Authors: Mengya Li, Pengfei Yan, Jie Liu, Ying Pei, Xuejing Zheng, Keyong Tang & Fang Wang

One-step acid hydrolysis was successfully employed to prepare carboxylated cellulose nanofibrils (CCNFs) from pomelo peel waste with the mixture of hydrochloric acid and citric acid (HCl/CA). Esterification occurs during acid hydrolysis, making the cellulose rich in carboxyl groups. The effect of the ratio of HCl to CA on the properties of the resulting CCNFs was investigated. Results showed that the prepared CCNFs were entangled with each other with diameters of 5–15 nm and lengths of 0.8–1.2 µm, depending on the CA content. With the increase of the CA proportion, the content of the carboxyl group was up to 1.10 mmol/g, resulting in a high surface charge with the ζ-potential value of –59.2 mV. These results demonstrated that the electrostatic repulsion plays a vital role in keeping the highly stable dispersibility of CCNFs. CCNFs also possess a crystallinity index of about 44.0% and thermal stability of up to 343 °C. Additionally, nanofibrils with a high aspect ratio exhibit potential applications as an excellent food pickering emulsion, which can stabilize soybean oil/water emulsions for at least 20 days.

全文链接：https://link.springer.com/article/10.1007/s10570-021-04392-7