Construction And Reversible Modulation Of Self-assembled Systems Based On Ferrocenyl Derivatives

In this thesis, a new approach to construction of redox controlled self-assembly wasproposed by introducing ferrocenyl group with reversible redox activity as functionalassembly blocks. The main goal is to establish the new reversible self-assembly methods bystudying the aggregation and disaggregation behavior of four self-assembly systems (theredox-controlled reversible self-assembly of ferrocenyl-terminated linear-dendriticamphiphilic block copolymers, the electrochemical-controlled reversible self-assembly offerrocene-containing amphiphilic block copolymers, the electrochemical-controlled reversibleself-assembly of polyelectrolytes-surfactants complex, and the reversible self-assembly ofh drophobicall modifed etho lated urethanes end-capped by ferrocene-containingdendrons), and the effect of chemical redox, electrochemical redox and β-CD inclusion ontheir aggregation and disaggregation in detail. The results would be useful for thedevelopment of reversible responsive functional self-assembly systems. The main contentsand the results are as follows:1. Novel linear-dendritic amphiphilic block copolymers Fc1CO2PEG2k, Fc2CO2PEG2kand Fc3CO2PEG2k were synthesized by the esterification reaction of poly(ethylene glycol)methyl ether with ferrocenyl-terminated alkyl substituted benzoic acid dendrons. Thesepolymers can reversibly self-assemble into various aggregates, such as spherical, wormlikemicelles, and vesicles, and also disassemble into irregular fragments in aqueous solution byredox reaction when changing the polymer concentrations. Furthermore, Rhodamine6G(R6G)-loaded polymer aggregates have been successfully used for the oxidation-controlledrelease of loaded molecules, and the release rate can be mediated by the concentrations ofoxidant and copolymers.2. A series of ferrocene-containing amphiphilic block copolymers PEG-b-Fc,PEG-b-PFc3and PEG-b-PFc8were synthesized. Under the same molar concentration andredox voltage, if the critical aggregation concentration (CAC) of ferrocene basedamphiphilic block copolymer is greater, its electrochemical redox rate is faster. PEG-b-Fc and Fc1CO2PEG2k in0.1M NaCl aqueous solution can form electrochemical-controlledreversible self-assembly and disassembly system.3. A new type of electrochemical redox active polyelectrolytes-surfactants complexswere prepared by ferrocenyl surfactant FTMA and double-hydrophilic block copolymerPEG-b-PAA. By adjusting the degree of polymerization of PEG and PAA segment, thestability of the polyelectrolyte-ferrocene surfactant complexs aqueous solutions wereobtained. The complexs aqueous solutions have good electrochemical redox activity, andthe electrochemical redox rates can be adjusted by redox voltage and complexsconcentration, which can form electrochemical-controlled reversible self-assembly anddisassembly system.4. Novel dendron hydrophobically modified ethoxylated urethanes (HEUR) with thesame hydrophilic portion but different terminal hydrophobic group numbers were preparedby using ferrocenyl-terminated alkyl substituted benzoic acid dendrons as new end-cappers.These HEUR can form redox-controlled and β-CD inclusion-controlled reversibleself-assembly and disassembly system in dilute aqueous solution. The solution viscositybehavior of these HEUR can be adjusted redox reaction and β-CD inclusion.