Modification of microcrystalline cellulose enhanced by impact milling and solvothermal process and its Pickering emulsion

Abstract

This paper attempts to apply high-speed impact grinding and solvothermal process to the surface modification of microcrystalline cellulose (MCC). The impact and shear forces were used to increase the specific surface area of MCC and reduce its particle size. In a closed ethanol solvothermal environment, the solubility, dispersibility and reactivity of lauric acid were improved, which enhanced its effect on MCC. The modified MCC (LA-MCC) was used to prepare Pickering emulsion. The experimental results show that the water contact angle of modified MCC increases from 55° of original MCC to 84° of LA-MCC, showing amphiphilicity. LA-MCC is an ideal micro/nano particle for Pickering emulsion. Emulsion prepared with 1.5% (w/v) LA-MCC and 3:7 (v/v) corn oil has a Zeta potential of −58.7 mV under neutral pH of 7, showing good stability. Emulsion index only decreases by 1.66% after seven days, and the emulsion remains stable after fifty days.