One-pot preparation of zwitterionic graphene nanosheets with exceptional redispersibility and its application in pickering emulsions. (February 2020)

• Record Type: Journal Article
• Authors: Hu, Jiawei; Hou, Jiarui; Huang, Shasha; Zong, Lu; Li, Xiaodi; Zhang, Zhijun; Duan, Yongxin; Zhang, Jianming
• Is Part Of: Carbon. Volume 157(2020)
• Page Start: 448
• Page End: 456
• Publication Date: 2020-02
• Subjects: Carbon -- Periodicals; Carbone -- Périodiques; Koolstof; Toepassingen; Electronic journals; 546.681
• DOI: 10.1016/j.carbon.2019.10.063
• Languages: English
• ISSNs: 0008-6223

Abstract

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. Graphical abstract: Image 1