An intelligent dual stimuli-responsive Pickering emulsion for highly efficiently producing waste frying oil-based biodiesel

Abstract

Directionally converting waste frying oil (WFO) to biodiesel is not only a crucial strategy for its clean and efficient utilization, but also a promising alternative for the large-scale substitution of petroleum-based fuels. However, the challenge of reducing mass transfer resistance between the alcohol/oil bi-liquid phases remains a major obstacle in the industrialization of WFO-based biodiesel (WFOBB). Additionally, both rapid emulsification and efficient demulsification still present bottlenecks that need to be addressed in emulsion reaction. Herein, the present study successfully demonstrates the fabrication of a novel Pickering interfacial catalyst with immobilized Brønsted-Lewis di-acid functionalized ionic liquids and photosensitizer (P(5[DVB]-[SP]-[ILs-2FeCl3])@SiO2@Fe3O4) through layer-by-layer self-assembly. This novel Pickering interfacial catalyst efficiently constructed an intelligent magneto-optical dual stimuli-responsive Pickering emulsion. The intelligent Pickering emulsion enables precise control over amphiphilic interfacial catalyst using Vis-light regulation, thereby significantly enhancing mass transfer in the biphasic methanol-WFO system while providing an optimal hydrophobic micro-environment for highly efficient WFOBB production. The intelligent Pickering catalyst exhibits exceptional catalytic performance in achieving a 92.4% yield of WFOBB, which is currently the highest reported value under similar conditions. Furthermore, the efficient demulsification and separation of this Pickering interfacial catalyst could be achieved through the synergistic effect of UV-irradiation-induced hydrophilicity and its magnetic property. These findings present a new avenue for advancing the development of WFOBB technologies, while also offering promising prospects for industrial applications of Pickering emulsion systems.