Degree Type

Thesis

Date of Award

2020

Degree Name

Doctor of Philosophy

Department

Materials Science and Engineering

Major

Materials Science and Engineering

First Advisor

Martin M Thuo

Abstract

Fabrication of functional materials with ordered micro-/macro structures are generally energy and time consuming, especially for traditional metal and metal alloy processing into which enormous energy is invested due to their high melting points. Undercooled liquid metals particles, however, are highly versatile not only being in liquid form at room temperature, but also possessing dynamic surfaces with potential chemical activity. Thus, autonomous functional material fabrication starting from metal could be achieved by coupling metastability of Undercooled Liquid Metal Core-Shell (ULMCS) with self-driven processes. First, ULMCS was applied in the BIOmimetic MetAl Pattering of soft substrate (BIOMAP). Without heat or chemical etching, packing, jamming and self-filtration of undercooled liquid metal particles were investigated in capillary-driven formation of natural structures (rose petal). Followed by chemical coalescence, obtained continuous metallic patterns exhibited high resolution in picking up delicate structural differences. Not only mimicking the structures, surface properties of fresh rose (hydrophobicity, Petal Effect) were also transferred to its metallic replica (metal rose). Then, Polymerization Induced Self-Assembly (PISA) was studied to modify undercooled metal particle assemblies autonomously. By restricting the metal/ligand reaction into narrow pores, polymer adduct with delicate structures formed directly upon metal particles and affected wetting property by transferring petal effect into lotus effect. Finally, the metal/ligand reaction between ULMCS and organic acid solution was operated upon templates. Narrow structures of the template directed reaction with capillary action (Directed Metal/ligand reaction, D-Met). Together with “coffee-ring effect”, aligned mix-component polymeric nanowires were formed upon Si substrate. Self-coordinating structure of nanowires resulted in wire continuity preservation with concomitant composition transformation after heat-treatment.

DOI

https://doi.org/10.31274/etd-20210114-23

Copyright Owner

Julia Jinling Chang

Language

en

File Format

application/pdf

File Size

89 pages

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