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Biomedical subjects

Chunyi Zhi

Publications and source records attributed to Chunyi Zhi.

10 recordsLinked to original sources
PubMed2006

Tubular carbon nano-/microstructures synthesized from graphite powders by an in situ template process.

Through the use of commercial graphite powders as the carbon sources, a variety of interesting tubular carbon nano- and microstructures, such as networked carbon nanotubes, aligned carbon microtubes with hexagonal cross-sections, aligned tapered carbon tubes, and hollow carbon microhorns, have been successfully synthesized. As-grown tubular carbon structures were characterized using scanning electron microscopy, transmission electron microscopy, and X-ray energy-dispersive spectroscopy. An in situ template mechanism was proposed to explain the possible growth process. The vibrational properties of the synthesized tubular carbon structures were also studied by Raman spectroscopy.

Journal Article↗
PubMed2006

SnO2 nanoparticle-functionalized boron nitride nanotubes.

Boron nitride nanotubes (BNNTs) were synthesized by a carbon-free chemical vapor deposition method using boron and metal oxide as reactants. Then SnO(2) nanoparticles were functionalized on them via a simple wet chemistry method. Detailed transmission electron microscopy (TEM) observations reveal that SnO(2) nanoparticles may cover the tube surface or be encapsulated in tube channels. The lattice distances of both BNNT and SnO(2) have been changed due to the strong interactions between them. The band gap energy of SnO(2) particles is found enlarged due to the size effect and interaction with BNNTs.

Boron Compounds↗
PubMed2006

Morphology-controlled synthesis of ZnO nanostructures by a simple round-to-round metal vapor deposition route.

One-dimensional ZnO nanostructures with different morphologies have been successfully synthesized through a simple round-to-round metal vapor deposition route at 550 degrees C with a zinc powder covered indium film as the source material. The structures and morphologies of the products were characterized in detail by using X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. Studies found that the morphology of the products can be easily tuned from one experimental round to another. Possible growth mechanisms for the formation of one-dimensional ZnO nanostructures with different morphologies are discussed. Photoluminescence studies show that there are sharp UV emission and broad defect-related green emissions for the products obtained in all experimental rounds. Relative intensity of the UV emission to defect-related emissions gradually increased from one experimental round to another.

Journal Article↗
PubMed2006

Purification of boron nitride nanotubes through polymer wrapping.

An effective method was proposed to remove obstinate boron nitride phase impurities in boron nitride nanotubes (BNNTs). The method is based on strong interactions between BNNTs and a conjugated polymer wrapping them and significant weight and size difference between BNNTs and impurities. The as-grown samples and purified samples were compared through detailed characterization, using scanning electron microscopy, transmission electron microscopy, and Raman and Fourier transformed infrared spectroscopy. The results reveal that impurities are effectively removed and resultant BNNTs possess perfect crystallization.

Journal Article↗
PubMed2006

Carbon nanotubes as nanoreactors for fabrication of single-crystalline Mg3N2 nanowires.

Due to fast decomposition of Mg3N2 in the presence of water in the atmosphere (Mg3N2+6H2O-->3Mg(OH)2+2NH3), the synthesis of single-crystalline Mg3N2 nanowires has been a challenge. Here, we demonstrate that carbon nanotubes may serve as nanoreactors for a simple thermal reaction process resulting in the first fabrication of high-quality, large-yield, single-crystalline Mg3N2 nanowires. The Mg3N2 nanowires are homogeneously sheathed over their entire lengths with very thin graphitic carbon tubular layers, which effectively prevent their decomposition (even when the samples are put into water or exposed to atmosphere for several months). We have systematically analyzed for the first time the Mg3N2 nanomaterial by means of transmission electron microscopy (TEM), high-resolution TEM, and electron diffraction. Successful fabrication of carbon sheath protected Mg3N2 nanowires may promote further experimental studies on their crystal structures and properties.

Adsorption↗
PubMed2005

Immobilization of proteins on boron nitride nanotubes.

We report for the first time that proteins are immobilized on boron nitride nanotubes. It is found that there is a natural affinity of a protein to BNNT; this means that it can be immobilized on BNNT directly, without usage of an additional coupling reagent. For the most effective immobilization, noncovalently functionalized BNNTs should be used. The effect of immobilization was studied using high-resolution transmission electron microscopy and energy dispersion spectroscopy.

Boron Compounds↗
PubMed2005

Perfectly dissolved boron nitride nanotubes due to polymer wrapping.

We report for the first time that boron nitride nanotubes (BNNTs) may be dissolved in organic solvents by wrapping them with a polymer. Transmission electron microscopy and cathodoluminescence studies indicate the strong pi-pi interactions between BNNTs and the polymer. A band gap ranging from 5.2 to 5.5 eV was documented for the BNNTs independent of their geometrical characteristics by using ultraviolet-visible absorption experiments on composite films and thin BNNT films prepared from solutions.

Journal Article↗