A5003641042- Electrospun Nanofibers in Biomedical Applications
- Diamond and Carbon-based Materials Research
- Metal and Thin Film Mechanics
- Ferroelectric and Piezoelectric Materials
- Force Microscopy Techniques and Applications
- Bone Tissue Engineering Materials
- Advanced Sensor and Energy Harvesting Materials
- Integrated Circuits and Semiconductor Failure Analysis
- Silk-based biomaterials and applications
- Acoustic Wave Resonator Technologies
- Carbon Nanotubes in Composites
- Semiconductor materials and devices
- Catalysis for Biomass Conversion
- Advanced materials and composites
- Ion-surface interactions and analysis
- Electronic and Structural Properties of Oxides
- Near-Field Optical Microscopy
- Biofuel production and bioconversion
- Supercapacitor Materials and Fabrication
- Laser-Ablation Synthesis of Nanoparticles
- Gold and Silver Nanoparticles Synthesis and Applications
- Orthopaedic implants and arthroplasty
- Catalysis and Hydrodesulfurization Studies
- Advanced Cellulose Research Studies
- Nanoparticles: synthesis and applications
University of Alabama at Birmingham
2015-2025
University of Łódź
2013
University of Maryland, College Park
1998-2006
University of Alabama
2003
Pennsylvania State University
1997
Helsinki Institute of Physics
1996
University of Helsinki
1996
A nanofibrous triphasic scaffold was electrospun from a mixture of polycaprolactone (PCL), type-I collagen and hydroxyapatite nanoparticles (nano-HA) with dry weight ratio 50/30/20, respectively. Scaffolds were characterized by evaluating fiber morphology chemical composition, dispersion HA particles nanoindentation. Scanning electron microscopy revealed fibers an average diameter 180 ± 50 nm, which coincides well the bundle characteristic native extracellular matrix bone. The fibers,...
A fundamental issue in ferroic systems (ferromagnetic and ferroelectric) is the scaling of order parameter (magnetization or polarization) with size. Specifically, ferroelectric thin films, deviations polarization can occur due to: (i) competition between thermal vibrations correlation energy (which aligns dipoles) (ii) damage during fabrication. These will have a profound impact on performance next generation high-density nonvolatile memories based spontaneous polarization. We combined...
The performance of biomaterials designed for bone repair depends, in part, on the ability material to support adhesion and survival mesenchymal stem cells (MSCs). In this study, a nanofibrous bone-mimicking scaffold was electrospun from mixture polycaprolactone (PCL), collagen I, hydroxyapatite (HA) nanoparticles with dry weight ratio 50/30/20 respectively (PCL/col/HA). cytocompatibility tri-component compared three other formulations: 100% PCL I (col), bi-component containing 80% PCL/20% HA...
Abstract Nanotechnologies allow the production of yarns containing nanofibres for use in composites, membranes and biomedical materials. Composite with a conventional thread core mechanical strength nanofibrous envelope functionality, e.g. biological, catalytic, have many advantages. Until now, such has been technologically difficult. Here, we show an approach to composite yarn whereby plume nanofibers generated by high throughput AC needleless collectorless electrospinning is wound around...
We report on the out-of-plane piezoelectric response (d33), measured via piezoresponse scanning force microscopy, of submicron capacitors fabricated from epitaxial PbZrxTi1−xO3 thin films. Investigations 1 μm2 and smaller show that substrate-induced constraint is dramatically reduced by nanostructuring. At zero field, experimentally values d33 for clamped as well are in good agreement with predictions thermodynamic theory. The theory also describes very field dependence key compositions...
Scaling of the ferroelectric and piezoelectric properties in Pt/SrBi2Ta2O9/Pt thin films was studied. Focused ion beam milling used to fabricate submicron devices (1×1, 0.5×0.5, 0.25×0.25, 0.09×0.09, 0.07×0.07 μm2) scanning force microscopy examine their response. It found that capacitors as small 0.09×0.09 μm2 exhibit good piezoelectric/ferroelectric (0.25×0.25 show resistance bipolar fatigue with up at least 109 cycles. The results were compared similar capacitor structures milled...
Electrospun fish gelatin (FGel) nanofibers (NF) mimic the natural bodies extracellular matrix's (ECM) structure and are an attractive material for many biomedical applications. However, FGel poor mechanical properties rapid dissolution in aqueous media paired with usually low productivity of typical electrospinning process necessitate further effort overcoming these issues. In this study, alternating field (AFES) fabricates cold water skin nanofibrous materials (FGel NFM) up to 10 wt.%...
We describe the use of a near-field scanning microwave microscope to quantitatively image dielectric permittivity and tunability thin-film samples on length scale 1 micron. demonstrate this technique with images local hysteresis loops 370 nm thick barium strontium titanate thin film at 7.2 GHz. also observe role annealing in recovery damaged region film. can measure changes relative as small 2 500, 0.03 V$^{-1}$.
Direct hysteresis measurements on single submicron structure sizes were performed epitaxial ferroelectric Pb(Zr,Ti)O3 thin films grown SrTiO3 with La0.5Sr0.5CoO3 (LSCO) electrodes. The samples fabricated by focused-ion-beam milling resulting in pad down to 200 nm×200 nm. influence of parasitic capacitance the measurement setup was eliminated applying an enhanced compensation procedure. No size effects observed capacitors milled 400 nm×400 Thus, a published increase Pmax1 for decreasing can...
We studied the effect of ion damage on properties 50 keV Ga+ focused beam fabricated lead-zirconate-titanate capacitors as a function dose. observed significant modification in chemical composition damaged layer due to loss lead and oxygen, gallium impurity accumulation. The 5–10 nm thick becomes dielectric after annealing does not recover its ferroelectric properties. This substantially reduces actual volume material sub-100 structures, can affect their performance.
We report observation of photon tunneling gated by light at a different wavelength in an artificially created array nanometer-scale cylindrical channels thick gold film. Polarization properties provide strong proof the enhanced nonlinear optical mixing nanometric involved process. This suggests possibility building class ``gated'' devices for massive parallel all-optical signal and image processing.
Abstract Hydroxyapatite (HA) nanoparticle—collagen composite materials with various HA/collagen weight ratios were prepared from dispersions using the solution deposition and electrospinning static or rotating collectors. The composites nanoparticle HA to collagen ratio of 80:20 can be easily in approach, whereas electrospun fibrous it was possible reach a maximum 30:70 while maintaining good structure. structure, surface morphology, nanoindentation properties these different...
Nanoparticles are used in an increasing number of biomedical, industrial, and food applications, but their safety profiles developing organisms, including the human fetus infant, have not been evaluated. Titanium oxide (TiO 2 ) nanoparticles, which commonly cosmetics, sunscreens, paints, food, shown to induce emphysema lung inflammation adult mice. We hypothesized that exposure newborn mice TiO would inhibit development. C57BL/6 were exposed (anatase; 8–10 nm) nanoparticles by intranasal...
ABSTRACT Poly(ε‐caprolactone) ( PCL) biopolymer nanofibers and micro‐fibers have been fabricated for the first time at rates up to 14.0 g per hour using a needleless collectorless alternating current electrospinning technique. By combining ac‐voltage, “green” low toxicity glacial acetic acid (AA) as solvent sodium acetate (NaAc) an additive, beadless PCL fibers with diameters tunable from 150 nm 2000 nm, varying surface morphology degree of self‐bundling are obtained. In this new approach,...
We describe the use of a near-field scanning microwave microscope to image permittivity and tunability bulk thin film dielectric samples on length scale about 1 μm. The is sensitive linear permittivity, as well nonlinear terms, which can be measured function an applied electric field. introduce versatile finite element model for system, allows quantitative results obtained. demonstrate at 7.2 GHz with 370 nm thick Ba0.6Sr0.4TiO3 LaAlO3 substrate. This technique nondestructive has broadband...
A 50 kV Ga+ focused ion beam was applied for milling submicron Pt-(La0.5Sr0.5)CoO3–Pb(NbxZryTiz)O3–(La0.5Sr0.5)CoO3–Pt-based ferroelectric capacitor heterostructures prepared by pulsed laser and sol-gel deposition techniques. The yields were found to be 0.22±0.02 μm3/nC Pb(NbxZryTiz)O3, 0.3.4±0.01 (La0.5Sr0.5)CoO3, 0.34±0.06 Pt layers. influence of the current its scan strategy, as well depth milling, on quality fabricated structures studied. minimum sizes down 0.017 μm2 top electrode, 0.04...