Electrochemical cell devices are increasingly being sought for energy conversion and storage applications due to their high efficiencies and their potential for operating free of greenhouse gas (GHG) emissions. Solid Acid Electrochemical Cells (SAECs), which most commonly employ CsH2PO4 (CDP) as the electrolyte component, are uniquely suited to meet the...
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...
Throughout history, the development of materials has relied heavily on the empirical judgment of scientists and engineers and on prolonged experiments proton to errors. Due to the complexity of material behavior, successful discovery of new candidates has been serendipitous, and down-selection of candidates remains a time-consuming process that requires repetitive...
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...
A fundamental materials science question is “why and how will this material form?” The experimental,computation, and time resources necessary to answer this question consume significant resources due to the
predominantly trial-and-error based approaches common in materials research. This dissertation reintroduces
a number of fundamental thermodynamics-based tools for the study of...
The extracellular matrix (ECM) is a masterwork of biology, and its development was a key part of the transformation from monocellular to multicellular life. With an ECM, cells acquired the ability to cooperatively build a dynamic support network that facilitated their movement, specialization, and communication. This ECM is a hierarchical...
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....
Understanding organization of soft materials on mesoscopic and nanoscopic scales is importantfor materials design. In this regard, non-van der Waals interactions such as hydrogen
bonding and electrostatic interactions offer great opportunities due to the richness and diversity
in morphological structures they produce. The primary reason for this is that these...
Protein-based biomaterials are widely used in biomedical applications and mechanical support because of their novel structural flexibility, biocompatibility and mechanical properties. Protein-based biomaterials outperform traditional synthetic materials in various environments as traditional materials lack the diverse chemical functionalities that proteins offer. Novel bioinspired techniques such as directed evolution offer the...
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...
The demand for low cost, unconventional electronics requires new materials with unique characteristics that the traditionally used silicon-based technologies cannot provide. Metal oxide semiconductors, such has amorphous indium gallium zinc oxide (a-IGZO), have made impressive strides as alternatives to amorphous silicon for electronics applications. However, to achieve the full potential...
There is no group of materials as diverse, complex, and ubiquitous as polymers. From plastic bags, to rubber tires, electronics, food packaging, water filtration and even aerospace applications, the penetration of polymer materials into all aspects of life make them very important materials throughout all engineering fields. However, this breadth...
Low-dimensional materials have emerged as a promising platform for ultrathin electronic and optoelectronic devices. The span of electronic properties covers the spectrum from metallic through small and medium bandgap semiconductors to large bandgap insulators, providing all the necessary components to fabricate a variety of devices. Compared to bulk-semiconductor based devices,...
Metal–Organic Frameworks (MOFs) is a class of material comprising organic linkers and inorganic, metal-ion-containing nodes, with diverse functionalities and wide-range of applications. Because of their porous nature and functional nodes and linkers, they are competent candidates for gas storage, separation, catalysis, and so on. Most MOFs, however, are intrinsically insulating,...
Mixed-dimensional heterojunctions between two-dimensional (2D) materials and organic semiconductors is a rapidly growing field. This is motivated by the promise of leveraging the extraordinary properties of 2D materials with the synthetic tunability and reconfigurability of organic electronics, allowing the realization of new physics or devices that are not possible in...
Thermoelectric materials are of particular interest in a variety of fields because of their ability to directly convert heat to electricity (and vice versa), however, they struggle to gain widespread adoption because of their low efficiency. A common strategy in the field of thermoelectricity is to introduce material defects into...
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...
The advancement of nanotechnology is at least partially dependent on the ability to synthesize and arrange complex nanostructures on a substrate. Nanolithography, or the patterning of materials at the sub-micrometer length-scale, has been traditionally performed using a number of methods such as conventional photolithography, ion-beam etching, and electron-beam lithography. While...
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....
Over 10 billion tons of concrete are produced for the construction industry every year, making concrete the second most used substance on Earth, only surpassed by water. With such high importance as a building material, there is significant need for the ability to accurately model concrete behavior. As a quasi-brittle...
Renewable energy technology, more so than ever before, is critical to the survival of humanity. For decades, concentrated efforts into designing and developing such novel devices resulted in the innovation of solar-driven photovoltaics that were competitive with nonrenewable alternatives. This thesis explores the dynamic behavior of alternative material candidates that...
Since its introduction as an artist’s pigment in the earth 20th century, titanium white has become one of the most common white pigments. The early formulations of titanium white contained anatase, which has been studied to facilitate degradation of oil paint under UV illumination. Around the 1940s production shifted to...
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...
The development of functional materials with rationally designed hierarchical structure is an interdisciplinary challenge. Looking to nature for inspiration, we use small molecules that
engage in directed self-assembly through carefully tuned intermolecular interactions to construct
materials that have structure at multiple length scales. In this work, supramolecular structures
formed using...
NiTi shape memory alloy (SMA) has drawn a great deal of attention for its various applications in the medical field (orthodontics, cardiovascular stents technology, etc.) and in other engineering fields (aerospace, aircraft, automotive, etc.) as it shows shape memory effect, superelasticity and biocompatibility. The fatigue-related issues, however, are pronounced in...
Large scale adoption of sustainable technologies for energy productionand storage can be greatly facilitated by scientific advances impacting efficiency, cost and availability. The study of materials is instrumental in both upgrading the performance of existing technologies and enabling the development of new ones, and ab-initio methods and machine learning represent...
The high-temperature oxidation/reduction behaviors of iron and its oxides are important to a variety of energy conversion and storage technologies, such as the solid-oxide iron-air battery and chemical looping combustion. The useful lifetime of iron redox materials is limited, however, by structural degradation arising from (i) sintering, accelerated by phase...
High performance polymers and their composites have wide ranging application in advanced and emerging material systems. The macroscale performance of these advanced materials is often defined by interfaces that induce nanoscale changes in the microstructure or molecular conformations (termed the ‘interphase’) of the polymer. Atomic force microscopy (AFM) is an...
Engineering responses of soft materials at hierarchical time and length scales is of great interest to both fundamental science and technological applications. In recent years, the hybridization between emerging soft condense matters and conventional hard condense matters keeps enriching the materials library of humankind and opens another largely-uncharted venue for...
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...
Solid acid fuel cells confer unique advantages over nearby technologies, such as polymer electrolyte membrane fuel cells (PEMFCs) or solid oxide fuel cells (SOFCs), due to the solid acid electrolyte – a solid-state, anhydrous, intermediate-temperature proton conductor.Despite these encouraging unique properties, solid acid fuel cells have performed unfavorably in comparison...
In the face of a changing climate caused by anthropomorphic release of carbon dioxide and other greenhouse gases, major governments have committed to the reduction of CO2 and other emissions over time, requiring increased reliance on forms of carbon-free renewable energy. The inherent intermittency of renewable electricity sources creates a...
Wireless power strategies are critical to system level implementation of bio-integrated devices. To achieve mechanically robust, manufacturable systems, batteries are often integrated as an on-board power source to support sensing, wireless communication and signal conditioning. Unfortunately, most sources of battery power use hazardous and environmentally harmful materials, which frustrate incorporation...
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...
Solid oxide fuel and electrolysis cells (SOFCs and SOECs) must be engineered with the entire lifetime of their performance in mind. Electrochemical activity will decrease as degradative processes take effect, leading to higher overpotentials and decreased power outputs. Materials science and engineering can stave off these inefficiencies through an understanding...
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...
Conventionally cross-linked polymers, which comprise the vast majority of commercial thermosets, cannot be decross-linked after curing or flow upon heating. Therefore, they cannot be effectively recycled into high-value products at end-of-life. Their lack of recyclability is due to the permanent cross-links, which restrict the flow of the chains in the...
The relationship between the structure and function of proteins is a fundamental problem in biology with implications for the future of biotechnology and global health. For example, changes to the structure of a coronavirus spike protein led to a global pandemic where our best defenses were vaccines that could only...
The effect of Alkali-Silica Reaction (ASR) on concrete mechanical behavior and the multi-physics considerations that come along are highly complex. Hydration and other chemical reactions occur at the micrometer scale. Hygro-thermal phenomena and concrete cracks due to ASR are typically studied at the meso-scale, i.e. at the aggregate level. At...
The on-going demand for miniaturized optical and on-chip photonic systems of the future has led to a few potential solutions in the literature. Recent advances in van der Waals and 2-dimensional materials signal a bright future for the next generation, compact electronic and photonic devices. With reduced dimensionality and material...
Ordered arrays of metallic nanoparticles (NPs) are a promising platform for technological applications and fundamental investigations due to their ability to excite surface lattice resonances (SLRs). SLRs can support extremely high local electric fields that have been used to realize exotic physical phenomena. The open cavity architecture lends itself to...
This dissertation explores ways to utilize physical parameters at the nanoscale interface to control the properties of mixed-dimensional heterojunctions (MDHJs). MDHJs combine the desirable properties of different classes of low-dimensional nanomaterials (materials that are quantum confined in at least one dimension). While MDHJs have achieved superlative performance for a variety...
As conventional electronic materials approach the device scaling limits, new types of materials and structures have been examined for potential use in future electronic and optoelectronic applications including transistors, light emitting diodes, and solar cells. In recent years, atomically thin or two-dimensional (2D) transition metal dichalcogenide (TMD) materials have emerged...
Dental enamel is a complex bio-composite with compositional and structural features across a wide range of length scales. Defects in these features can compromise enamel’s ability to protect the tooth, resulting in adverse health outcomes. Acquired defects like tooth decay are familiar to most people and are the subject of...
Recent developments have enabled L12-strengthened Co-based superalloys, which have thepotential to surpass Ni-based superalloys as the material of choice for the hottest sections of turbine
blades due to cobalt’s 40 ºC higher melting point. The most-studied branch of Co-based
superalloys are based on the L12 phase Co3(Al,W); however, there is...
Physiochemical phenomena in aqueous systems, such as corrosion, catalysis, and energy storage, are driven by the molecular-scale interactions of ionic species with charged solid surfaces. In particular, an electrical double layer (EDL) of ions forms within nanometers of a charged surface. The properties of the EDL have been explored from...
This thesis focuses on identifying structure-property-performance relationships in supported nanoparticle catalysts, where an active catalyst material is supported on a high surface area substrate. Identifying these relationships in supported nanoparticle catalysts can be quite challenging, as the complex structure of these catalysts results in numerous potential sources for changes to...
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...
The commercial success of personal computing has led to the rapid creation and proliferation of diverse electronic systems including desktops, laptops, tablets, mobile devices, and embedded systems. For the past five decades, silicon has served as the base material for computing electronics. However, with increasing demand for unconventional electronics (e.g.,...
The continuing increase in atmospheric CO2 to concentrations exceeding 400 ppm has attracted considerable attention from both scientists and policymakers. Industrial fossil fuel consumption generates a significant amount of CO2 emissions, and in particular, energy-intensive molecular separations that require thermal processes, such as distillation, drying, or evaporation, are responsible for...
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...
Complex microstructures are ubiquitous in nature. The evolution of these microstructures alters their morphology and topology and thus very often dictates material properties, such as mechanical, electronic, thermal, and magnetic properties. Thus, in order to predict and control material properties, it is essential to have robust and efficient techniques to...
Atomistic methods offer a powerful set of tools in the study of materials systems, as they allow materials scientists to ask questions with a high degree of specificity. They are well suited for studying and designing energy materials, critical due to the climate crisis, in part due to their ability...
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...
The effect of interfaces in solids on the overall charge transport properties has become a topic of growing importance for energy materials such as thermoelectrics. In some polycrystalline thermoelectric materials, the performance near room temperature is significantly limited due to thermally-activated electrical conductivity near room-temperature, which can be attributed to...
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...
Heteroanionic materials are a class of materials of interest for their unique and tunable electronic, ionic, thermal, and optical properties, which are distinct from their homoanionic counterparts due to their multi-anionic nature. Oxynitrides, a type of heteroanionic material, are useful catalysts due to the effect of mixing oxygen and nitrogen...
Given directives such as the UN Global Goals targeting sustainable development, the research presented herein makes but a small contribution to the advancement of alternative energy technologies. Nevertheless, the present work was largely motivated to address specific points of intrigue within the thermoelectrics community. The general principles demonstrated, however, may...
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...
Two-dimensional (2D) hybrid halide perovskites have been the response to their exciting but woefully unstable 3D counterparts. These 2D perovskites have been shown to have respectable stabilities as photovoltaic absorbers, yet they lag behind the 3D perovskites in terms of efficiency. With the need to catch up to the efficiencies...
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...
Directional freeze-casting is a porous materials fabrication technique that is used to create materials with complex, three-dimensional pore structures. Particle suspensions are solidified under a thermal gradient, promoting anisotropic growth of dendrites and incorporation of particles within interdendritic space. A fully-solidified directional freeze-cast structure is composed of dendrites that are...
Biomineralization relies on the regulation of localized environments to control how minerals are formed. Through the use of confinement and specific additives, the organism is able to change the energy landscape of nucleation and growth to build single crystals with unusual morphologies. In order to better understand the environments in...
A framework is developed that models point defect diffusion and interaction with pre-existing microstructures during irradiation, including defect-defect interactions and defect sinks. This framework uses a modified diffusion potential that includes not only defect concentration, but also intrinsic stresses from the pre-existing microstructure. Various microstructures are studied in {Fe} by...
Dendritic microstructures form during the solidification of a variety of metal parts, from traditionally cast engine blocks to 3D-printed specialty tooling. These dendrites can evolve through growth, coarsening, fragmentation, and the formation of a Columnar-to-Equiaxed Transition (CET), which all can greatly affect material properties. However, the basic science behind these...
The highly flexible nature of 2D materials has led to them becoming fundamental building blocks for achieving novel device physics and potential breakthroughs in practical technologies. 2D layers can be interfaced in a wide array of methods with themselves, other 2D layered materials, or materials of entirely different type or...
Non-planar and curved architectures of otherwise flat 2D materials present an important paradigm for nanoscale analysis and design of emergent material properties. Atomically-thin transition metal dichalcogenides (TMDs) have emerged at the forefront of the 2D materials field in recent years largely due to their attractive and tunable chemical, optical, and...
Herein, we present an overview of our studies of the morphology, dynamics, and formation of heterogeneous soft matter systems via the emerging technique of liquid phase transmission electron microscopy (LPTEM). This particular subset of materials, more commonly referred to as emulsions, is tremendously commercially and biologically relevant, encompassing applications in...
Interfacial science brings together diverse areas of interest such as electronic materials, quantum materials, bio-membranes and catalysts. In-situ X-ray characterization techniques can be used to understand the assembly of atoms, molecules and supported nanoparticles at interfaces in complex environments. This thesis work focuses on the use of various X-ray characterization...
An extensive set of functional electronic properties depends on the electronic structure. These properties are directly connected to the reciprocal-space representation of electronic structure. However, there is a complementary, real-space perspective that is described by combinations of atomic orbitals. Atomic orbitals are the components of electronic structures, analogous to how...
Modeling the mechanical performance of metal produced with additive manufacturing (AM) has proven to be a challenging task. In the as-built state, these materials have been shown to exhibit strong heterogeneity and anisotropy. Even after post-processing, such as heat treatment or hot isostatic pressing and depending on the alloy, some...
Over the last few years, there has been a transition away from traditional engineering materials to new advanced materials that exhibit complex architectures with improved mechanical properties. Most of the inspiration for these new materials comes from nature, where organisms have evolved an immense variety of macro and nanoscale shapes...
Graphene oxide (GO) is a heavily oxidized version of graphene, which is often made by oxidative chemical exfoliation from graphite powders. The reaction decorates the graphene sheets with oxygen-containing functional groups including hydroxyl and epoxide groups on the basal plane, as well as carboxyl groups on the edge, rendering the...
Structural colors originate from the interaction between the incident light and a surface with periodic submicron structures. They enable the creation of a spectrum of nonfading colors, potentially replacing toxic metal oxides and conjugated organic pigments. However, significant challenges remain, including lack of contrast needed for the complete gamut of...
As more thermoelectric materials/devices make it into the market for various applications, severalaspects need to be explored and optimized, beyond simply targeting high conversion efficiency at
the material levels. One critical aspect is the guarantee of mechanical stability at both the material
and the device level, which demands deeper understanding...
Superalloys strengthened by γ′(L12)-precipitates in γ(f.c.c.)-matrix exhibit superior high temperature mechanical properties and environmental resistance over long periods of operation, making them ideal candidates for aerospace and energy conversion applications. The emerging class of superalloys based on Co-Al-W ternary system was identified with a melting temperature 50-100 ˚C higher than...
The past decade has seen the rapid progress of deep learning, which becomes a game-changing technique in different data-intensive domains, with the availability of large scale data, cost-effective computing hardware and more advanced learning theory and algorithms. Despite of the rapid progress of deep learning methods in daily-life applications, such...
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...
Materials that exist as well-defined individual entities at the nanoscale typically have properties that sets them apart from their bulk form. Consequently, there has been much time and effort invested in developing new well-defined nanoscale entities, but few attempts to assemble them into bulk materials. On the other hand, there...
Melanin is a functional biopolymer most commonly associated with human skin pigmentation, where it serves as a radiation protection agent, shielding us from the harmful effects of UV radiation. However, melanin is also present in human ears, eyes, hair, and brains, serving a variety of functions. In fact, melanin...
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...
Superconductivity is a fascinating manifestation of quantum mechanics on a macroscopic scale that has led to greater insights of the strongly correlated physics of a large number of interacting electrons ever since its discovery $\sim$ 100 years ago in elemental Hg. The unconventional superconductors that are based on uranium offer...
At its core, the purpose of microscopy is to make objects and their underlying structures visible under high magnification. With the remarkable progress of electron microscopy, the sub-micron “high” magnification of light microscopy has been completely refashioned to encompass subatomic length scales. Unfortunately, higher-magnification does little to negate existing interpretability...
Plasmonic nanoparticles have very large absorption cross sections and can concentrate the local density of photon states on the nano scale. When they are coupled to molecules or semiconductor nanocrystals and form different hybrid nanostructures, various light-matter interaction processes can be significantly enhanced or manipulated, including optical responses like fluorescence...
Exploratory phase stability analysis in Materials Science has two primary goals: (a) Characterizing the evolution of the materials single phase field in composition space to identify solubility and electronic dopability limits and (b) Accelerated prediction of new phases of technological importance. In this thesis we reorganize defect theory --- the...
Colloidal crystal engineering with DNA offers new opportunities for materials scientists to build and program the structures of superlattices beyond what can be accomplished in Nature with atomic crystal lattices. Thus far, such materials primarily have been studied for their optical properties due to the insulating nature of the DNA...
The crystal structure of chalcogenides can vary from simple, ubiquitous structures of rock salt and zinc blende to unique structure types from the intricate packing of complex anionic building blocks. Exploratory synthesis and structural studies of novel chalcogenides containing these complex anions will augment the understanding of bonding in chalcogenides....
The era of quantum information science (QIS) can usher revolutionary new capabilities ranging from quantum computation to quantum sensing. At the core of these technologies is the fundamental unit of QIS, the quantum bit or qubit. The power of qubits over their classical counterparts lies in their ability to be...
Two-step, solar thermochemical water splitting using nonstoichiometric oxides has emerged as an attractive approach for large-scale hydrogen production. Perovskite-structured oxides, with their wide tunability, offer the potential for high fuel productivity at moderate operating temperatures. Given the vast chemical space, the materials development effort is carried out here in combination...
The heart of computational materials science lies in providing fundamental insights and understanding of materials behavior and properties across different scales. The significance of this task is highlighted by the Materials Genome Initiative and the emergence of computational tools and frameworks such as materials by design, microstructure sensitive design, and...
The successful isolation of graphene marked the advent of two-dimensional (2D) materials. Their atomically thin structures enable unprecedented electrical, optical, and mechanical properties, which have triggered significant research interests in the past decade. For instance, they are promising candidates for the fabrication of flexible electronics, biological sensors, battery electrodes, and...
Sea urchins are virtuosi of biomineralization, the process by which organisms build mineralized tissues. The embryonic animal exemplifies this with the formation of its endoskeletal spicule. The primary mesenchyme cells (PMCs) undertake spicule synthesis, which involves deposition of the initial granule, elongation of the spicule, and several choreographed changes...
A series of theories and models are developed and used to investigate the growth of protective oxide films on metal and alloy surfaces for cases in which Wagner's classical model of oxidation does not hold. First, irreversible thermodynamics is applied to formulate a model for the outward growth of rocksalt...
Nucleic acids not only are the building blocks of life but also a class of attractive macromolecular therapeutics. However, the delivery of therapeutic oligonucleotides into cells has been a major challenge due to their large size and highly negatively charged backbone. Spherical nucleic acids (SNAs) are a class of emerging...
Part I: Design of Photo-Responsive Molecules towards Biomedical ApplicationsThe use of light to control systems provides numerous advantages such as spatiotemporal precision, non-invasive penetration, and precise energy input. Specifically, molecules that undergo photoinduced cleavage, photoremovable protecting groups (PPGs) have emerged as an active area of research due to their broad...
Non-covalent and ion-specific interactions in the context of charged polymers are ubiquitous in nature and in synthetic applications. For example, mussels utilize metal-coordinate bonds to form tough underwater adhesion to a wide range of substrates. The sandcastle worm uses coacervation of oppositely charged polymers to build robust structures for self-defense....
Surface patterns that can reconfigure under external stimuli are important for tailoring diverse properties such as surface adhesion, optical transmittance, and wettability depending on the feature size and orientation. Wrinkling a stiff skin layer on a pre-strained elastomer substrate has emerged as a method to create responsive structures without using...
The complex structure of typical heterogeneous catalysts, where nanoparticles of active material are dispersed onto the surface of a thermally stable support with a high surface area, complicates the understanding of how the support can affect the resulting catalyst structure and properties. Using well-faceted and shape-controlled oxides as supports would...