Preparation and physicochemical properties of nanocellulose lightweight porous materials: The regulating effect of gelatin

The composite lightweight porous material (TOCNF-G-LPM) based on TEMPO-oxidized cellulose nanofibril (TOCNF) and gelatin were facilely prepared by ambient pressure drying using glutaraldehyde as crosslinking agent. The influence of gelatin addition on the physicochemical properties of TOCNF-G-LPM was investigated. The long-size entangled structure of TOCNF maintained the skeleton network of TOCNF-G-LPM while gelatin can adjust the characteristics of highly porous network (porosity of 98.53%–97.40%) and light weight (density of 0.0236–0.0372 g/cm3) with increasing gelatin concentration (0.2–1.0 wt%). The results of scanning electron microscopy (SEM) and confocal laser scanning microscope (CLSM) indicated that the internal structure of TOCNF-G-LPM became more ordered, uniform and denser as gelatin concentration increased. Introducing gelatin decreased water and oil absorption properties, but improved the thermal, mechanical properties and shape recovery ability of TOCNF-G-LPM at appropriate addition. Furthermore, TOCNF-G-LPM showed no significant effect on the growth and reproduction of Caenorhabditis elegans (C. elegans), confirming a good biocompatibility.