Title
One-pot preparation of zwitterionic graphene nanosheets with exceptional redispersibility and its application in pickering emulsions
Author
Jiawei Hu, Jiarui Hou, Shasha Huang, Lu Zong, Xiaodi Li, Zhijun Zhang, Yongxin Duan, Jianming Zhang
Year
2019
Journal
Carbon
Abstract
Using biomass materials as exfoliating agents to produce graphene is a promising strategy due to their biocompatibility, reproducibility and sustainability. However, it’s still a challenge to prepare high-concentration graphene dispersion using biomass exfoliating agents. Here, we present a green and facile method to prepare few layered graphene nanosheets in aqueous solution by one-pot ball milling in the presence of protein, casein (CN). The results show that CN protein could be acted as an efficient exfoliating and stabilizing agent, producing water-soluble graphene nanosheets with a concentration up to 2.14 mg ml−1. As CN protein contains both amino and carboxyl groups, thus the prepared graphene nanosheets decorated with CN protein (GN-CN) show zwitterionically charged character and thereby can be stably dispersed under both acidic and alkaline conditions. Moreover, the oven-dried GN-CN hybrid exhibits exceptional redispersibility in water with a concentration as high as 100 mg ml−1 and even more. Benefiting from the zwitterionic character, GN-CN shows the Pickering emulsion effect over a wide pH range. As a proof of concept, the application of the zwitterionic GN-CN as a Pickering emulsifier to prepare microcapsule phase change composite material has been successfully demonstrated.
Instrument
J-1500
Keywords
Circular dichroism, Secondary structure, Chemical stability, Nanostructures, Materials, Biochemistry