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Biomedical subjects

Daoben Zhu

Publications and source records attributed to Daoben Zhu.

105 records · Page 6Linked to original sources
PubMed2003

Novel electron donors containing multi-TTF units: synthesis and electrochemical properties.

The synthesis and electrochemical properties of five novel organosulfur electron donors containing two to four TTF nuclei are reported. The structures have been assigned by 1H NMR spectroscopy, infrared spectrometry and mass spectra. Cyclic voltammetry (CV) studies show that the multi-TTFs display nearly ideal redox behavior for the TTF system with no distinct interaction between the TTF units.

Electrochemistry↗
PubMed2003

Tower-like structure of ZnO nanocolumns.

The tower-like structure of ZnO nanocolumns grows normal to alumina substrates via pyrolysis and oxidation of ZnS, and is formed by stacking of ZnO nanocrystals layer upon layer.

Journal Article↗
PubMed2003

Preparation of silver nanocrystals in the presence of aniline.

The preparation and characterization of silver nanocrystals by chemical reduction of silver ions in the presence of aniline using hydrazine monohydrate (N(2)H(4).H(2)O) or sodium citrate as the reducing agent are described. A high yield of aniline-derivatized hexagonal silver nanoparticles is obtained by the reduction of Ag(2)SO(4) with N(2)H(4).H(2)O. An alternative strategy is the reduction of Ag(+) by citrate in the presence of aniline, by which the size and morphology of the Ag nanocrystals can be controlled to a certain degree by changing the concentration ratio of aniline to Ag(+). It is believed that the amount of aniline added in the starting solutions for the preparation influences the morphology of the Ag nanoparticles. In addition, the long Ag nanorods with a high mean aspect ratio are prepared in the presence of aniline at a low concentration or o-anisidine.

Journal Article↗
PubMed2002

Imaging as-grown [60]fullerene nanotubes by template technique.

In this contribution we have developed a useful and experimentally easy way to use C60 powder to directly fabricate C60 nanotubes with a mondisperse size distribution and uniform orientation. The structure of C60 nanotubes was confirmed by SEM, TEM, and FT-IR.

Journal Article↗
PubMed2002

Synthesis and self-assembly of 2,9,16-tri(tert-butyl)-23-(10-mercaptodecyloxy)phthalocyanine and the application of its self-assembled monolayers in organic light-emitting diodes.

2,9,16-Tri(tert-butyl)-23-(10-mercaptodecyloxy)phthalocyanine (8) and its disulfide (9) have been synthesized and characterized, and their self-assembling behaviors on gold substrates have been studied. Characteristic Q-bands were observed at about 630 nm in the UV/visible spectra of the self-assembling monolayers (SAMs). They were broadened and blue-shifted relative to those observed in solution. Binding energies for S2p have the same values (161.70 eV) and are in accord with those for gold thiolates. The application of the SAMs in organic light-emitting diode was investigated. It shows that the SAM promotes the hole injection process from the anode.

Journal Article↗
PubMed2002

Synthesis and characterization of three novel [60]fullerene derivatives toward self-assembled nanoparticles through interaction of hydrogen bonding.

[structure: see text] Three novel fullerene derivatives bearing a 2,6-bis(acylamino) pyridine unit as a hydrogen bonding motif displaying a dimerization tendency were synthesized and characterized by the cycloaddition reaction of alkyl azide to [60]fullerene. An SEM image of the dimerization system of compound 1 indicated spherical particles having a mean diameter of 15 nm with a rather narrow size distribution.

Journal Article↗
PubMed2002

A comparative study on photo-induced electron transfer from fluorescein to anthraquinone and injection into colloidal TiO2.

A dyad-anthraquinone-methyl ester of fluorescein-and its model compound-butyl ester-were synthesized. The effects of photo-induced electron transfer from fluorescein to an organic anthraquinone acceptor and injection into inorganic colloidal TiO(2) were studied respectively. It is found that the photo-induced electron transferring to an organic acceptor is much faster than injecting into inorganic colloidal particles when fluorescein was excited by visible light. While inorganic colloidal TiO(2) was excited by UV, the electron of fluorescein will inject into TiO(2).

Journal Article↗
PubMed2002

Thiosalicylic acid-functionalized silver nanoparticles synthesized in one-phase system.

A series of silver colloidal dispersions were prepared by two protocols, i.e., addition of the reductant-NaBH(4) and the stabilizer-thiosalicylic acid (TSA) into Ag(+) solution simultaneously or successively. The products were compared and characterized by TEM, electrochemical measurements, XPS, UV-vis, and FT-IR spectra. The size distributions of the Ag nanoparticles prepared by the former and latter protocols are bimodal and monodisperse, respectively. The analytic results of UV-vis spectra coincide with the TEM observation. A tentative explanation was given to the relationship between particle sizes and different synthetic protocols. The changes of the reduction potential of the reductant invoked a variance in particle diameter and size distribution. Electrochemical measurements corroborated our assumption. The composition information of TSA-derived silver nanoparticles was obtained from XPS and FT-IR spectroscopic measurements.

Journal Article↗
PubMed2002

A perfect carbon nanotube with two closed ends.

A perfect carbon nanotube with two closed ends consisting of graphitized carbon was experimentally observed. The large carbon nanotube, with a diameter of 187 nm and a length of 1.2 microns, was synthesized by pyrolysis of iron(II) phthalocyanine (FePc) under an Ar/NH3 flow at 900 degrees C on a nickel substrate. The structure and composition of the nanotube were determined by high-resolution transmission electron microscopy and electron energy loss spectroscopy. The carbon nanotube seems to grow spontaneously by some autocatalytic process.

Crystallization↗