Stability Properties Research Articles

Machine-Learning Prediction of Curie Temperature from Chemical Compositions of Ferromagnetic Materials.

Room-temperature ferromagnets are high-value targets for discovery given the ease by which they could be embedded within magnetic devices. However, the multitude of potential interactions among magnetic ions and their surrounding environments renders the prediction of thermally stable magnetic properties challenging. Therefore, it is vital to explore methods that can effectively screen potential candidates to expedite the discovery of novel ferromagnetic materials within highly intricate feature spaces. To this end, we explore machine-learning (ML) methods as a means to predict the Curie temperature (Tc) of ferromagnetic materials by discerning patterns within materials databases. This study emphasizes the importance of feature analysis and selection in ML modeling and demonstrates the efficacy of our gradient-boosted statistical feature-selection workflow for training predictive models. The models are fine-tuned through Bayesian optimization, using features derived solely from the chemical compositions of the materials data, before the model predictions are evaluated against literature values. We have collated ca. 35,000 Tc values and the performance of our workflow is benchmarked against state-of-the-art algorithms, the results of which demonstrate that our methodology is superior to the majority of alternative methods. In a 10-fold cross-validation, our regression model realized an R2 of (0.92 ± 0.01), an MAE of (40.8 ± 1.9) K, and an RMSE of (80.0 ± 5.0) K. We demonstrate the utility of our ML model through case studies that forecast Tc values for rare-earth intermetallic compounds and generate magnetic phase diagrams for various chemical systems. These case studies highlight the importance of a systematic approach to feature analysis and selection in enhancing both the predictive capability and interpretability of ML models, while being devoid of potential human bias. They demonstrate the advantages of such an approach over a mere reliance on algorithmic complexity and a black-box treatment in ML-based modeling within the domain of computational materials science.

Soluble hemp protein-xylose conjugates fabricated by high-pressure homogenization and pH-shifting treatments.

The process of Maillard conjugation occurs with plant proteins and sugars and can be influenced by several factors, such as processing time, pH, and shear force. By utilizing cavitation processes such as high-pressure homogenization (HPH) and pH-shifting, it is possible to regulate the degree of grafting, functional characteristics, and structural changes in the formation of conjugates. The present study aimed to improve the hemp protein concentrate (HPC) through two different conjugation techniques: HPH and pH-shifting-assisted processes. The best conjugation conditions for the conventional method were identified as a 1:2 HPC to xylose ratio, a pH of 10, and 3 h of treatment at 70 °C. The use of HPH and pH 12-shifting methods resulted in a remarkable 2.5-fold increase in grafting degree, requiring less processing time. Fourier transform infrared spectra confirmed the formation of conjugates. Conjugates produced through HPH with pH 12-shifting (MPHX) transformed into soluble glycoproteins with a particle size of 74 nm. MPHX solubility increased by 5.7-fold than HPC, reaching 85.7%, with a more negatively charged surface at -32.4 mV. Microimages showed cracked and sharp forms for conjugated proteins compared to untreated HPC. Additionally, MPHX conjugates demonstrated superior properties in emulsion stability, foaming capacity, and antioxidant activity compared to HPC and classical conjugates. The use of HPH and pH-shifting-assisted Maillard conjugation was highly effective in enhancing the functional attributes of hemp protein conjugates. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Theoretical Insights of Curvature Effects of FeN4-Doped Carbon Nanotubes on ORR Activity.

The advancement of metal-air batteries is critically contingent on the progression of efficient catalysts for the oxygen reduction reaction (ORR). The potential applications of a series of FeN4-doped carbon nanotubes (Fe-N4CNTs) of varying diameters as ORR catalysts were examined using density functional theory. We explored the stability and electronic properties of Fe-N4CNTs by analyzing the energy and examining the density of states. A marked dependence of the catalytic performance on the nanotube diameter was observed: as the transition from (5, 5) to (10, 10) Fe-N4CNTs occurred, the catalytic activity on the outer surface of the carbon tubes enhanced progressively, with the overpotential reducing from 0.94 to 0.86 V. Conversely, the catalytic activity on the inner surface of the carbon tubes decreased progressively with the overpotential also increasing from 0.62 to 1.04 V. In addition, we found that curvature significantly affected the electronic structure and charge transfer at the FeN4 site, regulating the adsorption and desorption of reactants, intermediates, and products during electrocatalysis and thus influencing the catalytic activity of the Fe-N4CNTs. This investigation offers valuable guidance for the design of Fe-based single-atom catalysts and the practical application of Fe-N-C materials.

Ab-initio investigation of stability and electronic properties of new yttrium-based solid solution of double transition metal YMXTx (M= Ti and zr; X= C and N; Tx= H, O, and F) MXenes

In this study, an extensive examination was carried out to explore the stability, and physical characteristics of a novel solid solution comprising two transition metals, namely YMXTx (M = Ti and Zr; X = C and N; Tx = H, O, and F) MXenes. The Quantum-Espresso computational package which is based on density functional theory (DFT) and pseudopotential techniques has been employed for performing calculations. The results obtained from the investigation of the structural, dynamic, and mechanical stability revealed that the YTiX and YZrX MXenes exhibited remarkable stability. These findings strongly suggest the feasibility and potential success of experimental synthesis of these materials. Furthermore, the result of cohesive energy indicated that Nitride-based MXenes (Y(Ti/Zr)N) are more stable than Carbide-based MXenes (Y(Ti/Zr)C). By performing comprehensive calculations of the total density of states and band structures, using various approximations such as LDA, GGA, and GGA + HSE06, the investigation revealed a metallic behavior in YMX MXenes. Additionally, the analysis of the TDOS revealed the presence of a pseudogap close to the Fermi level. This observation provides further evidence for the structural stability of the investigated mentioned MXenes. After undergoing saturation with different functional groups, it was observed that the YTiNH2 and YTiNF2 MXenes displayed semiconducting behavior, whereas YZrNO2 is classified as a non-conductive material, and the remaining monolayers exhibit metallic properties. Analyses of charge density and electron localization functions confirmed the metallic behavior of the studied MXenes. Modifying the electronic band gap of 2D MXenes, while also preserving structural stability, could lead to enhancing the application of these materials in optoelectronic devices.

Theoretical insight into physical characteristics of lead-free perovskites Rb2TlSbX6 (X = Cl, Br, I) for optoelectronic devices.

Novel optoelectronic and thermoelectric properties with broad compositional range, non-toxic nature and structural stability make halide-based double perovskites fascinating for flexible optoelectronic devices. In this work, the structural electronic, optical and transport properties of Rb2TlSbX6 (X = Cl, Br, I) were studied using density functional theory for optoelectronic devices. The elastic analysis demonstrates ductile nature, mechanical stability, anisotropic behaviour and feasibility for flexible optoelectronic devices. The band structure study using Tran-Blaha-modified Becke-Johnson (TB-mBJ) potential shows that all studied materials have direct bandgap. In addition, the bandgap of Rb2TlSbCl6 is more appropriate for optoelectronic devices. The small loss and maximum absorption in visible regions make these materials prime candidates for optoelectronic devices. The transport features indicate that all the studied double perovskites reflect p-type semiconducting behaviour as highlighted by positive Seebeck coefficient values. Furthermore, the high power factor values of Rb2TlSbX6 (X = Cl, Br, I) double perovskites make them suitable for thermoelectric device applications at high temperatures. Based on electronic optical and thermoelectric properties Rb2TlSbCl6 is the best candidate for flexible optoelectronic devices. In this paper, structural optimization of Rb2TlSbX6 (X = Cl, Br, I) double perovskites was conducted utilizing the Wien2k software based on first principle calculations with Perdew-Burke-Ernzerhof's generalized-gradient approximation (PBE-sol approximation). The TB-mBJ potential was employed to compute the accurate band gap of studied materials. The thermoelectric properties are evaluated with BoltzTraP code, showing a predominance of P-type charge carriers in all studied perovskites. This methodological strategy verifies the material's remarkable stability and optical properties and offers a solid framework for examining its potential in optoelectronic devices.

Polypyrrole Derivatives: Preparation, Properties and Application

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

Fabrication ofAMulti-functional SeparatorIncorporating Crown ether-PolyoxometalateSupramolecular CompoundforLithium-SulfurBatteries.

Recently, research on polyoxometalates (POMs) has gained significant momentum. Owing to their properties as electronic sponges, POMs catalystharbor substantial potential in lithium-sulfur battery research. However, POMs undergo a transformation into reduced heteropoly blue (HPB) during electrochemical reactions, which then dissolve into the electrolyte, resulting incatalyst loss. In this research, we amalgamated 18-crown-6(CR6)with K3PW12O40, (KPW), synthesized a novel POM-basedsupramolecular compound, and integrated it with graphene oxide(GO) to fabricate a multi-functional composite polypropylene (PP) separatorKPW-CR6/GO/PP. The crown ether array was employed to immobilizePOM and construct ion transport channels, thereby enhancing the Li+migration rate and capturing polysulfides. Subsequently, leveraging the stable structure and redox properties of POM, the polysulfide is catalyzed to transform and inhibit the shuttle effect, thereby protecting the Lianode.The lithium-sulfur batteries with the Crown ether-POM supramolecular compoundseparators, exhibit enhanced capacity and stability (1073.3mAh g-1at 1.0C, and 81.5% retention rate after 250 cycles). Thebattery (Sloading:3.2 mg cm-2) presents an initial specific discharge capacity of 543.4 mAh g-1at 0.5 C, with 89.8% of the capacity retained after 160 cycles.Thisunderlinesthe practical application potential of Crown ether-POM supramolecular materials in Li-S batteries.

Fabrication of Flame-Retardant Ammonium Polyphosphate Modified Phytic Acid-Based Rigid Polyurethane Foam with Enhanced Mechanical Properties

Ammonium polyphosphate (APP) and self-made nickel phytate (PANi) were used as modified materials to prepare green biomass rigid polyurethane foam (RPUF). The flame retardancy, thermal stability, smoke toxicity and mechanical properties of the modified RPUF were investigated by limiting oxygen index (LOI), a cone calorimetry (CONE) test, thermogravimetric analysis and a compression test. The results showed that the RPUF with 10 wt% APP (PANi/APP10) had the highest LOI of 26.5%. Its peak heat release rate (PHRR) and total heat release (THR) were reduced by 29.64% and 24.05% compared with PANi/APP0 without APP. And its smoke production rate (SPR) and total smoke release (TSR) decreased by 33.14% and 19.88%, respectively. Compared with pure RPUF, the compressive strength of PANi/APP10 was increased by 50%, mainly because APP itself was an ultra-fine powder, which was better compatible with the matrix and improved the hardness of the material. The results showed that the synergistic effect of the gas phase and the condensed phase mechanism could effectively improve the flame-retardant effect. The current research results provided a new strategy for the preparation of green and low-toxicity RPUF.

Therapeutic application of mesenchymal stem cell-derived exosomes in skin wound healing

Wound healing is a complicated obstacle, especially for chronic wounds. Mesenchymal stem cell-derived exosomes may be a promising cell-free approach for treating skin wound healing. Exosomes can accelerate wound healing by attenuating inflammation, promoting angiogenesis, cell proliferation, extracellular matrix production and remodeling. However, many issues, such as off-target effects and high degradation of exosomes in wound sites need to be addressed before applying into clinical therapy. Therefore, the bioengineering technology has been introduced to modify exosomes with greater stability and specific therapeutic property. To prolong the function time and the local concentration of exosomes in the wound bed, the use of biomaterials to load exosomes emerges as a promising strategy. In this review, we summarize the biogenesis and characteristics of exosomes, the role of exosomes in wound healing, and the therapeutic applications of modified-exosomes in wound healing. The challenges and prospects of exosomes in wound healing are also discussed.

Computational investigation of stochastic Zika virus optimal control model using Legendre spectral method

This study presents a computational investigation of a stochastic Zika virus along with optimal control model using the Legendre spectral collocation method (LSCM). By accumulation of stochasticity into the model through the proposed stochastic differential equations, we appropriating the random fluctuations essential in the progression and disease transmission. The stability, convergence and accuracy properties of the LSCM are conscientiously analyzed and also demonstrating its strength for solving the complex epidemiological models. Moreover, the study evaluates the various control strategies, such as treatment, prevention and treatment pesticide control, and identifies optimal combinations that the intervention costs and also minimize the proposed infection rates. The basic properties of the given model, such as the reproduction number, were determined with and without the presence of the control strategies. For R0<0\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$R_0<0$$\\end{document}, the model satisfies the disease-free equilibrium, in this case the disease die out after some time, while for R0>1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$R_0>1$$\\end{document}, then endemic equilibrium is satisfied, in this case the disease spread in the population at higher scale. The fundamental findings acknowledge the significant impact of stochastic phonemes on the robustness and effectiveness of control strategies that accelerating the need for cost-effective and multi-faceted approaches. In last the results provide the valuable insights for public health department to enabling more impressive mitigation of Zika virus outbreaks and management in real-world scenarios.

Deep-Learning-Guided Electrochemical Impedance Spectroscopy for Calibration-Free Pharmaceutical Moisture Content Monitoring.

The moisture content of pharmaceutical powders can significantly impact the physical and chemical properties of drug formulations, solubility, flowability, and stability. However, current technologies for measuring moisture content in pharmaceutical materials require extensive calibration processes, leading to poor consistency and a lack of speed. To address this challenge, this study explores the feasibility of using impedance spectroscopy to enable accurate, rapid testing of moisture content of pharmaceutical materials with minimal to zero calibration. By utilizing electrochemical impedance spectroscopy (EIS) signals, we identify a strong correlation between the electrical properties of the materials and varying moisture contents in pharmaceutical samples. Equivalent circuit modeling is employed to unravel the underlying mechanism, providing valuable insights into the sensitivity of impedance spectroscopy to moisture content variations. Furthermore, the study incorporates deep learning techniques utilizing a 1D convolutional neural network (1DCNN) model to effectively process the complex spectroscopy data. The proposed model achieved a notable predictive accuracy with an average error of just 0.69% in moisture content estimation. This method serves as a pioneering study in using deep learning to provide a reliable solution for real-time moisture content monitoring, with potential applications extending from pharmaceuticals to the food, energy, environmental, and healthcare sectors.

Highly Hydrophilic TiO2 Nanoparticles as Stabilizers of Pickering Emulsions with Photosensitive Lipophilic Compounds: Synthesis and Application.

Pickering emulsions are a very promising system for encapsulating and photoprotecting active ingredients. The highest photoprotection efficiency can be achieved when bare TiO2 nanoparticles are used as stabilizers. However, the main problem when using highly hydrophilic TiO2 nanoparticles is their inability to adsorb at the oil-water interface. Here, we developed emulsions stabilized by bare, highly hydrophilic TiO2 nanoparticles for the encapsulation and photoprotection of active lipophilic compounds. Emulsion stabilization occurs due to the formation of hydrogen bonds between hydroxyl groups on the particle surface and the carbonyl groups of the oil molecules. The stability and rheological properties of emulsions are explained by the properties of the initial hydrosols. The resulting Pickering emulsions demonstrated effective UV protection of α-lipoic acid. Our results pave the way for the formulation of Pickering emulsions with a widely used cosmetic oil and show for the first time the possibility of photoprotection of a lipophilic active substance using unmodified TiO2 nanoparticles.

Luminescence modulated by molecular conformation in stimuli-responsive polymorphs of dibenzothiaborinine dioxide-pyridylphenolate complex

Novel spirane organoboron complex, SO2-pp, composed of highly electron-accepting dibenzo[b,e][1,4]thiaborinine 5,5-dioxide scaffold and 2-(2-pyridyl)phenolate ligand exhibits moderate-to-strong fluorescence in solution and solid state. Photophysical properties of this system strongly depend on the conformation of the molecule. Specifically, due to the semi-labile nature of organoboron moiety as well as the asymmetric character of the ligand, two distinctive conformations can be distinguished. Their occurrence in the solid state is regulated by the crystallization conditions leading to the formation of two polymorphic phases exhibiting sky blue (SO2-pp-α, λ = 446 nm, ΦF = 70 %) and green (SO2-pp-β, λ = 489 nm, ΦF = 36 %) emission, respectively. Their crystal structures, stability and photophysical properties were comprehensively studied by DSC, single-crystal XRD and variable-temperature PXRD. Periodic DFT calculations showed that the lattice energy of SO2-pp-β polymorph is by 28 kJ‧mol−1 more favoured (7 kJ‧mol−1 per molecule, optimization in periodic boundary conditions) owing to more efficient intermolecular interactions in the crystal structure. In contrast, the molecule of the kinetic SO2-pp-α phase adopts more stable conformation (energy difference of 4.7 kJ‧mol−1, single-molecule DFT optimization) which can be ascribed to the formation of intramolecular C–H⋯O hydrogen bond interaction. Both forms show sensitive tricolor reversible response under mechanical and temperature stimuli. Under grinding, they gradually turn into cyan (λ = 479 nm) amorphous phase (SO2-pp-A). This process can be reversed by heating or exposure to CHCl3 vapours.

The Effect of Diphenylphosphate Intercalated Magnesium Aluminum Lanthanum Hydrotalcite on the Thermal Stability and Mechanical Properties of Poly(Vinyl Chloride)

The Effect of Diphenylphosphate Intercalated Magnesium Aluminum Lanthanum Hydrotalcite on the Thermal Stability and Mechanical Properties of Poly(Vinyl Chloride)

Thermal-Insulation Fillers’ Influences on the Heating Resistance of PDMS-Based Aerogel Layer

PDMS-based aerogel layers were synthesized as insulation layers by adopting mullite fiber (MF), hollow glass microspheres (HGM) and silica aerogel (SA) as the main fillers, and their loading amounts and content ratios were checked to investigate their effects on the thermal insulation properties in PDMS composites by thermal conductivity, thermal stability, and thermal insulation. The loading amount of nanofillers can significantly influence the insulation-layer performance, and the best performance with the lowest thermal conductivity of 0.0568 W/(m·K) was obtained by 10 wt% loading in PDMS with MF:SA:HGM = 2:2:1, which can achieve a temperature difference (∆T) of 67 °C on a 200 °C hotplate. Moreover, the variation of the filler content ratios can also affect the thermal insulation behavior when the loading amount is fixed at 10 wt%, and the best thermal barrier performance can be found for the sample with more SA as the filler (MF:SA:HGM = 1:3:1). The formed sample had the best thermal stability and thermal insulation property, which can stand a 9 min flame test without burning by butane spray gun, and the backside of the sample showed ∆T &gt; 500 °C for the whole test.

Siloxane-based segmented poly(urethane-urea) elastomers with enhanced mechanical properties, hydrophobicity and anti-calcification based on hierarchical phase separation for potential applications of polymeric heart valve

The polymeric heart valves have attracted considerable attention for treating valvular heart diseases with favorable biocompatibility, stability and adjustable mechanical properties. However, the thrombosis, calcification, and mechanical durability in the dynamic blood environment have limited further applications. Polycarbonate (PCDL) and polysiloxane (PDMS) had high flexibility, low toxicity, excellent hydrolytic and oxidative stability and efficient biocompatibility, but PCDL was susceptible to calcification and PDMS was susceptible to protein adsorption. To solve these difficulties, PDMS and PCDL were chosen as soft segments to combine the virtues of excellent biocompatibility, hydrolytic stability, and good anti-calcification and anti-protein adsorption, and a series of PCDL-PDMS poly(urethane-urea) elastomers (PCDL-PDMS PUU) were synthesized using a two-step polymerization reaction based on the amino-terminated polydimethylsiloxane (H2N-PDMS-NH2), polycarbonate diol (PCDL) and isophorone diisocyanate. The thermodynamic incompatibility between PDMS and PCDL and hierarchical hydrogen bonds were used to construct microscopic micro-separation, enabling the combination of enhanced mechanical strength, toughness, tear resistance and biocompatibility. The effect of the molar ratio of PCDL and PDMS and hierarchical H-bonding interactions on the physical properties, biostability and biocompatibility of PCDL-PDMS PUU were investigated. It was found the PCDL-PDMS PUU could achieve relatively stable mechanical strength behavior, and the Young’s modulus and tear strengths increased with the increasing proportion of H2N-PDMS-NH2. Meanwhile, PCDL-PDMS PUU showed low water uptake rate lower than 2 %, very good anti-hydrolysis performance, low hemolysis rate of less than 2 % and low adhesion to platelet cells. What’s more, PCDL-PDMS PUU showed enhanced calcification resistance when compared with a commercial polyurethane, ElastollanTM 1180A. Therefore, the results demonstrated that PCDL-PDMS PUU elastomers showed great potential to be explored as heart valves material considering high biostability, superior biocompatibility and mechanical performances.

Novel Stability Criteria of Asynchronously Switched Nonlinear Neutral Time-Delay Systems.

This article investigates the input-to-state stability and integral input-to-state stability for the switched nonlinear neutral systems (SNNSs) with multiple time-varying delays (MTVDs) and asynchronous switching. According to the fact that the switching signals of the controllers and the subsystems are inconsistent, novel stability criteria on the input-to-state stability and integral input-to-state stability properties for SNNSs with MTVDs and the asynchronous switching phenomenon are presented by multiple Lyapunov-Krasovskii functionals, the merging switching signal, and the mode-dependent average dwell time technique. Compared with the existing related works, our results are less conservative. Meanwhile, our proposed works not only investigate the effects of switches and neutral terms on the stability property for SNNSs but also study the case of the systems with MTVDs and asynchronous switching. Finally, two practical examples, including the practical coupled mass-spring-damper-pendulum system, are presented to show the effectiveness of our results.

Modulation of rapeseed protein nanoparticles by interaction with chitosan: Enhancing the physical stability, antioxidant activity and β-carotene slow-release properties of Pickering emulsion

This study aimed to investigate the physical stability, oxidation, digestibility and β-carotene sustained-release properties of Pickering emulsions stabilized by rapeseed protein (RP) complexed with chitosan (CS). The results showed that adding CS to RP decreased the RP mean particle size from 3575.0 to 130.9 nm, increased its zeta-potential from 29.6 to 41.4 mV, changed its tertiary structure, and enabled its uniform dispersion. Additionally, CS addition improved RP interfacial properties at air/water and oil/water interfaces, thereby enhancing its emulsification activity and stability. Rheological property analysis exhibited that RP/CS complex had a smaller storage modulus (G′) and loss modulus (G") as well as a higher apparent viscosity. Moreover, the RP/CS complex stabilized emulsions showed a smaller average particle size of 100–1500 nm, a higher zeta-potential of 58–66 mV and better physical stability, thus better tolerating environmental factors such as time, temperature and salt ions. Furthermore, the RP/CS complex stabilized emulsions showed better antioxidant properties with a lower peroxide value (POV) and thiobarbituric acid reactant value (TBARS). Finally, the RP/CS complex emulsions exhibited better antidigestive stability and could slow down the β-carotene release rate. These results provide a theoretical basis for the application of RP/CS complex as a new food emulsifier in the nanocolloid transport system.

Structural changes and grading mechanism of lignin during solid alkali-active oxygen extraction and grading

Cooking with active oxygen and solid alkali (CAOSA) is an efficient pretreatment method for biomass. For better grading of the lignin yellow liquor, the different lignin fractions and the recovered solid alkali were obtained using a simultaneous acid-alkali graded separation method. The results indicated that the recovery rate of solid alkali was 67.25 %, and the grading of lignin components was characterized by smaller dispersion coefficients, and more stable properties and structure. Lignin fractions with low dispersion coefficients possess more key structures, including the Phenol hydroxyl group (ArOH), Methoxy (OMe), and β-aryl ether (β-O-4), and have better thermal properties. The low molecular weight L4 has the highest ArOH content (2.1 mmol/g), which provides better antioxidant properties. The CAOSA process destroyed the S-unit and prevented lignin from condensation. Furthermore, the CAOSA process protected carbohydrates, which could effectively prevent them from dehydrating and re-polymerizing into pseudo-lignin. This allowed the pulp to remain natural, which was beneficial for subsequent transformation and utilization. Overall, the efficient separation of biomass components and lignin grading method proposed by combining the CAOSA process with the acid-alkali grading separation method has a strong application prospect and provides a theoretical basis for the high-value utilization of biomass and lignin.

Knittable hydrogel fiber with physically amorphous structure for multi-mode sensing capacities

Integrating both green forming character and multifunctionality for physically crosslinked hydrogel fibers is challenging, but intensively desirable for emerging applications. Herein, the amorphous multi-scale structure for continuously spinning polyvinyl alcohol (PVA) hydrogel fibers is achieved with an innovatively suppressed-freezing strategy. In particular, the antifreezing salt with salting-in effect is introduced into precursor solution, in which an exceptionally homogeneous yet weak approach of polymer chains is available under weakened repelling behavior of ice crystals using liquid nitrogen as the coagulation bath. Hence, a totally amorphous network with release of free hydroxyl groups is constructed for freeze-thawed PVA hydrogel fibers, which is further stabilized by water evaporation induced densification of polymer network. Such particular multi-scale structure interestingly endows the physical hydrogel fibers with tunable mechanical properties of superior extendibility, flexibility and elasticity in a wide range, along with integrated properties of excellent transparency, antifreezing and long-term stability. Moreover, the hydrogel fibers could be knitted into fabric-like materials with arbitrary shapes, of which the extendibility and toughness are tremendously improved. Notably, benefiting from the high transparency and homogeneous structure, the physical fibers and the corresponding fabrics demonstrate light transmittance ability and deformation responsiveness, which retains even in extreme condition (−196 °C). Together with ionic-conductivity, the PVA hydrogel fibers/fabrics as strain sensors intriguingly represent conductive/optical multi-mode sensations, which are capable of dynamically monitoring subtle and sophisticated human movements. The combined advantages enable this new generation of physical hydrogel fibers to promise potential for applications in wearable electronics, biomedicine, and information transmission.