A5073552964- Advanced NMR Techniques and Applications
- NMR spectroscopy and applications
- Membrane Separation and Gas Transport
- Metal-Organic Frameworks: Synthesis and Applications
- Polymer Nanocomposites and Properties
- Textile materials and evaluations
- Covalent Organic Framework Applications
- Carbon Dioxide Capture Technologies
- Polymer crystallization and properties
- Material Properties and Processing
- Advanced Battery Materials and Technologies
- Crystallization and Solubility Studies
- Material Dynamics and Properties
- Liquid Crystal Research Advancements
- X-ray Diffraction in Crystallography
- Zeolite Catalysis and Synthesis
- Advanced MRI Techniques and Applications
- Graphene research and applications
- Magnetism in coordination complexes
- Rheology and Fluid Dynamics Studies
- Solid-state spectroscopy and crystallography
- Fiber-reinforced polymer composites
- Fullerene Chemistry and Applications
- Identification and Quantification in Food
- Nanopore and Nanochannel Transport Studies
Georgia Institute of Technology
2016-2025
AID Atlanta
2013-2019
Czech Academy of Sciences, J. Heyrovský Institute of Physical Chemistry
2007
Los Alamos National Laboratory
2007
Emory University
2002-2004
Fraunhofer Institute for Biomedical Engineering
1999
Max Planck Institute for Polymer Research
1992-1996
Max Planck Society
1993-1995
Fraunhofer Society
1995
Poly(ethylene furanoate) (PEF), the furan-derived analogue to poly(ethylene terephthalate) (PET), can provide a fully biosourced alternative PET with greatly improved barrier properties and attractive thermal mechanical properties. The for PEF compared is unexpected due higher free volume of vs PET. Segmental motions related penetrant diffusion in both polyesters were studied using dynamic analysis, 13C–CP/MAS solid-state NMR variable contact-time experiments, centerband-only detection...
Here we report that a covalent organic framework (COF), which contains 2,5-di(imine)-substituted 1,4-dihydroxybenzene (diiminol) moieties, undergoes color changes in the presence of solvents or solvent vapor are rapid, passive, reversible, and easily detectable by naked eye. A new visible absorption band appears polar solvents, especially water, suggesting reversible conversion to another species. This reversibility is attributed ability diiminol rapidly tautomerize an iminol/cis-ketoenamine...
Nanoporous zeolitic imidazolate frameworks (ZIFs) form structural topologies equivalent to zeolites. ZIFs containing only one type of imidazole linker show separation capability for limited molecular pairs. We that the effective pore size, hydrophilicity, and organophilicity can be continuously drastically tuned using mixed-linker two types linkers, allowing their use as a more general platform. illustrate this remarkable behavior by adsorption diffusion measurements hydrocarbons, alcohols,...
Abstract Carbon molecular sieve (CMS) membranes have impressive separation properties; however, both chemical and morphology structures need to be understood better. Here we characterize CMS with the simplest polyimide (PI) PMDA/pPDA (PMDA=pyromellitic dianhydride, pPDA= p ‐phenylenediamine), using FTIR, solid‐state 15 N‐NMR 13 C‐NMR, XPS, XRD, Raman spectra study structure. We also compare gas properties for this a derived from more conventional PI precursor. The detailed characterization...
We demonstrate a method for controlled p-doping of the halide perovskite surface using molecular dopants, resulting in reduced non-radiative recombination losses and improved device performance.
We report the synthesis and structure of single-walled aluminosilicate nanotubes with microporous zeolitic walls. This quasi-one-dimensional zeolite is assembled by a bolaform structure-directing agent (SDA) containing central biphenyl group connected C10 alkyl chains to quinuclidinium end groups. High-resolution electron microscopy diffraction, along other supporting methods, revealed unique wall that hybrid characteristic building layers from two types, beta MFI. arises minimization strain...
Supported amines are a promising class of CO2 sorbents offering large uptake capacities and fast rates. Among supported amines, poly(ethyleneimine) (PEI) physically impregnated in the mesopores SBA-15 silica is widely used. Within these composite materials, chain dynamics morphologies PEI strongly influence capture performance, yet little known about macromolecule mobility confined pores. Here, we probe impact support-PEI interactions on structures at support interface corresponding which...
Solid-state cross-linking of elastin−mimetic fibers was investigated. Through available lysine residues, an protein polymer, poly((Val-Pro-Gly-Val-Gly)4(Val-Pro-Gly-Lys-Gly))39, modified to incorporate acrylate moiety. The degree functionalization could be varied by changing the reactant ratio anhydride elastin. Acrylate elastomeric (AME) proteins were associated with lower inverse transition temperatures than unmodified recombinant protein. temperature in turn dictated for fiber formation....
Rising atmospheric CO2 levels have triggered recent research into the science of amine materials supported on hard, porous such as mesoporous silica or alumina. While can give high uptakes and good sorption kinetics, they are difficult to utilize in practical applications due difficulty contacting large volumes CO2-laden gases with powder without significant pressure drops sorbent attrition. Here, we describe a simple approach based impregnation permanently microporous polymer, PIM-1,...
Abstract Solid‐supported amines having low molecular weight branched poly(ethylenimine) (PEI) physically impregnated into porous solid supports are promising adsorbents for CO 2 capture. Co‐impregnating short‐chain poly(ethylene glycol) (PEG) together with PEI alters the performance of adsorbent, delivering improved amine efficiency (AE, mol sorbed/mol N) and faster uptake rates. To uncover physical basis this gas capture performance, we probe distribution mobility polymers in pores via...
Investigations of high molecular weight recombinant protein triblock copolymers demonstrate unique opportunities to systematically modify material microstructure on both nano- and meso-length scales in a manner not been previously demonstrated for polymer systems. Significantly, through the biosynthesis BAB-type containing flanking, plastic-like end blocks an elastomeric midblock, virtually cross-linked protein-based materials were generated that exhibit tunable properties completely...
Abstract Low‐melting‐point solid‐state electrolytes (SSE) are critically important for low‐cost manufacturing of all‐solid‐state batteries. Lithium hydroxychloride (Li 2 OHCl) is a promising material within the SSE domain due to its low melting point (mp < 300 °C), cheap ingredients (Li, H, O, and Cl), rapid synthesis. Another unique feature this compound presence Li vacancies rotating hydroxyl groups which promote Li‐ion diffusion, yet role protons in ion transport remains poorly...
Effective drug delivery in brain tumors remains a major challenge oncology. Although local hyperthermia and stimuli-responsive systems, such as thermosensitive liposomes, represent promising strategies to locally enhance solid improve outcomes, their application intracranial malignancies unexplored. We hypothesized that the combined abilities of closed-loop trans-skull Magnetic Resonance Imaging guided Focused Ultrasound (MRgFUS) with those drugs can alleviate challenges survival gliomas....
Polymers of intrinsic microporosity (PIMs) are attractive materials for gas adsorption due to their high surface area and interconnected microporosity. However, the low CO2 affinity PIM-1 results in only a small amount physisorbed CO2, making addition higher species, such as basic amines, requirement use dilute applications. This has been previously accomplished by trapping added amines polymer pores, with deleterious consequences transport, regeneration energy, amine loss. To address these...
The highest sheet symmetry form of graphyne, with one triple bond between each neighboring hexagon in graphene, irreversibly transforms exothermically at ambient pressure and low temperatures into a nongraphitic, planar-sheet, zero-bandgap phase consisting intrasheet-bonded sp2 carbons. synthesis this carbon is demonstrated, other phases are described for possible future from graphyne without breaking bonds. While measurements theory indicate that the reacting becomes nonplanar because...
A cell-based theranostic system can be fabricated by attaching nanomedicines to the surface of carrier cells, but it remains a challenge achieve attachment without involving endocytosis. Herein, we address this developing multifunctional Janus nanoparticles with orthogonal properties for two opposite halves. When incubated hydrophobic half made polystyrene readily inserts into plasma membrane, whereas hydrophilic SiO2 grafted poly(ethylene glycol) protrudes away from cell surface....
In a search for biomarkers of health in whale sharks and as exploration metabolomics modern tool understanding animal physiology, the metabolite composition serum six (Rhincodon typus) from an aquarium collection was explored using 1H nuclear magnetic resonance (NMR) spectroscopy direct analysis real time (DART) mass spectrometry (MS). Principal components (PCA) spectral data showed that individual animals could be resolved based on their two unhealthy individuals discriminated remaining...