| pH, fluoride and thermo-responsive fluorescent chemosenors were designed and synthesized by Reversible addition-fragmentation chain transfer (RAFT) polymerization. And optical response of polymers were also investigated as follows:Simple-structured copolymers, poly(NIPMAMm-co-CPMAn), consisting of N-isopropyl-methacrylamide (NIPMAM) and (Z)-4-(1-cyano-2-(4-(dimethylamino)phenyl)vinyl)phenyl-methylacrylate (CPMA) units as thermo-and pH-responsive fluorescent signaling parts, respectively, were synthesized by RAFT polymerization. The copolymer PCN250 (m/n=250) showed absorbance enhancement or decrease at different pH value. However, the fluorescence intensity of this copolymer showed enhancement with a rise in temperature regardless of pH value in the range of pH= 4-10. In addition, fluorescence suppression of copolymer (PCN250) was observed with high proton concentration (pH=0.6-2.8) both in solution and film. Moreover, the Lower Critical Solution Temperature (LCST) value of the copolymers (PCN250 and PCN51) were very different just because of the different component incorporated in the copolymeric thermometers.Polymeric fluorescent chemosensors, poly(NIPMAMm-co-Napn) ([NIPMAM]/[Nap]= m/n), consisting of NIPMAM and 1,8-naphthalene imide derivate (Nap) units as thermo-and F- responsive signaling parts, respectively, were synthesized by RAFT polymerization. In DCM/DMSO (9/1, v/v) solution, the homopolymer PNap showed higher fluorescence enhancement than the copolymers (PNap24, PNap91 and PNap334), and the copolymers with lower [NIPMAM]/[Nap] value showed higher sensitivity than those with higher [NIPMAM]/[Nap] value. However, it was contrary to the polymer films on quartzs. Moreover, the LCST of the copolymers also depended on the ratio of [NIPMAM]/[Nap]. When the ratio of [NIPMAM]/[Nap] was 24, there was no LCST was observed at DMSO/H2O (1/4, v/v) solution system. What's more, the polymer PNap334 showed high reusability and high reveribility. |
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