Study On Synthesis And Properties Of Ferrocene- Based And (or) Azobenzene-based Compounds And Block Copolymers

Smart materials are a series of novel functional materials which can respond to external stimuli-signals. As advances of materials science, smart materials have important applications in military, architecture, health care and so on. Therefore, smart materials are attracting more and more researchers’attention.Herein, two sensing molecules with electro-signal unit, a pair of sensing molecules with both electro- and photo-signal units, four series of amphiphilic block copolymers functionalized by electro- or photo-responsive group, and a series of elelctrospinning fibers electrospun by photo-responsive amphiphilic block copolymers were synthesized and prepared. Their structures and composites were characterized and their ion-sensing properties, electro- or photo-responsive behaviors were studied.Two sensing molecules with electro-signal unit and a pair of sensing molecules with both electro- and photo-signal units were synthesized. Reversibility of CV curves was influenced by solvent’s polarity and scan rate. Sample 2 showed a good ability for selectively sensing H2PO4-, meanwhile sample 4 showed an excellent ability for selectively sensing HSO4- by CV curves. However, sample 4 showed a selective sense for F-, and sample 5 showed a selective sense for both F- and H2PO4- by UV-vis spectra. With appropriate concentration of sample 4 or sample 5, F- and H2PO4- could be recognized by naked eye. Possible mechanism of sensing process was proposed by results of J-plot.Three kinds of ferrocene-based block copolymers PEO-b-P(MMA-co-FcHEMA) with different block ratios were synthesized by atom transfer radical polymerization (ATRP). CV curves of polymers were similar to these of ferroceny derivatives. Polymers self assembled into spherical micelles, which diameters varied from 100 to 200 nm. Micelles would aggregate togother or disassemble after mixing with oxidant. However, no obvious morphology change would be found after adding reductant.Four kinds of azobenzene-based block copolymers PEO-b-P(MMA-co-MAAZOOHEE) with different block ratios were synthesized by ATRP. The π-π* transition band peak and n-π* transition band peak of azobenzene group, respectively located in 350 nm and 440 nm in UV-vis spectra. After UV light irradiation, π-π* transition band peak’s intensity decreased with blueshift, meanwhile, n-π* transition band peak’s intensity increased. After visible light irradiation, UV-vis spectra would reversibly recovery. Polymers would self assemble into spherical micelle-aggregates, which diameter ranged from 50 to 150 nm. After UV light irradiation, micelle-aggregates would disassemble to polymers. Introducing β-CD into polymers aqueous solution, the host-guest interaction between β-CD and azobenzene would lead to form micelle without aggregates. After UV light irradiation, micelles also disassembled into polymer and β-CD mixture solution.Four kinds of azobenzene-based block copolymers PEO-b-P(MMA-co-MAAZO) with different block ratios and substituent group were synthesized by ATRP. Polymers without nitro group, located the π-π transition band peak and n-π* transition band peak in 350 nm and 440 nm respectively. Polymers with nitro group, only located the π-π* transition band peak in 385 nm. After UV light irradiation, π-π* transition band peak’s intensity of polymers without nitro group, decreased with blueshift, meanwhile, n-π* transition band peak’s intensity increased. However, π-π* transition band peak’s intensity of polymers with nitro group, only decreased without blueshift. Polymers without nitro group self assembled into micelle-aggregates, and polymers with nitro group self assembled into micelle without aggregates. After UV light irradiation, micelle-aggregates and micelles would disassemble both.Three kinds of azobenzene-based block copolymers P(S-co-MAAZOOHEE)-b-PDMAEMA with different block ratios were synthesized by reversible additive fragment transfer polymerization (RAFT). The π-π* transition band peak and n-n* transition band peak of azobenzene group, respectively located in 350 nm and 440 nm in UV-vis spectra. After UV light irradiation, π-π* transition band peak’s intensity decreased with blueshift, meanwhile, n-π* transition band peak’s intensity increased. After visible light irradiation, UV-vis spectra would be reversibly recovered. Polymers self assembled into spherical micelles without aggregates, and diameter varied from 50 to 100 nm. Increasing temperature, would lead to micelle-diameter decreasing, and with UV light irradiation, diameter would also decrease.40 kinds of nano- or micro-meter fibers were prepared by electrospinning THF solution of block copolymers PEO-b-P(MMA-co-MAAZOOHEE). Several technical parameters were studied. Cylinder receiver and plate receiver have similar fibers’ morphology. Beads-fibers were prepared by low sample-injection rate, low working-voltage, low molecule weight and low concentration, meanwhile, fibers were prepared by high sample-injection rate, high working-voltage, high molecule weight and high concentration. Furthermore, before electrospinning, exposing to UV light 5 mins would result in fibers with even size and less beads.