Solvent Structure Controlled SeedGel Formation Investigated using Miscible Binary Solvent

Published

February 6, 2025

Author(s)

Yuyin Xi, Ruipeng Li, William Heller, Wei-Ren Chen, Kunlun Hung, Aurora Zemborain, Yun Liu

Abstract

The interconnected channels and high specific surface areas have made materials with bicontinuous structures great candidates for energy-related and biomedical applications. Their controllable structures also promise great possibilities for enabling new features in materials discoveries. Recently, solvent segregation driven gel (SeedGel) has been demonstrated to be a tunable and versatile way to stabilize bicontinuous structures in a binary solvent. Here, the structure properties of SeedGel prepared with miscible solvent, 3-methylpyridine (3MP)/water are systematically investigated using ultra-small angle neutron scattering (USANS) and small angle X-ray scattering (SAXS). The structures prepared with 3MP/water show similar behavior as one previous SeedGel prepared with lutidine/water. Interestingly, the deuteration of 3MP in this binary solvent significantly shifts the gelation temperature of SeedGel. It also demonstrates that both components of the binary solvent can be exchanged between the formed two domains in a SeedGel by changing the sample temperature. Importantly, the binary solvent used for the SeedGel preparation does not need to have a bulk phase transition as a function of temperature. Our results demonstrate that the correlation length due to the density fluctuation of the binary solvent is about the same at the gelation transition temperature for all studied SeedGels prepared with different binary solvents. Thus, this correlation length seems to be a key controlling parameter for the SeedGel formation. It is noted that this observation not only holds in binary solvents that show a bulk phase separation but also exists in miscible binary solvents without bulk phase separation. The results here thus open a window to prepare SeedGels with a new set of binary solvents that may have been overlooked before and provide guidance for choosing appropriate miscible binary solvents that can be used to prepare SeedGels.

Citation

Soft Matter

Pub Type

Journals

Keywords

SeedGel, Gel, SANS, USANS, binary solvent, bicontinuous

Citation

Xi, Y. , Li, R. , Heller, W. , Chen, W. , Hung, K. , Zemborain, A. and Liu, Y. (2025), Solvent Structure Controlled SeedGel Formation Investigated using Miscible Binary Solvent, Soft Matter (Accessed March 14, 2025)