Advanced flexible self-healing triboelectric nanogenerators for applications in complex environments.

With the advent of the smart era, the demand for clean energy is rising, and flexible triboelectric nanogenerators (F-TENGs) based on elastomers have garnered significant attention. Based on the principles of electrostatic induction and coupling, F-TENGs can convert mechanical motion into electrical energy and are widely utilized in wearable devices and blue energy. F-TENGs offer a simple design, ease of manufacturing, and flexible usage scenarios.

Skin-inspired polysaccharide-based hydrogels with tailored properties for information transmission application.

Conductive hydrogels have attracted significant research interest in flexible electronics owing to their intrinsic flexibility and biocompatibility. However, the rapid and sustainable fabrication of green conductive hydrogels with excellent mechanical and conductive properties remains a significant challenge. Inspired by the structure of human skin, modified polysaccharide-reinforced polyvinyl alcohol (PVA) ionic conductive hydrogels with tailored properties were developed through Zn coordination and Hofmeister effect.

Mixing Functionality in Polymer Electrolytes: A New Horizon for Achieving High-Performance All-Solid-State Lithium Metal Batteries.

Solid polymer electrolytes (SPEs) are a key materials component for all-solid-state lithium metal batteries (ASSLMBs). In these membrane-like films, accelerating Li migration while enhancing the mechanical strength of SPEs is challenging. Herein, we introduce a new concept of supramolecularly organized, cross-linked polymer electrolyte (PCPE) by mixing an ion-conducting, multi-arm boron-containing oligomer (MBO) solid plasticizer into a polyethylene oxide (PEO)-lithium salt matrix.

Polyvinyl alcohol/sodium alginate hydrogels with tunable mechanical and conductive properties for flexible sensing applications.

Despite the significant advantages of conductive hydrogels in flexible sensing, their further development is often hindered by limitations in strength and conductivity. In this work, the ionic conductive hydrogels with tunable mechanical and conductive properties were designed by utilizing sodium alginate (SA) to reinforce the polyvinyl alcohol (PVA) networks, followed by the respective introduction of LiSO, ZnSO, and Fe(SO), leveraging the Hofmeister effect and metal coordination. Consequently, the mechanical properties (σ = 0.

From a bio-based polyphenol diol intermedia to high-performance polyurethane elastomer: Thermal stability, reprocessability and flame retardancy.

In this work, a novel bio-based polyphenol diol intermediate (VDP) was synthesized through a combination of aldimine condensation and addition reactions, utilizing vanillin, 4,4'diamino diphenylmethane (DDM), and 9,10-dihydro-9-oxa-10-phospha-phenanthrene-10-oxide (DOPO) as reactants, then various contents of VDP was introduced covalently into the polyurethane backbone. The integration of VDP has notably improved the flame retardancy of polyurethane elastomer, the limiting oxygen index (LOI) of the elastomer was elevated from 23% to 30%, and reaches V-0 rating in the UL-94 vertical burning test. The enhancement of flame retardancy is attributed to the introduction of VDP units, which not only generate PO· and PO∙ that can capture active free radicals during combustion, but also releases non-flammable gases to improve the flame-retardant effect.

Preparation of Vitamin--Lignin Nanohybrids with Excellent Biological Activity and Fluorescence Performance.

As a natural renewable biomacromolecule, lignin has some inherently interesting properties such as fluorescence, antioxidation, and antibacterial performance. However, the unsatisfactory fluorescence and biological activities have greatly limited their value-added and large-scale applications. In this work, lignin nanoparticles (LNPs) grafted with vitamin B hybrid nanoparticles (LEVs) were obtained by using ethylenediamine and different contents of vitamin B through a simple hydrothermal method.

Enhancement of PLA crystallization, transparency, and strength by adding the long aliphatic chains grafted CNC.

The combination of crystallization, transparency, and strength is still a challenge for broadening the application of polylactic acid (PLA) films, while it is also difficult to balance. In this work, the long aliphatic chains of octadecylamine (ODA) were grafted onto the surface of cellulose nanocrystal (CNC) by tannic acid oxidation self-polymerization and Michael addition/Schiff base reaction between polytannic acid and ODA. Furthermore, the ODA grafted CNC (g-CNC) was used as green reinforcement for the PLA matrix and a series of PLA/g-CNC nanocomposite films were prepared by the casting method.

Biodegradable reactive compatibilizers for efficient in-situ compatibilization of poly (lactic acid)/poly (butylene adipate-terephthalate) blends.

The wide application of fully biodegradable polylactic acid/polybutylene terephthalate (PLA/PBAT) blends in environmentally friendly packaging were limited because of poor compatibility. Normal compatibilizers suffer from poor thermal stability and non-biodegradability. In this work, epoxy copolymer (MDOG) with different molecular structures were made of 2-methylene-1, 3-dioxoheptane, and glycidyl methacrylate as raw materials by free radical copolymerization.

Highly toughened poly (lactic acid)/poly (butylene adipate-terephthalate) blends in-situ compatibilized by MMA-co-GMA copolymers with different epoxy group content.

Poor compatibility limits the wide application of biodegradable poly (lactic acid)/poly (butylene adipate-terephthalate) (PLA/PBAT) blends in packaging industry. How to prepare compatibilizers with high efficiency and low cost by simple methods is a challenge. In this work, methyl methacrylate-co-glycidyl methacrylate (MG) copolymer with different epoxy group content are synthesized as reactive compatibilizers to resolve this issue.

Enhanced crystallization, heat resistance and transparency of poly(lactic acid) with self-assembling bis-amide nucleator.

The application of poly(lactic acid) (PLA) is limited by its low crystallization rate. Conventional methods to increase crystallization rate usually result in a significant loss of transparency. In this work, a bundled bis-amide organic compound N'-(3-(hydrazinyloxy)benzoyl)-1-naphthohydrazide (HBNA) was used as a nucleator to prepare PLA/HBNA blends with enhanced crystallization, heat resistance and transparency.

Enhanced flame retardancy and toughness of eco-friendly polyhydroxyalkanoate/bentonite composites based on in situ intercalation of P-N-containing hyperbranched macromolecules.

Polyhydroxyalkanoates (PHA) is a biodegradable polyester, and its application range is limited by the poor flame retardancy and low modulus. Bentonite (BNT) as a green inorganic filler can improve the modulus and flame retardancy of PHA to a certain extent. An in situ polymerization method was designed to intercalate P-N-containing hyperbranched macromolecules (HBM) among BNT layers (HBM-B) and to improve the flame retardancy while improving the dispersion of BNT in the PHA matrix.

A Quantitative Study on Branching Density Dependent Behavior of Polylactide Melt Strength.

Polymer melt strength (MS) is strongly correlated with its molecular structure, while their relationship is not very clear yet. In this work, designable long-chain branched polylactide (LCB-PLA) is prepared in situ by using a tailor-made (methyl methacrylate)-co-(glycidyl methacrylate) copolymer (MG) with accurate number of reactive sites. A new concept of branching density (φ) in the LCB-PLA system is defined to quantitively study their relationship.

Enhanced crystallization and storage stability of mechanical properties of poly(hydroxyalkanoate)s in the presence of hydrazide compounds with different configurations.

Slow crystallization rates and poor storage stability of mechanical properties limit the widespread use of biosynthesized poly(hydroxyalkanoate)s (PHA). Hydrazide compounds (HC) with a formula of CHCONHNHCO(CH)CONHNHCOCH (n = 4 and 8) were used as PHA nucleating agents to improve the crystallization and mechanical properties. The effects of HC structure and self-assembly on the crystallization kinetics and nucleation efficiency of PHA were systematically investigated.

Crystallization of microbial polyhydroxyalkanoates: A review.

Polyhydroxyalkanoates (PHAs), produced by the microbial fermentation, is a promising green polymer and has attracted much attention due to its excellent biocompatibility, complete biodegradability, and non-cytotoxicity. The physical properties of PHAs are closely related to their chemical and crystalline structure. Therefore, deep understanding and regulating the structure and crystallization of PHAs are the key factors to improve the performance of PHAs.

Design of Intrinsically Flame-Retardant Vanillin-Based Epoxy Resin for Thermal-Conductive Epoxy/Graphene Aerogel Composites.

Vanillin, as a lignin-derived mono-aromatic compound, has attracted increasing attention due to its special role as an intermediate for the synthesis of different biobased polymers. Herein, intrinsically flame-retardant and thermal-conductive vanillin-based epoxy/graphene aerogel (GA) composites were designed. First, a bifunctional phenol intermediate (DN-bp) was synthesized by coupling vanillin with 4, 4'-diaminodiphenylmethane and DOPO, and the epoxy monomer (MEP) was obtained by the epoxidation reaction with DN-bp and epichlorohydrin.

Highly-toughened PVA/nanocellulose hydrogels with anti-oxidative and antibacterial properties triggered by lignin-Ag nanoparticles.

In this study, Ag nanoparticles were firstly reduced on the surface of lignin nanoparticles (LNP) by direct reaction of silver nitrate without the use of a catalyst. Thermogravimetric analysis, Zeta potential and transmission electron microscopy measurements were performed to give evidence of the effectiveness of the reaction. After that, glutaraldehyde crosslinked PVA hydrogels, were produced by addition of unmodified LNP and Ag loaded LNP (LNP) in presence of cellulose nanocrystals (CNC).

Enhanced crystallization and storage stability of mechanical properties of biosynthesized poly (3-hydroxybutyrate-co-3-hydroxyhexanate) induced by self-nucleation.

The poor mechanical properties induced by unsatisfactory crystallization ability limit the widespread use of biosynthesized poly (3-hydroxybutyrate-co-3-hydroxyhexanate) (PHBH). In this work, poly (3-hydroxybutyrate) (PHB) with a high melting point was first used as a homogeneous nucleating agent to increase the crystallization rate of PHBH by a self-nucleation method with a wider processing temperature window and crystallization kinetics and storage stability of mechanical properties of the PHBH/PHB mixtures were systematically investigated. By controlling the processing temperature and PHB content, the crystal nucleus density and crystallization rate of PHBH could be greatly increased while secondary crystallization was inhibited.

Excellent UV Resistance of Polylactide by Interfacial Stereocomplexation with Double-Shell-Structured TiO Nanohybrids.

The durable application of polylactide (PLA) under atmospheric conditions is restricted by its poor ultraviolet (UV) stability. To improve the UV stability of polymers, titanium dioxide (TiO) is often used as a UV light capture agent. However, TiO is also a photocatalytic agent, with detrimental effects on the polymer properties.

Rheology-determined critical conditions for shear-induced crystallization of biosynthesized polyhydroxyalkanoates.

Shear-induced crystallization plays a crucial role in the manufacturing process of polymers. In this work, crystallization kinetics of biosynthesized polyhydroxyalkanoates (PHA) under different shear conditions were systematically investigated by rheometers. First, rheological properties of PHA melts were performed at different temperature to obtain mastercurves via the time-temperature superposition principle at 170 °C as a reference temperature.

The crystallization behavior of poly(lactic acid) with different types of nucleating agents.

The effects of six nucleating agents (NAs), i.e., orotic acid (OA), potassium salt of 3,5-bis(methoxycarbonyl)benzenesulfonate (LAK-301), substituted-aryl phosphate salts (TMP-5), talc (TALC), N',N'-dibenzoyladipohydrazide (TMC-306) and N,N-(ethane-1,2-diyl)bis(N-phenyloxalamide) (OXA), on the crystallization behavior of poly(lactic acid) (PLA) were compared by DSC.

Interfacial modification on polyhydroxyalkanoates/starch blend by grafting ​in-situ.

The interfacial adhesion between polyhydroxyalkanoates (PHAs) and native starch is poor. To improve the interfacial adhesion, PHAs were in-situ grafted onto starch using dicumyl peroxide (DCP) as a free radical initiator. The grafting reaction was carefully characterized and confirmed by gel analysis and Fourier transform infrared spectroscopy (FT-IR).

Crystallization behaviours of bacterially synthesized poly(hydroxyalkanoate)s in the presence of oxalamide compounds with different configurations.

Bacterially synthesized poly(hydroxyalkanoate)s (PHAs) suffers from low crystallization rate which is enhanced by using tailor-made oxalamide compounds as nucleators. The influence of nucleator configurations on the crystallization behaviour of the PHAs was investigated using differential scanning calorimetry (DSC), polarized optical microscopy (POM) and X-ray diffraction (XRD). The oxalamide compounds with ringy terminal structures (cyclohexyl and phenyl), notably the phenyl group, show higher nucleation efficiency and a better compatibility in the PHAs matrix, while the linear terminal structure (n-hexane) has poor nucleation effect.

Rapid Stereocomplexation between Enantiomeric Comb-Shaped Cellulose-g-poly(L-lactide) Nanohybrids and Poly(D-lactide) from the Melt.

In this work we report the in situ preparation of fully biobased stereocomplex poly(lactide) (SC-PLA) nanocomposites grafted onto nanocrystalline cellulose (NCC). The stereocomplexation rate by compounding high-molar-mass poly(D-lactide) (PDLA) with comb-like NCC grafted poly(L-lactide) is rather high in comparison with mixtures of PDLA and PLLA. The rapid stereocomplexation was evidenced by a high stereocomplexation temperature (Tc-sc = 145 °C) and a high SC crystallinity (Xc-sc = 38%) upon fast cooling (50 °C/min) from the melt (250 °C for 2 min), which are higher than currently reported values.

[Surgical treatment of calcaneus fracture involving posterior subtalar articular facet].

Objective: To investigate the methods of reduction and stable fixation for the treatment of calcaneus fracture involving posterior subtalar articular facet.

Methods: From September 2004 to September 2008, 31 cases(38 feet) of calcaneus fracture involving posterior subtalar articular facet were treated with open reduction and plate fixation through L incision. There were 24 males and 7 females, with an average age of 39.