Self-assembly and Pattern Formation - From Nanoconfined Ion Transport in Liquid Crystals to Dissipative Pattern Formation in Electroferrofluids

This thesis is a study of equilibrium and out-of-equilibrium branches of self-assembly and pattern formation. On one hand, equilibrium self-assembly is used to create functional nanostructures; in particular 2D ion transporting liquid crystals. The second part of this dissertation presents a facile approach to drive colloidal nanoparticles out of thermodynamic equilibrium with electric fields and their further control using magnetic fields. Publication I presented the simplicity and modularity of the branch of supramolecular self-assembly to create functional nanoscale structures. Herein, ionic self-assembly of single or double tailed basic surfactant molecules with an acidic ionic liquid was used to yield nanosegregated supramolecular complexes. A representative of this family of complexes, di-n-nonylamine 1-(4-sulfobutyl)-3-methylimidazolium hydrogen sulfate (DiC9-IL), was studied in detail. This complex presented well-defined nanoscale alternating alkyl and ionic layers wherein the ionic layers facilitated confined anisotropic 2D ion transport. Publications II and III took the well know magnetic material, ferrofluid, and made it electrically active to drive the dispersed nanoparticles out of equilibrium using electric fields. Publication II showed how these nanoparticles can be used to create nonequilibrium concentration gradients. Next, the magnetic nature of nanoparticles was exploited to generate instabilities and patterns on these gradients using magnetic fields. Publication III took this system a step further, highlighting the interplay of orthogonal electric and magnetic fields to generate hybrid dissipative patterns of varying degrees of complexity. Additionally, the effect of water and AOT concentrations on the behaviour of the system was also addressed. Overall, the thesis contributes to the current body of knowledge in equilibrium and out-of-equilibrium systems, specifically supramolecular ionic self-assembly and dissipative pattern formation in a new class of material, electroferrofluid. This thesis points to what could be a future direction for research in material science: consideration of functional supramolecular materials in out-of-equilibrium scenarios.