Tuning assembly behavior of conjugated polymers through DNA nucleobases: From supramolecular design to emerging functions

• Main Authors: Wen-yu Ji, 紀玟伃
• Other Authors: Shiao-Wei Kuo
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/91118499019435121392

碩士 === 國立中山大學 === 材料與光電科學學系研究所 === 104 === Supramolecular chemistry is a powerful strategy for molecular design due to simple molecular recognition, controllable properties, self-assembly behaviors, and good processability. Conjugated polymers with good conductivity and light-emitting properties have been widely used in optoelectronic applications. Based on the concepts mentioned above, we prepared novel supramolecular conjugated polymer for further discussions. Our study is divided into two parts. Part Ι: Water-soluble Fluorescent Nanoparticle Fabrication Based On Heterocomplementary Multiple Hydrogen Bonding Interactions, Part Π: Stimuli- responsive conjugated polymers for surface-relief grating fabrication. In Part Ι, we used Suzuki-coupling polymerization to synthesize two different polymers of PC-N3 and PTC-N3 with different conjugated systems. After post-functionalization with CuAAC “click” reaction, nucleobase-contained conjugated polymers PC-T and PTC-T were successfully synthesized and structure confirmation was proceeded via FT-IR, 1H and 13C NMR measurements. The supramolecular motifs have been introduced to conjugated systems and the effect of non-covalent interaction has been discussed. The glass transition temperature of PC-T and PTC-T were enhanced by strong multiple hydrogen-bonding interaction between thymine (T) base pair based on DSC results. The water-soluble fluorescent nanoparticles were then prepared with hydrophilic polymer PEG-A through heterocomplementary hydrogen bonding between Adenine (A) and Thymine (T) DNA nucleobases. TEM images revealed that the size of nanoparticles of PC-T:PEG-A and PTC-T:PEGA were 140 and 160 nm, respectively. Via the cytotoxic test also shows that nanoparticles with good biocompatibility. These new materials may provide a potential route towards water-soluble Light emitter and cell imaging applications. In Part Π, We used different conjugated unit to discuss the molecular properties according to the construction of supramolecular system in Part I. Two polymers PTCAzo-N3 and PTCAzo-T have been synthesized through facile organic reactions. After characterization, we found that side-chain induced supramolecular network can efficiently improve the thermal properties and film-forming properties, which is consist with our previous discussion. Futhermore, azobenzene functionality may lead to a change in entire optical properties and perform unique behavior. Under the illumination of diffracted laser beam, the polymer films form special surface relief grating structure. Supramolecular blending system therefore plays an important role in controlling the height of these gratings. The materials proposed in this study provide unconventional strategies to fabricate optical storage devices and may have a promising future for various applications.