Preparation,Properties And Applications Of Carbon Dots Grafted Polymer Hybrid Materials

Carbon dots(CDs)are a novel type of carbon nano materials.Compared with traditional inorganic quantum dots,carbon dots have better biocompatibility and easy surface functionalization.Meanwhile the fluorescence of carbon dots also has the advantages of strong stability and anti photobleaching.This makes carbon dots have good application prospects in the fields of photocatalysis,sensors,information storage et al.However,the functionality of carbon dots is single.In order to endow carbon dots a new range of applications,scientists often modify polymers on the surface of carbon dots.Herein,the functionalized carbon dots were synthesized by reversible addition-fragmentation chain transfer(RAFT)polymerization,and functional carbon dots in different application fields were prepared.The main research content are as follows:1.A series of acrylamide phenylboric acid(AAPBA)with different lengths were successfully modified on the surface of carbon dots by RAFT polymerization(CD-g-poly(AAPBA)).The reaction of p H to CD-g-poly(AAPBA)with different chain length is different.The fluorescence intensity of short chain CD-g-poly(AAPBA)would gradually increase with the increase of p H,while the fluorescence intensity of long chain CD-g-poly(AAPBA)would gradually quench with the increase of p H.Glucose has fluorescence quenching ability to CD-g-poly(AAPBA)with different chain length.The ability of quenching fluorescence to CD-g-poly(AAPBA)increases with the shortening of chain length.Also,the fluorescence intensity of CD-g-poly(AAPBA)has a good linear relationship with glucose concentration and p H.2.Carbon dots grafted with tetraphenylethylene and N-isopropylacrylamide block polymer(CD-g-poly(TPE-block-NIPAM))was synthesized.CD-g-poly(TPE-block-NIPAM)showed aggregation-induced emission(AIE)when it was in water.And it shows no cytotoxicity and was easily internalized by living cells and show high fluorescence.3.Carbon dots grafted with tetraphenylethylene,spiropyrane and N-isopropylacrylamide block polymer was synthesized(CD-g-poly((TPE-block-SPA)-co-NIPAM)).CD-g-poly((TPE-block-SPA)-co-NIPAM)shows aggregation-induced emission.When CD-g-poly((TPE-block-SPA)-co-NIPAM)was irradiated by ultraviolet light,the intensity of emission wavelength located in 455 nm would gradually decrease and the intensity of emission wavelength located in 625 nm would gradually increase.However,when CD-g-poly((TPE-block-SPA)-co-NIPAM)was irradiated by visible light,the intensity of emission wavelength located in 455 nm would gradually increase and the intensity of emission wavelength located in 625 nm would gradually decrease.And CD-g-poly((TPE-block-SPA)-co-NIPAM)was easily internalized by living cells and shows blue-green and red fluorescence.