Tsung-Yeh Yang

Photosynthesis and structure of electroless Ni–P films by synchrotron x-ray irradiation

The authors describe an electroless deposition method for thin films, based on the irradiation by an x-ray beam emitted by a synchrotron source. Specifically, Ni–P films were deposited at room temperature. This synthesis is a unique combination of photochemical and electrochemical processes. The influence of the pH value on the formation and structural properties of the films was examined by various characterization tools including scanning electron microscopy, x-ray diffraction, and x-ray absorption spectroscopy. Real time monitoring of the deposition process by coherent x-ray microscopy reveals that the formation of hydrogen bubbles leads to a self-catalysis effect without a preexisting catalyst. The mechanisms underlying the deposition process are discussed in details.

Synchrotron X‐Ray Synthesized Gold Nanoparticles for Tumor Therapy

Highly concentrated gold nanoparticles (20 ± 5 nm) were produced by an x‐ray irradiation method. The particles were then examined for the interactions between gold and tumor cells under x‐ray radiation conditions. The biological effects of gold nanoparticles were investigated in terms of the internalization, cytotoxicity and capability to enhance x‐ray radiotherapy. The results of this investigation indicated that x‐ray derived gold nanoparticles were nontoxic to CT‐26 cell line and immobilized within cytoplasm. The irradiation experiments provided further evidence that gold nanoparticles were capable of enhancing the efficiency of radiotherapy.

Hybrid MOS/CNTs materials for gas sensing

Most of the gases detecting metal oxide semiconductors are operated at temperatures above 250oC. It is not energy efficient for MOS gas sensors to operate at such high temperature. To solve this problem, research and investigations are trying to obtain new MOS sensing materials that can operate at ambient temperature. In this study, gas sensing materials consisting of MOS and carbon nanotubes (CNTs) are developed for detecting gases at lower temperature. The hybrid system, MWCNTs/TiO2, demonstrates the possibility of detecting the gases at ambient temperature with high energy efficiency.

Nanoparticle Decoration of Carbon Nanotubes by X‐Ray Irradiation

Titanium oxide (TiO2) nanoparticles were immobilized onto the surfaces of multiwall carbon nanotubes (MWNTs) by a facile synchrotron X‐ray exposure method. The influence of processing parameters such as beam dose and duration on the structures and properties of nanoparticle/nanotube hybrid were investigated by X‐ray Absorption Spectroscopy (XAS), Raman spectroscopy, Transmission Electron Microscopy (TEM). The influences of synchrotron x‐ray exposure on the sol‐gel process and structure of produced TiO2 nanoparticles were also investigated. Furthermore, the locations of functional groups between TiO2 and MWNTs were also probed. This new approach is envisaged to be quite promising for the synthesis of novel nanocomposite materials.

Poly (methyl methacrylate) Formation and Patterning Initiated by Synchrotron X‐ray Illumination

A facile radiation method was developed to obtain micro‐sized poly (methyl methacrylate) (PMMA) particles and create patterned coating on different substrates by a synchrotron x‐ray induced dispersion polymerization. The polymerization of MMA monomer and well defined patterning was successfully realized. The produced PMMA particles and patterning were characterized by Fourier transformation infrared (FTIR), 1H‐Nuclear Magnetic Resonance (NMR), and Scanning Electron Microscope (SEM). The observed patterning contrast essentially derived from a variation of size, density and morphology of particles and the type of substrate materials used.