A5007355000- Boron and Carbon Nanomaterials Research
- Semiconductor Quantum Structures and Devices
- Graphene research and applications
- Pickering emulsions and particle stabilization
- Material Dynamics and Properties
- Advanced Semiconductor Detectors and Materials
- Carbon Nanotubes in Composites
- MXene and MAX Phase Materials
- Cellular Mechanics and Interactions
- Fullerene Chemistry and Applications
- Surfactants and Colloidal Systems
- Force Microscopy Techniques and Applications
- High Entropy Alloys Studies
- High-Temperature Coating Behaviors
- Theoretical and Computational Physics
- Chalcogenide Semiconductor Thin Films
- Liquid Crystal Research Advancements
- Advanced Polymer Synthesis and Characterization
- Quantum Dots Synthesis And Properties
- Thermal properties of materials
- Diamond and Carbon-based Materials Research
- nanoparticles nucleation surface interactions
- Advanced Theoretical and Applied Studies in Material Sciences and Geometry
- Silicon Nanostructures and Photoluminescence
- Advanced Materials and Mechanics
National Research Council Canada
2002-2024
University of Illinois Urbana-Champaign
1977-2013
University of Massachusetts Amherst
2009-2012
Syracuse University
2007-2008
National Academies of Sciences, Engineering, and Medicine
2000-2003
Institute for Microstructural Sciences
2000
Jeonbuk National University
1995-1997
Advances in the synthesis and scalable manufacturing of single-walled carbon nanotubes (SWCNTs) remain critical to realizing many important commercial applications. Here we review recent breakthroughs SWCNTs highlight key ongoing research areas challenges. A few applications that capitalize on properties are also reviewed with respect ways which science can enable advances these While primary focus this is framework SWCNT growth, draw connections mechanisms underlying other 1D 2D materials...
We study the organization of topological defects in a system nematogens confined to two-dimensional sphere (S2). first perform Monte Carlo simulations fluid hard rods (spherocylinders) living tangent plane S2. The is adiabatically compressed until we reach jammed nematic state with maximum packing density. exhibits four +1/2 disclinations arrayed on great circle. This arises from high elastic anisotropy which splay (K1) far softer than bending (K3). also introduce and lattice model S2...
Boron nitride nanotubes (BNNTs) exhibit a range of properties that hold great potential for many fields science and technology; however, they have inherently low chemical reactivity, making functionalization specific applications difficult. Here we propose covalent BNNTs via reduction chemistry could be highly promising viable strategy. Through density functional theory calculations the electron affinity their binding energies with various radicals, reveal reactivity can significantly...
Abstract High-entropy alloy (HEA) nanoparticles (NPs) exhibit unusual combinations of functional properties. However, their scalable synthesis remains a significant challenge requiring extreme fabrication conditions. Metal salts are often employed as precursors because low decomposition temperatures, yet contain potential impurities. Here, we propose an ultrafast (< 100 ms), one-step method that enables the continuous HEA NPs directly from elemental metal powders via in-flight alloying. A...
Recent experiments on vesicles formed from block copolymers with liquid-crystalline side chains reveal a rich variety of vesicle morphologies. The additional internal order ("structure") developed by these self-assembled copolymer can lead to significantly deformed as result the delicate interplay between two-dimensional ordering and shape. inevitable topological defects in structured spherical topology also play an essential role controlling final morphology. Here we develop minimal...
We recently demonstrated scalable manufacturing of boron nitride nanotubes (BNNTs) directly from hexagonal BN (hBN) powder by using induction thermal plasma, with a high-yield rate approaching 20 g/h. The main finding was that the presence hydrogen is crucial for growth BNNTs. Here we investigate detailed role numerical modeling and in situ optical emission spectroscopy (OES) reveal both thermofluidic fields chemical pathways are significantly altered favor rapid simulation indicated...
We study the rich crystalline phase behavior of amphiphilic spherical Janus colloids using a new formulation self-consistent phonon theory that includes coupled translational and rotational entropic enthalpic contributions to free energy. In contrast homogeneous spheres, broken symmetry can result in more exotic crystals possess distinct orientational patterns, also plastic crystals. Ground states are identified based on compatibility between patch geometry particles (e.g., coverage, number,...
High-purity semiconducting single-walled carbon nanotubes (sc-SWCNTs) are promising for portable and high-sensitivity gas sensors because of their excellent physical electrical properties. Here, we describe the synthesis a novel indigo-fluorene-based copolymer (PFIDBoc) that has been designed to selectively enrich sc-SWCNTs with purity (>99.9%) yet contain latent function in form tert-butoxy (t-BOC)-protected amine can be later revealed exploited dioxide (CO2) sensing. SWCNTs wrapped PFIDBoc...
Solid-state electrolyte batteries are expected to replace liquid lithium-ion in the near future thanks their higher theoretical energy density and improved safety. However, adoption is currently hindered by lower effective ionic conductivity, a quantity that governs charge discharge rates. Identifying highly ion-conductive materials using conventional calculations experimental validation both time-consuming resource-intensive. While machine learning holds promise expedite this process,...
Polymer characteristics influence the chiral selectivity and yield in enrichment of (7,6) from Signis SG76 toluene by various fluorene homopolymers copolymers. Fluorene such as poly(9,9-di-n-dodecylfluorene) (PFDD) copolymers with anthracene poly[(9,9-dihexylfluorenyl-2,7-diyl)-co-(9,10-anthracene)] (PFH-A) result high selectivities up to 67 72%, respectively. The is calculated optical absorption using a known extinction coefficient also evaluated Raman scattering photoluminescence...
We examine the mechanism of bundling cytoskeletal actin filaments by two representative proteins, fascin and espin. Small-angle X-ray studies show that increased binding from linkers drives a systematic \textit{overtwist} their native state, which occurs in linker-dependent fashion. Fascin bundles into continuous spectrum intermediate twist states, while espin only allows for untwisted fully-overtwisted bundles. Based on coarse-grained, statistical model protein binding, we interplay between...
Soft spheres interacting via a hard core and range of attractive repulsive 'soft-shoulder' potentials self-assemble into clusters forming variety mesophases. We combine mean-field theory developed from lattice model with level surface analysis the periodic structures soft-sphere aggregates to study stable morphologies for all clustering potentials. develop systematic approach thermodynamics mesophase assembly in low-temperature, strong-segregation predict generic sequence phases including...
Abstract Highly crystalline and few-walled boron nitride nanotubes (BNNTs) had been synthesized by laser ablation using only ammonia borane as a precursor. As molecular precursor, supplied both B N atoms with ratio of 1:1, BNNTs were formed via the homogeneous nucleation BN radicals, not growth from nano-droplets, which is generally accepted mechanism laser-grown BNNTs. Owing to absence amorphous impurities, van der Waals interaction among became effective thus BNNT fibers was spontaneously...
We investigate crystalline order on a two-dimensional paraboloid of revolution by assembling single layer millimeter-sized soap bubbles the surface rotating liquid, thus extending classic work Bragg and Nye planar bubble rafts. Topological constraints require configurations to contain certain minimum number topological defects such as disclinations or grain boundary scars whose structure is analyzed function aspect ratio paraboloid. find defect agree with theoretical predictions propose...
Point defects are ubiquitous in two dimensional crystals and play a fundamental role determining their mechanical thermodynamical properties. When formed on curved background, finite length grain boundaries (scars) generally needed to stabilize the crystal. We provide continuum elasticity analysis of defect dynamics crystals. By exploiting fact that any point can be obtained as an appropriate combination disclinations, we analytical determination elastic spring constants dislocations within...
Increasing attention has been given to amine–copper formate complexes for their use as low-cost printable conductive inks. The structure of amine ligands coordinated copper centers reported dictate the properties molecular inks, such stability and printability, thereby influencing reduction pathway during thermolysis. Yet, underlying mechanism by which is oxidized when complexed with still not fully understood. Here, we propose a mechanistic dehydrogenation decarboxylation examine critical...
Finding the ground states of identical particles packed on spheres has relevance for stabilizing emulsions and a venerable history in literature theoretical physics mathematics. Theory experiment have confirmed that defects such as disclinations dislocations are an intrinsic part state. Here we discuss remarkable behavior vacancies interstitials spherical crystals. The strain fields isolated forced by topology literally rip apart, typically into dislocation fragments combine with to create...
Surface functionalization is an essential step to successfully harness the properties of boron nitride nanotubes (BNNTs) in several applications. Currently available methods are prohibitively costly for commercial use and have significant environmental impacts. Here, we show that a low-pressure, capacitively coupled radio-frequency (RF, 13.56 MHz) glow discharge plasma reactor can be used effectively carry out surface chemical BNNTs. This low-pressure vacuum gas handling system incorporates...
The high-temperature plasma process has demonstrated great potential in growing high-quality boron nitride nanotubes (BNNTs) with small diameters (∼5 nm) and few walls (3-4 walls) led to successful commercialization a high production rate approaching 20 g/h. However, the is still accompanied by of BN impurities (e.g., a-BN, shell, flakes) whose physicochemical properties are similar those BNNTs. This renders post-purification very challenging thus hampers development their practical...
We construct a coarse-grained model of parallel actin bundles crosslinked by compact globular bundling proteins, such as fascin and espin, necessary components filopodial mechanosensory bundles. Consistent with structural observations bundles, we find that the optimal geometry for crosslinking is overtwisted, requiring coherent change helical filaments. study linker-dependent thermodynamic transition bundled filaments from their native state to overtwisted map out ``twist-state'' phase...
Raman spectroscopy has been used to assess the concentration dependence of optical phonons in In1−xGaxAs epilayers grown by chemical beam epitaxy on InP(100). The alloy composition was varied from x=0.325 x=0.55 cover technologically important and physically interesting range where strain changes sign at x=0.468 negative positive. spectra were curve resolved reveal GaAs-like longitudinal optic (LO), disorder induced, InAs-like LO, transverse phonons. An examination phonon frequencies showed...