The addition of cobalt ions in the aluminum-chitosan liquids which are solidified by lyophilization to generate cotton-like aerogel composites. Uniform incorporation of cobalt-aluminum hydroxide ions onto chitosan leads nanofibrils to serve as a hierarchical template to support mixed metal hydroxides in the aerogel composites. | Vietnam Journal of Science and Technology 56 (1A) (2018) 135-145 CHITOSAN-TEMPLATED LIGHTWEIGHT SPINEL CoAl2O4 NANOFIBRIL AEROGELS Chau The Lieu Trang1, *, Nguyen Duc Cuong1, 3, Dang Thi Thanh Nhan1, 2, Do Dang Trung4 1 Department of Chemistry, University of Sciences, Hue University, 77 Nguyen Hue, Hue City 2 Department of Chemistry, University of Education, Hue University, 34 Le Loi, Hue City 3 School of Hospitality and Tourism, Hue University, 22 Lam Hoang, Hue City 4 Department of Basic Sciences, University of Fire Fighting and Prevention, 243 Khuat Duy Tien, Thanh Xuan, Ha Noi * Email: chauthelieutrang@ Received: 15 August 2017; Accepted for publication: 21 March 2018 ABSTRACT We present lightweight macro-mesoporous spinel CoAl2O4 nanostructured aerogels derived from water-soluble aluminum-chitosan complexes. Chitosan nanofibrils interact with aluminum ions to swell into hydrogels. The aluminum-induced swelling is extended to dissolve the hydrogels in water to form a homogeneous aluminum-chitosan aqueous solution. The addition of cobalt ions in the aluminum-chitosan liquids which are solidified by lyophilization to generate cotton-like aerogel composites. Uniform incorporation of cobalt-aluminum hydroxide ions onto chitosan leads nanofibrils to serve as a hierarchical template to support mixed metal hydroxides in the aerogel composites. We investigated the thermal removal of chitosan template in the composites to obtain spinel CoAl2O4 aerogels that truly replicate spider web-like fibrillar networks of chitosan template. Enlarged porosity, high crystallinity, and lightweight make the CoAl2O4 aerogels useful as a colorful nano-pigment for magnetic ceramics. Keywords: chitosan nanofibrils, biotemplating, spinel CoAl2O4 aerogels, lightweight materials. 1. INTRODUCTION Ceramic aerogels with lightweight and thermal characteristics are an exciting class of highly porous materials for applied technologies [1]. These materials can be used as .
