Fengcai Lin

Development of organic–inorganic hybrid beads from sepiolite and cellulose for effective adsorption of malachite green

Organic–inorganic hybrid adsorbents based on sepiolite and cellulose were prepared through an easy-to-handle procedure. Hydrogen-bonding existed between the silanol groups (Si–OH) on the sepiolite surface and the hydroxyl groups of the cellulose structure resulting in the formation of hybrid beads with good synergistic effects. Incorporation of the inorganic molecule sepiolite into the renewable polymer cellulose opened an opportunity for the development of alternative environment-friendly adsorbents with improved adsorption efficiency as well as enhanced thermal stability compared with neat cellulose beads. The utility of the obtained sepiolite/cellulose beads was demonstrated by investigating their performance for the removal of malachite green (MG). The maximum adsorption capacity of MG on sepiolite/cellulose beads was close to the calculated results from the Langmuir adsorption isotherm, and the adsorption kinetics followed well to the pseudo-second-order model.

Effect of silicone oil heat treatment on the chemical composition, cellulose crystalline structure and contact angle of Chinese parasol wood

The effect of silicone oil heat treatment (SOTH) on the chemical composition, cellulose crystalline structure, thermal degradation and contact angle of Chinese parasol wood were examined in this study. Samples were heated at 150°C, 180°C and 210°C for 2h and 8h, after SOHT chemical composition, fourier transformed infrared (FTIR), thermogravimetric analysis (TGA) and X-ray diffraction (XRD) of the treated samples were evaluated. Results showed that the chemical components of the wood were affected after SOHT particularly when treated at 210°C for 8h. Changes in the chemical components was due to the degradation of biopolymer components of the wood during SOHT. The crystallinity index of cellulose and contact angle of the SOHT samples was increased. The findings demonstrate the potential of SOHT for modification of wood. Thus an economical and eco-friendly approach to thermally modified wood was achieved in this study.

One-pot construction of cellulose-gelatin supramolecular hydrogels with high strength and pH-responsive properties

Inspired by the supramolecular structure of cellulose, cellulose-gelatin supramolecular hydrogels with high strength and pH-sensitivity were constructed in a basic-based solvent system, ethylene diamine/potassium thiocyanate (EDA/KSCN) with the aid of cyclic freezing-thawing. The investigation on the characteristics of supramolecular hydrogels revealed that repeated freezing-thawing cycles played an important role in the formation of the physical cross-linked supramolecular network structure between cellulose and gelatin. The mechanical properties of supramolecular hydrogels were much higher than pure cellulose and gelatin hydrogel, and the compressive strength was 9.6 times higher than that of pure gelatin hydrogel. The synergistic effect between hydrogen-bonding interaction and the reinforcement of regenerated cellulose nanofibrils (CNF) contributed to the superior mechanical performance. Furthermore, the swelling kinetics tests showed that the supramolecular hydrogels exhibited excellent pH-responsibility, indicating potential applications in biomedical fields. Thus, a straightforward route to construct natural polymer-based hydrogels with supramolecular structure through physical crosslinking strategy without employing hazardous crosslinking agents was developed, paving the way for the design of new types of hydrogels.

Microfibrillated cellulose enhancement to mechanical and conductive properties of biocompatible hydrogels

A combination of conductive polymer with natural biomass is an ideal alternative to the classical conductive materials. In this study, PPy/SA/TOMFC composite hydrogels were fabricated by incorporation of TEMPO-oxidized microfibrillated cellulose (TOMFC) into the alginate-based matrix along with the in situ polymerization of pyrrole monomer. It was found that the mechanical and conductive properties of the composite hydrogels were associated with the concentration of TOMFC, which facilitated the formation of more compact 3D network structures and the growing of PPy conductive network. The mechanical properties of the synthesized hydrogels were significantly enhanced by incorporation of higher amount of TOMFC. In addition, with the introduction of 5.0 wt% TOMFC, the electrical conductivity of composite hydrogels could be ten times higher than that of PPy/SA hydrogels. Moreover, the obtained PPy/SA/TOMFC hydrogels exhibited tunable swelling properties and good biocompatibility, making them promising candidates for the use as biomaterial.