کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5184326 | 1381045 | 2010 | 7 صفحه PDF | دانلود رایگان |
A strategy for covalent grafting of biocompatible polymers onto sidewalls of multi-walled carbon nanotubes (MWNTs) via UV-initiated free-radical polymerization is presented. The effects of the irradiation doze(time) and monomer/MWNTs ratio on the stability of the corresponding aqueous dispersions were investigated. It was found that stable dispersions of MWNTs modified with polyacrylamide, poly(N-isopropylacrylamide), poly[poly(ethylene glycol) methacrylate] and poly(sodium methacrylate) can be obtained by irradiation with UV light for at least 5 min at an irradiation dose rate of 5.7 J/cm2 min at a minimum monomer/CNTs ratio of 200:1. Biocompatibility of polymer-modified MWNTs was assessed using the standard MTT-dye reduction assay and compared to pristine MWNTs. As a rule, all polymer-functionalized nanotubes examined in this study were non-cytotoxic up to concentration 150 μg/mL and, remarkably, MWNTs-g-PNIPAAm did not exhibit cytotoxicity even at the highest concentration studied (300 μg/mL). MWNTs modified with stimuli-sensitive polymers underwent a reversible transition from well-dispersed nanotubes in water to precipitate triggered by changes in temperature or pH.
Journal: Polymer - Volume 51, Issue 12, 28 May 2010, Pages 2465-2471