tailieunhanh - Báo cáo hóa học: " Synthesis of Polymer Grafted Magnetite Nanoparticle with the Highest Grafting Density via Controlled Radical Polymerization"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Synthesis of Polymer Grafted Magnetite Nanoparticle with the Highest Grafting Density via Controlled Radical Polymerization | Nanoscale Res Lett 2009 4 1090-1102 DOI s11671-009-9365-z NANO EXPRESS Synthesis of Polymer Grafted Magnetite Nanoparticle with the Highest Grafting Density via Controlled Radical Polymerization Kothandapani Babu Raghavachari Dhamodharan Received 9 March 2009 Accepted 26 May 2009 Published online to the authors 2009 Abstract The surface-initiated ATRP of benzyl methacrylate methyl methacrylate and styrene from magnetite nanoparticle is investigated without the use of sacrificial free initiator in solution. It is observed that the grafting density obtained is related to the polymerization kinetics being higher for faster polymerizing monomer. The grafting density was found to be nearly 2 chains nm2 for the rapidly polymerizing benzyl methacrylate. In contrast for the less rapidly polymerizing styrene the grafting density was found to be nearly chain nm2. It is hypothesized that this could be due to the relative rates of surface-initiated polymerization versus conformational mobility of polymer chains anchored by one end to the surface. An amphiphilic diblock polymer based on 2-hydroxylethyl methacrylate is synthesized from the polystyrene monolayer. The homopolymer and block copolymer grafted MNs form stable dispersions in various solvents. In order to evaluate molecular weight of the polymer that was grafted on to the surface of the nanoparticles it was degrafted suitably and subjected to gel permeation chromatography analysis. Thermogravimetric analysis transmission electron microscopy and Fourier transform infrared spectroscopy were used to confirm the grafting reaction. Keywords Poly benzyl methacrylate Atom transfer radical polymerization Magnetite nanoparticle Electronic supplementary material The online version of this article doi s11671-009-9365-z contains supplementary material which is available to authorized users. K. Babu R. Dhamodharan El Department of Chemistry Indian Institute of Technology Madras Chennai 600 036 India e-mail .