Photophysical Properties of Poly(2-methoxy-5-octyloxy)-p-phenylene Vinylene/SWNTs Composites

The photoelectric composites of poly(2-methoxy-5-octyloxy)-p-phenylene vinylene/single-walled carbon nanotubes(PMOCOPV/SWNTs)were prepared by dehydrochlorination in-situ polymerization.The results of Fourier transform infrared spectroscopy and Raman spectroscopy indicate that PMOCOPV is coated on the surface of SWNTs.The composite dimensions were observed by highly resolution transmission electron microscope,the diameter of PMOCOPV/SWNTs is about 47 nm and the thickness of the coated PMOCOPV is about 25 nm.The absorption of PMOCOPV/SWNTs is strengthened with the contents of SWNTs increasing,and a blue shift of the absorption peak can be clearly observed in the UV-Vis spectrum.Photoluminescence spectroscopy indicates that the maximum emission wavelength of the PMOCOPV/SWNTs is blue-shifted and intensity of photoluminescence decreases with increasing SWNTs concentration.PMOCOPV/SWNTs shows fluorescence quenching,which involved the inter-molecular photo-induced charge transfer process.The optical band gap of PMOCOPV/SWNTs decreases gradually with the contents of SWNTs increasing.Third-order optical nonlinear susceptibility of PMOCOPV/SWNTs composites was measured by degenerate four wave mixing.The results show that the third-order nonlinear optical responses of PMOCOPV/SWNTs composites are enhanced gradually when SWNTs content increased,which can be attributed to inter-molecular photo-induced electron transfer and π-π electron coupling between PMOCOPV and SWNTs.