Research Of Selective Surface Modification And Controllable-assembly Of Gold Nanorods Nanorods

With the rapid development of nanotechnology，nanomaterial hasbeen widely studied and applied at synthesis material, microelectronics,aerospace technology, energy, environment, medicine, biotechnology dueto its excellent mechanical, optical, electrical, magnetic properties andgood biocompatibility. Nanomaterial’s properties are related to itsbuilding blocks, surface properties, size and morphology, therefore,design and synthesis nanoparticles with different size, morphology andstructure have been a hot research field. Controlled assembly for1D,2D, and3D microarrays of nanoparticles have excellent optical andelectrical properties, lead them to have extensive and importantapplications in nanoscience and biological science.According to the distribution of CTAB on the surface of goldnanorods, we functionalize gold nanorods with polymer brushes throughthe Au-S bond, and controlled assembly of nanocrystals. With the help ofscanning electron microscopy(SEM), transmission electron microscopy(TEM) and UV-visible absorption spectroscopy (UV-vis), theexperimental results are analyzed and discussed.1. Synthesis of gold nanorods, initiator and polystyreneOriginal CTAB-stabilized Au nanorods (AuNR@CTAB) weresynthesized by a seeded growth method.The nanorods have an aspectratio between2-4.7. The ATRP initiator were prepared by EsterificationReaction with2-hydroxyethyl disulfide,2-bromo-2-methyl-propionylchloride and triethylamine. Finally, we synthesized polystyrene withdisulfide bond by the atom transfer radical polymerization (ATRP). BySEM, TEM and UV-visible absorption spectrum, the experimental resultsare analyzed.2.Surface modification of gold nanorods and their self-assemblyWe functionalize gold nanorods with polystyrene(PS) by the“grafting to” method. The “grafting to” method takes advantage ofreaction between gold nanorods and the terminal group of end-functionalized polymers. Second we controlled assembly of goldnanorods and got the “End-by-end” structure. We prepared theamphiphilic gold nanorods that the methoxy-poly(ethyleneglycol)-thiol(PEG, MW=5kDa) at both end of gold nanorods and PS atside of gold nanorods. Through self-assembly, we got the “Side-by-side”structure. By SEM, TEM and UV-visible absorption spectrum, theexperimental results are analyzed.3. We prepared the polystyrene nanowires in the AAO template bysimple radical polymerization, and preliminary studied the reactionconditions.