Crosslinked hemicellulose citrate–chitosan aerogel foams

The applications for hemicellulose are currently very narrow, because of its low molecular weight and varying chemical composition. In this research, novel applications for modified hemicellulose are developed making it a valuable biomaterial for absorbency applications in health care and medical textiles. The incorporation of carboxylic acid groups into hemicellulose via reaction with citric acid followed by cross linking with chitosan greatly improve the properties relative to hemicellulose, chitosan, a cellulose sponge product, and hemicellulose citrate alone. Optimum conditions for the cross linking of the hemicellulose citrate–chitosan include a 2.5 h reaction time at 110 °C with pH 3.5, a solid to liquid ratio of 1:100 and a hemicellulose citrate to chitosan ratio of 1:1 (w/w). The hemicellulose citrate–chitosan crosslinked foam is elastic, very soft, highly porous and durable. The hemicellulose citrate–chitosan can absorb up to 100 g of a saline solution per gram of material and up to 80 g of water per gram of material. Analysis of the hemicellulose citrate–chitosan foams with FTIR, DMA, and SEM confirms the crosslinked and hygroscopic behavior of the materials.