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The surface fractal behavior of polyaniline–dodecylbenzenesulfonate salt (PANI–DBSA) and polyaniline–chlorophyll (PANI–Chll) has been studied using a small-angle X-ray scattering technique. The measurements indicate that the surface of PANI–DBSA and PANI–Chll can be described by the fractal behavior. The scattering intensity, I , is shown to obey the I ( q )∝ q − α relation for values of the scattering vector q between the q -values of 0.14–1.41 nm −1 for PANI–DBSA and 0.12–1.27 nm −1 for PANI–Chll, respectively, with the α -values smaller than four, which is given by Porod’s law. The surface fractal dimension, D s , is found to be 2.46 and 2.15 in agreement with surface fractals.

We have investigated the infrared active modes in undoped and Er 3+ doped trans-(CH) x . The characteristic infrared absorption bands are always observed at 875 cm −1 , 1000 cm −1 , 1125 cm −1 , 1275 cm −1 and 1375 cm −1 for Er 3+ doped trans-(CH) x . Our experiments have shown, for the first time, that the intensity of these absorption bands is obviously increased by the implantation of Er 3+ ions. The intensity of the absorption band at 1375 cm −1 which is associated with the number of charged centers increases with the dopant concentration. It is a charged soliton mode. The increase of other bands (for example at about 875 cm −1 , etc) is also caused by Er 3+ , but their increases are lower than that of band at 1375 cm −1 . The absorption band at 875cm −1 is attributed to the localized phonon mode around a soliton, and hence, we think it is doping induced infrared active mode.

Low frequency Raman scattering from fractal vibrational modes in polypyrrole is investigated. The polypyrrole was prepared by the chemical and electrochemical method, and the polypyrrole obtained was characterized by the infrared spectrum and X-ray diffraction. The experimental results show the broad band distribution between 30 and 140 cm −1 and the Raman peak at 65,77,116 cm −1 for exciting line with 5145 A were observed. According to the fractal theory, we point out for the first time that the low frequency Raman spectra may be from localized fractal vibrational mode in polypyrrole molecule chian with the intensity of the Raman light scattering expressed as a function of frequency shift, fractal and spectral dimensions. The fraction dimension is estimated according to the experimental data. The Raman spectra are well explained in terms of a fraction description of localized vibrations.

We investigated the electron paramagnetic resonance (EPR) spectra of undoped, FeCl3- and iodine-doped poly(para-phenylene) (PPP) prepared by the method of Kovacic. EPR measurements are used to characterize electronic states relevant for carrier transport in doped PPP. We found a novel dependence of room temperature linewidth (DELTAH(pp)) and spin density (N(spin)) on the dopant concentrations for iodine-doped PPP, namely, DELTAH(pp) first decreased and increased, and then decreased and increased again with increasing iodine concentration in the iodine-doped PPP. The corresponding value of N(spin) first increased and decreased, and then increased and decreased again with increasing iodine concentration in PPP. However, the changes in DELTAH(pp) and N(spin) with FeCl3 concentration in FeCl3-doped PPP differ from those of iodine-doped PPP. We explain the different EPR properties in FeCl3-doped and iodine-doped PPP.

This paper reports the results of study devoted to the photocatalytic degradation of phenol in aqueous suspension TiO2 and polyaniline (PAn)/TiO2 powders under UV irradiation or sunshine. The results indicated that the comparison of photoactivity of PAn/TiO2 was better than the other and the efficiency is better. By surface photovaltaic spectroscopy(spv) technique and ESR, it is found that the surface state of TiO2 is changed when TiO2 is dopped by PAn.

The results of experimental studies of resonant Raman scattering (RRS) spectra from Er 3+ implantation doped and partially isomerized polyacetylene are presented. Thin cis-(CH) x films were synthesized by the method of rare earth complex catalysis polymerization. Doping technique is ion implantation. The surface density of implanted Erbium ion is about 5×10 13 /cm 2 . In the case of cis-(CH) x , RRS bands at 1160, 1270 and 1540 cm −1 have been observed λ L = 488 nm (10K) and it was shown clearly that a shift in frequency of the peaks assigned to the remaining trans segments occurs during the isomerization process. In the case of Er 3+ doped cis-(CH) x , Er 3+ induced Raman bands at 1145, 1320 and 1510 cm −1 have been measured ( λ L = 488 nm, RT) for the first time and it is observed that the Raman bands from Er 3+ doped trans/cis-(CH) x are shifted to lower frequencies. We point out that the effect of Er 3+ dopant is associated with the defects. The experimental results are discussed by using the model based on the hypothesis that the sample properties can be interpreted in terms of a bimodal distribution of long and short conjugation length segments (for trans-(CH) x ) and the bipolaron microscopic model on the basis of multi-phonon lattice relaxation theory (for cis-(CH) x ). Our studied results support further the bimodal distribution model and the bipolaron microscopic model.