Lugito G.,No. 1 University Road |
Wang L.-Y.,No. 1 University Road |
Woo E.M.,No. 1 University Road
Macromolecular Chemistry and Physics | Year: 2014
Etching agents, including methylamine (MA) and several others, are used in many studies for exposing the crystal assembly in contrast to amorphous domains in polymer samples, for better morphology contrast. The selection of etching agents must be careful, so as not to alter the original chemical and crystal nature; otherwise misinterpretation may be a consequence. Apparently, the MA-vapor treatment does not simply just induce physical etching through peeling off a covered layer from the polymer samples as many investigators so believed, but also causes severe chemical changes in many aliphatic and aromatic polymers. The chemical reactions between MA and the polyesters ultimately lead to different chemical structures, alteration in spherulites and lamellae, and sometimes completely different lamellar structures with a different melting peak, with -C(=O)O- in the polymers being replaced with -C(=O)NH- bonding. This study uses three examples of polyesters to amply exemplify the necessity of due care in avoiding chemical etching. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Tung H.-T.,No. 1 University Road |
Song J.-M.,No.1 Sec. 2 Da Hsueh Road |
Feng S.-W.,700 Kaohsiung University Rd |
Kuo C.,No. 1 University Road |
Chen I.-G.,No. 1 University Road
Physical Chemistry Chemical Physics | Year: 2010
Through studying the optical, electrical and photocatalytic properties of anatase TiO2 films with different preferred orientations, (101) and (004), this study clarified the relationship between the formation of metallic nanowires by thermally assisted photoreduction process and surface atomic bonding conditions of TiO2. Experimental results show that the (101) anatase films which yielded much more Ag nanowires than the (004) oriented films and exhibited more complex superficial atomic bonding, which could be demonstrated by the Gaussian bands in photoluminescence spectra. This might lead to higher carrier concentration and mobility, as well as longer life time for photo-exited electrons and consequently a greater photocatalytic activity for reducing metallic ions. The fact that the anatase (101) surface acted as the preferred nucleation sites for Ag nanowires was supported by high resolution transmission electron microscopy lattice image of a TiO2 nanofiber where an Ag nanowire was grown. © the Owner Societies 2010.
Chen H.,No. 1 University Road |
Chang H.-W.,No. 1 University Road |
Shei S.-C.,33.sec.2 |
Sheu M.-L.,No. 1 University Road
Electronics Letters | Year: 2014
Reverse-bias operations for a light-emitting diode can quickly screen the weakness of the device. Electromigration around the electrode on the lateral and vertical directions can be observed by optical microscope images, scanning electron microscope images and energy dispersive spectroscopy. The failure process caused by the electromigration can be revealed by the changes of forward-bias and reverse-bias electroluminescence images and the emergence of the reverse-bias EL may be attributed to the diffusion of gold. Furthermore, the increase of the leakage current may supress the forward-bias band to band recombination current especially near the metal contact. © The Institution of Engineering and Technology 2014.