Chapter 31 - Liquid-liquid interface as scaffold for self-assembly of nanostructures into functional materials

Abstract

The interface between two immiscible liquids, having a thickness of the order of a few nanometers, offers an important scaffold for the self-assembly of nanoscale substances that can offer novel and inexpensive routes to higher-order assemblies with improved properties. In 1907, Pickering discovered that colloidal solid particles could be adsorbed onto the liquid-liquid interface to stabilize emulsion droplets. The colloidal particles get adsorbed onto liquid-liquid interface driven by the reduction in interfacial energy. Since a liquid–liquid interface is not mechanically constrained, the process of self-assembly becomes advantageous to most of the nanostructured systems; however, such processes require adequate stabilization of the nanoparticles at interfaces with a high degree of organizational selectivity. Numerous innovative approaches have been explored to engineer interfacial ordering effects for the organization of nanoscale materials into both two and three dimensions, including membranes, capsules, core–shell structures, heterodimeric alloyed nanostructures, Janus particles, and giant supramolecular assemblies with distinct functionalities. Understanding and improvement are essential to explore these materials in developing more effective technology in diverse arenas of real-time applications ranging from the replacement of the present filtration processes, optical devices to biomedical markers and to design novel smart materials suitable for miniaturized lab-on-chip and other microfluidics devices. Insight into the advantages and challenges could pave the avenue in achieving desired functional materials and interfaces with applications in diverse arenas of physical, chemical, materials, biological, and biomedical sciences.