Browsing by Author "Li, Yu-Jen"

Now showing 1 - 2 of 2

Formation mechanism of a nanotubular polyanilines prepared by an emulsion polymerization without organic solvent
(2008-09-09)
Hsieh, Bi-Zen
;
Chuang, Hung-Yi
;
Chao, Liang
;
Li, Yu-Jen
;
Huang, Ying-Jie
A nanotubular polyaniline (PANINT) was prepared from a simple emulsified polymerization method without oil solvent present. A mechanism of the formation of the nano-fibers/tubes was proposed to show that it started with the connecting arrangement of the neighboring anilinium micelles before and during polymerization, which resulted in the formation of the intermediate morphology of centipedes converting into rod-like nanofibers later. The obtained PANINTs displayed not only nanofibrous structure but owned an unusual dispersing behavior in toluene. SEM and TEM showed the dendrite-like networks of nanofibers connected and glued together by the free (not complexed to polyaniline backbone) n-dodecylbenzene sulfonic acid (DBSA) molecules. After removing the free DBSA by acetone, the clear/well-defined empty nanotubes can be seen from TEM in the magnified micrograph. The Atomic force microscopic (AFM) microgaphs demonstrated the cottage like surface morphology of the un-perturbed PANINTs and the morphology was converted to an anisotropic/oriented rods after rubbing on the wet/ cast PANINTs' dispersion of toluene before entire evaporation. (c) 2008 Published by Elsevier Ltd.
Synthesis and Characterization of Poly(n-undecyl isocyanate)/Polyaniline Polyblend
(2010-07-05)
Li, Yu-Jen
;
Ho, Ko-Shan
;
Lo, Wan-Ting
;
Yang, Shin-Shiao
;
Chao, Liang
Poly(n-undecyl isocyanate) (PUDIC)/n-dodecylbenzenesulfonic acid (DBSA)-doped polyaniline (PANIDBSA) polyblend was prepared and the effect of the H-bonding between these two polymers on the compatibility, conjugation chain length of PANIDBSA, and helixity of PUDIC in the polyblend system were studied. The monomer and polymer were characterized by NMR spectra and the polyblend was analyzed by FTIR, UV-vis spectra, and wide-angle X-ray diffraction. It was found when the blend composition of the PUDIC was higher than 10%, the WAXD patterns demonstrated lower angle shifting for the peaks at around 2 theta = 2-2.5 degrees, referring to the distance between the layers of the layered structure of PANIDBSA crystalline with increasing PUDIC, indicating the expansion of the layered structure of PANIDBSA. The FTIR spectra illustrated the presence of an absorption peak at 1700 cm(-1) shift to higher wave number with PUDIC due to its H-bonding with PANIDBSA. The UV-vis spectra of PANIDBSA described a blue-shift of the lambda(max) with PUDIC, indicating that the presence of PUDIC in the polyblend system can interrupt and decrease the conjugation chain length of PANIDBSA. The optical activity of the helical PUDIC decreased notably with the presence of PANIDBSA, resulting from the reversed helical effect (de-nature) of H-bonding. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 117: 1-7, 2010