Abstract: Objective: To evaluate the antibacterial ability of a kind of polymeric quaternary ammonium compound grafted on titanium surface by ATRP. Methods: Titanium surface was grafted with poly(dimethylaminoethyl methacrylate) brush (PDMAEMA) by ATRP and further decorated with 1-bromohexadecane to synthesis polyquaternium. The modified surfaces were characterized using contact angle measurements, X-ray photoelectron spectroscopy (XPS), and attenuated total reflectance Fourier transform infrared (FTIR). The antibacterial performance of the modified surfaces was evaluated with the streptococcus mutans (S.m) and Escherichia coli (E. coli) attachment test by fluorescence microscope and scanning electron microscope. Results: Contact angle measurements, XPS, and FTIR showed the aimed products were successfully deposited on Ti surface. No matter gram-positive S.m or gram-negative E. coli, there were a lot of live bacteria and little dead bacteria on the Ti surface, however, almost full of dead bacteria on the modified Ti surface. Furthermore, modified surface showed great antibacterial ability after 4h and 24h. The results of SEM were the same as that of FM that the bacteria on modified surface were much less than bare titanium. Conclusion: A kind of polymeric quaternary ammonium compound was successfully grafted on the titanium surface. And the modified surface possessed great antibacterial ability.

Key words: Titanium, Polymeric brush , ATRP, Quaternary ammonium , Antibacteria