Studies On Synthesis Of Carboxyl-Modified P3HT And Its Composite Nanocrystals

Poly(3-methylthiophene)(P3HT)is a new kind of organic conjugated polymer that has emerged in recent years.It has the characteristics of light weight,thin thickness and good environmental stability.P3 HT with high molecular weight and regular structure also has excellent optoelectronic properties and thus becomes an important donor material for preparing optoelectronic devices.The properties of hybrid nanocomposites composed of P3 HT and semiconductor nanocrystals have perfect performances which are closely related to the interface of two phase.The organic-inorganic nanocomposites linked together by chemical bonds have good interfacial compatibility,so the charge transfer energy between two phases can be more effective.Therefore,functionalized P3 HT has certain research value and application prospect.The major research works of this article were as the following:(1)The synthesis and characterization of two carboxylic-functionalized P3 HT.Using 4-(bromomethyl)benzoic acid and 4-aminophenylacetic acid,the hydrazoate were prepared by azido reaction.Ethynyl-terminated P3 HT derivatives was prepared by GRIM method.Using ethynyl-terminated P3 HT and two kinds of azide as raw material,P3HTC1 and P3HTC2 was prepared by “Click reaction”.(2)Using P3HTC1 and P3HTC2 as donor materials,CdSe materials as receptors,two kinds of the nanocomposites were synthesized by in-situ injection method.The nanocomposites were characterized by FT-IR,XRD,TEM,UV-vis,PL and TG,etc.The results show that the product are zero-dimensional microsphere and particle size was6.65 nm and 7.94 nm respectively,and the morphology and distribution is very regular and uniform.The optimum ratio of raw materials is 1: 2 and the optimum reaction temperature are 180℃.Using CdS materials as receptors,the CdS/P3HTC1 and CdS/P3HTC2 nanocomposites are zero-dimensional microsphere and particle size was 3.5nm and 4nm respectively.The optimal amount of P3HTC1 and P3HTC2 is 9mg,and the optimal reaction temperature is 180℃.Compared with the fluorescence spectra of the nanocrystals synthesized by unmodified P3 HT,the four kinds of composite nanocrystals all showed different degrees of photoluminescence quenching.The conversion efficiencies of the battery devices fabricated with the active layer materials of CdSe/P3HTC1 and CdSe/P3HTC2 were 0.069% and 0.064%,respectively,which was higher than that of CdSe/P3 HT devices.(3)CdS/P3 HT nanocomposites were prepared by Heck reaction.Thealkenyl-terminated P3 HT derivatives were prepared by GRIM method.Using cadmium acetate as a cadmium source and TOP-S as S precursor,hexagonal phase CdS nanorods with a diameter of 4nm and a length of 20 nm were prepared.Using the method of ligand exchange,the CdS nanorods and 4-bromobenzoic acid are connected to each other.Finally,the final product were obtained through connecting alkenyl-terminated P3 HT with4-bromobenzoic acid covered CdS nanorods by the Heck reaction.Compared with the traditional method of physical blending,there was a significant degree of fluorescence quenching in the fluorescence spectra of chemically bonded CdS/P3 HT composites.