Design, Synthesis And Self-assembly Of Conjugated Rod-coil Block Copolymers

Conjugated rod-coil block copolymer is one of the special type of polymers which containsdifferent rod (lipophilic) and coil (hydrophilic) segments. It combines the excellent properties ofa variety of polymers and it is a kind of superior functional polymer material. Compared with thegeneral polymers, rod-coil block copolymers have the following advantages: controlled molecularweight, narrow molecular weight distribution, easily designed molecular structure and composition,the regulated charge density and the unique self-assembly properties. It is believed that conjugatedrod-coil block copolymers could spark the future evolution of nanostructured polymers formultifunctional device applications. It contains rod-coil block polymers and coil-coil blockpolymers. Due to the thermodynamic incompatibility of two blocks and the regular arrangement ofrod blocks, it has special self-assembly properties. So it has become a research hotspot inoptoelectronic information materials. In this background, two series of asymmetric conjugatedrod-coil block copolymers were designed and synthesized. And then studied their photophysicalproperties, self-assembly behaviors and cell imaging applications.(1) A novel asymmetric rod-coil diblock polymers were designed and synthetized via the Suzukicoupling reaction and atom transfer radical polymerization (ATRP). The rod segment is“benzene-fluorene-benzene” structure, and the coil segment is poly polyethylene glycol acrylate ormethacrylate.(2) The properties of asymmetric diblock polymer (P1PAA-50) were studied, which containphotophysical properties in aqueous solution and the self-assembly behaviors at differentconcentrations, different mixing ratio of the solvent. And the optical properties, particle size andmorphology of self-assembly structures were characterized. The results show that the nanoparticlesize can be regulated by controlling the P1PAA-50concentration and the solvent (water/tetrahydrofuran) ratio. What’s more? The low cytotoxicity of the polymer was demonstrated byMTT assay and cell imaging shows that nanospheres can be absorbed efficiently by the cells andcumulated in the cytoplasm.(3) Water-soluble conjugated rod-coil block polymer P1PEG was designed and synthetized. Thephotophysical properties under different concentrations, and the self-assembly behavior in benignsolvents (methanol and water) were studied. Finally, the fluorescent-magnetic nanoparticles(diameter:~12nm) were successfully prepared. And they have good water solubility. The morphology properties of these fluorescent-magnetic nanoparticles were characterized bytransmission electron microscopy (TEM) and dynamic light scattering (DLS).