作者：Houyong Yu, Somia Yassin Hussain Abdalkarim,Heng Zhang， Chuang Wang,and Kam Chiu Tam
关键字：Recyclable acids hydrolysis, Cellulose nanocrystals, High yield, Food emulsion
论文来源：期刊
发表时间：2019年

Cellulose nanocrystals (CNCs) have great potentials in many applications, such as high-performance nanocomposites. However, there are many challenges in the industrial production of CNCs, such as high cost of acid recovery, acid disposal, low yield, and poor thermal stability. In this study, a simple process to extract CNCs via recyclable acid hydrolysis of microcrystalline cellulose (MCC) is presented. A high yield (up to 87.8%) of carboxylate CNCs was obtained using recyclable citric/hydrochloric acid  mixtures compared to the 53.9% yield for sulfated CNCs via recyclable H2SO4 hydrolysis. The mild acid mixtures could be readily recovered and recycled three times and showed a slight effect on the size of CNCs, carboxyl content of citrate CNC surface, zeta potential value, and thermal stability. Both charged citrate CNCs and sulfate CNCs were excellent food Pickering emulsion stabilizers for soybean oil/water emulsion droplets, whose diameter decreased with increasing CNC contents. This work provides a simple and low-cost pathway to recover mineral or organic acids for the sustainable and green production of CNCs with high yield and thermal stability while addressing the environmental issue of acid disposal in large-scale production of CNCs.