A5061436534- Advanced biosensing and bioanalysis techniques
- Polymer Nanocomposites and Properties
- Material Properties and Applications
- Material Dynamics and Properties
- DNA and Biological Computing
- Phase Equilibria and Thermodynamics
- Rheology and Fluid Dynamics Studies
- Carbon Nanotubes in Composites
- Molecular Junctions and Nanostructures
- Supramolecular Self-Assembly in Materials
- Graphene and Nanomaterials Applications
- Gold and Silver Nanoparticles Synthesis and Applications
- Modular Robots and Swarm Intelligence
- Polymer crystallization and properties
- Nanocluster Synthesis and Applications
- Advanced Theoretical and Applied Studies in Material Sciences and Geometry
- Nanopore and Nanochannel Transport Studies
- Bone Tissue Engineering Materials
- Nanoparticle-Based Drug Delivery
- Architecture and Computational Design
- Polymer Nanocomposite Synthesis and Irradiation
- Elasticity and Wave Propagation
- RNA Interference and Gene Delivery
- Material Science and Thermodynamics
- Design Education and Practice
Columbia University
2019-2025
Wesleyan University
2016-2021
Sharif University of Technology
2012
Controlled colloid bonding using DNA Colloidal particles can act as analogs of atoms for studying crystallization and packing behavior, but they don't naturally bond together the way do. Short strands are one versatile to link colloidal (see Perspective by Tao). Kim et al. designed a series gold colloids with ligands that reversibly bound or released neighboring via opened closed hairpin loops. Liu devised set pack into origami structures. Inside each structure were cage nanoparticle. These...
Advances in nanoscale self-assembly have enabled the formation of complex architectures. However, development strategies toward bottom-up nanofabrication is impeded by challenges revealing these structures volumetrically at single-component level and with elemental sensitivity. Leveraging advances nano-focused hard x-rays, DNA-programmable nanoparticle assembly, inorganic templating, we demonstrate nondestructive three-dimensional imaging complexly organized nanoparticles multimaterial...
Reduced graphene oxide nanoribbons functionalized by amphiphilic polyethylene glycol (rGONR–PEG) were applied to attach arginine-glycine-aspartic acid (RGD)-based peptide and cyanine dye 3 (cy3) for targeting ανβ3 integrin receptors on human glioblastoma cell line U87MG its selective fluorescence imaging, respectively. The rGONR–PEG suspension with a concentration of 100 μg mL−1 showed ∼14 2.4-fold higher near infrared (NIR) absorption at 808 nm than GONR (with dimensions ∼80 × 1 μm) rGO–PEG...
Using molecular simulations on model polymer nanocomposites at fixed filler loading, we show that interfacial dynamics are affected less with decreasing nanoparticle (NP) size. However, the glass transition temperature ${T}_{g}$ changes substantially more for an extremely small NP. The reason this apparent contradiction is mean NP spacing decreases particle Thus, all polymers effectively sufficiently NPs, resulting in relatively large shifts, even though effects smaller. For larger...
Engineering the assembly of nanoscale objects into complex and prescribed structures requires control over their binding properties. Such might benefit from a well-defined bond directionality, ability to designate engagements through specific encodings, capability coordinate local orientations. Although much progress has been achieved in our design nano-objects, challenges creating such nano-objects with fully controlled modes understanding fundamental properties are still outstanding. Here,...
While glass formation of linear chain polymer melts has widely been explored, comparatively little is known about in star melts. We study the segmental dynamics via molecular simulations and examine cooperative nature motion In particular, we quantify how architecture polymers, i.e., number arms length those arms, affects transition temperature Tg, non-Gaussian displacements, collective string-like monomers, role connectivity motion. Although varying f mass Ma can significantly influence...
We perform coarse-grained simulations of model unentangled polymer materials to quantify the range over which interfaces alter structure and dynamics in vicinity interface. study interfacial zone around nanoparticles (NPs) polymer-NP composites with variable NP diameter, as well at solid substrate free surface thin supported films. These both segmental packing mobility an zone. Variable size allows us gain insight into effect boundary curvature, where film is limit zero curvature. find that...
The ability to fabricate materials and devices by-design at small scales, largely based in advances lithographic additive manufacturing methods, has led the tremendous technological progress of last decades. However, growing need structure 3D nanoscale matter for emergent functions, according design a massively parallel manner, requires new means material fabrication. Here, we demonstrate concept experimental realization encoded assembly nanoparticles into prescribed, hierarchically ordered...
The modification of interfacial polymer behavior is one the primary sources property modifications polymer–nanoparticle (NP) composites (PNC). For strongly favorable interactions, large NPs exhibit a "bound" layer which has much longer relaxation time than surrounding matrix. difference between bound and matrix decreases as NP size decreases. Using molecular simulations, we explore degree to structure, thus properties, depends on NP. We find that for larger NPs, chains orient with their...
We use molecular dynamics simulations to study how the chain length affects structure and segmental of polymer–nanoparticle (NP) composites at semidilute NP concentrations. For NPs having relatively strong interactions with polymer, we can approximate system as an ideal dispersion, which isolates effect direct among NPs. By varying both N concentration, examine regimes where size (i.e., radius gyration Rg) is small compared separation d (d/Rg > 1), well cases d/Rg < 1, so that chains readily...
Recent studies have demonstrated novel strategies for the organization of nanomaterials into three-dimensional (3D) ordered arrays with prescribed lattice symmetries using DNA-based self-assembly strategies. In one approach, nanomaterial is sequestered DNA origami frames or "material voxels" and then coordinated based on voxel geometry corresponding directional interactions its valency. While symmetry defined by valency bonds, a larger-scale morphological development affected assembly...
The functionalization of nanoparticles (NPs) with DNA has proven to be an effective strategy for self-assembly NPs into superlattices a broad range lattice symmetries. By combining this the origami approach, possible structures have been expanded include cubic diamond lattice. This symmetry is particular interest, both due inherent synthesis challenges, as well potential valuable optical properties, including complete band-gap. Using these lattices in functional devices requires robust and...
The motion of NPs masks the bound layer relaxation time signal in intermediate scattering function.
The ability to fabricate materials and devices by-design at small scales, largely based in advances lithographic additive manufacturing methods, has led the tremendous technological progress of last decades. However, growing need structure 3D nanoscale matter for emergent functions, according design a massively parallel manner, requires new means material fabrication. Here, we demonstrate concept experimental realization encoded assembly nanoparticles into prescribed, hierarchically ordered...