Polymer Structure Research Articles

Effect of Heat Treatment on the Supramolecular Structure of Copolymers Based on Poly(propylene glycol fumarate phthalate) with Acrylic Acid

Previous studies investigating the thermal decomposition of p-PGFPh:AA copolymers in an inert atmosphere have provided only a general understanding of the changes that occur during thermolysis. Comprehensive studies are required to gain a better understanding of these processes [1]. The most comprehensive information on the influence of various factors on both the kinetics and the supramolecular structure of the resulting products can be obtained by combining the method of thermal analysis with IR, mass spectrometry, and scanning electron microscopy. The compounds studied have two different compositions, namely p‑PGFPh:AA 6.77:93.23 mol % and p-PGFPh:AA 86.67:13.33 mol %. These compounds were then subjected to a thermolysis process, which resulted in the emission of gases and a decrease in sample weight. The degradation process can be divided into three stages: 1) Depolymerization of the main chain; 2) Depolymerization of the side chain; 3) Final decomposition. These processes occur sequentially at different temperature ranges. According to TG- and DTG studies, complete decomposition of p-PGFPh:AA copolymers occurred at Tterm = 340–350 °C. In this temperature range, a slight loss of sample mass (less than 10 wt %) was observed along with a slight gas evolution. The main gaseous products from the transformation of the studied samples were CO and CO2. This was supported by IR-CO (2000–2200 cm−1) and CO2 (2310–2370 cm−1) as well as mass spectrometric observations. The final products resulting from the thermolysis of p-PGFPh:AA copolymers were examined under an electron microscope. The results showed a similar morphological pattern of mesostructures with sizes ranging from 0.3–1.5 μm, which were observed depending on the porous structure of the initial polymer material. Based on the experimental data, it can be concluded that the p-PGFPh:AA copolymers (in proportions of 6.77:93.23 mol % and 86.67:13.33 mol %) have a relatively high degree of resistance to heating and do not undergo any changes in chemical composition, particle size and shape. In conclusion, the results clearly indicate that the selection of conditions for pyrolysis plays a crucial role in increasing the thermal stability of polymeric materials. This method allows for purposeful changes in the structure and properties of polymers.

Ir(I)-Bi(III) Donor-Acceptor Adducts Stabilized by Dispersion Interactions between the Metal Pincer Ligands and Their Possible Self-Assembly Forming Molecular 1D Semiconductors.

Structure, stability, and electronic properties of the bimetallic {[IrI(terpy)(Me)]-[BiIIINNN]}n monomeric, oligomeric, and polymeric structures (n = 1-3 and ∞; terpy = terpyridine; Me = methyl; BiNNN = bismuth triamide) and their derivatives (designated as (Bi·Ir)n structures) were studied theoretically by DFT cluster and periodic calculations. Stable Bi·Ir adducts (monomers) were formed with short Bi-Ir bonds (<2.7 Å) and Gibbs free binding energies larger than 20 kcal/mol for all systems. The substitution of the pincer ligands of Ir(I) and Bi(III) complexes by the electron-donating (NH2) and electron-withdrawing (NO2, F, CF3) groups, respectively, enhanced the Ir → Bi charge transfer, substantially stabilizing the Bi·Ir monomers. The monomers from the unsubstituted complexes can be considered as dispersion stabilized adducts, and they may form spontaneously (Bi·Ir)n layered oligomers/polymers with semiconducting properties. The self-assembly of monomers into oligomers/polymers is hindered by bulkier protecting groups on the Bi(III) complex, such as tBu and SiMe3.

Hydrothermal syntheses, structures and properties of two zinc complexes based on an azobenzene carboxylate ligand

Abstract Two zinc complexes [Zn(LH)2(phen)] (1) and [Zn(L)(H2O)] n (2) (LH− = 2-hydroxy-5-((3-nitrophenyl)azo)-benzoate, phen = 1,10-phenanthroline) were synthesized by hydrothermal methods and characterized by elemental analysis and IR spectroscopy. Complexes 1 and 2 crystallize in mononuclear and polymeric structures, respectively, where ligands L 2− are coordinated to the zinc ions via their carboxylate and phenolate groups in η 2,μ 2,κ 2 and η 2,μ 2,κ 1 mode, respectively. Introduction of the auxiliary chelating phen ligand results in the chelation of the zinc ions in 1 through both the phen ligand and the carboxylate group of the first LH− anion assisted further by the monodentate carboxylate group of the second LH− anion. In complex 2 the L 2− anions act as tridentate ligands utilizing their carboxylate and phenolate groups to coordinate to three zinc ions. The phenolate oxygen atom bridges two zinc ions resulting in the generation of a layer structure. Fluorescence measurements have indicated that complexes 1 and 2 exhibit similar luminescence emissions around 393 and 387 nm, respectively, which originate from intra-ligand π-π* transitions. The emission intensities were strengthened relative to the sodium complex NaLH owing to the enhancement of the rigidity of the aromatic system through the coordination interactions of the ligands with the more tightly bound zinc ions. Furthermore, the suspension of complex 2 can be used to selectively detect Fe3+ cations via the luminescence quenching process.

Preparation of biochar from anaerobic digested sludge for enhancement of sludge dewatering

Effective dewatering is vital for both sludge treatment and resource recovery. This study focuses on converting post-anaerobic digested sludge into biochar to enhance sludge dewatering. The sludge-derived biochar is further modified with polyacrylamide (PAM-ADBC) and applied with sulfuric acid-modified montmorillonite (HMTS) for better performance. Significant advancements in dewatering were noted, even at reduced HMTS (0.1 g/g DS) and PAM-ADBC (25 g/kg DS) dosages. These improvements resulted in a remarkable 41.96% enhancement in capillary suction time (17.2 s) and a notable 20.26% reduction in moisture content (66.33%), respectively, all while maintaining a stable pH level. HMTS, with leached cations, improved dewatering by decomposing the extracellular polymeric substance structure through electro-neutralization to release the internal bound water within sludge flocs. Simultaneously, PAM-ADBC coagulated decomposed sludge particles into larger flocs to form a skeletal structure with itself to discharge internal water in compression dewatering. This study introduces a resource recovery method for anaerobically digested sludge and highlights its potential for sustainable utilization.

Using ion mobility spectrometry to understand signal dilution during tandem mass spectrometry sequencing of digital polymers: Experimental evidence of intramolecular cyclization.

Optimizing the structure of digital polymers is an efficient strategy to ensure their tandem mass spectrometry (MS/MS) readability. In block-truncated poly(phosphodiester)s, homolysis of C-ON bonds in long chains permits the release of smaller blocks amenable to sequencing. Yet the dissociation behavior of diradical blocks was observed to strongly depend on their charge state. Polymers were ionized in negative mode electrospray and activated in-source so that blocks released as primary fragments can be investigated using ion mobility spectrometry (IMS) or sequenced in the post-IMS collision cell. Collision cross sections (CCS) were derived from arrival times using a calibration procedure developed for polyanions using the IMSCal software. A multistep protocol based on quantum methods and classical molecular dynamics was implemented for molecular modeling and calculation of theoretical CCS. Unlike their triply charged homologues, dissociation of diradical blocks at the 2- charge state produces additional fragments, with +1m/z shift for those holding the nitroxide α-termination and -1m/z for those containing the carbon-centered radical ω-end. These results suggest cyclization of these diradical species, followed by H• transfer on activated reopening of this cycle. This assumption was validated using IMS resolution of the cyclic/linear isomers and supported by molecular modeling. Combining IMS with molecular modeling provided new insights into how the charge state of digital blocks influences their dissociation. These results permit to define new guidelines to improve either ionization conditions or the structural design of these digital polymers for best MS/MS readability.

Biochemical activity of peats of different genesis

The results of the study of enzymatic activity of peats of the three bogs of upper and lowland types – Saim, Bolshoye and Tungusovskoye (Tomsk region) are presented. The peculiarities of organic matter formation of peats of different types are given. It is shown that the properties of peats with up to eight different plants in their composition are a consequence of the different structure of polymers of the original plants. The activity indices of enzymes invertase, protease, catalase, polyphenol oxidase, nitrate and nitrite reductase in the peats of different genesis are determined. Thus, at the type level, the extreme values of nitrate and nitrite reductase activity in the peats of the upland bog are equal to 3.60–4.94 mg of reduced NO3– /24 h/g and 3.52–7.01 mg of reduced NO2–/24 h/g, respectively, lowland bog – 4.66–19.33 mg of reduced NO3–/24 h/g and 0.9–13.0 mg of reduced NO2 –/24 h/g, fluvial bog – 8.77–22.29 mg of reduced NO3–/24 h/g and 0.2–13.6 mg of reduced NO2 –/24 h/g. The activity of the enzyme in peats and in mineral soils is compared with the activity estimation according to the D.G. Zvyagintsev scale. Peats are found to show a wider range of invertase values than indicated by the scale. The need to develop a gradation of enzymatic activity assessment for peats is identified. Probably, the activity of enzymes on peat OM transformation may increase when external conditions change towards warming. In the future, it is suggested to develop an evaluation cadastre of peats by enzymatic activity, which will allow, through a balanced selection of peats for agricultural production, to ensure the required quality of products, their environmental safety and economic efficiency.

Rational design and efficient synthesis of cyclic polymers with visualized molecular topology and unique dielectric properties

Cyclic polymers without chain ends have attracted increasing attention because of the unique physical properties. However, the direct visualization of cyclic topology remains a formidable challenge, because the cyclic chains with flexible backbone or strong intramolecular interaction usually existed in a coiled state rather than cyclic topology. Herein, monocyclic and bicyclic polymers were prepared via blocking-cyclization technique, and the molecular topology of cyclic polymer containing phenyl pendant was directly observed depending on the reduced intrachain entanglement. The structure and characteristics of cyclic polymers were investigated, and the difference between cyclic polymer and linear counterpart was demonstrated. Compared to linear polymer, cyclic polymer exhibited improved dielectric properties, and bicyclic polymer displayed further increased dielectric constant and energy storage density than monocyclic polymer possessing the same repeating units. Therefore, this research presents a facile strategy in the design and construction of cyclic polymers with directly visualized topology and unique dielectric properties.

Fabrication and characterization of bio-nanocomposite from sweet potato starch and Moringa oleifera leaf extract loaded with carbon quantum dots from Coffea arabica grounds

The study aims to generate and characterize a bio-nanocomposite film derived from sweet potato starch and Moringa oleifera leaf extract and carbon quantum dots (CQDs) derived from Arabica coffee grounds employing the solvent casting method. The effect of various concentrations of CQDs (0–400 ppm) was investigated on the physicochemical properties, UV-barrier, antioxidant properties, and biodegradability of the bionanocomposite (BNC) films. The morphological surface of the bio-nanocomposite was examined using scanning electron microscopy (SEM). Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were performed to evaluate the thermal stability of the samples. Mechanical properties, including tensile strength (TS) and elongation at break (EB), were also assessed. The results show that the incorporation of CQDs with starch-based biofilms had a remarkable impact on the properties of BNC. SEM images confirm the homogeneous structure of the films with slight granulations. Colorimetric analysis indicates the increase in color difference of BNCs as the concentration of CQDs varied. The BNC100 formulation confirmed batter opacity, transparency, and UV-barrier properties while BNC50 possessed significant improvement in tensile, elongation as well as a substantial increase in the melting point. FTIR and XRD analysis confirmed proper chemical interactions among the components within the polymeric structure of the BNC film. In addition, CQD integration has also steadily enhanced the antioxidant properties and biodegradability of BNC films. The fabricated films with CQDs have demonstrated a better quality in terms of optical properties, physical properties, thermomechanical properties, biodegradation rate, and antioxidant behavior that suggest the film's application in food packaging or other relevant fields.

In situ borneol-modified polyester with antibacterial adhesion and long-term fungal-repellent properties

Polyester is widely used in biomedical, textile, and food packaging fields. Therefore, enhancing it with antimicrobial properties would be a significant advancement. In this paper, a series of borneol-triazine polyesters (BTPs) with different structures are synthesized through room temperature polycondensation. The structure and composition of BTPs are systematically characterized by 1H NMR, FTIR and GPC. Antimicrobial results reveal that the ability of BTPs to resist bacterial or fungal adhesion is directly related to the polymer structure. When the polymer chain of BTPs adopts a rigid structure, they exhibit excellent anti-adhesive and inhibitory performances against both Gram-negative bacteria (Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus). Meanwhile, the as-synthesized BTPs poses a fungal-repelling effect on common fungal strains (Aspergillus niger) for up to 30 d. Further studies have shown that a stereochemical structure brought by borneol is key for imparting effective antimicrobial properties to BTPs. In addition, BTPs are non-leaching materials with low cellular cytotoxicity. Taking into consideration, BTP provides a potential strategy for preparing a new class of antimicrobial polyester materials.

Revisiting the Determination of the Degree of Deacetylation Using Potentiometric Titration: A New Equation for Modified Chitosan.

Chitosan is a biopolymer that can be subjected to a variety of chemical modifications to generate new materials. The properties of modified chitosan are affected by its degree of deacetylation (DDA), which corresponds to the percentage of D-glucosamine monomers in its polymeric structure. Potentiometric titration is amongst the simplest, most readily available, and most cost-effective methods of determining the DDA. However, this method often suffers from a lack of precision, especially for modified chitosan resins. This is in large part because the equation used to calculate the DDA does not consider the molecular weight of the chemically modified monomeric units. In this paper, we introduce a new equation that is especially suited for modified chitosan bearing three different types of monomers. To test this equation, we prepared naphthalene-chitosan resins and subjected them to potentiometric titration. Our results show that our new equation, which is truer to the real structure of the polymeric chains, gives higher DDA values than those of the routinely used equations. These results show that the traditional equations underestimate the DDA of modified chitosan resins.

Multihierarchical Regulation To Achieve Quantum Dot Nanospheres with a Photoluminescence Quantum Yield Close to 100.

Quantum dots (QDs) exhibit superior brightness and photochemical stability, making them the preferred option for highly sensitive single-molecule detection compared with fluorescent dyes or proteins. Nevertheless, their high surface energy leads to nonspecific adsorption and poor colloidal stability. In the past decades, we have found that QD-based fluorescent nanoparticles (FNs) can not only address these limitations but also enhance detection sensitivity. However, the photoluminescence quantum yield (PLQY) of FNs is significantly lower compared with that of original QDs. It is urgent to develop a strategy to solve the issue, aiming to further enhance detection sensitivity. In this study, we found that the decrease of PLQY of FNs prepared by free radical polymerization was attributed to two factors: (1) generation of defects that can cause nonradiative transitions resulting from QD-ligands desorption and QD-shell oxidation induced by free radicals; (2) self-absorption resulting from aggregation caused by incompatibility of QDs with polymers. Based on these, we proposed a multihierarchical regulation strategy that includes: (1) regulating QD-ligands; (2) precisely controlling free radical concentration; and (3) constructing cross-linked structures of polymer to improve compatibility and to reduce the formation of surface defects. It is crucial to emphasize that the simultaneous coordination of multiple factors is essential. Consequently, a world-record PLQY of 97.6% for FNs was achieved, breaking through the current bottleneck at 65%. The flexible application of this regulatory concept paves the way for the large-scale production of high-brightness QD-polymer complexes, enhancing their potential applications in sensitive biomedical detection.

Responsive Acrylamide-Based Hydrogels: Advances in Interpenetrating Polymer Structures.

Hydrogels, composed of hydrophilic homopolymer or copolymer networks, have structures similar to natural living tissues, making them ideal for applications in drug delivery, tissue engineering, and biosensors. Since Wichterle and Lim first synthesized hydrogels in 1960, extensive research has led to various types with unique features. Responsive hydrogels, which undergo reversible structural changes when exposed to stimuli like temperature, pH, or specific molecules, are particularly promising. Temperature-sensitive hydrogels, which mimic biological processes, are the most studied, with poly(N-isopropylacrylamide) (PNIPAm) being prominent due to its lower critical solution temperature of around 32 °C. Additionally, pH-responsive hydrogels, composed of polyelectrolytes, change their structure in response to pH variations. Despite their potential, conventional hydrogels often lack mechanical strength. The double-network (DN) hydrogel approach, introduced by Gong in 2003, significantly enhanced mechanical properties, leading to innovations like shape-deformable DN hydrogels, organic/inorganic composites, and flexible display devices. These advancements highlight the potential of hydrogels in diverse fields requiring precise and adaptable material performance. In this review, we focus on advancements in the field of responsive acrylamide-based hydrogels with IPN structures, emphasizing the recent research on DN hydrogels.

Synthesis, characterization, and structural analysis of hetero Ni(II)–Na(I) and Homo Ni(II)–Ni(II) dinuclear complexes with a flexible tridendate schiff base ligand

Two different novel [Ni(II)–Na(I)]n and Ni(II)–Ni(II)] complexes have been synthesized successfully using a flexible tridentate Schiff base ligand. These complexes are characterized by IR and single crystal X–ray analysis and the optical properties of these complexes have been studied by UV spectroscopy (solution and solid). The [Ni(II)–Na(I)]n complexes are repeatedly connected with another Ni(II)–Na(I) unit to yield a linear polymeric chain. The Ni(II)–Ni(II) complex shows the nature of supramolecular dimeric cluster. These results are evidenced by x-ray structural analysis. Both as-obtained complexes are shown in different structures, such as hetro metal [Ni(II)–Na(I)]n] and homo metal [Ni(II)–Ni(II)]coordination environments with the same ligand. The first one forms a linear polymeric structure whereas the second one forms a cluster. The more intense band at 2104 cm1 is assigned to the NCS ligand of compound 1. A sharp band at 1068 cm1 together with a band at 625 cm1 in compound 2 is assigned to the ClO4 stretching vibrations and these bands are evidence for the presence of ionic perchlorate (non–coordinated). The electronic spectra of compounds 1 and 2 are recorded in ACN solvent to exhibit a broad peak around 380 nm due to d-d transition.

Dumbbell-Shaped, Block-Graft Copolymer with Aligned Domains for High-Performance Hydrocarbon Polymer Electrolyte Membranes.

Given the environmental concerns surrounding fluoromaterials, the use of high-cost perfluorinated sulfonic acids (PFSAs) in fuel cells and water electrolysis contradicts the pursuit of clean energy systems. Herein, we present a fluorine-free dumbbell-shaped block-graft copolymer, derived from the cost-effective triblock copolymer, poly(styrene-b-ethylene-co-butylene-b-styrene) (SEBS), for polymer electrolyte membranes (PEMs). This unique polymer shape led to the alignment of the hydrophobic-hydrophilic domains along a preferred orientation, resulting in the construction of interconnected proton channels across the membrane. A bicontinuous network allowed efficient proton transport with reduced tortuosity, leading to an exceptional ionic conductivity (249 mS cm-1 at 80 °C and 90 % relative humidity (RH)), despite a low ion exchange capacity (IEC; 1.41). Furthermore, membrane electrode assembly (MEA) prepared with our membrane exhibited stable performance over a period of 150 h at 80 °C and 30 % RH. This study demonstrates a novel polymer structure design and highlights a promising outlook for hydrocarbon PEMs as alternatives to PFSAs.

Dumbbell‐Shaped, Block‐Graft Copolymer with Aligned Domains for High‐Performance Hydrocarbon Polymer Electrolyte Membranes

AbstractGiven the environmental concerns surrounding fluoromaterials, the use of high‐cost perfluorinated sulfonic acids (PFSAs) in fuel cells and water electrolysis contradicts the pursuit of clean energy systems. Herein, we present a fluorine‐free dumbbell‐shaped block‐graft copolymer, derived from the cost‐effective triblock copolymer, poly(styrene‐b‐ethylene‐co‐butylene‐b‐styrene) (SEBS), for polymer electrolyte membranes (PEMs). This unique polymer shape led to the alignment of the hydrophobic‐hydrophilic domains along a preferred orientation, resulting in the construction of interconnected proton channels across the membrane. A bicontinuous network allowed efficient proton transport with reduced tortuosity, leading to an exceptional ionic conductivity (249 mS cm−1 at 80 °C and 90 % relative humidity (RH)), despite a low ion exchange capacity (IEC; 1.41). Furthermore, membrane electrode assembly (MEA) prepared with our membrane exhibited stable performance over a period of 150 h at 80 °C and 30 % RH. This study demonstrates a novel polymer structure design and highlights a promising outlook for hydrocarbon PEMs as alternatives to PFSAs.

Lifecycle Assessment of Strategies for Decarbonising Wind Blade Recycling toward Net Zero 2050

The wind energy sector faces a persistent challenge in developing sustainable solutions for decommissioned Wind Turbine Blades (WTB). This study utilises Lifecycle Assessment (LCA) to evaluate the gate-to-gate carbon footprint of high-profile disposal and recycling methods, aiming to determine optimal strategies for WTB waste treatment in the UK. While this article analyses the UK as a case study, the findings are applicable to, and intended to inform, recycling strategies for WTB waste globally. Long-term sustainability depends heavily on factors like evolving energy grids and changing WTB waste compositions and these must be considered for robust analysis and development strategy recommendations. In the short to medium term, mechanical recycling of mixed WTB waste is sufficient to minimise Global Warming Potential (GWP) due to the scarcity of carbon fibre in WTB waste streams. Beyond 2040, carbon fibre recycling becomes crucial to reduce GWP. The study emphasises the importance of matching WTB sub-structure material compositions with preferred waste treatment options for the lowest overall impact. Future development should focus on the extraction of carbon fibre reinforced polymer (CFRP) structures in WTB waste streams, commercialising large-scale CFRP structure recycling technologies, establishing supply chains, and validating market routes for secondary carbon fibre products. In parallel, scaling up low-impact options, like mechanical recycling, is vital to minimise WTB waste landfilling. Developing viable applications and cost-effective market routes for mechanical recyclates is necessary to displace virgin glass fibres, while optimising upstream recycling processes based on product requirements.

Scintillation and structural properties of copolymers and mixtures of styrene, 9-vinylcarbazole and 4-vinylbenzyl chloride based plastic scintillators

The research team has developed new plastic scintillators in the form of microspheres, called PSm, by combining styrene, 9-vinylcarbazole (VK), and 4-vinylbenzyl chloride (VBC). The primary objective of this study was to explore the feasibility of incorporating the fluorescent solute (VK) into the polymer structure to prevent its leaching out when PSm are utilized in liquid flow through detection systems or organic solvents. The secondary aim was to examine the impact of adding the chlorine functional group to the scintillation polymer, with the intention of replacing it with an extractant in the future to create covalently linked PSresins.The findings of the study reveal that the homopolymer of polyvinylcarbazole (PVK) performs poorly while used as a unitary scintillator system for plastic scintillation measurements. However, the incorporation of monomers in the form of copolymers with styrene has a more significant impact on scintillation properties compared to the mixture of homopolymers. In the case of 9-vinylcarbazole (VK), its presence at a weight proportion of 10% leads to an increase in scintillation efficiencies, although it is still inferior to the classical PS. Conversely, the situation is different for 4-vinylbenzyl chloride (VBC), where the chlorine in the copolymer results in higher quenching, and the polymer is also less resistant to organic solvents due to the formation of short polymer chains. For VBC, the mixture of polymers yields better results and enables the production of covalently linked PSresins.

Diffusion of small-size aliphatic alcohols and the chemical actuation of shape memory polyurethane

Three types of aliphatic alcohols (methanol, ethanol, and 1-propanol) are used to actuate a programmed ESTANE ETE 75DT3 (abb. SMP-E), a polyether-based polyurethane shape memory polymer (SMP). In this paper, we analyze the diffusion behavior of these small molecules in SMP-E and the relationship between the solvent diffusion and shape recovery using a weight gain study and small-angle x-ray scattering (SAXS). From the results, all three alcohols show behavior similar to Fickian diffusion in SMP-E. During the diffusion process, the molecular switch (MS) of thermoplastic SMP-E transforms from the glassy state to the rubber-like state depending on the time-dependent local alcohol concentration. The diffusion of small molecules enhances shape recovery and the related evolution of the polymer structure. As a feedback effect, the rate of diffusion changes as small molecules penetrate into the sample. To study this issue, we used three methods to determine the diffusion coefficients at short, intermediate and long times. The data on short time diffusion reflects the glassy state of the sample. The intermediate times correspond to 50% solvent saturation, where the shape recovery is nearly completed. The long-time analysis, on the other hand, provides an average diffusion coefficient for the entire process. The SAXS results show the diffusion path and provide evidence that the alcohol molecules equally diffuse into both MS and entropy elastic component phase of SMP-E.

A robust network binder enables high‐performance silicon anode via localized linking by small molecules

AbstractThe importance of network binder for improving cycling lifespan of silicon (Si) anode needs no further emphasis. However, the linear structure of natural polymer hardly creates a robust network binder. Herein, we propose a facile strategy of establishing a robust network binder by using small molecules of tartaric acid (TA) to locally link sodium carboxymethyl cellulose (CMC). Through hydrogen or covalent bonds, the resultant CMC‐TA binder exhibits improved tensile and adhesive properties. The Si anode using CMC‐TA binder delivers a satisfactory specific capacity of 2213 mAh g−1 after 100 cycles at the rate of 0.2 C, with a capacity retention rate of 68.8%. This result has well confirmed the effectiveness of using small molecules to reinforce hydrogen‐bonding linking between CMC and between Si particles for a high‐performance Si anode.

Investigation into the thermal noise propagation mechanism within composite materials for gravitational wave detection systems

The thermal transmission properties of polymer-based composites, commonly used in satellites, are crucial for high-precision thermal management applications. The study constructed the structures of polyimide polymers and polyimide/graphene interfaces based on molecular dynamics and fluctuation dissipation theorem. Optical parameters were determined through first-principles calculations, and the thermal transport from a microthermal source was simulated using Reverse Non-Equilibrium Molecular Dynamics (RNEMD) and the modified four-dimensional transfer matrix method (M4D-TMM). Simulations of polymers, interface structures, and interfacial thermal radiation models investigated the transmission dynamics of microthermal sources during heat transport. Findings showed that the differences in the temperature fields formed within the polymer from microthermal heat sources were less than 20 K for heat source inputs ranging from 0.002 W/m² to 20 GW/m². With a microthermal source, the heat diffusion was extensive, the heat transport was continuous, and the temperature field remained stable. At the level of the heat source up to the intermolecular energy level, the temperature field distribution showed significant instability, leading to nonlinear effects. Within the interface structure, the continuity of heat diffusion increased as the heat source intensified. The interface structure demonstrated enhanced temperature sensitivity and improved stability, with minimal fluctuations of only 0.59 %. The increase in heat flux perpendicular to the interface structure was ascribed to near-field radiative heat transfer. As the temperature difference decreased to less than 0.1 K, the influence of evanescent waves on radiative heat flux nearly disappeared. Phonon polaritons maintained temperature stability during thermal transport through micro- and nanoscale gaps. Integrating thermal conduction principles in polyimide polymers and interface structures with near-field thermal radiation provides a theoretical framework for high-precision thermal management in gravitational wave detection.