Defence of doctoral thesis in the field of engineering physics, MSc Tomy Cherian

Title of the doctoral thesis is "Self-assembly and Pattern Formation - From Nanoconfined Ion Transport in Liquid Crystals to Dissipative Pattern Formation in Electroferrofluids"

We live in a world surrounded by electronic devices powdered by batteries, be it TV remotes, mobile phones, laptops, or cameras. With the advent of electric cars, the importance of technological innovation in batteries has been brought to the central stage. Here, the safety of batteries is a nagging cause of concern with incidents of leakage, fire, and explosion due to flammable liquid electrolytes.

The first part of this dissertation addresses this issue by design of materials based on low volatile conductive liquids called ionic liquids. They are combined with simple surfactant molecules, self-assembling at nanoscale to create crystalline assemblies that have nanochannels for ion conduction. The promising ion conduction values, along with easy tunability of nanostructure highlight how ionic liquid-based self-assembled materials could indeed be a viable alternative to conventional electrolytes.

The second part of this dissertation focusses on pattern formation. Nature presents myriad of intrinsically complex and beautiful patterns and assemblies at all sizes and scales that inspire artists and scientists alike. Examples include ice crystals, arrangement of flower petals, wavy stripes on deserts and spiral shaped galaxies. On a fundamental level, patterns in nature are a result of interplay of multiple forces that consume and dissipative energy. Understanding their formation by developing lab scale materials has been a longstanding challenge in the field of material science.

In this dissertation a novel class of nanomaterial, electroferrofluid, that respond to electric and magnetic forces is developed to achieve microscale patterns. By tuning the strength of these forces an array of stunningly complex patterns with varying electrical and magnetic properties are generated. Apart from their visual appeal, one could foresee the use of this responsive multifunctional material in future optical and electronic devices.

Opponent is Professor Rafal Klajn, Weizmann Institute of Science, Israel

Custos is Professor Olli Ikkala, Aalto University School of Science, Department of Applied Physics

Contact details of the doctoral student: [email protected]

The public defence will be organised via Zoom. Link to the event

The dissertation is publicly displayed 10 days before the defence in the publication archive Aaltodoc of Aalto University

Electronic thesis

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