| In this thesis, multilayer hybrid films composed of azide-functional polymers (P(VBA-AA)) and polyphenylene dendrimer stabilized gold nanoparticles (G2SH-AuNPs-Alk) with numerous naked alkynes in their peripheries were successfully constructed by using a layer-by-layer (LbL) technique based on "click" chemistry which is widely used at present. The gold nanoparticles empolyed in the hybrid films were fabricated by using polyphenylene dendrimer (G2SH) as stabilizer via the Brust-Schiffrin method (Two-Phase Synthesis), which allows the facile synthesis of thermally stable and air-stable Au NPs of reduced dispersity and controlled size for the first time. And the azide-functional polymers were synthesized by reversible addition-fragmentation chain transfer ploymerization (RAFT) approach. The specific contents of this thesis are described as follows.1. Polyphenylene dendrimer G2SH with triisopropylsilyl (TiPS) substituted alkynes was first synthesized, and this process involved a series of chemical reactions, such as Diels-Alder cycloaddition, condensation reaction, the deprotection of TiPS and nucleophilic substitution. The intermediate and final products were characterized by FT-IR,1H NMR,1C NMR and high-resolution mass spectrometry (HRMS).2. Polyphenylene dendrimer-gold nanoparticles were successfully fabricated by Brust-Schiffrin method. They have the shape of sphere and very narrow size distribution. The as-prepared gold nanoparticles were characterized by several chemical instruments and the results reveal that (a) the average core size of Au NPs was increased as the augment of the gold/thiol mole ratios, but this increasement is not too large; (b) when the toluene solution of Polyphenylene dendrimer-gold nanoparticles was reserved for more than five months in the air at about 4℃, no precipitations were observed in the bottom of this solution. However, from the transmission electron microscopy (TEM) images, it can be seen that the size of some Au NPs was indeed inreased and this led to un-uniform of the overall size; In addition, (c) although the overall size of Au NPs became ununiformal, superlattice structures were observed when the Au NPs solution evaporated slowly; Finally, (d) the result of TGA show that weight loss didn't appear until the temperature came up to 200℃, and the losed proportion was less than 15% even at 300℃. These mean that Au NPs have excellent thermal stabilization.3. Clickable species for constructing the multilayer hybrid film were prepared. Firstly, the deprotection of G2SH-Au NPs was carried out at 70℃, and then a number of naked alkynes in their peripheries could be obtained. After this reaction, the diameter of gold particles did not change so much, which suggested again that polyphenylene dendrimer could effectively prevent the nanoparticles'aggregation. Furthermore, the azide- functional polymer P(VBA-AA) was characterized by gel permeation chromatography (GPC) and the results show that the polydispersity index (PDI) is narrow (1.28).4. By empolying the quartz as substrate, multilayer hybrid films were constructed by the combination of layer-by-layer technique and "click" chemistry. The success of the assembly of the hybrid film was confirmed by UV-vis, X-ray photoelectron spectroscopy (XPS), atomic force microscope (AFM) and contact angle. |
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