Hou–Yong Yu

A facile approach for extracting cellulose nanocrystals (CNCs) was presented through hydrochloric acid hydrolysis of cellulose raw materials under hydrothermal conditions. The influences of preparation parameters, such as reaction time, reaction temperature, and acid-to-cellulose raw material ratio, and different neutralization methods on the yield, microstructure and properties were studied. A high yield of up to 93.7%, crystallinity of 88.6%, and a maximum degradation temperature (Tmax) of 363.9 °C can be achieved by combining hydrochloric acid hydrolysis under hydrothermal conditions and neutralization with ammonia, compared with only 30.2%, 84.3% and 253.2 °C for sulfuric acid hydrolysis, respectively. More importantly, good stability of aqueous CNC suspensions can also be obtained due to the existence of ammonium groups, which can easily be removed through simple heat treatment before using the CNCs.

A simple approach was developed to isolate cellulose nanocrystals (CNCs) with carboxylic groups from microcrystalline cellulose (MCC). The effect of reaction time on the morphology, microstructure, and thermal stability of isolated CNCs was investigated. The rod-like CNCs with size of 200–250 nm in length and about 15–20 nm in width were obtained by one-step citric/hydrochloric acid (C6H8O7/HCl) hydrolysis of MCC. The CNCs extracted at 4 h showed the highest carboxylic group content which led to a high absolute zeta potential value up to 46.63 mV. Moreover, these CNCs may be used as cationic dye adsorbent (methylene blue) and efficient flocculants with excellent coagulation–flocculation capability to kaolin suspension with a turbidity removal of 99.5%.

A novel core/shell compound has been developed by coating a spherical LiFePO4 structure with a specific π-bond character planar polymer (polyacene, PAS). The electronic conductivity, low-temperature character, and tap density of the LiFePO4–PAS composite were significantly improved compared to LiFePO4, which may lead to use in lithium-ion battery applications. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2089/2006/c0578_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.