Study Of The Self-assembly Behavior Of Gold Nanoparticles Within Micro Confinement

At the nanoscale,the gold nanoparticles is one of the most stable metal nanoparticles compared with other metal particles.Gold nanoparticles with unique electrical,optical,and catalytic performance,were widely used in various fields.Nanoparticles of super structure relative to a single gold nanoparticle have more unique performance.To construct advanced and complex gold super structure nanoparticles,obtain the widespread attention in recent years.A unique chemical environment surface was provided by gold nanoparticles,and we can control particle performance through change the species of modification on the particles surface.At present,it is reported that a lot of modification method on the surface for the nanoparticles,such as the ligand exchange method,surface grafting method and surface polymerization and so on.The modified gold nanoparticles as building unit can self-assembled nanostructures under the action of the hydrogen bond,electrostatic,the roles of host-guest and hydrophilic-hydrophobic effect.This thesis used the method of "graft to",as well as gold and thiol strong covalent bonding effect,the hydrophobic thiol polystyrene was grafted to the surface of gold nanoparticles（Au@PS）.The modified particles were self-assembled in the special reaction atmosphere,and getted the special structure of vesicles.In the same way,the thiol polystyrene and thiol polyethylene glycol（PEG）were grafted to the surface of the gold nanoparticles（Au@PEG/PS）,and as a building unit,successful builded vesicle structure.This paper mainly has the following several aspects:1:Use of hydrophobic polymer（PS-SH）modified gold nanoparticles,and then we can construct gold nanoparticles vesicles.First,we use the sodium citrate reduction method to get 14 nm and 30 nm gold nanoparticles,and then thiol polystyrene was grafted to the surface of gold nanoparticles.Through switch the common solvent to the selective solvents,we can get the gold nanoparticles vesicles.2:We use the thiol polyethylene glycol（PEG-SH）and thiol polystyrene（PS-SH）to modify the surface of gold nanoparticles.At first,we make PS-SH and PEG-SH dissolved,and then modified the gold nanoparticles.In the two phase of chloroform and water solvent,we obtained self-assembly amphiphilic gold nanoparticles vesicles.3:The hydrophobic vesicle structure embedded small molecules fluorescence,and applicated in surface enhanced Raman scattering（SERS）.In the process of Au@PS for self-assembling,we used the oil soluble fluorescent molecules(C₁₈H₁₇N₂BF₂,C₂₂H₂₀N₃BF₂)that were embedded into vesicles.Under the limit of nanoscale space,the small molecules fluorescence was successfully embedded into vesicles when the hydrophobic gold nanoparticles were in the self-assembly process.And then we explored the embedding efficiency and quantity of fluorescent molecules.The construction unit of hydrophobic gold nanoparticles vesicles were based on gold nanoparticle chains.The amino-benzenethiol as Raman signal molecule,the Raman signal of hydrophobic vesicles were resulted in enhancement significantly.The construction unit of hydrophilic gold nanoparticle vesicles were gold nanoparticles,and the Raman signal was relatively weak.Through the Raman Effect,it further confirmed that the hydrophobicity of gold nanoparticle vesicles were builded by gold nanoparticles chains,and the hydrophilic gold nanoparticles vesicles were made up of gold nanoparticles.