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The escalating focus on environmental concerns and the swift advancement of eco‐friendly biodegradable batteries raises a pressing demand for enhanced material design in the battery field. The traditional polypropylene (PP) that is monopolistically utilized in the commercial LIBs is hard to recycle. In this work, we prepare a novel water degradable separators via the cross‐linking of polyvinyl alcohol (PVA) and dibasic acid (tartaric acid, TA). Through the integration of non‐solvent liquid‐phase separation, we successfully produced a thermally stable PVA‐TA membrane with tunable thickness and a high level of porosity. These specially engineered PVA‐TA separators were implemented in LiFePO4 (LFP)|separator|Li cells, resulting in superior multiplicative performance and achieving a capacity of 88 mAh g−1 under 5 C. Additionally, the straightforward small molecule cross‐linking technique significantly reduced the crystalline region of the polymer, thereby enhancing ionic conductivity. Notably, after cycling, the PVA‐TA separators can be easily dissolved in 95 °C hot water, enabling its reutilization for the production of new PVA‐TA separators. Therefore, this work introduces a novel concept to design green and sustainable separators for recyclable lithium batteries. [ABSTRACT FROM AUTHOR]

We introduce a simple synthetic strategy to selectively degrade bottlebrush networks derived from well‐defined poly(4‐methylcaprolactone) (P4MCL) bottlebrush polymers. Functionalization of the hydroxyl groups present at the terminal ends of P4MCL side chains with α‐lipoic acid resulted in bottlebrush polymers having a range of molecular weights (Mn = 45–2200 kg mol−1) and a tunable number of reactive dithiolane chain ends. These functionalized chain ends act as efficient crosslinkers due to radical ring‐opening of the dithiolane rings under UV light. The resulting redox‐active disulfide crosslinks enable mild electrochemical or chemical degradation of the SS crosslinks to regenerate the starting bottlebrush polymer. P4MCL side chains and the disulfides can be degraded simultaneously using harsher reducing conditions. This combination of bottlebrush architecture with facile disulfide crosslinking presents a versatile platform for preparing highly tunable elastomers that undergo controlled degradation under mild conditions. [ABSTRACT FROM AUTHOR]

Biological conversion of methane into poly-β-hydroxybutyrate (PHB) presents a promising strategy for addressing greenhouse gas emissions and plastic pollution. This study presents a novel approach for the production of PHB from methane using Methylosinus trichosporium 11131. The integrated two-phase process involves the generation of high-density methanotrophic biomass in phase I, followed by the enrichment of PHB in phase II using nutritional modulation. Under optimal growth conditions, a biomass titer of 3.82 ± 0.01 g/L was achieved, and subsequent nitrate starvation led to the accumulation of PHB (41.24 ± 0.83 % w/w). Further optimization by exposing the cells to excess methane concentration (5% v/v) and nitrate starvation increased the PHB content to 52.42 ±1.03% w/w. The scalability of the process was demonstrated in a 5-L stirred tank bioreactor, yielding a PHB concentration of 2.02 ± 0.04 g/L. The suitability of the extracted PHB as a degradable food packaging material was evaluated by a comprehensive analysis of its thermal, structural, mechanical, physical, and molecular properties. Our results suggest that the PHB obtained from Methylosinus trichosporium 11131 can serve as a promising alternative to petroleum-based plastics due to its superior properties and biodegradability. Overall, this study presents an innovative biotechnological approach for the conversion of methane into a valuable biopolymer and highlights its potential as a sustainable alternative to conventional plastics. [ABSTRACT FROM AUTHOR]

Heterogeneity is a fundamental characteristic of oil and gas reservoirs. The key measure improving the acidizing effect of heterogeneous reservoirs is diversion methods, which diverting agents are used to plug the high permeability layer and promote acid acting on the low permeability layer. In order to solve the problems of uncontrollable gelation time and serious damage of synthetic polymer diverting agents. A novel diverting agent SAXG with high strength and biodegradability was formed through semi-interpenetration using biomaterials sodium alginate (SA)and xanthan gum(XG). The optimal mass percentage of the system was optimized to 0. 7% SA+0. 3% XG with the goal of deformation and gelation time. The rheological properties and delayed gelation characteristics of this diverting agent were tested by rheometer；The degradability of the system was described with the content of residue；The difference between SAXG semi-interpenetrating network and SA gel was confirmed through scanning electron microscope(SEM)；Finally, the core flow experiment was used to verify the divert acidizing effect of SAXG. The results showed that the gelation time range of SAXG is 14 to 456 min；The SAXG can be completely degraded in saline and acid solutions；The permeability of the core after diversion acidizing increased by 2. 85 times compared to conventional acidification；The recovery rate of core permeability after degradation reached 98. 6%. The SAXG can effectively promote the diversion of acid solution, thereby improving the effectiveness of acid stimulation. [ABSTRACT FROM AUTHOR]

Vat photopolymerization 3D printing has proven very successful for the rapid additive manufacturing (AM) of polymeric parts at high resolution. However, the range of materials that can be printed and their resulting properties remains narrow. Herein, we report the successful AM of a series of poly(carbonate‐b‐ester‐b‐carbonate) elastomers, derived from carbon dioxide and bio‐derived ϵ‐decalactone. By employing a highly active and selective Co(II)Mg(II) polymerization catalyst, an ABA triblock copolymer (Mn=6.3 kg mol−1, ÐM=1.26) was synthesized, formulated into resins which were 3D printed using digital light processing (DLP) and a thiol‐ene‐based crosslinking system. A series of elastomeric and degradable thermosets were produced, with varying thiol cross‐linker length and poly(ethylene glycol) content, to produce complex triply periodic geometries at high resolution. Thermomechanical characterization of the materials reveals printing‐induced microphase separation and tunable hydrophilicity. These findings highlight how utilizing DLP can produce sustainable materials from low molar mass polyols quickly and at high resolution. The 3D printing of these functional materials may help to expedite the production of sustainable plastics and elastomers with potential to replace conventional petrochemical‐based options. [ABSTRACT FROM AUTHOR]

The utilization of leather waste (LW) in a polyurethane (PU) matrix makes a smart and novel shape stable phase change material (SSPCM). This is essential for sustainability as it reduces landfill waste after use. The PU is synthesized in bulk with a 90% yield, using biodegradable polycaprolactone diol and bio‐based polyol (castor oil), along with tolylene‐2,4‐diisocyanate. PL and PLG composites are prepared by blending of constituent components PU (P), LW (L), and poly(glycidyl methacrylate) (PGMA, G), as specified by their code names. Role of LW (hydrogen bonding and chemical crosslinking) and morphology are elucidated by FTIR and SEM, respectively. Self‐healing time (2 h), shape fixity ratios (Rf) (PL: 60–80% and PLG: 60–70%) and shape recovery ratios (Rr) (100% for both) are determined at 60°C. PLG displays faster shape recovery in water (<30 s) compared to air (>300 s). Shape stability and thermal properties of the SSPCM are examined using the temperature responsive leakage study, TGA, and DSC. This research introduces a new approach for using leather waste (LW) in SSPCM, with self‐healing and 100% Rr. This material may find application where SSPCM with high durability and flexibility is essential such as textile and footwear materials. [ABSTRACT FROM AUTHOR]

[Display omitted] Conventional piezoelectric nanogenerators (PNGs) face challenges in terms of degradation and reusability, which have negative environmental implications. On the other hand, biocompatible and degradable piezoelectric materials often exhibit lower piezoelectric response. In this study, potassium sodium niobate (KNN) powder and the biodegradable polymer poly(ε-caprolactone) (PCL) were used to fabricate piezoelectric composite films through solution casting. By constructing staggered electrodes, the total polarized charges quantity is increased, achieving a larger current output. The three-unit PNG (3-PNG) based on the composite film with 15 wt% KNN powder, reaches a maximum output current of 0.85 μA, which exhibits higher charging efficiency compared to 1-PNG. Moreover, the prepared 3-PNG can effectively harvest mechanical energy from human activities and maintain a stable output after 10,000 cycles of bending and releasing. The film exhibits complete degradation when exposed to acidic, neutral, and alkaline solutions. This research provides a promising option for environmentally friendly piezoelectric materials selected and output performance enhanced through optimized structural designs, making them more suitable for practical applications. [ABSTRACT FROM AUTHOR]

Flexible electronics are striving in modern society, and they impose harsh and urgent requirements for flexibility on electronic package substrates. However, traditional materials, including ceramics, metals, or polymers are lack of flexibility. Herein, a polyurethane named PU‐D1Q1VF1 is proposed via incorporating carefully selected biobased units and synergistic dynamic bonds, and the PU‐D1Q1VF1 not only meets the basic requirements of flexibility but also possesses properties of self‐heal, UV‐protection, reprocessability, and degradability. The polycaprolactone diol (PCL diol) was employed as the soft segment, and the bis(2‐hydroxyethyl) disulfide (HEDS) and lignin derived model monomer hydroquinone were selected as chain extenders. Moreover, carefully synthesized bio‐based monomer (E)‐4‐(((furan‐2‐ylmethyl)imino)methyl)‐2‐methoxyphenol (VF) was used as the capping agent, which could facilitate the self‐healing process of the PU‐D1Q1VF1. [ABSTRACT FROM AUTHOR]

Wood presents excellent opportunities for sustainable urbanism as a renewable building material. Here, the chemical synthesis of a novel wood composites (3%PFeW) which owns flame‐retardance, water resistance, and degradability is investigated. The 3%PFeW is composed of porous wood framework impregnated with citric acid, 1,8‐octanediol, and the flame retardants (Fe3O4 and 2‐carboxyethyl phenyl hypophosphite (CEPPA)). The 3%PFeW's effective flame retardancy is realized by the introduction of Fe3O4 and CEPPA. Self‐extinguish phenomenon of 3%PFeW happens after being removed from flame. Moreover, 3%PFeW holds an LOI value of 27, reaching V0 flame retardant standard. The 3%PFeW exhibits exceptional water resistance, being proven by its water contact angle (100 °) as well as the low absorbed water content (only 6.5% after soaking 7 days). In addition, the wood composite shows degradable after immersion in NaOH for several days (71.37% degradation content after 7 days), which facilitates the recycling and reutilization of the wood framework after utilization. The modified wood with flame‐retardant, water resistant, and degradable capabilities shown here provides an appealing composite toward building area. [ABSTRACT FROM AUTHOR]

Objective To investigate the physicochemical and biological properties of a new calcium sulfate-based root canal sealer for deciduous teeth containing calcium sulfate hemihydrate, barium sulfate, chlorhexidine acetate, and polyethylene glycol 400 (PEG 400). Methods This study was reviewed and approved by the Ethics Committee. The calcium sulfate hemihydrate and barium sulfate powders with different mass percentages were mixed with liquid PEG 400 at a powder-to-liquid ratio of 3∶1, and chlorhexidine acetate was added to a concentration of 0.2 mg/mL according to the volume of PEG 400. The above materials were mechanically ground at 250 r/min for 24 h to obtain a calcium sulfate-based root canal sealer for deciduous teeth. The sealer was classified into different groups according to mass percentages of components. The mass percentages of components were optimized by performing time, fluidity, and radiopacity experiments, and then the pH, mass loss in vitro, and microscopic morphology of the optimal sealer were evaluated. The antimicrobial properties of the sealer were evaluated by a bacterial-material cocultivation method. The cytocompatibility of the sealer was evaluated by a CCK-8 assay and cytomorphological staining, and its biocompatibility was evaluated by a subcutaneous tissue embedding assay. Results After optimization, mass percentage of calcium sulfate hemihydrate was 80 wt%, and the mass percentage of barium sulfate was 20 wt%. The flowability and radiopacity of the sealer were in accordance with international standards. The pH stabilized between 6-7. On the 7th and 14th days, the pH in the water group was significantly greater than that in the PBS group (PP>0.05). In vitro degradation experiments, the mass loss of the sealer was approximately 15.17% during the preimmersion period, and rate of mass loss decreased after 3 weeks, reaching only approximately 8.33%. X-ray diffraction (XRD) and scanning electron microscopy (SEM) revealed that the main component of the sealer after hydration was calcium sulfate dehydrate. In bacterial growth assays and cytological tests, the sealer showed significant inhibition of the growth of E. faecalis (PPP>0.05). Both the sealer group and the control group (Vitapex and zinc oxide eugenol) caused mild inflammatory reactions in tissue sections. Conclusion In this study, a new type of root canal sealer for deciduous teeth was designed based on calcium sulfate, which has good physicochemical properties and strong antibacterial properties and meets biocompatibility requirements. This study provides an idea for the development of a new type of root canal sealer for deciduous teeth.

Mulch was prepared using composted sugarcane leaves, with polyvinyl alcohol and cationic starch as adhesives, through compression molding. The study aimed to investigate the effects of different adhesives on the mechanical properties, thermal oxidative degradation performance, and biodegradability of the covering materials. The results indicated that, when the adhesive dosage was consistent, cover material A, which utilized polyvinyl alcohol as the adhesive, exhibited higher tensile strength and elongation at break compared to cover material B, which employed a blend of polyvinyl alcohol and cationic starch. Specifically, at an adhesive dosage of 20%, cover material A achieved a tensile strength of 0.46 MPa and an elongation at break of 7.72%, representing the highest values among all experimental groups. There was minimal disparity in the thermal oxidative degradation performance between materials prepared with either adhesive; however, a higher quantity of adhesive led to decreased biodegradability performance. After being buried in soil for 120 days, the degradation exceeded 40% for both materials, resulting in loss of their original shape and strength properties. In conclusion, while sugarcane leaves-based biodegradable materials demonstrate favorable degradation performance, further enhancements are necessary to improve their mechanical properties. These materials have potential applications as substitutes for plastic mulch.

Abstract This study developed a kind of PEG-crosslinked O-carboxymethyl chitosan (O-CMC–PEG) with various PEG content for food packaging. The crosslinking agent of isocyanate-terminated PEG was firstly synthesized by a simple condensation reaction between PEG and excess diisocyanate, then the crosslink between O-carboxymethyl chitosan (O-CMC) and crosslinking agent occurred under mild conditions to produce O-CMC–PEG with a crosslinked structure linked by urea bonds. FT-IR and 1H NMR techniques were utilized to confirm the chemical structures of the crosslinking agent and O-CMC–PEGs. Extensive research was conducted to investigate the impact of the PEG content (or crosslinking degree) on the physicochemical characteristics of the casted O-CMC–PEG films. The results illuminated that crosslinking and components compatibility could improve their tensile features and water vapor barrier performance, while high PEG content played the inverse effects due to the microphase separation between PEG and O-CMC segments. The in vitro degradation rate and water sensitivity primarily depended on the crosslinking degree in comparison with the PEG content. Furthermore, caused by the remaining –NH2 groups of O-CMC, the films demonstrated antibacterial activity against Escherichia coli and Staphylococcus aureus. When the PEG content was 6% (medium crosslinking degree), the prepared O-CMC–PEG−6% film possessed optimal tensile features, high water resistance, appropriate degradation rate, low water vapor transmission rate and fine broad-spectrum antibacterial capacity, manifesting a great potential for application in food packaging to extend the shelf life.

Copyright of Journal of Prevention & Treatment For Stomatological Diseases is the property of Journal of Prevention & Treatment For Stomatological Diseases Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Polymers undergoing controlled degradation are of significant current interest. Among the classes of degradable polymers, self-immolative polymers (SIPs) are attracting increasing attention due to their ability to completely depolymerize from end to end following the cleavage of their endcap or backbone. Their amplified responses to stimuli, along with their ability to readily tune the stimulus to which they respond by changing only their endcap, are useful features for a variety of applications. This review covers the major classes of SIPs, including poly(benzyl carbamate)s, poly(benzyl ether)s, polyphthalaldehydes, polyglyoxylates, polydisulfides, polythioesters, and their related derivatives along with their endcaps. Distinctive features of their syntheses and depolymerizations are discussed. Applications of SIPs including imaging and sensing, therapeutics, gels, micro- and nanopatterning, transient or recyclable materials, and adhesives are described. We conclude with some challenges and future perspectives for the field. [ABSTRACT FROM AUTHOR]

Environmentally friendly crosslinked polymer networks feature degradable covalent or non‐covalent bonds, with many of them manifesting dynamic characteristics. These attributes enable convenient degradation, facile reprocessibility, and self‐healing capabilities. However, the inherent instability of these crosslinking bonds often compromises the mechanical properties of polymer networks, limiting their practical applications. In this context, environmentally friendly dual‐crosslinking polymer networks (denoted EF‐DCPNs) have emerged as promising alternatives to address this challenge. These materials effectively balance the need for high mechanical properties with the ability to degrade, recycle, and/or self‐heal. Despite their promising potential, investigations into EF‐DCPNs remain in their nascent stages, and several gaps and limitations persist. This Review provides a comprehensive overview of the synthesis, properties, and applications of recent progress in EF‐DCPNs. Firstly, synthetic routes to a rich variety of EF‐DCPNs possessing two distinct types of dynamic bonds (i.e. imine, disulfide, ester, hydrogen bond, coordination bond, and other bonds) are introduced. Subsequently, complex structure‐ and dynamic nature‐dependent mechanical, thermal, and electrical properties of EF‐DCPNs are discussed, followed by their exemplary applications in electronics and biotechnology. Finally, future research directions in this rapidly evolving field are outlined. [ABSTRACT FROM AUTHOR]

The preparation of biodegradable mulch film with paper-based materials has become a significant focus in mulch film development due to the serious pollution caused by plastic mulch film. This study utilized the esterification cross-linking reaction of LA, PVA, and GA to coat the surface of paper as the substrate. FTIR, TGA, XRD, SEM, tensile testing, and oxygen, water vapor barrier performance tests were performed. The optimal conditions for film preparation were determined to be a 10 % PVA aqueous solution, 5 % GA content, and a PVA/LA/GA ratio of 1:2:1. The resulting film paper exhibited a dry strength of 6.52 kN/m, a wet strength of 0.23 kN/m, a tearing degree of 969.35 mN, a Cobb value of 12.04 g/m2, a water vapor transmission rate of 573.27 g m−2 24 h−1, and an oxygen transmission rate of 7.373 cm3 m−2 24 h−1. After a 6-week landfill degradation test, the film showed a degradation rate of 25.3 %, while still maintaining a tensile strength of 1.89 kN/m. Field application tests in greenhouses confirmed that the film paper facilitated the growth of strawberry, its mechanical and barrier properties suitable for a biodegradable paper mulch. [ABSTRACT FROM AUTHOR]

Biocompatible optical devices are breakthrough illumination, imaging, and biomedical sensing technologies. Despite the noteworthy developments in silk, cellulose, and hydrogel-based optics, such approaches rely on expensive precursors and intricate fabrication. Therefore, agar extracted from red algae emerges as a promising biodegradable alternative as an edible, low-cost, and renewable material. This paper overviews the state-of-the-art of agar-based optical devices. Firstly, we revisit this phycocolloid's fundamentals and highlight its appealing mechanical, optical, and electrical characteristics. Subsequently, we summarize the available agar elements, slab waveguides, and optical fibers. Lastly, we discuss their advantages and challenges by envisaging opportunities for future developments and applications. [ABSTRACT FROM AUTHOR]

Traditional epoxy resins are made from non‐renewable fossil resources, which are difficult to reprocess and recycle, and their flammability makes them unsafe during use. In this experiment, an epoxy resin containing Schiff base (TA‐VAN‐EP) was synthesized successfully with biomass‐derived raw materials. This new material not only had favorable mechanical properties but also had good flame retardancy and degradation properties. The chemical structure of TA‐VAN‐EP was characterized by Fourier transform infrared (FTIR) spectroscopy and 1H nuclear magnetic resonance (NMR) spectroscopy. Its mechanical properties, thermal stability, flame‐retardant properties, and other properties were tested. The results showed that, compared with the pure epoxy resin (EP), the mechanical properties of TA‐VAN‐EP were significantly improved, and the glass transition temperature (Tg) was increased from 152°C to 190°C. Additionally, TA‐VAN‐EP reached a V‐1 rating during the UL‐94 test, and the limited oxygen index (LOI) value increased from 24.7% to 28.4%. Also, the total heat release (THR), smoke production rate (SPR), and total smoke release (TSR) decreased extremely. Moreover, TA‐VAN‐EP demonstrated good degradation performance under acidic conditions. In conclusion, this work provided a new idea for the production of bio‐based flame‐retardant epoxy resin with promising degradable abilities and mechanical properties. [ABSTRACT FROM AUTHOR]

This study developed a kind of PEG-crosslinked O-carboxymethyl chitosan (O-CMC–PEG) with various PEG content for food packaging. The crosslinking agent of isocyanate-terminated PEG was firstly synthesized by a simple condensation reaction between PEG and excess diisocyanate, then the crosslink between O-carboxymethyl chitosan (O-CMC) and crosslinking agent occurred under mild conditions to produce O-CMC–PEG with a crosslinked structure linked by urea bonds. FT-IR and 1H NMR techniques were utilized to confirm the chemical structures of the crosslinking agent and O-CMC–PEGs. Extensive research was conducted to investigate the impact of the PEG content (or crosslinking degree) on the physicochemical characteristics of the casted O-CMC–PEG films. The results illuminated that crosslinking and components compatibility could improve their tensile features and water vapor barrier performance, while high PEG content played the inverse effects due to the microphase separation between PEG and O-CMC segments. The in vitro degradation rate and water sensitivity primarily depended on the crosslinking degree in comparison with the PEG content. Furthermore, caused by the remaining –NH2 groups of O-CMC, the films demonstrated antibacterial activity against Escherichia coli and Staphylococcus aureus. When the PEG content was 6% (medium crosslinking degree), the prepared O-CMC–PEG−6% film possessed optimal tensile features, high water resistance, appropriate degradation rate, low water vapor transmission rate and fine broad-spectrum antibacterial capacity, manifesting a great potential for application in food packaging to extend the shelf life. [ABSTRACT FROM AUTHOR]

Polylactic acid (PLA) is a new type of biodegradable material, the degradation product is pollution-free, and meets the requirements of sustainable development. PLA can be used as a substitute for plastics due to its excellent biocompatibility and heat-resistant properties, and is widely used in production and life. This paper reviews three different PLA synthesis pathways and compares their advantages and disadvantages, describes the current modification of PLA focusing on mechanical properties and flame retardant properties, summarizes the methods of domestic and foreign scholars of PLA modification, summarizes the application pathways of modified PLA in food packaging, textiles, medical supplies and greenhouse membranes, and summarizes the development trend of PLA in the future with a view to provide a better solution for the future development of PLA technology and PLA to promote carbon peaks, heat resistance, and other properties. The future development trend of PLA is summarized in order to provide a reference for the future development of PLA technology. [ABSTRACT FROM AUTHOR]

Currently, the rising environmental concerns caused by nonbiodegradable food packaging materials have promoted the research and development of biodegradable alternatives. Polyvinyl alcohol (PVA) was selected as the substrate, and zinc oxide nanoparticles (ZnONPs) and titanium dioxide nanoparticles (TiO2NPs) were blended and modified with PVA, respectively. Based on the electrostatic spinning technology to prepare fiber membranes with high strength and UV blocking properties for grapes preservation. The study indicated that the tensile strength of PVA fiber membranes increased by 243% and 209% when ZnONPs and TiO2NPs were added at 1%, respectively. Under UV radiation, the PVA/ZnO composite membranes exhibited superior UV absorption than the PVA/TiO2 composite membranes. After conducting TG tests, it was found that the addition of ZnONPs decreased the thermal stability of the fiber membranes, while TiO2NPs could improve the thermal stability. Both composite membranes could extend grapes' shelf life, but the PVA/ZnO composite membranes were more effective at maintaining freshness than the PVA/TiO2 composite membranes. [ABSTRACT FROM AUTHOR]

In hot and arid desert regions, degradable chemical sand-fixing agents are efficient in dealing with problems caused by wind-blown sand movement without damaging the environment. This study aimed to develop a set of biodegradable sand-stabilizing substances, cellulose acetate (CA)-based waterborne polyurethane (WPU), utilizing CA as a partial hydroxyl provision through an acetone-based technique. The findings demonstrate that all the CA/WPU sand-fixing agents had unique, evenly spherical particles and were fully capable of degradation. The CA/WPU-2 sand-fixing agent contained 20 % polypropylene glycol (PPG) of CA. It showed strong viscosity, thermal stability, and water resistance. Furthermore, seed germination will be hindered by the CA/WPU-2 sand-fixing agent due to its superior sand-fixing capability compared to pure WPU. Consequently, it is suitable for application in arid regions where plant survival is difficult. CA/WPU-6 contained 120%PPG of CA. it showed outstanding O2 permeability and hydrophilicity due to its significant use of cellulose acetate. In addition, it demonstrated higher wind-blown sand resistance compared to popular commercial sand-fixation production. Furthermore, it sustained a consolidation strength lower than the highest penetration capability for herbaceous plant seeds. Therefore, CA/WPU-6 is a suitable option for establishing vegetation in dry situations. The results of this study address the demand for sustainable production and cost reduction, offering significant potential for industrial applications.

Abstract Degradable wearable electronics are attracting increasing attention to weaken or eliminate the negative effect of waste e-wastes and promote the development of medical implants without secondary post-treatment. Although various degradable materials have been explored for wearable electronics, the development of degradable wearable electronics with integrated characteristics of highly sensing performances and low-cost manufacture remains challenging. Herein, we developed a facile, low-cost, and environmentally friendly approach to fabricate a biocompatible and degradable silk fibroin based wearable electronics (SFWE) for on-body monitoring. A combination of rose petal templating and hollow carbon nanospheres endows as-fabricated SFWE with good sensitivity (5.63 kPa−1), a fast response time (147 ms), and stable durability (15,000 cycles). The degradable phenomenon has been observed in the solution of 1 M NaOH, confirming that silk fibroin based wearable electronics possess degradable property. Furthermore, the as-fabricated SFWE have been demonstrated that have abilities to monitor knuckle bending, muscle movement, and facial expression. This work offers an ecologically-benign and cost-effective approach to fabricate high-performance wearable electronics.

Exogenous stimuli-activated catalytic therapies for cancer, such as photodynamic therapy, have significant clinical potential. Despite the recent progress, the low catalytic production efficiency of reactive oxygen species (ROS) and the overexpression of glutathione (GSH) in the tumor microenvironment (TME) are major challenges for exogenous stimulative catalytic therapy. Bismuth-based heterojunction nanomaterials can generate ROS under various exogenous stimuli. Based on this, we developed an exogenously excited bismuth-based heterojunction nanocatalyst Bi-Bi2O3–xSx-PEG (BOP) for the photocatalytic treatment of tumors with photothermal synergism. The high photocatalytic activity of BOP is attributed to its heterojunction structure, oxygen vacancy, and local surface plasmon resonance effect, which enable suitable band potential and rapid electron transfer. The GSH consumption characteristic of BOP in TME can also enhance oxidative stress damage, amplify the toxicity of ROS, and induce cell apoptosis. BOP's remarkable photothermal conversion ability contributes to local hyperthermia and synergistic enhancement of photodynamic efficacy. This platform provides a method for constructing an efficient photocatalyst and a strategy for synergistically enhancing photocatalytic therapy by thermal damage and oxidative stress. [ABSTRACT FROM AUTHOR]

Degradable wearable electronics are attracting increasing attention to weaken or eliminate the negative effect of waste e-wastes and promote the development of medical implants without secondary post-treatment. Although various degradable materials have been explored for wearable electronics, the development of degradable wearable electronics with integrated characteristics of highly sensing performances and low-cost manufacture remains challenging. Herein, we developed a facile, low-cost, and environmentally friendly approach to fabricate a biocompatible and degradable silk fibroin based wearable electronics (SFWE) for on-body monitoring. A combination of rose petal templating and hollow carbon nanospheres endows as-fabricated SFWE with good sensitivity (5.63 kPa−1), a fast response time (147 ms), and stable durability (15,000 cycles). The degradable phenomenon has been observed in the solution of 1 M NaOH, confirming that silk fibroin based wearable electronics possess degradable property. Furthermore, the as-fabricated SFWE have been demonstrated that have abilities to monitor knuckle bending, muscle movement, and facial expression. This work offers an ecologically-benign and cost-effective approach to fabricate high-performance wearable electronics. [ABSTRACT FROM AUTHOR]

Polyglycolic acid (PGA) has good environment protection property. In laboratory study, the mechanical property, the particle sizes, the thermal stability of the PGA molecules and the crystal density of PGA before and after high temperature soaking are analyzed, the thermal stability of PGA in water and oil is studied, and the application potential of PGA as a temporary plugging agent for drill-in fluids is evaluated. It was found that the physiochemical properties of PGA are highly affected by the liquid environment of a drilling fluid and temperature. In water-based drilling fluids, PGA will degrade at 100 ℃ to oligomers because of the pH of the drilling fluid, and the thermal stability of the PGA molecules and the mechanical strength of PGA are all decreased as well. Strong acid (pH< 5) and strong base (pH< 9) both accelerate the degradation of PGA, and PGA degrades faster in strong base environment than in strong acid environment. In high temperature oil-based drilling fluids, the PGA particles first swell and then peel and break, and the main body of the PGA particles turns from plastic to brittle, resulting in a decrease in the tensional and compressive strengths of the particles to some extent. PPA plugging experiment shows that after 8 d of soaking in an oil environment, the PGA particles exhibit good plugging performance. These studies show that PGA is more suitable for use in oilbased drilling fluids than in water-based drilling fluids. [ABSTRACT FROM AUTHOR]

In this paper, aliphatic polycarbonate (APC) was successfully prepared from low-boiling organic matter and aliphatic diols in waste electrolyte by ester exchange reaction and polycondensation reaction, and the process conditions were optimized to investigate the effects of catalyst type and dosage, type of aliphatic diol raw material, transesterification temperature, polycondensation temperature, polycondensation time, and polycondensation vacuum degree on the yield and molecular weight of the product. The structure and properties of the product APC were tested using Fourier transform infrared spectrometer (FTIR), H nuclear magnetic resonance spectra (1HNMR), differential scanning calorimetry (DSC), thermal gravity analysis (TG), gel permeation chromatography (GPC), and electronic universal testing machine were used to test the structure and properties of the product APC. The results showed that the lithium biimidazole catalyzed the best effect and the synthesized APC had the correct structure and great properties, including good thermal stability, mechanical properties, and degradation properties. The product was degraded under the action of enzyme for 12 days, and its degradation rate could reach more than 98%, meeting the use standard of degradable polycarbonate. It has a good application prospect. [ABSTRACT FROM AUTHOR]

A series of hybrid hydrogels of poly(ethylene glycol) (PEG) were synthesized using gelatin as a crosslinker and investigated for controlled delivery of the first-generation cephalosporin antibiotic, Cefazedone sodium (CFD). A commercially available 4-arm-PEG–OH was first modified to obtain four-arm-PEG–succinimidyl glutarate (4-arm-PEG–SG), which formed the gelatin–PEG composite hydrogels (SnNm) through crosslinking with gelatin. To regulate the drug delivery, SnNm hydrogels with various solid contents and crosslinking degrees were prepared. The effect of solid contents and crosslinking degrees on the thermal, mechanical, swelling, degradation, and drug release properties of the hydrogels were intensively investigated. The results revealed that increasing the crosslinking degree and solid content of SnNm could not only enhance the thermal stability, swelling ratio (SR), and compression resistance capacity of SnNm but also prolong the degradation and drug release times. The release kinetics of the SnNm hydrogels were found to follow the first-order model, suggesting that the transport rate of CFD within the matrix of hydrogels is proportional to the concentration of the drug where it is located. Specifically, S1N1-III showed 90% mass loss after 60 h of degradation and a sustained release duration of 72 h. The cytotoxicity assay using the MTT method revealed that cell viability rates of S1N1 were higher than 95%, indicating excellent cytocompatibility. This study offers new insights and methodologies for the development of hydrogels as biomedical composite materials.

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this report, cellulose nanofiber-modified polyvinyl alcohol/sodium alginate (CNF/PVA/SA, CPS) composite aerogels were prepared by cyclic freezing and green cross-linking. The properties of aerogels with different CNF additions were investigated, and the samples were tested and characterized for swelling, water retention, porosity, and biocompatibility. The tensile resistance of the composite aerogel was enhanced when the CNF addition was 5 wt%, which was 52% higher than that without CNF. The results of hemolysis tests showed that the cellulose aerogel composites exhibited excellent performance in terms of biocompatibility and hemocompatibility. Therefore, CPS showed great potential in medical environments. [ABSTRACT FROM AUTHOR]

Nanomedicines receive great attention in cancer treatment. Nevertheless, nonbiodegradable and long-term retention still limit their clinical translation. Herein, we successfully synthesize a hypoxia-triggered degradable porphyrinic covalent organic framework (HPCOF) for antitumor therapy in vivo. HPCOF possesses wide absorption in near infrared region (NIR) which endows HPCOF excellent photothermal conversion efficiency and photoacoustic (PA) imaging ability. Moreover, HPCOF exhibits excellent photodynamic and photothermal effect under special-wavelength laser irradiation. For the first time, the in vitro and in vivo tests demonstrate that HPCOF shows effective therapeutic effect for the combination of PDT and PTT under the monitoring of PA imaging. Importantly, in tumor region, HPCOF could be triggered by hypoxia microenvironment and collapsed gradually, then cleared from the body after treatment. This work fabricates a novel COF for cancer treatment and testifies great potential of HPCOF in clinical application with reducing long-term toxicity.

Hydrogels are particularly suitable materials for loading drug delivery agents; their high water content provides a biocompatible environment for most biomolecules, and their cross-linked nature protects the loaded agents from damage. During delivery, the delivered substance usually needs to be released gradually over time, which can be achieved by degradable cross-linked chains. In recent years, biodegradable hydrogels have become a promising technology in new methods of disease treatment and drug delivery methods due to their many advantageous properties. This review briefly discusses the degradation mechanisms of different types of biodegradable hydrogel systems and introduces the specific applications of degradable hydrogels in several new methods of disease treatment and drug delivery methods. [ABSTRACT FROM AUTHOR]

Medical imaging is widely used clinically and in research to understand disease progression and monitor responses to therapies. Vascular imaging enables the study of vascular disease and therapy, but exogenous contrast agents are generally needed to distinguish the vasculature from surrounding soft tissues. Lanthanide-based agents are commonly employed in MRI, but are also of growing interest for micro-CT, as the position of their k-edges allows them to provide enhanced contrast and also to be employed in dual-energy micro-CT, a technique that can distinguish contrast-enhanced blood vessels from tissues such as bone. Small molecule Gd3+ chelates are available, but are excreted too rapidly. At the same time, a lack of rapid clearance from the body for long-circulating agents presents toxicity concerns. To address these challenges, we describe here the use of self-immolative polymers for the development of new degradable chelates that depolymerize completely from end-to-end following the cleavage of a single end-cap from the polymer terminus. We demonstrate that tuning the end-cap allows the rate of depolymerization to be controlled, while tuning the polymer length enables the polymer to exhibit long circulation times in the blood of mice. After successfully providing one hour of blood contrast, depolymerization led to excretion of the resulting small molecule chelates into the bladder. Despite the high doses required for micro-CT, the agents were well tolerated in mice. Thus, these self-immolative polymeric chelates provide a new platform for the development of medical imaging contrast agents. Vascular imaging is used clinically to diagnose and monitor vascular disease and in research to understand the progression of disease and study responses to new therapies. For techniques such as magnetic resonance imaging and x-ray computed tomography (CT), long circulating contrast agents are needed to differentiate the vasculature from surrounding tissues. However, if these agents are not rapidly excreted from the body, they can lead to toxicity. We present here a new polymeric system that can chelate hundreds of lanthanide ions for imaging contrast and can circulate for one hour in the blood, but then after end-cap cleavage breaks down completely into small molecules for excretion. The successful application of this system in micro-CT in mice is demonstrated. [Display omitted] [ABSTRACT FROM AUTHOR]

Cell-releasing hydrogel carriers enhance cell-based therapies by improving retention and viability within target tissues. We previously demonstrated tunable cell release from a hydrolytically labile β-thioester-containing polyethylene glycol-based hydrogel. However, the macromer synthesis dependent on thiol-Michael addition leads to batch variability and heterogeneous hydrogel properties. Herein, we report a new synthetic route with improved control of macromer molecular weight and characterize the resulting hydrogel properties. The resulting PEG dithioester acrylamide (PEGDTEA) hydrogel demonstrates a more controlled synthetic route to generate targeted molecular weights with reduced couplings, creating a more predictable and tunable hydrogel microenvironment for precise cell delivery applications. [ABSTRACT FROM AUTHOR]

Poly(butylene glutarate) (PBG) was evaluated as a processing aid for hot-melt extrusion of poly(hydroxybutyrate-co-hydroxyhexanoate) (PHBHHx). The presence of PBG reduced the melt viscosity and storage and loss moduli of PHBHHx, and the magnitude of these effects increased with higher PBG loadings. The optimal content of PBG in PHA was observed to be 10 wt%, and was shown to accumulate at the wall/die surfaces of the extruder, acting as a slip agent. The enhancement in processability given by PBG was evidenced through elimination of melt fracture and preservation of molecular weight. [ABSTRACT FROM AUTHOR]

Additive manufacturing with vat photopolymerization (VP) as an emerging manufacturing method addresses various goals for enhanced sustainability including waste reduction, dematerialization, and the customization of intricate and complex 3D parts. Unsaturated polyesters (UPEs) recently gained attention as a sustainable material source for lithographic additive manufacturing. While previous methods demonstrated the printability of UPE-based resins, these studies lack the solvent-free approach demonstrated herein. Furthermore, the effective depolymerization of polyester thermosets has remained relatively unexplored. This report demonstrates structure–property relationships and subsequent solvent-free VP of UPEs with PEGDA-575 as a reactive diluent with effective depolymerization of polyester thermosets through base-catalyzed methanolysis. [ABSTRACT FROM AUTHOR]

Due to the low melt index of polylactic acid (PLA) polymer, it is difficult to melt-blown processing. Here, a new modified method to obtain a high melt index of PLA polymer and melt-blown nonwoven cloth was studied. PLA polymers are modified by the thermally degraded method of stannous octoate (Sn(Oct)2) and polyethylene glycol (PEG) to obtain a high melt index (1054 g/10 min) in comparison with a low melt index (23 g/10 min) of original unmodified PLA polymer. The fiber of modified PLA polymer melt-blown cloth is obviously thinner, having sub-micron fibers, the smallest fiber is about 200 nm. From our test, modified PLA polymer melt-blown cloth has good oil absorption, oil–water separation, and potential air filtration property. In terms of degradation, the modified PLA polymer melt-blown cloth showed excellent degradation performance in basic aqueous solutions at 55 °C at pH 12, reaching a degradation rate of around 95% at 60 h. [ABSTRACT FROM AUTHOR]

Copyright of Oilfield Chemistry is the property of Sichuan University, Oilfield Chemistry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Designing sustainable materials with tunable mechanical properties, intrinsic degradability, and recyclability from renewable biomass through a mild process has become vital in polymer science. Traditional phenolic resins are generally considered to be not degradable or recyclable. Here we report the design and synthesis of linear and network structured phenolic polymers using facile polycondensation between natural aldehyde‐bearing phenolic compounds and polymercaptans. Linear phenolic products are amorphous with Tg between −9 °C and 12 °C. Cross‐linked networks from vanillin and its di‐aldehyde derivative exhibited excellent mechanical strength between 6–64 MPa. The connecting dithioacetals are associatively adaptable strong bonds and susceptible to degradation in oxidative conditions to regenerate vanillin. These results highlight the potential of biobased sustainable phenolic polymers with recyclability and selective degradation, as a complement to the traditional phenol‐formaldehyde resins. [ABSTRACT FROM AUTHOR]

Polymer networks based on cyclodextrin and polyethylene glycol were prepared through polyaddition crosslinking using isophorone diisocyanate. The envisaged material properties are the hydrophilic character, specific to PEG and cyclodextrins, and the capacity to encapsulate guest molecules in the cyclodextrin cavity through physical interactions. The cyclodextrin was custom-modified with oligocaprolactone to endow the crosslinked material with a hydrolytically degradable character. SEM, DTG, and FTIR characterization methods have confirmed the morphology and structure of the prepared hydrogels. The influence of the crosslinking reaction feed was investigated through dynamic rheology. Further, thermal water swelling and hydrolytic degradation in basic conditions revealed the connectivity of the polymer network and the particular influence of the cyclodextrin amount in the crosslinking reaction feed on the material properties. Also, levofloxacin was employed as a model drug to investigate the drug loading and release capacity of the prepared hydrogels. [ABSTRACT FROM AUTHOR]

The development of a single polymer chain with the dual functions of self‐healing and degradation is challenging. Herein, we report the synthesis of self‐healing and degradable polymers (SDP) via the integration of hierarchical hydrogen bonding groups and degradable polycaprolactone (PCL) segments. The dynamic reconstruction of hierarchical hydrogen bonding endowed the as‐prepared polymers with excellent self‐healing properties. The degradation properties were regulated via the proportion of PCL in the soft segments. The incorporation of PCL segments resulted in better degradability and improved the tensile strength of the polymer from 9.2 to 28.3 MPa. The as‐prepared polymers could recover their mechanical properties after self‐healing. The temperature‐dependent Fourier‐transform infrared spectra (FT‐IR) indicated that the hierarchical hydrogen bonding was capable of dissociation and re‐association with a variation in the temperature. The as‐synthesized sustainable polymers, which exhibit self‐healing properties and degradability, are expected to be useful in future energy and environmental applications. [ABSTRACT FROM AUTHOR]

A novel smart material is developed, which is synthesized by succinic anhydride, epoxy resin, and zinc acetylacetone hydrate. The smart material has excellent properties of self‐healing, shape memory, and degradation. The experimental results of performance characterization show that the material has good thermal stability. The glass transition temperature is adjustable between 100 and 120°C, and the storage modulus can reach 20 GPa. The maximum thermal expansion at 50°C is less than 15%, the thermal expansion equilibrium time at 120°C is less than 5 min, and the maximum thermal expansion is 131%. The stress relaxation time at 120°C is more than 2 h, which can slowly self‐heal on the basis of maintaining the mechanical strength. When the NaOH content is 1.5%, the degradation equilibrium can be reached in about 3 h, and the maximum degradation rate is 86%. The comprehensive performance evaluation shows that after hot rolling at 120°C/16 h, the material has no effect on the rheology and filtration properties. When plugging the fracture width of 5 × 4 mm, the pressure bearing capacity reaches 10 MPa. Its main mechanism is temperature‐sensitive expansion, and the stress relaxation effect heals and blocks the micro pore throat. [ABSTRACT FROM AUTHOR]

Abstract The process of transcatheter arterial chemoembolization is characterized by the ability to accurately deliver chemotherapy drugs with minimal systemic side effects and has become the standard treatment for unresectable intermediate hepatocellular carcinoma (HCC). However, this treatment option still has much room for improvement, one of which may be the introduction of nanomaterials, which exhibit unique functions and can be applied to in vivo tumor imaging and therapy. Several biodegradable and multifunctional nanomaterials and nanobeads have recently been developed and applied in the locoregional treatment of hepatocellular cancer. This review explores recent developments and findings in relation to micro-nano medicines in transarterial therapy for HCC, emerging strategies to improve the efficacy of delivering nano-based medicines, and expounding prospects for clinical applications of nanomaterials.

Polyolefins with periodic unsaturation in the backbone chain are sought after for synthesizing chemically recyclable polymers or telechelic polyolefin macromonomers. Here we introduce a bottom‐up synthesis of unsaturated high‐density polyethylene (HDPE) via copolymerization of ethylene with dimethyl 7‐oxabicyclo[2.2.1]hepta‐2,5‐diene‐3,5‐dicarboxylate followed by post‐polymerization retro‐Diels–Alder to unveil hidden double bonds in the polymer backbone. The incorporation of this "Trojan Horse" comonomer was varied and a series of unsaturated HDPE polymers with block lengths of 1.2, 1.9, and 3.5 kDa between double bonds was synthesized. Cross metathesis of unsaturated HDPE samples with 2‐hydroxyethyl acrylate yielded telechelic ester terminated PE macromonomers suitable for the preparation of ester‐linked PE. These materials were depolymerized and repolymerized, making them suitable candidates for chemical recycling. The ester‐linked PE displayed thermal and mechanical properties comparable to commercial HDPE. [ABSTRACT FROM AUTHOR]

Implantable sensors normally require devices with excellent biocompatibility and flexibility as well as wireless communication. Silk fibroin (SF) is an ideal material for implantable electronic devices due to its natural biodegradability and biocompatibility. In this work, we prepared SF protein materials with different force/chemical properties through mesoscopic regulation, and realized full protein replacement from substrate to dielectric elastomer for implantable sensors, so as to achieve controlled complete degradation. In wireless tests simulating intracranial pressure, the SF-based all-protein sensor achieved a sensitivity up to 4.44 MHz/mmHg in the pressure range of 0–20 mmHg. In addition, the sensor is insensitive to temperature changes and tissue environments, and can work stably in simulated body fluids for a long time. This work provides a wireless passive, all-protein material solution for implantable pressure sensors. [ABSTRACT FROM AUTHOR]

A series of glucose‐based degradable superabsorbent hydrogels with potential to tackle issues associated with sustainability, flooding, and drought has been designed and fabricated. These hydrophilic networks were constructed through integrating glucose as a primary building block –into cyclic oligomers and block polymers, which were combined into mechanically‐interlocked slide‐ring crosslinked materials. Crosslinking of slide ring α‐cyclodextrin/poly(ethylene glycol)‐type polyrotaxanes with acid‐functionalized ABA triblock copolymers comprised of mercaptopropionic acid‐functionalized poly(glucose carbonate (ethyl propargyl carbonate))‐b‐poly(ethylene glycol)‐b‐mercaptopropionic acid‐functionalized poly(glucose carbonate (ethyl propargyl carbonate)), afforded degradable superabsorbent hydrogels through establishment of chemically‐labile ester linkages, in addition to glycosidic and carbonate groups of the polymer precursors. With an emphasis on development of fundamental synthetic design strategies to achieve high‐performance superabsorbent hydrogels that could behave as robust materials, which are derived from natural components and exhibit hydrolytic degradability, effort went into optimization of the composition, structure, and topology leading to water uptake capacities >30× by mass. Investigations of composition‐structure‐topology‐morphology effects on properties as a function of variations of PEG main chain length, degree of α‐cyclodextrin coverage, and concentration of pre‐gel solution, indicated that the slide‐ring polymer and triblock copolymer networks feature high water uptake, tunable mechanical properties, and sustainability with construction from renewable natural products and in‐built degradability. [ABSTRACT FROM AUTHOR]