Preparation And Characterization Of Core-shell Structure Nanoparticles

In recent years, considerable effort has been devoted to the design and controlled fabrication of core-shell nanoparticles with function properties. The interest in such material stems from the fact that their (optical ,electrical , catalysis, etc) are a function of their size, composition, morphology, and structure order etc. Alkanethiolate- protected nanoparticles have been among the important research topics due to their difference from conventional colloids and nanoparticles prepared by other routes (micelle and polymer stabilization, stabilization with small organic ligands, gas-phase cluster formation ) in that they can be isolated in solvent-free form and redissolved without change, recrystallized from parent solution, and dissolved in many organic solvents. Therefore, effective strategies are required in order to meet the ever-increasing demands palced on materials synthesis anf performance. In this dissertation, we have tried to find new methods to design and construct novel alkanethiolate –protected nanomaterials. The main results and conclusions of the dissertation are listed as follows:Dodecanethiol -protected Cu2S nanoparticles were synthesized in a two-phase system using basic copper hydroxide (Cu(OH)x(x-2)) as precursor. The particle size was dependent upon the molar ratio of dodethiolate to Cu(OH)x(x-2). An increase of the ratio gives a shift of the particles size ranging from 10-20nm to 70-120nm. Dodecanethiol was found to play three important roles in the experiment: acting as transferring, protecting and reducing reagent. TOAB (tetra-n-octyl-ammonium bromide) serves as a catalyst initiating the reaction between dodecanethiol and Cu(OH)x(x-2). When it is absent, nanoparticles were not formed and white floccules were observed in the bottom of toluene phase .