A5000228134- Graphene research and applications
- Pickering emulsions and particle stabilization
- Photonic Crystals and Applications
- Additive Manufacturing and 3D Printing Technologies
- Advanced Sensor and Energy Harvesting Materials
- Graphene and Nanomaterials Applications
- Advanced Materials and Mechanics
- Slime Mold and Myxomycetes Research
- Carbon and Quantum Dots Applications
- Nanomaterials and Printing Technologies
- Bone Tissue Engineering Materials
- Supramolecular Self-Assembly in Materials
- Innovative Microfluidic and Catalytic Techniques Innovation
- Nanowire Synthesis and Applications
- Calcium Carbonate Crystallization and Inhibition
- Additive Manufacturing Materials and Processes
- Advancements in Battery Materials
- Injection Molding Process and Properties
- Polymer composites and self-healing
- Biocrusts and Microbial Ecology
- 3D Printing in Biomedical Research
- Nanofabrication and Lithography Techniques
- 2D Materials and Applications
- Spectroscopy and Laser Applications
- Nonlinear Optical Materials Studies
Singapore University of Technology and Design
2022
Massachusetts Institute of Technology
2018-2021
Northwestern University
2010-2014
Graphene oxide (GO) nanocolloids-sheets with lateral dimension smaller than 100 nm-were synthesized by chemical exfoliation of graphite nanofibers, in which the graphene planes are coin-stacked along length nanofibers. Since upper size limit is predetermined diameter nanofiber precursor, distribution GO nanosheets much more uniform that common from powders. The can be further tuned oxidation time. Compared to micrometer-sized, regular sheets, nano has very similar spectroscopic...
Oxidative etching of graphene flakes was observed to initiate from edges and the occasional defect sites in basal plane, leading reduced lateral size a small number etch pits. In contrast, highly defective oxide its form resulted rapid homogeneous fracturing sheets into smaller pieces. On basis these observations, slow more controllable route designed produce nanoporous by hydrothermal steaming at 200 °C. The degree concomitant porosity can be conveniently tuned time. contrast nonporous...
Abstract Colloidal assembly is an attractive means to control material properties via hierarchy of particle composition, size, ordering, and macroscopic form. However, despite well‐established methods for assembling colloidal crystals as films patterns on substrates, within microscale confinements such droplets or microwells, it has not been possible build freeform crystal structures. Direct‐write assembly, a process combining the bottom‐up principle self‐assembly with versatility...
Reconfigurable metamaterials require constituent nanostructures to demonstrate switching of shapes with external stimuli. Yet, a longstanding challenge is in overcoming stiction caused by van der Waals forces the deformed configuration, which impedes shape recovery. Here, we introduce stiff memory polymers. This designer material has storage modulus ∼5.2 GPa at room temperature and ∼90 MPa rubbery state 150 °C, 1 order magnitude higher than those previous reports. Nanopillars diameters ∼400...
Abstract Materials made by directed self‐assembly of colloids can exhibit a rich spectrum optical phenomena, including photonic bandgaps, coherent scattering, collective plasmonic resonance, and wave guiding. The assembly colloidal particles with spatial selectivity is critical for studying these phenomena practical device fabrication. While there are well‐established techniques patterning crystals, often require multiple steps the fabrication physical template masking, etching, stamping, or...
To translate the exceptional properties of colloidal nanoparticles (NPs) to macroscale geometries, assembly techniques must bridge a 10 6 ‐fold range length. Moreover, for successfully attaining final mechanically robust nanocomposite material, some intrinsic NPs’ have be maintained while minimizing density strength‐limiting defects. However, nanoscale building blocks into macroscopic dimensions, and their effective properties, are inherently affected by precision conditions required...
Fluorescence quenching microscopy (FQM) is demonstrated as a low-cost and high-throughput technique for seeing graphene-like 2D sheets such MoS2. FQM provides high contrast layer resolution comparable to those of scanning electron microscopy, but allows the imaging samples deposited on arbitrary substrates, including non-conductive substrates quartz. Solution fluorescence studies suggest that should be feasible many other materials WS2, Bi2Te3, MoSe2, NbSe2, TaS2.
Fluorescence quenching microscopy (FQM), an optical technique originally developed for imaging graphenebased sheets on arbitrary substrates is extended by J. Huang and co-workers page 3253 to other two-dimensional materials, such as molybdenum disulfide (MoS2) (background image). The panels in the main image are MoS2 flakes imaged reflectance mode (left), FQM (middle), scanning electron (right).
Evaporative self-assembly of semiconducting polymers is a low-cost route to fabricating micrometer and nanoscale features for use in organic flexible electronic devices. However, most cases, rate limited by the kinetics solvent evaporation, it challenging achieve uniformity over length- time-scales that are compelling manufacturing scale-up. In this study, we report high-throughput, continuous printing poly(3-hexylthiophene) (P3HT) modified doctor blading technique with oscillatory meniscus...
Nanoporous silicon (NPSi) can be used in a wide range of applications including nanofiltration, thermoelectrics, photovoltaics, and catalysis. Metal-assisted chemical etching (MACE) is an electrochemical, solution-based NPSi fabrication process that relies on control over catalyst deposition to obtain the desired porous structure. In this paper, blade-casting explored as template-free, self-assembly technique for MACE catalyst. Mixtures silica (SiO2) gold-core silica-shell nanoparticle...
3D printing is used to self-assemble surface-functionalized nanoparticles into supercrystalline macrostructures. The obtained columns feature high strength, favorably comparing hierarchical composite materials, known for their exceptional mechanical properties. Further details can be found in the article, number 2000352, by A. John Hart, Gerold Schneider and co-workers.
We investigate the initiation of cracks in vertically freestanding water-saturated colloidal pillars constructed using a direct-write technique. Paradoxically, form during drying at free end, far from substrate, where particle network is unconstrained contracting its volume as it bears compression by uniform capillary pressure acting outer surface. This explained dominant balance wetting energy terms, which follows simple relationship between size and pillar dimensions that captures presence...
Reconfigurable metamaterials require constituent nanostructures to demonstrate switching of shapes with external stimuli. For generality, such would touch and stick other surfaces in one its configurations. Yet, a longstanding challenge is overcoming this stiction caused by Van der Waals forces, which impedes shape recovery. Here, we introduce stiff yet self-recovering material system based on acrylic acid, tested it high-aspect ratio structures, where recovery weak. This designer has...