Renewable and sustainable biobased materials: An assessment on biofibers, biofilms, biopolymers and biocomposites

Carbon dots (CDs) have been studied for years as one of the most promising fluorescent nanomaterials. However, CDs with red or solid-state fluorescence are rarely reported. Herein, through a one-pot solvothermal treatment, hydrophobic CDs (H-CDs) with blue dispersed emission and red aggregation-induced emission are obtained. When water is introduced, the hydrophobic interaction leads to aggregation of the H-CDs. The formation of H-CD clusters induces the turning off of the blue emission, as the carbonized cores suffer from π-π stacking interactions, and the turning on of the red fluorescence, due to restriction of the surfaces' intramolecular rotation around disulfide bonds, which conforms to the aggregation-induced-emission phenomenon. This on-off fluorescence of the H-CDs is reversible when the H-CD powder is completely dissolved. Moreover, the H-CD solution dispersed in filter paper is nearly colorless. Finally, we develop a reversible two switch-mode luminescence ink for advanced anti-counterfeiting and dual-encryption.

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Hydrophobic carbon dots with blue dispersed emission and red aggregation-induced emission.

Recent progress on polymer materials for additive manufacturing

Ionic liquids (ILs) have now been acknowledged as reaction media for biotransformations. The first three examples were reported in this field in 2000, and since then, numerous applications have been reported for biocatalytic reactions using ILs. Two topics using ILs for enzymatic reactions have been reviewed from the standpoint of biocatalyst mediating organic synthesis; the first is “Biocatalysis in Ionic Liquids” which includes various types of biocatalytic reactions in ILs (section 2): (1) recent examples of lipase-mediated reactions using ILs as reaction media for biodiesel oil production and for sugar ester production, (2) oxidase-catalyzed reactions in ILs, (3) laccase-catalyzed reactions, (4) peroxidase-catalyzed reactions, (4) cytochrome-mediated reactions, (5) microbe-mediated hydrations, (6) protease-catalyzed reactions, (8) whole cell mediated asymmetric reduction of ketones, (10) acylase-catalyzed reactions, (11) glycosylation or cellulase-mediated hydrolysis of polysaccharides, (12) hydroxyni...

Ionic Liquids as Tool to Improve Enzymatic Organic Synthesis.

A multifunctional gelatin-based aerogel with superior pollutants adsorption, oil/water separation and photocatalytic properties

Phase change materials (PCMs) applied in the energy storage and temperature control system are crucial for energy conservation and environmental protection. In this work, boron nitride (BN)@chitosan (CS) scaffolds with three-dimensional (3D) porous structures were fabricated. And effective thermal conductive pathways could be created in the resultant scaffolds. By introducing polyethylene glycol (PEG) into the BN@CS scaffolds, composite PCMs with large latent heat of fusion and excellent shape-stability were obtained. In particular, a high thermal conductivity up to 2.77 W m−1 K−1 could be reached at a relatively low content of BN (27 wt%). Moreover, they also exhibited a satisfactory energy storage density of 136 J g−1. This work demonstrated a facile and environmentally friendly strategy to simultaneously achieve enhancement of thermal conductivity, high energy storage density, shape stability and outstanding thermal repeatability for composite PCMs, which held promising potential in waste heat recovery, cooling system and temperature control system.

High thermal conductive shape-stabilized phase change materials of polyethylene glycol/boron nitride@chitosan composites for thermal energy storage

Research on water purification has recently revolved around nanomaterials because of their large specific surface area. However, there are still some problems associated with the preparation, application, and recovery of nanomaterials. Herein, we report for the first time a novel approach for one-step synthesis of porous hybrid fibers (PHFs), which can be used as an effective adsorbent for dye removal from polluted water. A low-cost biopolymer cellulose was chosen as the matrix of the fibers, whereas a NaOH solution was applied as the coagulation bath for the cellulose spinning dope that contained a certain amount of FeCl3. The obtained Fe(OH)3@Cellulose PHFs exhibited a multiscaled pore structure, with the in situ generated Fe(OH)3 nanoparticles uniformly distributed on the regenerated cellulose nanofibrous network of the fibers. These structural attributes are quite advantageous for an efficient adsorbent. The maximum Congo red removal capacity of the Fe(OH)3@Cellulose PHFs reached 689.65 mg/g, which wa...

Fabrication and Characterization of Highly Porous Fe(OH)3@Cellulose Hybrid Fibers for Effective Removal of Congo Red from Contaminated Water

Mass production of high thermal conductive boron nitride/nanofibrillated cellulose composite membranes

Continuous liquid interface production of alginate/polyacrylamide hydrogels with supramolecular shape memory properties.

Antibacterial hydrogels have been intensively studied due to their wide practical potential in wound healing. However, developing an antibacterial hydrogel that is able to integrate with exceptional mechanical properties, cell affinity, and adhesiveness will remain a major challenge. Herein, a novel hydrogel with antibacterial and superior biocompatibility properties was developed using aluminum ions (Al³⁺) and alginate–dopamine (Alg-DA) chains to cross-link with the copolymer chains of acrylamide and acrylic acid (PAM) via triple dynamic noncovalent interactions, including coordination, electrostatic interaction, and hydrogen bonding. The cationized nanofibrillated cellulose (CATNFC), which was synthesized by the grafting of long-chain quaternary ammonium salts onto nanofibrillated cellulose (NFC), was utilized innovatively in the preparation of antibacterial hydrogels. Meanwhile, alginate-modified dopamine (Alg-DA) was prepared from dopamine (DA) and alginate. Within the hydrogel, the catechol groups of Alg-DA provided a decent fibroblast cell adhesion to the hydrogel. Additionally, the multitype cross-linking structure within the hydrogel rendered the outstanding mechanical properties, self-healing ability, and recycling in pollution-free ways. The antibacterial test in vitro, cell affinity, and wound healing proved that the as-prepared hydrogel was a potential material with all-around performances in both preventing bacterial infection and promoting tissue regeneration during wound healing processes.

Wei Zhang

Papers

High thermal conductive shape-stabilized phase change materials of polyethylene glycol/boron nitride@chitosan composites for thermal energy storage

Fabrication and Characterization of Highly Porous Fe(OH)3@Cellulose Hybrid Fibers for Effective Removal of Congo Red from Contaminated Water

Mass production of high thermal conductive boron nitride/nanofibrillated cellulose composite membranes

Continuous liquid interface production of alginate/polyacrylamide hydrogels with supramolecular shape memory properties.

A Mussel-Inspired Antibacterial Hydrogel with High Cell Affinity, Toughness, Self-Healing, and Recycling Properties for Wound Healing