Two-dimensional (2D) materials and heterostructures have attracted significant attention for a variety of nanoelectronic and optoelectronic applications. At the atomically thin limit, the material characteristics and functionalities are dominated by surface chemistry and interface coupling. Therefore, methods for comprehensively characterizing and precisely controlling surfaces and interfaces are required to realize...
Use of bio-renewable polysaccharides to produce materials with a high technological impact has gained a lot of attention recently. Efforts have been made, for example to produce triboelectric generators from cotton, as well as, nanostructures of chitosan gels for drug delivery. Another well-known example is the use of β-Cyclodextrin (β...
Deformation in materials with a hierarchical microstructure is expected to be complex because of the interaction between the units that form such a microstructure. The complexity of deformation would be even higher when additional inelastic deformation modes are active in such materials, apart from traditional elastic and plastic deformation modes....
This dissertation presents a comprehensive study of thin-film LiMn2O4 (LMO) cathodes applied in lithium ion batteries (LIBs). The primary aim was to establish fundamental understanding of the relationship between interfacial LMO chemistry/electrochemistry and its detrimental drawback, i.e. fast capacity fade over long term cycling, and then develop effective mitigation methods....
Semiconductor nanowires, such as group IV and III-V nanowires, shows distinct electrical, optical and mechanical properties from their bulk counterparts due to their nanoscale size and 1-D morphology. For example, the quantum confinement effect modulates the band gap of a semiconductor nanowire when its diameter approaches or below the exciton...
Solvent-rich polyelectrolyte complexes display a wide range of rheological properties, when different environmental parameters are applied. Due to the low energy barrier of the complexation (~10 kT), these materials possess tunable properties, with the states of these materials varying from Newtonian liquids to very tough hydrogels. This thesis aims to...
Connecting structure and function in nanoscale engineered materials and devices relies on the analysis of the fundamental arrangement of matter, frequently under dynamic conditions. The demand to image structures at fundamental length scales has touched inorganic materials, biology, and frequently hybrid hard/soft materials with unique phenomena driven by heterogeneous components....
The Controlled, Site-Isolated Synthesis of Polyelemental Nanostructures in Polymer Nanoreactors Pengcheng Chen Polyelemental nanoparticles are an attractive class of materials due to their potential applications, which span the fields of catalysis, plasmonics, electronics, magnetics, targeted drug delivery, and bio-imaging. However, conventional synthetic methods for such structures are limited, especially when...
Localized corrosion involves the selective attack of a metal at a small, exposed site. This can be particularly devastating for load-bearing structures like bridges, which can fail catastrophically even with very little material loss. Unfortunately, such corrosion is very hard to prevent, predict, and detect. Corrosion can be prevented by...
The study of magnetic frustration has attracted considerable interest in the fields of materials science and condensed matter physics. Artificial Spin Ices (ASIs) are the primary systems in which magnetic frustration has been studied. To date, most studies on ASIs have been on fully periodic systems. In this thesis, we...
Plasmonic metasurfaces are leading the development of next-generation optical devices with unprecedented compactness and functionality. In contrast to bulk refractive optics, these planar surfaces manipulate light with rationally designed subwavelength building blocks. This thesis focus on how emerging materials and design methods advance the eld of metasurfaces. Chapter 1 reviews...
Organic semiconductors are an active area of research with great promise for delivering next generation electronics and clean energy technologies. As the field matures, understanding the connection between molecular structure, materials’ properties, and device performance will be critical in finding the right material for an intended application. An effective strategy...
Increasing industrialization and the resulting negative environmental impacts highlight the need to develop alternative renewable energy sources. The Sun is a massive source and organic solar cells are a growing field of study. As new materials are synthesized, the efficiencies of organic solar cells continue to grow, but without an...
One of the grand challenges in materials chemistry and nanochemistry is the development of functional materials through ordered, hierarchical structures using synthetic building blocks. Nature has done this through evolution of molecular components such as nucleic acids, saccharides, lipids, amino acids, and inorganic crystals. The precise spatial positioning of these...
This thesis centers around the development and application of novel high throughput lithography tools. These advances help: 1) establish the field of nanocombinatorics, where massive libraries (termed megalibraries) of materials can be prepared in a positionally encoded manner and then screened for functional activity, and 2) advance stereolithographic 3D printing...
Functional electronic materials are difficult to design due to the complex interplay among chemistry, atomic structure, and electrical properties. This dilemma is further amplified in transition metal compounds which can defy the band-theory description of non-correlated electrons. Exploring the vast possible design space completely with experiments or first-principles simulations is...
Biomaterials have immense potential for studying fundamental biological processes and developing therapies to help regenerate or replace the structure and function of injured tissues. In order to accomplish this, they need to be designed to mimic the structure and function of Nature’s most important material, the extracellular matrix (ECM) surrounding...
The dissertation systematically delineates the mechanically-guided deterministic assembly of three-dimensional (3D) mesostructures by compressive buckling, covering topics from mechanics concepts, design and analysis, fabrication techniques, to application opportunities. The development of approaches to form complex 3D functional mesostructures in advanced materials is a topic of broad interest, thanks to the...
SAMDI-MS (Self-Assembled Monolayers for MALDI-TOF Mass Spectrometry) couples the use of chemically-defined self-assembled monolayers of alkane thiolates on gold surfaces with MALDI-TOF mass spectrometry for rapid characterization of the surfaces. Reactions performed on the surfaces can be quantified directly by detection of the reaction substrates and products. This rapid detection...
Electrostatic interactions mediated by ionic environments play a central role in physical processes across materials science, chemistry and biology. Key biological phenomena, such as the condensation and packaging of DNA, ion transport across cellular membranes and the enzymatic action of proteins, rely on the complex interplay between nanoscale electrostatic, osmotic...