Environmental-friendly, flexible silk fibroin-based film as dual-responsive shape memory material.

Bio-based shape memory materials have attracted wide attention due to their biocompatibility, degradability and safety. However, designing and manufacturing wearable bio-based shape memory films with excellent flexibility and toughness is still a challenge. In this work, silk fibroin substrate with a β-sheet structure was combined with a tri-block shape memory copolymer to prepare a transparent composited shape memory film.

Piezoelectric Interlayer Enabling a Rechargeable Quasisolid-State Sodium Battery at 0 °C.

Solid-state sodium (Na) batteries (SSNBs) hold great promise but suffer from several major issues, such as high interfacial resistance at the solid electrolyte/electrode interface and Na metal dendrite growth. To address these issues, a piezoelectric interlayer design for an NaZrSiPO (NZSP) solid electrolyte is proposed herein. Two typical piezoelectric films, AlN and ZnO, coated onto NZSP function as interlayers designed to generate a local stress-induced field for alleviating interfacial charge aggregation coupling stress concentration and promoting uniform Na plating.

Preparation and properties of chitin/silk fibroin biocompatible composite fibers.

In the present world chitin is used enormously in various fields, such as biopharmaceuticals, medical and clinical bioproducts, food packaging, etc. However, its development has been curbed by the impaired performance and cumbersome dissolution process when chitin materials are dissolved and regenerated by physical or chemical methods. To further obtain the regenerated chitin fiber material with improved performance, silk fibroin was introduced into the chitin matrix material, and chitin/silk fibroin biocompatible composite fibers were obtained by formic acid/calcium chloride/ethanol ternary system and top-down wet spinning technology.

Selective and effective adsorption of cesium ions by metal hexacyanoferrates (MHCF, M = Cu, Co, Ni) modified chitosan fibrous biosorbent.

Selective and effective adsorptive removal of radiocesium is of great importance in terms of nuclear waste management and environmental remediation, but is still challenging because of its radioactive and non-complexing nature. Herein, metal hexacyanoferrates (MHCF, M = Cu, Co, or Ni) modified fibrous chitosan was prepared by multiple sequential adsorption and self-assembly approach, and applied for the selective and effective adsorption of Cs. The physically supported MHCF in chitosan fibers showed good crystallinity and stability, and the obtained fibrous composite has high specific surface area (18.

Adsorption of Co and Sr in aqueous solution by a novel fibrous chitosan biosorbent.

In this study, a novel fibrous chitosan biosorbent was prepared using LiOH/KOH/urea/HO (4.5:7:8:80.5 by weight) as spinning solvent.

Facile fabrication of a polyvinyl alcohol-based hydrophobic fluorescent film the Hantzsch reaction for broadband UV protection.

Excessive exposure to ultraviolet (UV) light is harmful to human health. However, the traditional preparation of anti-UV films through the doping of UV absorbers leads to unstable products. Chemical modification of polyvinyl alcohol (PVA) to fabricate functional derivatives expand the application of these materials.

An Innovative Solvent-Responsive Coiling-Expanding Stent.

Coronary artery disease is the "first killer" in the world, while the classical treatment for this disease is to implant stent. An ideal vascular stent should be nontoxic with self-expanding characteristics, quick expanding speed, and appropriate mechanical supporting property. However, no existing vascular stent covers all properties.

Injectable chitin hydrogels with self-healing property and biodegradability as stem cell carriers.

To meet the demands of various therapeutic tasks, injectable hydrogels with tunable mechanical properties and degradability are highly desired. Herein, we developed an injectable chitin hydrogel system with well-manipulated mechanical properties and degradability through dynamic acylhydrazone crosslinking catalyzed by 4-amino-DL-phenylalanine (Phe-NH). The mechanical properties and degradability of the hydrogels could be easily adjusted by varying the solid content, while their gelation time could be maintained at a constant level (∼130 s) by altering Phe-NH content, thereby ensuring the good injectability of hydrogels.

Robust chitin films with good biocompatibility and breathable properties.

Chitin is the second abundant polysaccharide after cellulose, and has been demonstrated to possess various applications in the fields of the biomaterials, water treatment, etc. Here, mechanically strong chitin films were successfully fabricated from chitin solution in NaOH/urea aqueous system with cooling by chemical crosslinking with epichlorohydrin (ECH). The results indicated that tensile strength and elongation at break of the chitin film prepared by using the weight ratio of ECH to chitin solution of 6:100 enhanced significantly to achieve 139 MPa and 43%, respectively, showing highly strong strength and elongation.

Super Strong All-Cellulose Composite Filaments by Combination of Inducing Nanofiber Formation and Adding Nanofibrillated Cellulose.

In this work, super strong all-cellulose multifilaments were obtained from cellulose dissolved in LiOH/urea system by inducing nanofiber formation, and were simultaneously reinforced by the introduction of TEMPO-oxidized nanofibrillated cellulose (NFC) with mean diameter of 20 nm. The all-cellulose composite filaments (CF) containing only 3 wt % NFC exhibits a high orientation that Herman's parameter is 0.89.

High-Strength Films Consisted of Oriented Chitosan Nanofibers for Guiding Cell Growth.

Chitosan has biocompatibility and biodegradability; however, the practical use of the bulk chitosan materials is hampered by its poor strength, which can not satisfy the mechanical property requirement of organs. Thus, the construction of highly strong chitosan-based materials has attracted much attention. Herein, the high strength nanofibrous hydrogels and films (CS-E) were fabricated from the chitosan solution in LiOH/KOH/urea aqueous system via a mild regenerating process.

Bilayer hydrogel actuators with tight interfacial adhesion fully constructed from natural polysaccharides.

Smart hydrogel actuators with excellent biocompatibility and biodegradation are extremely desired for biomedical applications. Herein, we have constructed bio-hydrogel actuators inspired by the bilayer structures of plant organs from chitosan and cellulose/carboxymethylcellulose (CMC) solution in an alkali/urea aqueous system containing epichlorohydrin (ECH) as a crosslinker, and demonstrated tight adhesion between two layers through strong electrostatic attraction and chemical crosslinking. The bilayer hydrogels with excellent mechanical properties could carry out rapid, reversible, and repeated self-rolling deformation actuated by pH-triggered swelling/deswelling, and transformed into rings, tubules, and flower-, helix-, bamboo-, and wave-like shapes by effectively designing the geometric shape and size.

Ultra-Stretchable and Force-Sensitive Hydrogels Reinforced with Chitosan Microspheres Embedded in Polymer Networks.

An ultra-stretchable and force-sensitive hydrogel with surface self-wrinkling microstructure is demonstrated by in situ synthesizing polyacrylamide (PAAm) and polyaniline (PANI) in closely packed swollen chitosan microspheres, exhibiting ultra-stretchability (>600%), high sensitivity (0.35 kPa ) for subtle pressures (<1 kPa), and can detect force in a broad range (10 Pa-10 MPa) with excellent electrical stability and rapid response speed, potentially finding applications for E-skin.

An approach for prominent enhancement of the quality of konjac flour: dimethyl sulfoxide as medium.

In this paper, an approach to improve several konjac flour (KF) qualities by dimethyl sulfoxide (DMSO) addition using various concentrations at different temperature levels was proposed. Also, various properties of native and refined KF, including transparency, chemical composition and rheological properties have been investigated. The results showed that the KF refined by 75% DMSO achieved 27.

Homogeneous synthesis of chitin-based acrylate superabsorbents in NaOH/urea solution.

A modified freezing-thawing cyclic (FTC) process was applied to dissolve the chitin in NaOH/urea solution. A transparent homogeneous solution was obtained. It was utilized directly for preparing the superabsorbent polymers (SAPs) by grafting copolymerization under static solution conditions without nitrogen protection.

Nanogels fabricated by lysozyme and sodium carboxymethyl cellulose for 5-fluorouracil controlled release.

Lysozyme (Ly) and sodium carboxymethyl cellulose (CMC) were used to fabricate nanogels by a convenient method without using any chemical treatment except simple heating to achieve the denaturation temperature of Ly. The prepared nanogels were characterized by dynamic laser scattering (DLS), rheological analysis, transmission electron microscopy (TEM), field emission scanning electron microscope (FE-SEM) and X-ray photoelectron spectroscopy (XPS). The nanogels are of spherical shape with average hydrodynamic diameter of 241 nm and the swelling ratio of nanogels is about 5.