The Research Of A Novel Biocide Using Poly Quaternary Ammonium Salt Grafted Silica Gel

In this paper, the method of preparing a novel biocide using poly quaternary ammonium salt grafted Silica gel was studied. Treated by activating agent, the Silica gel was grafted with organic functional groups, then they reacted with high-molecular-weight polyethylenimine (PEI) in the organic solvent, therefore PEI was grafted covalently on the surface of Silica gel. Finally, modified by the alkyl halide such as bromohexane and iodomethane, the PEI grafted on the surface of Silica gel were converted to high-molecular-weight antimicrobial quaternary ammonium salts, and the novel biocide were prepared. The antimicrobial groups were grafted on the surface of Silica gel by covalent bonds.The technics of preparation of biocide has been optimized in choosing activating agent and Silica gel in this paper. And the results indicate that 4-Bromobutane chloride and Y-chlopropyltrimethoxysilane were used as activating agent respectively to prepare two kinds of novel biocides, and the cheap and low-poisonous y-chlopropyltrimethoxysilane was a preferable activation substances. And the cost of biocide was reduced significantly.The bactericidal capabilities of the product prepared according to optimal conditions were evaluated, and its characters were displayed by analyzing infrared absorption spectrum (IR) of the novel biocide. IR analysis testifies that the high-molecular-weight antimicrobial groups were grafted successfully on the surface of Silica gel .The biocidal tests indicate that the bactericidal capacities of the biocide to typical microorganisms such as Gram positive(S. aureus) and Gram negative bacteria(E. coli), Yeast and Penicillium, Spirulina plantensis are obvious.After the further biocidal tests by above-cited typical microorganisms, some parameters in application are determined such as Minimal inhibited concentration (MIC), the optimal using concentration ,the optimal time range,etc.The biocidal tests to the same sample were carried out in the different time and different using times, the results show that the novel biocides can maintain good biocidal efficiency even if they were placed for a long time or used many times,...