Preparation of Self-Assembling Matrix from Dendritic-Linear Copolymers Based on a Solvent-Induced Phase Separation Mechanism

• Main Authors: Shang-JuHsieh, 謝尚儒
• Other Authors: Chuh-Yung Chen
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/96755427731580875599

博士 === 國立成功大學 === 化學工程學系碩博士班 === 98 === Fabrication of nanometer and micrometer scale ordered structures at low price is an essential objective of a wide range application, such as current science and technology for the miniaturization of electronic, optic, and magnetic device, and sensors etc. Numerous methods such as photolithography or chemical vapor deposition have successfully fabricated ordered structures over a wide range of length scales, however, still require tedious multiple-step processes with high costs. Notable, the method using molecular self-organization is a good way that one can directly produce the ordered two- or three-dimensional structures and tailored surfaces by a single step. In addition, with the rapid development of synthetic chemistry, many new molecular structures can be designed to investigate the role of polymer topology on the physical and chemical properties of macromolecules in traditional, block, hyperbranch, and, in particular, dendritic copolymers. Among them, dendritic macromolecular chemistry has recently attracted significant attention due to its various functions and the properties that result from its special structures and characteristics. This investigation proposes a straightforward method for synthesizing various kinds of self-assembling dendritic-linear copolymer to create ordered films via solvent-induced phase separation. In first section of this study, the various kinds of HPAM dendron, HPAM-GX-S dendritic macroinitiator, GMA-HPAM dendritic macromonomer, and MA-APM dendritic macromonomer were synthesized by using the divergent growth method. Moreover, the end-chain dendritic-linear copolymers, HPAM-co-PS, were developed by using the thiol-caprolactam initiation or free radical polymerization system with the dendritic macroinitiator and styrene monomer. And the side-chain dendritic-linear copolymers, PGMA-HPAM-r-PS and PMA-APM-r-PS, were synthesized via free radical polymerization involving the styrene monomer and the dendritic macromonomer, GMA-HPAM or MA-APM. Furthermore, all kinds of the dendritic-linear copolymer films were prepared by using the solvent-induced phase separation method at room temperature. The morphological structures on the all kinds of the dendritic-linear copolymer films showed the self-assembling behavior as functions of dendritic segments in the generation and content in electronic microscope. There existed an ordered structure on the copolymer film surfaces when the dendritic segment contents approximately reached a critical equilibrium. In addition, the interactions in the dendritic-linear copolymer affected the surface morphologies of the dendritic-linear copolymer films, and it made the dendronized copolymer, HPAM-co-PS, to show a phase separation membrane structure, and the side-chain dendritic-linear copolymers, PGMA-HPAM-r-PS and PMA-APM-r-PS, to show a microporous membrane structure. In second section of this study, the self-assembling dendritic-linear copolymers were used for various kinds of material application. The dendritic-linear PGMA-HPAM-r-PS copolymer was used as templates for the molecular imprinting films. The solution, with monomers, the crosslinking agent, and the pototinitiator, was coated onto the surface of templates. Then , the molecular imprinting film RG-25 was received via the UV-light initiation and the stripping procedure. Moreover, the homogeneous composition of the surface of the membrane with the hexagonally ordered arrays was received by the dendritic-linear PGMA-HPAM-r-PS copolymer, was used as a template, via the alkali treatment. Furthermore, the dendritic-linear PGMA-HPAM-r-PS copolymers were used as template for the growth of nanomaterials. The dendritic segments in the copolymer were the coordination sites for chelating cadmium ions, and served as nano-templates for the growing of CdS nanocrystals (quantum dots). The diameters of the CdS nanocrystal on the dendritic-linear copolymer template were uniform in the range of 5 to 8 nm. In particular, large-area, the hexagonally-ordered CdS nanocrystal-array domains were discovered over the dendritic-linear copolymer template in this study. Finally, the dendritic-linear copolymers were used as the dispersing agent for the blend of PS and PMMA homopolymers. When the content of the dendritic-linear copolymer reached at 40 wt% in the blending system, the ordered surface morphology of the blending membrane could be received.