Bamboo Cellulose And Its Derivative Nanomaterials

As the most abundant polysaccharide in bamboo, cellulose receives much attention in the development of green functional materials. Here, the optimal parameters of cellulose extraction, effects of acid treatments on bamboo cellulose nanocrystals, and the internal interaction of cellulose based nanocomposites were studied.The content of cellulose in bamboo powder is42.3%. Bamboo cellulose was extracted from bamboo powder by alkali-bleaching extraction methodology. To get the optimal parameters of more extraction content of cellulose and bigger removal rate of hemicellulose and lignin, the samples under varying treatment concentration, temperature and treatment times were characterized by FTIR, XRD, TG/DTG The results showed that cellulose with high purity, high yield, and high crystallinity index can be obtained by treating bamboo powder at a concentration of2.0wt%sodium hydroxide solution,90℃, and alkali treatment was repeated three more times (4h per time) followed by bleaching treatment.Cellulose nanocrystals prepared from bamboo cellulose by means of sulfate acid, hydrochloric acid, phosphoric acid, and the mixture of acetic acid and nitrate were found in the length of3-200nm,20-85nm,20-40nm,6.5-20nm, respectively. Moreover, nanocrystals made from the uses of sulfuric acid and phosphoric acid possessed higher crystallinity index and lower thermal stability than those from the uses of hydrochloric acid and acetic acid. Under the treatment of hydrochloric acid, and acetic acid-nitric acid systems, the resulting cellulose crystallites appeared to be wormlike and spherical particles, respectively. In addition, colloidal suspensions of CNS exhibited excellent stability. Then the effects of the concentration of acetic acid, reaction temperature and time on the structure and property of cellulose whiskers were also investigated. It was found the crystallinity index of cellulose whiskers was affected by the concentration of acetic acid, reaction temperature and time. Cellulose nanocrystals with high crystallinity index can be obtained by treating bamboo cellulose in6.5M acetic acid-nitric acid solution for2.0h, at the temperature of60℃. Moreover, the experimental parameters had no significant effect on the thermal stability of the cellulose whiskers.At last, cellulose/Fe0nanocomposite was prepared by a simple in-situ reduction method. Results suggest that Fe0changed the chemical structure of cellulose nanocrystals, reduced the crystallinity index and thermal stability of the cellulose nanocrystals.