Producing Aerogels from Rice Straw Cellulose Obtained by a Green Method and Its Starch Blending

Cellulose and starch-cellulose composite aerogels were obtained using green cellulose from rice straw (RS) purified with a more environmentally friendly process. Pure starch aerogels were also obtained for comparison purposes. The effect of the aerogel cross-linking with polyamideamine-epichlorohydrin (PAE) was also analysed. The properties of the cellulose aerogels were in the range of those reported using other RS cellulose fibres with similar compositions. Blending with starch implied a decrease in the liquid water absorption capacity but an increase in the mechanical strength, flexibility, and oil absorption capacity, compared to pure cellulose aerogels. Cross-linking with PAE promoted the water adsorption capacity of all aerogels and the oil absorption capacity and mechanical strength of cellulose aerogels. However, PAE did not benefit the strength and oil absorption capacity of aerogels containing starch due to their specific interactions that negatively affect the aerogel structure. Therefore, it was possible to obtain cellulose and cellulose-starch composite aerogels from RS green cellulose with modulated properties for different applications.