Characterization of cellulose II nanoparticles regenerated from 1-butyl-3-methylimidazolium chloride

Regenerated cellulose nanoparticles (RCNs) including both elongated fiber and spherical structures were prepared from microcrystalline cellulose (MCC) and cotton using 1-butyl-3-methylimidazolium chloride followed by high-pressure homogenization. The crystalline structure of RCNs was cellulose II in contrast to the cellulose I form of the starting materials. Also, the RCNs have decreased crystallinity and crystallite size. The elongated RCNs produced from cotton and MCC had average lengths of 123 +/- 34 and 112 +/- 42 nm, and mean widths of 12 +/- 5 and 12 +/- 3 nm, respectively. The average diameter of spherical RCNs from MCC was 118 +/- 32 nm. The dimensions of the various RCNs were all well fitted with an asymmetrical log-normal distribution function. The RCN has a two-step pyrolysis, different from raw MCC and cotton that have a one-step process. (C) 2013 Elsevier Ltd. All rights reserved.