Study On Self - Assembly Behavior Of Block Copolymer And Dye Molecule In Gas Expanded Liquid

In this work, the self assembly behavior and properties of the self assembly fluorescent complex (SAFC) formed between dye molecule4and polystyrene-block-poly(4-vinylpyridine)(PS-b-P4VP) in CO2-expanded liquids (CXLs) was investigated. The IR spectra of SAFC indicated that CXLs makes hydrogen-bonding much easier to form between the P4VP blocks and dye molecule4. With the pressure of CXLs increasing, the fluorescence intensity increased due to the formation of hydrogen bond between P4VP segment and dye molecule4, then dye molecule4(which was coupled with P4VP) was confined only in the central portion of the vesicle walls due to the location of P4VP and triggered the RIR process.1. Three diblock copolymers with different relative block length were synthesized via RAFT.2. Dye molecule4with a partially propeller-shaped and fluoranthene-based biphenol structure has been synthesized. The FL properties of dye molecule4in ethylene glycol and methanol mixtures, as well as in various solvents were investigated, respectively. Both deprotonation equilibrium and the RIR effect are plausible mechanisms to its unique FL behavior.3. The SAFC exhibited a series of morphological transitions from vesicle, worm-like rod, to sphere aggregates by increasing the molar ratio of4VP to dye molecule4. Moreover, this study helps the research and potential applications for a wide range of dye molecules and block copolymers coupled with hydrogen bond.