CHAPTER 6: Bijels Formed by Solvent Transfer-induced Phase Separation

This chapter introduces the formation of bijels via solvent transfer-induced phase separation (STrIPS). STrIPS bijels are generated by triggering spinodal decomposition of a ternary liquid mixture composed of oil, water, solvent and surface-active nanoparticles. Bicontinuous oil/water channel networks are stabilized by interfacial jamming of the nanoparticles. Continuous production of STrIPS bijel fibers, planar films and microparticles is realized via a scalable route amenable to mass production. STrIPS bijels have asymmetric internal structures, with small domains on the surface and larger internal domains. We discuss the dependency of STrIPS bijel domain organization and size based on variation of nanoparticle concentration and surface functionalization. Moreover, we introduce a microfluidic technique to measure the fracture strength of STrIPS bijels. Mechanical reinforcement of STrIPS bijels is realized by interfacial nanoparticle cross-linking and sol–gel chemistry. Furthermore, applications of STrIPS bijels in reactive separations and as nanocomposite ultrafiltration membranes are introduced. The chapter concludes with an outlook and future perspectives on fundamental research, as well as applications for STrIPS bijels.