Tetraethoxysilane Research Paper

Tetraethoxysilane (TEOS, 99%), chloropropyltriethoxysilane (CPTES, 99%), absolute ethanol (EtOH, 99%) and other chemicals were purchased from Merck and Sigma Aldrich companies and used without further purification. Ciprofloxacin was purchased from Pars Daru Company.

Preparation of modified magnetic silica NPs (Fe3O4@SiO2~Cl)
Initially, the magnetic NPs prepared through a coprecipitation method and coated with a silica layer via a modified sol-gel method [20]. In brief, FeCl3.6H2O (0.036 mol) and FeCl2.4H2O (0.018 mol) were dissolved in deionized water (20 mL) and stirred for 30 min under nitrogen gas atmosphere at 60 °C. Then, NH3 (10 mL, 25%) was added into the solution and the solution color is immediately changed to black. Stirring was continued for more 1 h at 60 °C. The magnetite NPs was collected from the solution using an external magnet, washed several times with deionized water and ethanol, and
The reaction mixture was refluxed at 140 °C for 24 h. The functionalized NPs were magnetically filtered and washed with DMF, and finally with deionized water. The solid sample was then dried at 100 °C for 24
Then, isocyanide (1 mmol) was added to the reaction mixture and continued stirring for 4 h at 60 °C. After completion of the reaction, as indicated by TLC, the catalyst was magnetically separated and filtrated solution was diluted with 2 mL deionized water to afford products. The new derivative compounds were characterized by 1H and 13C NMR. The following is the spectral data of