Browsing by Author "Lin, Jin-Shyong"

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Fabrication and characterization of eutectic gold-silicon (Au-Si) nanowires
(2008-09-12)
Lin, Jin-Shyong
;
Chen, Chien-Chon
;
Diau, Eric Wei-Guang
;
Liu, Tzeng-Feng
;
材料科學與工程學系
Hypoeutectic, eutectic and hypereutectic gold-silicon (Au-Si) alloys were synthesized using vacuum smelting. When Au and Si were smelted in a vacuum chamber near 1100 degrees C, Si-(g), Si-2(g), Si-3(g), SiO2(g), Au-(g), SiO2(s) and Au2O3(s) were formed rapidly; the quantities of Au and Si lost were estimated from thermodynamic formulas. The nano- and microstructures of the Au-Si,eutectic compound were characterized with a SEM and a TEM, which showed a discontinuous phase of Si dispersed and mounted within a matrix phase of Au. Cracks that formed about the Au-Si interface made the Au-Si eutectic brittle. From an Au-Si alloy of superior quality as a bulk material, eutectic nanowires of average diameter 60 nm were fabricated after the alloy was melted and injected into an anodic aluminum-oxide (AAO) template. (C) 2008 Elsevier B.V. All rights reserved.
Fluorescence dynamics of zinc protoporphyrin in solution and inside anodized aluminum oxide (AAO) nano-channel arrays
(2006-12-01)
Lin, Jin-Shyong
;
Chen, Yu-Chying
;
Chen, Chien-Chon
;
Luo, Li-Yang
;
Diau, Eric Wei-Guang
The excited-state relaxation dynamics of zinc protoporphyrin (ZnPP) in THF solution and inside nano-channel arrays of anodized aluminum oxide (AAO) have been investigated with time-correlated single-photon-counting (TCSPC) fluorescence spectra with S-2 excitation (lambda(ex) = 435 nm). We used three initial concentrations of immersion - 4.8 x 10(-6), 4.8 x 10(-5) and 4.8 x 10(-4) M - to examine the extent of aggregation of ZnPP inside the AAO nano-channel arrays of two pore sizes - 15 and 70 nm. Only one decay component corresponds to the aggregation of ZnPP in THF solution, whereas at least two decay components are required to describe the transient behavior of ZnPP inside AAO. The observed systematic variation of the decay coefficients and the corresponding amplitudes of the ZnPP/AAO samples are consistent with the observation of steady-state spectra of the system reported previously (JCCS 2006, 53, 201), but through fluorescence lifetime measurements we further highlight the significance of aggregation of ZnPP in the specific nanoporous environment that is not achievable in ZnPP/THF solutions in large concentrations.
Self-cleaning characteristics on a thin-film surface with nanotube arrays of anodic titanium oxide
(2008-08-01)
Chen, Chien-Chon
;
Lin, Jin-Shyong
;
Diau, Eric Wei-Guang
;
Liu, Tzeng-Feng
;
材料科學與工程學系
Self-cleaning of a surface of nanotube arrays of anodic titanium oxide (ATO) is demonstrated. The ATO was prepared in fluoride ion containing sulfate electrolytes with a structure of 0.4 mu m length, 100 nm pores diameter, 120 nm interpore distance, 25 nm pore wall thickness, a 8x10(9) pores cm(-2) pore density, and 68.2% porosity. Prepared as thin films either directly from a Ti foil or on a glass substrate, these arrays have the property that water drops spread quickly over the surface of the films without irradiation. In contrast, a flat anatase TiO2 film requires irradiation with UV light for several minutes before the contact angle decreases to zero. The observed self-cleaning behavior of the ATO thin films is due to the capillary effect of the nanochannel structure and the superhydrophilic property of the anatase TiO2 surface inside the tube.