PNNL

Abstract

Surfactant molecules found in soaps and detergents can self-assemble into a great variety of morphologies (e.g., spherical micelles, cylindrical micelles, and lamellar phases). The resulting morphology is highly affected by ionic strength, temperature, and flow conditions. In particular, cylindrical micelles in the presence of inorganic or organic salts can self-assemble into large flexible and elongated wormlike micelles. In equilibrium, the wormlike micelles transition from slightly entangled to branched and, finally, to multi-connected structures with increasing salt concentration. In our work, by introducing external flow conditions via microfluidics, these micellar structures can follow very different trajectories on the phase map and new nanoporous structures can be created. This flow induced approach offers great potential to create novel materials and nanoporous scaffolds from wormlike micelles under ambient temperature and pressure, without any chemical and thermal means (1). As a result, this work provides attractive solutions for synthesizing new biocompatible materials under ambient conditions with biosensing, encapsulation, catalysis, photonics, and self-healing applications.