Tunable Thermo-Reversible Bicontinuous Nanoparticle Gel Driven by the Binary Solvent Segregation
Yuyin Xi, Ronald S. Lankone, Li Piin Sung, Yun Liu
Bicontinuous porous structures due to colloidal self-assembly are an important class of solid framework for various applications.1–3 And non-equilibrium process, such as gel formation, is a powerful route to stabilize bicontinuous structures.4 Here, a novel solvent segregation driven gel (SeedGel) is proposed and demonstrated to arrest bicontinuous structures using particles dispersed in a binary solvent similar to the widely studied bicontinuous interfacially jammed emulsion gel (Bijel). However, different from Bijel, by tuning the particle surface to be preferentially wetted by one component of the binary solvent, nanoparticles in SeedGel are jammed into one of the solvent domains upon solvent phase separation during gelation. SeedGel shows excellent thermal structural reversibility and reproducibility, tunable domain size, adjustable gel transition temperature, and amazing optical property. Due to the universality of the solvent driven particle phase separation in a binary solvent dispersion, SeedGel is potentially useful for a wide range of colloidal systems.