چكيده به لاتين
Abstract:
Growing applications of colloidal silica demands a procees with lower producting cost. Perlit is amineral ore wich is available, abundent and rich of silica. Glasspowderis a valuable reused material which using it as a precursor not only have commercial benefits, but also is beneficial in enviromental aspects. So perlit and glasspowder has been used as precursors in this project. Process of synthetising colloidal nano silica consists of two parts: purification and peptization of gel. In purification, precursor reacts with acid and alakine. Sodium siliccate solution which is produced from alkaline reaction has been mixed with solfuric acid so that silica gel has been produced. Factors which have been investigated in this section are: concentration of acid and alkalin, Temprature of alkaline and pH of gel production. In peptization part, silica gel has been mixed with aqueous solotion of sodium hydroxid and then has been put in an autoclave for hydrothermal peptization. The Tempratures of two hydrothermal steps of peptization and time of second step have been investigated. For characterization of synthetised nano colloidal silica, Dynamic Laser Scattering (DLS), X-ray flourocense (XRF), Field Emission Scanning Microscopy Electron (FESEM), Transmission Electron Microscope (TEM), Fourier Transformed Infrared Spectroscopy (FTIR) and adsorption and desorption of nitrogen, have been used. Whith choosing the optimum levels of factors colloidal nano silica can be produced in range of 15-27nm from glasspowder and 8-74nm from perlit.
Keywords: colloidal nano silica, peptization, glasspowder, perlit
