Materials Science Forum Vol. 644

Abstract: The properties of polymer/semiconducting nanoparticle (NP) composites-materials used in hybrid, bulk-heterojunction photovoltaic materials-are dependent on the interaction of the NPs and polymer. Composite films of water soluble polymers and CdS NPs have been produced both by synthesizing the NPs within the polymer matrix and by adding the CdS NPs, containing a capping agent, to the polymer. The composites have been characterized by microscopy as well as 1H, 13C and 113Cd solid-state NMR. When synthesizing the NPs within the polymer, the polymer matrix plays a role in the cadmium sulfide NP nucleation, growth and structure. In the blended system, the dominant interaction between the glycerol capping agent and sulfonated polymer is observed to be hydrogen bonding.

Abstract: WO3/FTO/Glass and WO3:Mo/FTO/Glass thin films were deposited using the pulsed spray pyrolysis technique. The Molybdenum doped thin films were deposited using 2,4,6,8 and 10 % at . concentration in the starting solution. The influence of molybdenum concentration on the structural, electrical, optical and electrochromic properties of WO3:Mo thin films have been systematically studied using Scanning Electron Microscopy (SEM), Selected Area Diffraction Patterns (SAED) in Conventional Transmission Electron Microscopy (CTEM), High Resolution Electron Microscopy (HREM) and Atomic Force Microscopy (AFM). The electrochemical behavior of our materials was studied using cyclic voltammetry both to induce electrochromic behavior and to characterize the electric charge injection and extraction processes. It was found that samples with 2% at. of molybdenum concentration in the starting solution, show the best electrochromic behavior with the highest efficiency and durability. The influence of structural details in our films and their evolution with the molybdenum incorporation, for a fixed substrate temperature on the electrochromic properties of our WO3:Mo thin films has been followed wherever possible.

Abstract: The synthesis of poly(acrylonitrile-butadiene-styrene) (ABS) was carried out using the mass-suspension process, high cis polybutadiene (PB), benzoyl peroxide (BPO) as the initiator and modified and unmodified nanoparticles of zinc oxide (nano-ZnO). X-ray diffraction (XRD) and Fourier transform infrared (FTIR) were used to characterize the ZnO nanoparticles. A Universal tensiometer, Brokfield viscosimeter and transmission electronic microscopy (TEM) were used to characterize ABS. The employment of nano-ZnO induced an impressive morphologic modification and transformed the highly occluded salame morphology of poly(styrene-acrylonitrile) (SAN) to a highly dispersed one in its matrix. During the reaction, a decrease in the total production of SAN was observed due to the interaction between radicals produced by the initiator and nano-ZnO, causing a molecular weight increase of SAN. The nano-ZnO also induced a decline in the phase inversion and extended the period of occurrence. ABS without nano-ZnO yielded higher mechanical properties than one without any nanoparticles.