2 gives aliphatic polycarbonates with high atom economy, although the chemical and physical properties of the resulting polycarbonates are not necessarily satisfactory. Introducing the third monomers into this ROCOP system provides new terpolymers, and the thermal, optical, mechanical or degradation properties can be added or tuned by incorporating new polymer backbones derived from the third monomers at the expense of the CO2 content. Here we review the terpolymerization reactions of epoxides, CO2, and the third monomers such as cyclic anhydrides, lactones, lactides, heteroallenes, and olefins. The development of catalysts and the control of the polymer structures are described together with the chemical and physical properties of the resulting polymers. [ABSTRACT FROM AUTHOR]

Introduction: A novel fluorescent magnetic molecularly imprinted polymer (FMMIP) was developed for the effective extraction of malathion (MLT) and chlorpyrifos (CPS) from agricultural water sources. Methods: The FMMIP was confirmed to have a stable polymer structure with significant thermal resilience through comprehensive characterization using techniques such as TEM and TGA. The magnetic properties of the FMMIP facilitated easy separation by external magnetic fields, with a notable magnetization of 0.006 emu/g. Kinetic and isotherm studies revealed that adsorption of MLT and CPS onto the FMMIP conformed best to the pseudo-first-order model and Freundlich isotherm, suggesting a predominance of physisorption mechanisms and heterogeneous binding sites. Results and Discussion: The FMMIP demonstrated exceptional adsorption capacities, achieving a maximum of 93 mg/g for MLT and 69 mg/g for CPS. Regeneration trials indicated that the FMMIP maintains its high adsorptive performance over multiple cycles, highlighting its potential for sustainable use. Statistical validation confirmed the method's reliability, with RSD values for MLT and CPS at 6.5% and 7.3%, respectively, and LODs determined to be 1.26 mg/L for MLT and 1.22 mg/L for CPS. The strong R2 values of 0.992 for MLT and 0.998 for CPS from the adsorption studies substantiate the method's effectiveness. This study demonstrates that the synthesized FMMIP is a promising material for removing MLT and CPS, supporting its application in environmental clean-up initiatives to protect and preserve ecosystems. [ABSTRACT FROM AUTHOR]

Patterning of various surface properties, including roughness, wettability, adhesiveness, and mechanical properties, can markedly enhance the functionality of test systems. Thus, porous polymethacrylates prepared by polymerization‐induced phase separation (PIPS) represent a promising class of functional materials for the construction of miniaturized test systems. Different porosity, surface chemistry, and wettability are achieved in porous polymethacrylates with different precursor compositions. Nevertheless, only wettability microstructuring has been highlighted for these materials thus far. Here, the study presents a novel method for the direct and selective deposition of porous polymethacrylate films with different surface chemistry and porosity. The selective adhesion of omniphobic–omniphilic wettability patterns is used to facilitate the polymer pattern formation. The feasibility of patterning with different monomers and porogenic solvents is demonstrated. The topological study confirms the selective application of polymer structures with different thickness and roughness. The wettability characterization of the omniphobic material shows no significant changes caused by the operations performed. Thus, a new pattern with a greater difference in the wettability of the areas is produced in the process. Discontinuous dewetting of different liquids is performed. The use of poly(2‐hydroxyethyl methacrylate‐co‐ethylene dimethacrylate) (HEMA‐EDMA) modified patterns for precise living cell patterning is also demonstrated. [ABSTRACT FROM AUTHOR]

In this work a novel method for synthesis of 1,8-dihydroxynaphthalene melanin was presented, as well as the physicochemical properties, molecular structure, and characteristics of the pigment. The proposed synthesis protocol is simple and cost-effective with no enzymes or catalysts needed. The final product is not adsorbed on any surface, since the pigment is the result of autooxidation of 1,8-dihydroxynaphthalene. Performed analyses revealed that the solubility, optical and paramagnetic properties are typical for melanins, and in the EPR spectra an unusual hyperfine structure was observed. The molecular structure of the pigment consists of three different layers forming polar and non-polar surfaces. Additionally, the presence of ether bonds presence was revealed. The developed method creates new opportunities for melanin research and eliminates the need to extract melanins from biological samples, which often lead to structural changes in isolated melanins, which undermines the reliability of analyses of the properties and structure of these polymers. On the other hand, the ubiquity of melanins in living organisms and the diversity of their biological functions have let to the growing interest of researchers in this group of pigments. The analyses carried out show that the obtained synthetic DHN polymer can be considered as a model DHN-melanin in mycological studies and material research. [ABSTRACT FROM AUTHOR]

Polymers containing lactam structures play a crucial role in both natural biological systems and human life, and their synthesis, functions and applications are of utmost importance for biomimetics and the creation of new materials. In this study, we developed an efficient heterogeneous Pauson–Khand polymerization (h‐PKP) method for the controlled synthesis of main‐chain poly(γ‐lactam)s containing α, β‐unsaturated γ‐lactam functionalities using readily available internal alkynes and imines. The molecular weights of the resulting poly(N−Ts/γ‐lactam)s can be precisely controlled by adjusting the ratio of phenyl formate and nickel. These polymers exhibit high solid‐state luminescence and demonstrate rapid and sensitive dual responsiveness to light and acid stimuli. They further demonstrate strong reactive oxygen species (ROS) generation capability. The unique dual‐emission peaks observed in poly(N−H/γ‐lactam)s obtained through post‐treatment under acidic conditions demonstrate a mechanism of aggregation‐induced intermolecular excited‐state proton transfer specific to lactam structures. The efficient one‐pot synthetic method for poly(γ‐lactam) provides a novel strategy for constructing polymers with γ‐lactam structures in the main chain and the simple and efficient post‐modification method offer a versatile toolbox for functionalizing poly(γ‐lactam)s to expand their potential applications. [ABSTRACT FROM AUTHOR]

In this study, a new system was developed to carry out simultaneous near-infrared (NIR) and small-angle X-ray scattering (SAXS) measurements. Aged polypropylene (PP) was examined with the NIR–SAXS system to demonstrate how it can be utilized to derive pertinent information about the polymer structure. Pairs of SAXS profiles and NIR spectra of PP in its initial state and after aging were measured to derive an in-depth understanding of the aging phenomenon. The SAXS profiles of the PP samples showed a clear shift of the SAXS peak to the lower q direction induced by the thermal aging, indicating an increase in the length of the long-period structure. Two-trace two-dimensional (2T2D) asynchronous correlation spectra derived from NIR spectra clearly revealed that the aging treatment leads to a substantial increase in the spectral intensity of the regularity bands representing the longer helix present in a folded lamellar structure. In other words, it suggests that the long helix structure is more abundantly present than the short helix structure in the aged PP than in the initial PP. By combining the information derived from the SAXS profiles and NIR spectra, the details of the aging-induced variation were clearly determined. Namely, aging causes additional crystallization of the PP by developing more helical structures, which involves an increase in the lamellar thickness as well as a decrease in the amorphous region. The growth of the rigid crystalline phase restricts the elastic deformation in the amorphous structure, which eventually induces the deterioration of PP by making the polymer hard but brittle. Such observation, in turn, implies that retarding or accelerating the crystallized structure of PP substantially works to control the progress of aging. [ABSTRACT FROM AUTHOR]

Polymers play a crucial role in modern construction, particularly in the context of underground engineering structures. Foamable polymer (FP) is commonly used for grouting to remediate civil engineering construction. The foaming expansion process produced different microstructures based on the surrounding geological conditions, resulting in the appearance of a crystal structure and cellular structure at the interface in turn. When the crystal structure was located at the interface of the concrete or rock, it was known as a molded skin. To study the water-plugging effect of FP applied in underground structures, this study visualized water intrusion into FP by using nuclear magnetic resonance (NMR) analysis and determined the sealing pressure threshold. Two empirical formulas were obtained to verify the sealing pressures of FP. The water infiltration process was observed as "microfoamed molded skin to polymer cellular structure to partial foamed cracks to microfoamed molded skin." When there was preexisting damage on the polymer surface, water directly contacted the cellular structure and accumulated on the molded skin, decreasing the sealing pressure threshold. The maximum sealing threshold pressure of the polymer was approximately 1.50 MPa, increasing exponentially with density, while foaming reduced density. In simulated crack grouting tests, that threshold of polymers increased from 0.74 MPa with the increased polymer density. This study provided a means of verifying the water-plugging effect of grouting in geological engineering structure disasters. [ABSTRACT FROM AUTHOR]

Solution‐processed conjugated polymers have been widely used in the fields of electronic skin, wearable devices, and organic optoelectronic devices, due to their excellent optoelectronic properties, flexibility, and low cost. The aggregate structure of conjugated polymers determines the efficiency of charge carrier transport, thereby affecting the optoelectronic performance of the devices. In this work, we regulated the crystalline behavior and aggregated state structure of D‐A conjugated polymers by controlling the interaction between solvents and conjugated polymers. By using the Hansen solubility parameter radius (Ra) to screen different polar and nonpolar solvents, we found that in nonpolar solvents with a larger Ra, the polymer exhibited strong intermolecular aggregation, while in solvents with a smaller Ra, the polymer showed almost no ordered aggregation. During the subsequent film formation process, we extended the crystallization time of the conjugated polymer by controlling the solvent atmosphere. Films prepared in nonpolar solvents with a larger Ra showed the formation of large‐sized fibers, exhibiting a mixed orientation of face‐on and edge‐on. On the other hand, films prepared in solvents with a smaller Ra formed smaller fibers, mainly with an edge‐on orientation. In‐situ film absorption spectroscopy indicated that the aggregation state of the polymer in nonpolar solvents with a larger Ra could be maintained through a memory effect during the film formation process, while the aggregation behavior of the polymer in solvents with a smaller Ra underwent significant changes. Ultimately, the films prepared in solvents with a larger Ra exhibited higher charge carrier mobility. [ABSTRACT FROM AUTHOR]

The coordination sphere and steric variations in iron catalysts present a fascinating strategy for adjusting monomer regio- and stereoselective enchainment, leading to the development of novel polymer structures in isoprene polymerization. This study investigates a range of iron complexes with variations in the coordination spheres (bidentate and tridentate) and steric/electronic properties of side arms to evaluate their impact on isoprene polymerization. X-ray analysis revealed that the tridentate Fe-NMe2 complex has a dinuclear structure with a μ2-O bridge, where each iron center is monoligated in an octahedral geometry. In contrast, the bidentate Fe-NHPh crystallizes as an ion pair, consisting of a trisligated [L3Fe]2+ cation and counteranions [FeCl4]− and [Cl]−. Toward isoprene polymerization, iron complexes with tridentate ligands bearing NMe2 or NiPr2 side arms exhibited high catalytic activity, whereas those with NH2 or OH side arms showed significantly lower activity. In addition, both bidentate iron complexes were also highly active precatalysts, with activities reaching up to 1.8 × 105 g (IP) per mol (Fe) per h. Variations in the ligand framework led to significant differences in polymer molecular weights, ranging from 37.5 × 103 g mol−1 to 272.8 × 103 g mol−1, with narrow to broad dispersities. Of significant note, tridentate iron complexes were particularly effective for 3,4 monomer addition (up to 63%), resulting in isopropenyl-enriched polyisoprene. In contrast, bidentate complexes showed a nearly equal preference for both 1,4 and 3,4 additions (1,4/3,4 ≈ 50/50). Polyisoprenes with a high number of isopropenyl pendant groups are highly sought after for post-functionalization and the production of high-performance resins. [ABSTRACT FROM AUTHOR]

Organic electrode materials offer multi‐electron reactivity, flexible structures, and redox reversibility, but encounter poor conductivity and durability in electrolytes. To overcome above barriers, we propose a dual elongation strategy of π‐conjugated motifs with active sites, involving the extended carbazole and electropolymerized polymer, which enhances electronic conductivity by the electronic delocalization of electron‐withdrawing conjugated groups, boosts theoretical capacity by increasing redox‐active site density, and endows robust electrochemical stability attributed to the nanonetwork feature of polymer structures. As a proof‐of‐concept, 5,11‐dihydridoindolo[3,2‐b]carbazole (DHIC) is selected as the model cathode material for a dual‐ion battery, with elongated carbazole groups functioning both as redox‐active centers and polymerization anchors. Electrochemical comparisons and theoretical simulations validate the excellent specific capacity, accelerated reaction kinetics, and enhanced anion storage stability imparted by the dual elongated π‐conjugated system containing both carbazole motif and electropolymerized DHIC (pDHIC). Simultaneously, the coordination interaction between pDHIC and anions is innovatively evidenced through operando electron paramagnetic resonance spectra. As anticipated, pDHIC cathode delivers an unprecedentedly high specific capacity of 197 mAh/g at 50 mA/g, far outperforming graphite cathodes, and maintains excellent cycling stability with a capacity retention of 86.1 % over 500 cycles. This synergetic strategy sheds light on the performance revolution of organic electrode materials. [ABSTRACT FROM AUTHOR]

This study presents an experimental measurement of interfacial thermal resistance (ITR) at polymer–polymer interfaces using a multi‐layered bulk sample approach. ITR is commonly measured using thin‐film techniques, but new advancements enable testing in bulk materials with multilayered structures. However, traditional multilayer fabrication is often resource‐intensive and lacks consistency. This study introduces a simple rotational overlapping method for fabricating multi‐layered polymer samples for bulk ITR measurement. Combining numerical simulations with experimental validation, researchers optimize layer overlapping conditions using measured viscosity data of high‐density polyethylene (HDPE), polypropylene (PP), and polylactic acid (PLA). Samples are fabricated at viscosity‐matching temperatures, and shear forces from stirring disks create uniform layer patterns. Computational fluid dynamics (CFD) simulations elucidate the layer formation mechanism, enabling the fabrication of samples with over 112 layers within a 4.6 mm thickness. ITR testing reveals a direct correlation between layer number and thermal resistance. PE‐PP samples exhibit an average ITR of 9.58 × 10−6 K m2 W−1, with a 10.32% increase in resistance from 38 to 112 layers. Similarly, PE‐PLA samples with an ITR of 1.31 × 10−5 K m2 W−1 show a 2.8% increase from 5 to 23 layers. Overall, The experimental procedure provides valuable data to advance the understanding of ITR in polymer–polymer interfaces. [ABSTRACT FROM AUTHOR]

Hydrogels, as valuable biomaterials, have limited applications owing to their mechanical fragility. This study presents a structural modification approach to strengthen hydrogels mechanically. First, the precursor hydrogel undergoes deformation through stretching and twisting, resulting in a helical polymer structure and a deformation gradient. This deformed structure is then stabilized by densification and additional crosslinking. The twisted hydrogel shows improved extensibility and toughness owing to enhanced stress transfer in its unique structure. Additionally, multiple hydrogel strands are assembled hierarchically into ropes and cables, exhibiting advantageous mechanical properties such as high energy dissipation and durability. These reinforced mechanical features lead to considerable performance improvements in applications such as strain sensing and impact absorption. Furthermore, practical utility is demonstrated in areas including posture correction and injury prevention. The hydrogel reinforced by this method has the potential to be used in various fields where both mechanical properties and biocompatibility are crucial. [ABSTRACT FROM AUTHOR]

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Seven types of plastics were pyrolyzed in a fluidized bed reactor: post-consumer recycled (PCR) high-density polyethylene (HDPE), PCR polypropylene (PP), HDPE virgin resins with two different molecular weights, virgin resins of low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and PP. Pyrolysis produced non-condensable gases (C1–C3), liquid phase products (C4–C40), and solids (C40+ and chars), with alkane, alkene, alkadiene, aromatic, and multi-cycloaromatics as the predominant compounds. The polymer structure had the greatest impact on product distribution, with minimal influence from molecular weight. Branches in polyethylene (PE) acted as thermal defects initiating degradation. Higher branch density in PE led to increased concentrations of aromatics, branched alkanes, and internal alkenes. PP and PE exhibited distinct degradation mechanisms, with PP requiring less energy for decomposition and yielding more oil. Pyrolysis oil from PCR HDPE and PCR PP contained a higher proportion of branched compounds. Additives in PCR plastics may promote isomerization during pyrolysis. [ABSTRACT FROM AUTHOR]

One‐pot processes have emerged as a powerful strategy in (macro)molecular synthesis: integrating a multicatalytic process maximizes efficiency, reduces waste, improves profitability, and provides versatile tools for designing of more sustainable processes without compromising selectivity and activity. This review article provides a critical overview of the application of one‐pot transformations in polymerization, with the goal of synthesizing polymers with tailored structures and functions for a wide range of applications. Recent advances in one‐pot polymerization techniques are highlighted, including examples from controlled polymerization methods such as atom transfer radical polymerization, reversible addition‐fragmentation chain transfer polymerization, and ring‐opening polymerization, among others. Special emphasis is placed on the design and optimization of reaction conditions, catalyst systems, and monomer combinations to achieve precise control over polymer structure and functionality. [ABSTRACT FROM AUTHOR]

In this work, three carboxymethyl starches (CMS) were obtained by the two-step reaction process of carboxymethylation with different degrees of substitution (0.16, 0.33, and 0.36). From these samples, (bio)polyelectrolyte complexes ((bio)PECs) were obtained with chitosan (Chit) by the mixing of individual solutions of polymers (0.25 wt.%) at different volume ratios. The effect of the biopolymer and ionized groups of z ratios, pH, and degree of substitution of CMS in the formation of PEC were evaluated by turbidimetry and dynamic light scattering. The results showed that increasing the amount of CMS samples (ratio of z) led to an increase in the efficiency of the formation of (bio)PEC using CMS with a high DS value. Using the turbidimetry method for the chitosan and CMS mixtures, it was observed that the formation of (bio)PEC is divided into four transition zones delimited by pH transition points, and the stoichiometric complexation (z = 1) is achieved at a pH that displayed morphological changes "pHmorph", which is a single point for Chit:CMS 1, and for Chit:CMS 2 and Chit:CMS 3, this is a range of 4.9–6.4 and 4.3–6.4, respectively. Analysis of the structural properties of the structures of (bio)PECs by dynamic light scattering was characterized by monomodal distribution, and the main observed effect was associated with an increase in the value of Davg with an increase in the ratio of Chit:CMS. [ABSTRACT FROM AUTHOR]

The relevance of the hemodialysis procedure is increasing worldwide due to the growing number of patients suffering from chronic kidney disease. Taking into account the structure of dialysis polymer membranes is an important aspect in their development to achieve the required performance of hemodialyzers. We propose a new mathematical model of mass transfer that allows hollow-fiber membrane structural parameters to be taken into account in simulating the clearance (CL) of hemodialyzers in a way that does not require difficult to achieve close approximation to the exact geometry of the membrane porous structure. The model was verified by a comparison of calculations with experimental data on C L obtained using a lab-made dialyzer as well as commercially available ones. The simulations by the model show the non-trivial behavior of the dialyzer clearance as a function of membrane porosity ( f p ) and the arrangement of pores (α). The analysis of this behavior allows one to consider two strategies for increasing the C L of the dialyzer by optimizing the polymer membrane structure: (1) creating a membrane with a well-structured pore system (where α → 1) since doubling α at a high enough f p can lead to an almost tenfold increase in C L ; (2) increasing the porosity of the membrane characterized by a random arrangement of pores (α → 0), where, at a relatively low α , a sharp increase in C L is observed with a small increase in f p over a certain threshold value. [ABSTRACT FROM AUTHOR]

Based on a combination of hexagonal honeycomb and re-entrant honeycomb cells, the concept of novel hybrid cell structures was developed. Experimental studies and numerical analyses of the behaviour of the analysed structures under in-plane compression in two compression directions were carried out. Explicit finite element analyses with an explicit integration scheme, incorporating plastic deformation and ductile damage evolution models, were employed to analyse the entire deformation process, including plastic and damage stages. Good agreement was obtained between the results of the numerical analyses and the experimental studies. [ABSTRACT FROM AUTHOR]

Binary blends of polyterpenes are employed comprising cis‐1,4‐polyfarnesene (PF) with a bottlebrush architecture, and linear cis‐1,4‐polyisoprene (PI) as model systems toward supersoft polymer melts. The bottlebrush PF results in a low plateau modulus (GN0≈3.5×104${G}_{N}^{0}\approx 3.5\ensuremath{\times{}}{10}^{4}$ Pa) that can further be reduced with the addition of PI. Depending on the fraction of short PI chains in the athermal and nearly isofrictional blends, plateau moduli in the range from 1 to 10 kPa can be achieved. Tube dilation is very efficient in the present binary blends as compared to more common blends comprising long/short or linear/star chains of identical polymer structure. [ABSTRACT FROM AUTHOR]

Sulfur‐containing polymers with unique structures and fascinating properties have attracted much attention recently, the efficient and economic synthetic approaches for various sulfur‐containing polymers have rapidly developed. Herein, the multicomponent reaction of elemental sulfur, isocyanide, and alcohol was designed at mild condition in the presence of NaOH, and the corresponding NaOH‐assisted multicomponent polymerization of elemental sulfur, diisocyanides, and diols were developed at room temperature or 40 °C in air, to produce poly(O‐thiocarbamate)s with well‐defined structures, high molecular weights (Mws up to 32 500 g/mol) and high yields (up to 99 %). The facilely available monomers, mild condition, and high efficiency of this MCP enabled scale‐up synthesis of poly(O‐thiocarbamate)s, and 7.33 g polymer was obtained in 98 % yield. These functional poly(O‐thiocarbamate)s could enrich Au3+ from aqueous solution with high enrichment capacity (983 mg⋅Au3+/g) and high efficiency (>99.77 %) in 1 min, demonstrating superior gold enrichment performance and their potential industrial and economic values. [ABSTRACT FROM AUTHOR]

By combination of UV curing and frontal polymerization, interpenetrating polymer networks (IPNs) based on diglycidyl ether of bisphenol‐A (DGEBA) epoxy resin and polydicyclopentadiene (PDCPD) were prepared by UV‐induced simultaneously frontal polymerization in this paper. Compared with the net DGEBA cured polymer, the tensile strength, elongation at break and impact strength of the IPNs were simultaneously improved. The maximum tensile strength and elongation at break of the IPNs reached 100 MPa and 4.64%, respectively, and the maximum impact strength reached 7.34KJ/m2 with an improvement of 115.2% over that of the net DGEBA cured polymer. Thermogravimetric analysis (TGA) results revealed that the IPNs could enhance the thermal stability. Data of the differential scanning calorimetry (DSC) and TGA testing shows that the IPN shows a single glass transition temperature (Tg) which is between the Tg of DGEBA and DCPD, indicating homogeneous phase and highly cross‐linked IPN formed. Morphologies and molecular structure of the IPNs polymer were observed by scanning electron microscope (SEM) and characterized by Fourier transform infrared spectroscopy (FTIR), respectively, whose results also proved the formation of ideal IPNs structures. [ABSTRACT FROM AUTHOR]

Hydrogel‐based microchannels with biologically similar morphologies and properties can provide excellent platforms for advanced tissue/organ formation in vitro. However, there are still many restrictions on channel morphology, material selection, tubing connections, etc. Here, a novel and versatile method is proposed that couples cononsolvency photopolymerization, which enables the incorporation of porous structures into hydrogels, with on‐chip microchannels formed by buckling of a thin film. This method provides a hydrogel‐based microchannel with improved permeability while maintaining its mechanical properties by incorporating a continuous porous structure into a synthetic polymer network with excellent mechanical properties. Furthermore, by culturing vascular endothelial cells into the microchannel, it is demonstrated that the microchannel works as a vessel‐on‐a‐chip platform that can be used for the evaluation of barrier function, fabrication of various channel shapes, and development of co‐culture systems. This method, which can be adapted to various swellable hydrogels, can provide platforms with properties and functions tailored to the tissue/organ and, thus, it will contribute to the creation of physiologically relevant biological models. [ABSTRACT FROM AUTHOR]

Side‐chain liquid‐crystal epoxy polymers (SCLCEPs) are valued for their unique properties, which combine LC side chains with epoxide‐based polyether main chains for ordered molecular arrangements. They have high thermal conductivity and optical properties due to their low polydispersity and high crystallinity. Achieving optimal thermal conductivity in SCLCEPs involves addressing factors such as mesogen nature, polymer design, and alignment within the polymer structure. Balancing these factors enhances their suitability for heat dissipation in advanced materials. In this study, SCLCEPs with a polyethylene glycol backbone and laterally arranged mesogens are synthesized via anionic ring opening of mesogenic epoxides with unique LC phases. These monomers, which feature biphenyl mesogens attached to glycidyloxy ether and different alkyl chain lengths on the other side, is designed to facilitate mesogen self‐assembly and interaction. The resulting polymers exhibited higher crystallinity and LC phases than the monomers. Notably, because of their LC nature, their thermal conductivity exceeds 0.48 W·m−1 K−1 and increases with shortened alkyl chain lengths, reaching 0.57 W·m−1 K−1. This research expands the applications of SCLCEPs in advanced fields requiring enhanced thermal properties. [ABSTRACT FROM AUTHOR]

Thermoelectric materials, as key materials for realizing efficient conversion of thermal and electrical energy, are crucial for renewable energy utilization and efficient energy management. However, materials with high negative thermoelectric coefficients are relatively rare. Herein, inspired by the structure and function of plant stem which is capable of blocking heavy metal ions, chitosan/CuCl2 hydrogel (ChCu) with a huge negative thermoelectric coefficient is reported. The ChCu displayed lamellar porous structure, which is constructed synergistically by freeze‐casting technique and complexation between Cu2+ and chitosan. In a ChCu hydrogel subjected to a temperature gradient, most of the Cu2+ is immobilized within the chitosan matrix by complexation, while the thermal migration of the unbound Cu2+ is further intercepted by the special layered porous structure. On the contrary, Cl− migrates unhindered to the cold end and accumulates, which realizes selective migration and distribution of ion/counterion. As a result, ChCu exhibits a thermoelectric coefficient as high as ‐23.8 mV K−1, and can respond rapidly with a thermal voltage of 4.0 mV under a small temperature difference (ΔT = 0.3 K). This work reveals the significant influence of the polymer aggregate structure on the thermal diffusion of ions, providing an innovative strategy in designating thermoelectric materials with high‐performance, high‐efficiency and environmentally friendly. [ABSTRACT FROM AUTHOR]

The paper presents the production of thermoplastic starch (TPS) mixtures using potato starch and two types of plasticizers: glycerol and sorbitol. The effects of plasticizers, citric acid, organically modified montmorillonite clay nanofiller (OMMT) and an additive based on ultrahigh molecular weight siloxane polymer on the structure and physical–mechanical and thermal properties of TPS samples were analysed. Starch mixtures plasticized with glycerol were obtained, where the starch/glycerol mass ratio was 70:30, as well as starch mixtures plasticized with glycerol and sorbitol, with a starch/glycerol/sorbitol mass ratio of 60:20:20. The starch gelatinization process to obtain TPS was carried out in a Brabender Plasti-Corder internal mixer at 120 °C, with a mixing speed of 30–80 rpm, for 10 min. The obtained results indicate that by adding 2% (weight percentage) of citric acid to the TPS mixtures, there is an improvement in the physical–mechanical properties, as well as structural changes that can indicate both cross-linking reactions by esterification in stages and depolymerisation reactions. The sample of TPS plasticized with glycerol, which contains OMMT, shows an increase in tensile strength by 34.4%, compared to the control sample. [ABSTRACT FROM AUTHOR]

A new Pb(II) polymer [Pb(dic)]n1 (H4dic = 5-(3′,4′-Dicarboxylphenoxy) -isophthalic acid) was synthesized. synthesized under hydrothermal conditions. The compound crystallizes in the Triclinic system, space group P-1 with a = 7.3690(2), b = 11.0528(3), c = 11.2613(3) Å, α = 62.4120(10)°, β = 83.7290(10)°, γ = 75.6590(10)°, V = 787.58(4) Å3, Z = 2, Mr = 774.60, Dc = 3.266 Mg/m3, μ = 21.411 mm−1, F(000) = 696, the final R = 0.0240 and wR = 0.0610 for 2923 observed reflections with I > 2σ(I). The compound presents a three-dimensional (3D) network extended by dic4- anions in which the dic4- anions employ a chelating coordination mode. Infrared spectroscopy, elemental analyses, thermogravimetric analysis and the single-crystal X-ray diffraction properties of 1 are also investigated. [ABSTRACT FROM AUTHOR]

The performance of organic field-effect transistors (OFETs) is highly dependent on the dielectric–semiconductor interface, especially in ion-gel-gated OFETs, where a significantly high carrier density is induced at the interface at a low gate voltage. This study investigates how altering the alkyl side chain length of donor–acceptor (D-A) copolymers impacts the electrical performance of ion-gel-gated OFETs. Two difluorobenzothiadiazole-based D-A copolymers, PffBT4T-2OD and PffBT4T-2DT, are compared, where the latter features longer alkyl side chains. Although PffBT4T-2DT shows a 2.4-fold enhancement of charge mobility in the SiO2-gated OFETs compared to its counterpart due to higher crystallinity in the film, PffBT4T-2OD outperforms PffBT4T-2DT in the ion-gel-gated OFETs, manifested by an extraordinarily high mobility of 17.7 cm2/V s. The smoother surface morphology, as well as stronger interfacial interaction between the ion-gel dielectric and PffBT4T-2OD, enhances interfacial charge accumulation, which leads to higher mobility. Furthermore, PffBT4T-2OD is blended with a polymeric elastomer SEBS to achieve ion-gel-gated flexible OFETs. The blend devices exhibit high mobility of 8.6 cm2/V s and high stretchability, retaining 45% of initial mobility under 100% tensile strain. This study demonstrates the importance of optimizing the chain structure of polymer semiconductors and the semiconductor–dielectric interface to develop low-voltage and high-performance flexible OFETs for wearable electronics applications. [ABSTRACT FROM AUTHOR]

Machine learning-assisted prediction of polymer properties prior to synthesis has the potential to significantly accelerate the discovery and development of new polymer materials. To date, several approaches have been implemented to represent the chemical structure in machine learning models, among which Mol2Vec embeddings have attracted considerable attention in the cheminformatics community since their introduction in 2018. However, for small datasets, the use of chemical structure representations typically increases the dimensionality of the input dataset, resulting in a decrease in model performance. Furthermore, the limited diversity of polymer chemical structures hinders the training of reliable embeddings, necessitating complex task-specific architecture implementations. To address these challenges, we examined the efficacy of Mol2Vec pre-trained embeddings in deriving vectorized representations of polymers. This study assesses the impact of incorporating Mol2Vec compound vectors into the input features on the efficacy of a model reliant on the physical properties of 214 polymers. The results will hopefully highlight the potential for improving prediction accuracy in polymer studies by incorporating pre-trained embeddings or promote their utilization when dealing with modestly sized polymer databases. [ABSTRACT FROM AUTHOR]

Biodegradable polymers such as polylactic‐co‐glycolic acids (PLGA) are used for various implantable devices such as tissue scaffolds, drug delivery devices, and biosensors in different forms. However, high‐resolution patterning of biodegradable polymers on implantable devices has not been explored much yet. While electrohydrodynamic printing (EHD) can achieve high‐resolution printing compared to other printing methods, EHD printing of PLGA solutions is rarely attempted due to unstable printing. Such printing instability originates from the volatile nature of PLGA inks, and it causes nozzle clogging or change of ink conditions during printing. Here, PLGA ink formulation and a voltage input profile are studied for stable and high‐resolution EHD printing. Addition of glycerol at an optimal ratio as well as the control of voltage pulse shape strongly influenced both the stability and resolution of EHD printing of PLGA patterns. With the optimized inks and voltage inputs, stable printing of PLGA micropatterns down to 5 µm is achieved on both conductive and insulating surfaces for controlled drug release. Furthermore, use of a ring type electrode allows for EHD printing of PLGA micropatterns on 3D surfaces of PLLA tubes and stent struts. [ABSTRACT FROM AUTHOR]

In mineral processing operations, it is essential to effectively remove the fine particles in slime and tailings slurry with appropriate methods. In this study, a unique two-stage flocculation scheme was developed for achieving effective separation of fine kaolinite particles from water by polyacrylamide. The slurry turbidity and flocculation kinetic parameters were used to characterize the effect of the dosing ratio between the first and second stage on the kaolinite flocculation behavior and settling rate. The results showed that the maximum kaolinite settling rate and the minimum turbidity of slurry supernatant was achieved when 60% and 40% polyacrylamide was added in the first and second stage, respectively. Focused beam reflectometer (FBRM) and particle video microscope (PVM) results showed that the flocs formed in the first stage of dosing were large in size but small in fractal dimension and no significant sedimentation was observed. The second stage of dosing produced large size of flocs with large fractal dimension, which settled fast in slurry. Fourier transform infrared spectroscopy (FTIR) results showed that polyacrylamide was mainly adsorbed on the surface of kaolinite by hydrogen bonding and kaolinite particle flocculation was achieved by trapping and coiling of the polymer chain structure. The two-stage dosing process accomplished effective flocculation and rapid settlement of fine kaolinite particles. The findings from this study provide a feasible approach for mining companies to optimize the flocculation and sedimentation of fine particles. [ABSTRACT FROM AUTHOR]

We present machine‐learning interatomic potentials (MLIPs) for simulations of Si–C–O–H compounds. The MLIPs are constructed from moment tensor potentials (MTPs) and were trained to a library of configurations that included polysiloxane structures, hypothetical crystalline and amorphous SiCOH structures, and trajectories of Si–C–O–H systems obtained via ab initio molecular dynamic (aiMD) simulations at elevated temperatures. Passive, active, and hybrid learning strategies were implemented to develop the MLIPs. The MLIPs reproduce vibrational properties of polymers and SiCOH structures obtained from aiMD simulations, thus providing a tool to identify chemical units and distinct structural characteristics through their vibrational properties. Simulations of the polymer‐to‐ceramic transformation show the development of mixed tetrahedra in SiCO ceramics and align with experimental observations. Million‐atom simulations for several nanoseconds highlight the precipitation of graphitic nanosheets from a carbon‐rich SiCO precursor. Atomistic simulations with the MLIPs deliver details of chemical reaction mechanisms during the pyrolysis of polysiloxanes, including methane abstraction and Kumada‐like rearrangements that transform the siloxane backbone. While the MLIPs still leave room for systematic improvement, they deliver simulations with "density functional theory (DFT)‐like" quality at low and high temperatures. [ABSTRACT FROM AUTHOR]

The present study synthesized silver nanoparticles supported on a thermosensitive polymer with a core–shell structure, formed by a polystyrene (PS) core and a poly(N-isopropylacrylamide) (PNIPAM)/Poly(N, N-methylenebisacrylamide) (MBA) shell. The PS core was synthesized via semicontinuous heterophase polymerization at a flow of 0.073 g/min, enabling polystyrene nanoparticles with an average size (Dz) of 35.2 nm to be obtained. In the next stage, the conditions required for polymerization synthesis were established in seeded microemulsion using PS nanoparticles as seed and semicontinuously adding the thermosensitive shell monomer (PNIPAM/MBA) under monomer-flooded conditions to favor shell formation. The non-homopolymerization of PNIPAM/MBA was demonstrated by obtaining nanoparticles with a core–shell structure, with average particle sizes of 41 nm and extremely low and narrow polydispersity index (PDI) values (1.1). The thermosensitive behavior was analyzed by QLS, revealing an average shrinkage of 4.03 nm and a percentage of shrinkage of 23.7%. Finally, silver nanoparticles were synthesized on the core–shell heat-sensitive nanoparticles in a colloidal solution containing the latices, while silver nanoparticles were anchored onto the cross-linked heat-sensitive network via the formation of complexes between the Ag+ ions and the nitrogen contained in the PNIPAM/MBA network, favoring anchorage around the network and maintaining a size of 5 nm. [ABSTRACT FROM AUTHOR]

This research introduces an RI sensor for detecting various alcohol species with a designed twisted polymer optical fiber (POF) sensor. The sensor is developed via a straightforward twisting technique to form an effective coupling mechanism. The sensor works on intensity variation where coupled intensity varies when different types of alcohol are added. The structure relies on the twisting of two fibers, where one fiber is used as the illuminating fiber and the other fiber is used as the receiving fiber. Five different types of alcohol are tested (methanol, ethanol, propanol, butanol, and pentanol) as a substant. The experimental results reveal that the sensor is able to detect all five distinct substants effectively by optical power intensity variation. Moreover, the sensor's sensitivity is analyzed with different factors such as the influence of the bending radius and the coupling length, which reveals that the sensing parameters could be customized depending on specific requirements. The sensor demonstrated consistent responses in repeatability tests, with minimal variation across multiple measurements, highlighting its stability. Additionally, the study explores temperature's influence, revealing a sensitivity shift for every degree Celsius of change. This POF-based alcohol sensor represents a significant leap forward in optical sensing technology. [ABSTRACT FROM AUTHOR]

This article reports recent advances in thermally induced phase separation technology in fabricating microporous scaffold polymeric membranes as devices suitable for the controlled release of insect repellent. The key aspects, such as the crystallization behavior and morphological study of the polymeric membrane‐based repellent, were reported and discussed. Studies demonstrated that trapping of such repellents into microporous polymeric materials can be achieved by spinodal decomposition of the polymer/liquid repellent system. Usually, solubility is enhanced at elevated temperatures. Rapid cooling of such solution below the UCST leads to the formation of cocontinuous phase structures by decomposition. The polymer then forms an open‐cell structure with the repellent trapped inside. Approaches to forming such an open‐cell polymer structure containing mosquito repellent were successfully performed and confirmed with the SEM and POM techniques. It showed the structure of a polymer and liquid repellent prepared by spinodal decomposition, providing proof that thermally induced spinodal decomposition is a route to trap liquid mosquito repellent into a microporous polymer matrix. Additionally, the effects of polymer type, repellent nature, cooling conditions, and fillers on the morphology and performance of TIPS membranes are also discussed. Finally, challenges in developing microporous polymeric membrane‐based repellent using TIPS technology are addressed. [ABSTRACT FROM AUTHOR]

Full-scale physical modelling was used to evaluate the response of modular polymer stormwater collection structures when subjected to design-truck loading that was sustained for 1 week (i.e. a parked vehicle) and when buried with minimum soil cover. Surface loading was applied on a steel load pad that simulates one-half of the AASHTO design-truck single-axle that was held constant for 1 week to assess the stability of the buried system and demand on the platen and column components of the modules to allow independent load rating of the buried structure. No collapse or limiting state occurred. The 1-week creep buckling resistance was found to be nearly four times the factored column demand to 1-week loading for both module types. New insight into the time-dependent behaviour of the soil–structure system was gained by comparing the buried response to creep tests conducted on isolated columns and platens. The response of the buried soil–structure system was less severe than unconstrained creep. Column loads were found to not increase with time. Bending deflections increased by 1.04 to 1.26 times when buried rather than by 3.0 to 3.4 times for unconstrained creep as platen creep when buried was greatly restrained by the soil. [ABSTRACT FROM AUTHOR]

In this study, the effect of the polymer matrix structure on the rheological and electrical percolation threshold of polymer/carbon black (CB) conductive polymer composites (CPCs) was investigated. Poly(lactic acid) (PLA) and high‐density polyethylene (HDPE) were used as polymer matrices. Through rheological analyses, an increase in complex viscosity was observed with increasing CB concentration, accompanied by a reduction in the Newtonian plateau. Additionally, an increase in the solid‐like behavior was observed, suggesting the formation of a percolated network. The rheological percolation threshold was found to be 5.13% CB mass fraction for the PLA/CB composite and 10.72% for the HDPE/CB composite. Electrical conductivity results were fitted to the sigmoidal Boltzmann model, and its derivative was used to identify the electrical percolation threshold. For PLA/CB, this threshold was reached at 5.39% CB mass fraction, while for HDPE/CB, it occurred at 5.75%. Morphology analysis by scanning electron microscopy and atomic force microscopy indicated that the polymer matrix structure affected the distribution/dispersion of the CB particles within the polymer matrix. Highlights: The effect of polymer matrix structure on polymer/CB CPCs was investigated.The crystallinity of the polymer matrix affected the percolation threshold.PLA/CB showed higher conductivity than HDPE/CB CPCs. [ABSTRACT FROM AUTHOR]

Self-assembled non-covalent nanoparticle-polymer hybrids, that can combine a variety of desired properties in a single material with highly dynamic structure, have great potential in the field of functional nanosystems. In this study, we present a method for preparing such hybrids from silica nanoparticles and polymer structures of polystyrene-block-polyacrylic acid (PS-b-PAA). We show that the surface chemistry of the nanoparticles has a major influence on the encapsulation efficiency and the localization of the particles in the vesicles. Furthermore, an increase in vesicle size was observed with higher vesicle loading. A particular highlight of this work is that the morphology of the hybrids could be subsequently modified by adjusting the solvent composition. It was also found that the presence of the particles led to faster transitions due to the increased free energy of the system. This type of morphological change therefore offers promising potential applications, such as self-healing materials. [ABSTRACT FROM AUTHOR]

The utilization of 3D printing technology has transformed the possibilities for design adaptability and manufacturability. This study delves into the mechanical response and energy absorptivity of resin‐based lattice structures when subjected to compression, specifically examining structures fabricated from Tough 2000 (ductile) and Rigid 10K (brittle) resin materials using a stereolithography 3D printer. The analysis encompasses various types of lattice designs (such as cubic‐primitive, circular, triangular, and hexagonal), gradient structures, and combined shape configurations with varying strut dimensions. The primary objective is to provide significant findings regarding the compressive performance of these resin lattice structures produced through 3D printing. Analysis results show that graded and combined lattice designs have better compressive behavior compared to regular shapes with the same strut thickness. In addition, and for strut thickness of 0.5 mm, combined lattice designs show better energy absorption capabilities compared to regular shapes. [ABSTRACT FROM AUTHOR]

The increasidng demand for implants due to the aging populations highlights the necessity for applying highly functional coatings on the surface of implants. This study investigates the implications of applying a chitosan/polylysine composite coating on anodized titanium surfaces, aiming for improved biocompatibility, bioactivity, and anti-bacterial properties. Titanium substrates were anodized at 40 volts for a duration of two hours, followed by dip coating with the chitosan/polylysine composite. Fourier-transform infrared (FTIR) analysis was employed to characterize the polymer structure, while field emission scanning electron microscopy (FESEM) and energy-dispersive X-ray spectroscopy (EDS) techniques were utilized to evaluate nanotube morphology and the coating structure. Results showed that samples containing 1.5% polylysine exhibited noticeable anti-bacterial properties and cell viability above fifty percent. Subsequent immersion in simulated body fluid (SBF) for a duration of two weeks revealed the formation of apatite crystals on the coated samples, indicating that the samples are bioactive. Furthermore, polylysine contributed to enhanced resistance against degradation in phosphate-buffered saline (PBS) solution. Overall, the chitosan/polylysine composite coating exhibited promising mechanical and biomedical characteristics, suggesting its potential for applications in orthopedic implants. [ABSTRACT FROM AUTHOR]