The Preparation Of Functional Materials Through Polymerization Induced Self-assembly

Polymeric nanomaterials have attracted great attention because of their application in drug delivery, catalysis, fluorescence detection, environmental field, etc. The traditional method for preparing polymeric nanomaterials is through the self-assembly of polymer in a selective solvent. The morphologies of polymeric nanomaterials were affected by the composite of the solvent and the component of polymer. Various morphologies have been fabricated in this method during the past decades. However, there are limitations with the traditional method, such as the self-assembly procedure is performed in the diluted solution and the process is time-consuming. To address these problems, a new method has received much attention, which was used to prepare polymer nanoparticles through the polymerization induced self-assembly. Our groups have prepared nanoparticles via the polymerization of St in methanol or ethanol using macromolecule as a chain transfer agent. Armes et al. reported that the dispersion polymerization of different monomers in ethanol or aqueous phase fabricated nanoparticles using macromolecule as a chain transfer agent. Even though, there are a lot of reports about preparing polymer nanoparticles through polymerization induced self-assembly, but those researches were focused on morphology transformation of nanoparticles and the theory of self-assembly, and nanoparticles were lacking of functional properties. In this dissertation, we focus on the constructing functional nanoparticles, in order to enrich the application of polymerization induced self-assembly in preparing functional nanoparticles. The primary results were listed as follows:1. Fluorescence nanoparticles were prepared via the dispersion polymerization of CzEMA in the mixture using PDMAEMA-CPADB as chain transfer agent. After being heated at 70℃ in this mixture, CzEMA is soluble, however, PCzEMA is insoluble. As the DP (degree of polymerization) of CzEMA gradually increased in PDMAEMA-PCzEMA, polymer nanoparticles were fabricated during the phase separation. Polymer aggregations with various morphologies can be prepared with different molar ratios of CzEMA/PDMAEMA-CPADB and solid contents, such as micelles, nanowires, lamellas and vesicles.’H NMR spectra and GPC traces were used to track the polymerization process. Due to carbazole groups contained in polymer chains, we studied the fluorescence intensity of nanoparticles with various morphologies. The result indicates that the fluorescence intensity of nanoparticles increases as polymer aggregations changing from micelles to vesicles. According to theoretical studies of self-assembly of block polymer and fluorescence mechanism of carbazole groups, we can use the changes of fluorescence intensity of nanoparticles to study the stretch of polymer chains in nanoparticles. Although Eisenberg et.al provided the theoretical studies, but no experiments has been reported to demonstrate that.2. Polymer aggregations were prepared by the dispersion polymerization of St in ethanol using P(DMAEMA-co-TMSPMA)-CPADB as a chain transfer agent. Various morphologies of nanoparticles were fabricated through adjusting the polymerization time, such as micelles, nanowires, vesicles. PDMAEMA can be used as reducing agent for in situ reduction of gold precursor and stabilizing agent of gold nanoparticles. Au-polymer hybrid naoparticles were prepared by in situ reduction of HAuCl4, without need of additional reducing agent. On the other hand, polymer aggregates self-crosslink through the hydrolysis and condensation of the methoxysilyl groups, which increases the stability of hybrid nanoparticles.