Study Of Soft Nano-coupling Between Gold And Silica Nano-particles

The synthesis of composite nano-particle is an area of high interest in recent years."Hard-coupling"is a conventional method used so far,but it is not convenient and has many disadvantages,such as harsh synthetic condition,high cost and so on.In this paper,an new idea,"soft-nano-coupling"is introduced for the first time.We have taken the Reversible Addition-Fragmentation Chain Transfer Polymerization?RAFT?to synthesis a series of macromolecular coupling agent then were used to couple nanoparticles.We have synthesisd diblock copolymers,triblock copolymer and random copolymer,it was used as coupling agent.Gel permeation chromatography?GPC?,dynamic light scattering?DLS?and transmission electron microscopy?TEM?were used to characterize the samples,the successful coupling between SiO₂ and gold nano-particles to make composite nano-particle was confirmed.The results are as follows,?1?Molecular weight control,predetermined degree in the polymerization and kinetic process have been studied in our research.At the same time we found the polymers can be influenced by multiple factors,such as different monomers,the amount of monomer,different solvent,the amount of solvent and initiator etc.Following conclusions could be arrived molecular weight can be controlled during the polymerization process,the polymerization can be reach predetermined degree of polymerization,and the process of polymerization conforms to the first-order kinetic equation.We got optimum condition in polymerization.?1?The best solvent of the polymerization is anisole;?2?The best ratio between initiator and RAFT reagent is 10%;?3?Monomer conversion should below 35%;?4?The degree of polymerization should not be too high.?2?The homolymer,diblock copolymer,triblock copolymer,random copolymer and?-Lipoic acid modified triblock copolymer was synthesized via RAFT polymerization.The homlymer include PGMA_42,PGMA₇₁,PGMA₂₂₀,POE₃₈ etc.Diblock copolymers include POE₃₈-b-PGMA₅₄,POE₃₈-b-PGMA₅₈,POE₃₈-b-PGMA₈₈,POE₃₈-b-PGMA₁₁₇ etc.Triblock copolymer include POE₃₈-b-PGMA₅₄-b-PMPS₁₀,POE₃₈-b-PGMA₁₁₇-b-PMPS₁₁1 etc.Random copolymer include PGMA-co-POE-1,PGMA-co-POE-2,PGMA₄₄-co-PMPS₃₂2 etc.?-Lipoic acid modified triblock copolymer include P?LMA-co-GMA?₇₁-b-POE₃₀-b-PMPS₁₈,P?LMA-co-GMA?6-b-POE1-b-PMPS1?POE₃₈-b-P?LMA-co-GMA?₁₁₇-b-PMPS₁₁ etc.?3?We have synthesized Au NPs and SiO₂ NPs and used the polymer as coupling agent to connect SiO₂ and gold Nanoparticles.The polymer we have used include triblock copolymer POE₃₈-b-PGMA₅₄-b-PMPS₁₀,driblock copolymer PGMA₂₂₀-b-PMPS₅₃,random copolymer PGMA₄₄-co-PMPS₃₂.TEM and DLS were used to characterize the samples,the successful coupling between SiO₂ and gold nano-particles to make composite nano-particle was confirmed.