Morphology transcription process from CMC micelles to inorganogel and its effect on the properties of alumina particle

Abstract

In this study, a carboxymethyl cellulose (CMC)-mediated sol–gel process was developed to synthesize the alumina hydoxide whiskers. During the process, inexpensive inorganic salts were used as precursors and supercritical drying method was used to extract the water in hydrogel. The influences of CMC on the gel formation and the particle morphology were investigated. The results show that the formation of CMC–aluminium hydroxide organic–inorganic hybridgels led to a morphology transcription process from CMC micelles to aluminium hydroxide gel, as a result, the precursor with whiskerious morphology was obtained. Such specific morphology of the precursor delayed phase transformation from transition- to α-alumina greatly, and the ability resistant to sintering was highly enhanced. At presence of CMC, the acicular alumina calcined at 1200 °C for 4 h had surface area of 79.6 m 2 g −1, much higher than the spherical sample (50 m 2 g −1) without CMC. Because of being straightforward, inexpensive and versatile, the approach could be potentially used to prepare other materials with controllable morphologies and might be potentially extended to mass-production.