Research On Poly (Acrylic Acid)-block-polyacrylonitrile Polymeric Micelles And Nanomaterials

Amphiphilic block copolymers can self-assemble into spherical micelle with a shell of hydrophilic segments and a core of hydrophobic segments in aqueous solution, which have attracted great attention for their potential applications in preparation of nano-materials. In this thesis, the synthesis followed with micellization of PAA-b-PAN amphiphilic block copolymers, the hydrogen-induced co-aggregation between PAA-b-PAN micelles with the other micelles, and the preparation of magnetic carbon nanoparticles by using PAA-b-PAN micelles as templates were studied. The main work and results are as follows:1. Poly(t-butyl acrylate)-polyacrylonitrile diblock copolymer (PtBA-b-PAN) was synthesized by atom transfer radical polymerization. After hydrolysis with trifluoroacetic acid, poly(acrylic acid)-polyacrylonitrile amphiphilic diblock copolymer (PAA-b-PAN) was yielded and self-assembled into micelles in aquous solutions. These polymers were characterized by gel permeation chromatography (GPC), Fourier-transfrom infrared (IR) spectroscopy, and H nuclear magnetic resonance (1H NMR) spectroscopy respectively. The results showed that PAA-b-PAN copolymers with narrow distribution were obtained successfully by ATRP. The laser light scattering (LLS) and transmission electron microscopy (TEM) were used to characterize the size and morphologies of micelles, as well as the effects of pH values of solutions on micelles. The results revealed that PAA-b-PAN copolymers could assemble into spherical micelles with PAA shells and PAN cores, and their hydrodynamic radii are about 20 nm. The micelles changed with the changes of pH values of solutions, when the pH values increase form 6.5 to 9.8, they increase in their sizes and change from dense structures to loose structures. 2. PDMS-g-PEO graft copolymers synthesized by our lab were used to prepare micelles in aqueous solution. LLS and TEM were used to investigate the co-aggregation of PAA-b-PAN micelles and PDMS-g-PEO micelles induced by hydrogen-bonding, as well as the great influences affected by pH values, unit moral ratios (r) of PAA/PEO, and standing time. The results revealed that PDMS-g-PEO could self-assemble into micelles with some PEO grafts interlocking with each other and with collapsed PDMS chains as the core and the other PEO grafts as the corona, their radii were about 140 nm. It's found that the aggregation occurred below the pH value of 3.5. And at r form 0.61 to 1.21, the PAA-b-PAN micelles were absorbed to the shells of PDMS-g-PEO micelles and formed slightly larger spherical-like aggregates with...