Browsing by Author "WU, SH"

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CHARACTERIZATION OF DIAMOND FILMS DEPOSITED USING C3H6OX-H2 GAS-MIXTURES
(1993-04-13)
CHEN, CF
;
CHEN, SH
;
HONG, TM
;
WU, SH
;
交大名義發表
Diamond films were synthesized using the vapour of hydrocarbon liquids,, such as C3H6O (propylene oxide), C3H6O2 (1,3-dioxolane) and C3H6O3 (dimethylcarbonate), diluted by a large amount of hydrogen as gas mixtures. The surface morphologies of the diamond films still possessed well-defined facets when the hydrocarbon concentrations were 1.2 vol.%, 0.5 vol.% and 0.3 vol.% for C3H6O3-H-2, C3H6O2-H-2 and C3H6O-H-2 gas mixtures respectively. Diamonds of good quality, according to Raman measurements, were obtained using C3H6O3-H-2, C3H6O2-H-2 and C3H6O-H-2 gas mixtures. Optical emission spectroscopy was used to examine the species in the plasma during the process of diamond growth. Our results show that the characteristics of diamond growth were related to the oxygen content, i.e. O-to-C ratios, of C3H6Ox (x = 1, 2, 3). We found that the diamond formation region could be extended to higher hydrocarbon concentrations for C3H6O3-H-2 mixtures than for C3H6O-H2 and C3H6O2-H2 MixtUreS because of the larger amounts of atomic hydrogen and oxygen-containing species, such as atomic oxygen, oxygen molecules and OH radicals, in the plasma of the C3H6O3-H-2 mixture. Obviously, there was a higher etching rate, resulting in a diamond formation region with a lower growth rate for the C3H6O3-H-2 mixture.
SYNTHESIS AND THERMAL-BEHAVIOR OF SIDE-CHAIN LIQUID-CRYSTALLINE POLYMETHACRYLATES CONTAINING TOLANE-BASED MESOGENIC SIDE-GROUPS
(1994-04-30)
HSIEH, CJ
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WU, SH
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HSIUE, GH
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HSU, CS
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應用化學系
The synthesis and characterization of nine polymethacrylates containing 4-alkoxy-4'-tri-fluoromethyltolane, 4-alkoxy-4'-cyanotolane, and 4-alkoxy-4'-nitrotolane side groups were described in this study. The phase behavior of the prepared monomers and polymers was characterized by differential scanning calorimetry, optical polarizing microscopy, and x-ray diffraction. All of the obtained monomers exhibit no mesophase, while most of the synthesized polymers reveal enantiotropic mesomorphism. The polymethacrylate containing 4-propanyloxy-4'-nitrotolane side groups was the only one which shows no mesomorphic behavior. Both the spacer length and the nature of terminal groups have profound influence on the phase transition temperatures and thermal stability of the mesophase. The polymers with longer spacers tend to form a more ordered mesophase with a wider temperature range. Among three polymers with the same spacer length, the polymer with a trifluoromethyl terminal end group is inclined to form a more ordered mesophase than the other two polymers. No side chain crystallization occurred for all obtained polymers. (C) 1994 John Wiley & Sons, Inc.