Synthesis of Organic Functionalized Silica from Rice Husk as an Antibacterial Agents

In the present study, silica-aminothiazole (RHAC-ATH) and silica-aminophenol (RHAC-AMPH) have been prepared and characterized by different techniques. Fourier-Transform Infrared (FTIR) and elemental analysis(CHNS) proved that the modified silica was successfully functionalized with aminothiazole and aminophenol. The X-ray diffraction technique proved the amorphous nature of the prepared material, with maximum intensity obtained at 21-23 degrees (2 theta). Scanning Electron Microscopy (SEM) technique showed that the particles of RHAC-ATH resemble cauliflower while those of RHAC-AMPH have a more regular shape that resembles cubes. EDX analyses of RHAC-ATH and RHAC-AMPH showing nitrogen and other elements in the solid ligands. Thermogravimetric analysis of the prepared materials indicated that the loss of the adsorbed H2O occurred between 25 and 120 degrees C while the residuals decomposed at 600 degrees C. The antimicrobial activity of the prepared compounds was investigated against Staphylococcus aureus and Escherichia coli bacteria. The results showed that E.coli bacteria were resistant to the studied concentrations (0.25-8 mu g\mL) of the prepared compounds, while they lost their ability to produce toxin at concentrations (1-8 mu g\mL) of RHAC-ATH. S. aureus bacteria were sensitive to concentrations of 8 mu g\ml of RHAC-ATH and (4-8 mu g\mL) of RHAC-AMPH, but they lost their ability to produce hemolysin toxin at 2 mu g\mL concentrations.