Phytic acid and graphene oxide functionalized sponge with special-wettability and electronegativity for oil-in-water emulsion separation in single-step

• Published in: Journal of hazardous materials Vol. 435; p. 129003
• Main Authors: Feng, Lidong, Gao, Yue, Hou, Xuan, Dan, Hongbing, Wei, Yao, Yin, Weiyan, Gao, Baoyu, Yue, Qinyan
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 05.08.2022
• Subjects: Absorption demulsification; Amphipathicity; Emulsions; Flame retardant; Graphite; in-situ purification; Macroporous substrate; Phytic Acid; Water - chemistry; Wettability; Macroporous substrate; Flame retardant; Absorption demulsification; in-situ purification; Amphipathicity
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2022.129003

Developing an emulsion separation material with one-step in-situ purifying capability and improved security in applications, especially for subsequent scale-up, is valuable but remains a challenge. Herein, the amphiphilic sponge (PA@RGO@MS) was prepared via impregnation and in-situ growth of the negatively charged hydrophilic phytic acid (PA) and the hydrophobic reduced graphene oxide (RGO) on the surface of the melamine sponge (MS) and applied in emulsion purification. The mechanics, wettability, absorption performance of the PA@RGO@MS were analyzed to identify its potential for stable demulsification. Results show that the PA@RGO@MS could purify emulsions (turbidity removal rate = 99.7%; TOC removal rate = 94.14%) in-situ in one step by simple shock absorption, profited from the hydrophilic and demulsification capability of PA, oil absorption of RGO, and wide reaction and storage space of MS. Targeting the emulsion with distinct properties (density, viscosity, and concentration) of the oil phase, the PA@RGO@MS could efficiently enable the purification. Meanwhile, the powerful flame-retardant granted from PA ensures the safe shipment and storage of sponges. The favorable cyclability (turbidity removal rate > 98.5% and TOC removal rate > 89.5% after 10 cycles) and diversified operating modes enhance the practical value of the PA@RGO@MS. [Display omitted] •The PA@RGO@MS was successfully fabricated by impregnation and in-situ growth.•The PA and RGO@MS undertake the task of demulsification and oil absorption, respectively.•The PA@RGO@MS could efficiently realize one-step in-situ emulsion purification.•The PA@RGO@MS could achieve emulsion separation in multiple ways.•The PA@RGO@MS owns enhanced security during storage or transportation.