Study On Controllable Synthesis Of POSS-P(NIPAm-co-NBDAE) And Its Fluorescent Responsive Behavior

Recently,the study of environmental stimulus-response polymers provides an advantageous platform for the development of polymer intelligengt materials.Incorporiting fluorescent material into PNIPAm,to prepare new materials with fluorescence temperature-sensitive properties has become a research hotspot in developing intelligent new materials.These new materials have many important potential applications in the fields of fluorescence temperature sensing,trace ion detection,drug loading and controlled release,and their monitoring.In this paper,POSS-?NIPAm-co-NBDAE?andP?NIPAm-AAPBA-NBDAE?wereprepared respectively and their environmental stimulus-response fluorescent behavior were studied in detail.The specific content of the paper is as follows:?1?In the first section,aminopropylisobutyl polyhedral oligomeric silsesquioxane?POSS-NH₂?was decorated with 3-benzylsulfanylthio-carbonylsufanylpropionic acid?BSPA?to prepare a POSS-containing RAFT agent?POSS-BSPA?,4-chloro-7-nitro-2,1,3-benzoxadiazole?NBDCl?asthematernaldyetoprepare?2-acryloyloxyethylamino?-7-nitro-2,1,3-benzoxadiazole?NBDAE?fluorescent monomer;a reversible-fragmentation addition?RAFT?copolymerization of N-isopropylacrylamide?NIPAm?and NBDAE was conducted under action of POSS-BSPA and AIBN to synthesize a novel thermosensitive fluorescence hybrid polymer POSS-P?NIPAm-co-NBDAE?.The reaction process and structure was investigated by FTIR,¹HNMR,DSC and GPC.The fluorescence response behaviors of it to F^-and ambient temperature were investigated by photoluminescence?PL?in solution of H₂O or THF,and the related mechanism was discussed.The results show that,in aqueous solution,the fluorescence emission of the polymer is influenced greatly by ambient temperature;while that is little influenced in THF solution.Moreover,F^-has a relatively slight effect on its fluorescence emission in water,and it can be quenched in THF dramatically.?2?In the second section,N-isopropylacrylamide?NIPAm?,acrylic acid?AA?and?2-acryloyloxyethylamino?-7-nitro-2,1,3-benzoxadiazole?NBDAE?were conducted a copolymerzation by free radical polymerization method,and P?NIPAm-AA-NBDAE?nangel was synthesized firstly,then 3-aminophenylboronic acid?3-PBA?decorated P?NIPAm-AA-NBDAE?nangel was prepared with the aid of N-Ethyl-N'-?3-dimethylaminopropyl?carbodiimide hydrochlorid?EDC?as condensating agent and the condensation reaction between carboxyl acid group?-COOH?and amino group.The micro-structure of the as-prepared nanogel was characterized by FTIR,TEM and DLS.And its responsive performance to stimuli,such as,temperature,pH and glucose were studied by PL in detail,and the related mechanism was discussed.The results show that,the particle size of the nanogel is about 50 nm,and its fluorescence emission is influenced greatly by temperature,pH value and glucose concentration in water solution.Moreover,its fluorescence emission is also affected by PBA content in the decorated nangel.