Effect of catalyst on formation of poly（methyl methacrylate） brushes by surface initiated atom transfer radical polymerization

摘要

Poly(methyl methacrylate)(PMMA) brushes were synthesized from silicon wafers via surface initiated atom transfer radical polymerization(SI-ATRP).Energy disperse spectroscopy(EDS) and atomic force microscopy(AFM) confirmed that PMMA brushes were successfully prepared on the silicon wafers,and the surface became more hydrophobic according to the contact angle of 69°.It is found that CuCl/1,1,4,7,10,10-hexamethyl triethylenetetramine(HMTETA) system is more suitable than CuBr/N,N,N′,N″,N″-pentamethyl diethylenetriamine(PMDETA) system to control the free radical polymerization of MMA in solution.Nevertheless,better control on the thickness of PMMA brushes was achieved in CuBr/PMDETA than in CuCl/HMTETA due to higher activity and better reversibility of the former system.