In present research, we synthesized cobalt-based silica nanocomposites (Co-SiO2) from cobalt nitrate [Co(NO3)2] and tetraethoxysilane (TEOS) precursors by using a simple sol-gel method followed by supercritical drying techniques. The physicochemical and textual properties of the as synthesized nano composites were thoroughly investigated. The results indicated that the Co-SiO2 aerogels demonstrated homogeneous dispersion cobalt nanoparticles within silica matrix with mesoporous morphology, large specific surface area (802 m2/g) and larger pore size (9 nm) with less volume shrinkage. The physicochemical properties of the cobalt based silica nanomaterial were characterized by XRD, SEM, N2 adsorptiondesorption and FTIR techniques. Cobalt-based silica nanocomposites can be produced using TEOS-based precursor and supercritical drying techniques. The prepared (Co-SiO2) nanocatalyst due to its magnetic nature with higher surface area (802 m2/g) can be utilized in many emerging fields such as catalysis, water desalination, water splitting, gas-sensing application and organic pollutant degradation.

The present work involved a thorough study on silane-modified silica filler with special focus on its chemical interaction with polydimethylsiloxanes (PDMS) and the structural model of the modified filler. The samples prepared by addition of modified silica were characterized by Fourier transform infrared spectroscopy (FTIR), specific surface test, scanning electron microscopy (SEM) and fluorescent microscope. FTIR results confirmed the successful silica surface modification with silane coupling agent. The sample containing 80 phr (parts per hundreds of rubber) modified filler with weak ratio of Si–OH/Si–C group absorbance areas (A 1/A 0) showed weak formation of filler agglomerates while a stronger interfacial interaction could take place between the modified silica and PDMS. Specific surface results showed that the dispersion of silica can be improved when the amount of silane modifier to silica reached 2.0 wt%. SEM and fluorescent microscope showed that the filler aggregation was observed in cases of higher silica loading. As expected, when the silica with surface treatment was compared with those without surface modification, the filler particles were found to be fairly well dispersed in PDMS matrix.

The SiO2-LiBr hybrid porous materials were prepared by the sol-gel method. This process was obtained by the hydrolysis and condensation tetraethyl orthosilicate (TEOS) with replacement of ethanol from alco gel by the drying at ambient temperature to obtain xerogel structure. The alcogel samples were synthesized from TEOS, EtOH, H2O, HCl, NH4OH and LiBr. The total molar ratio of the compounds was 1: 9: 4: 8 x 10-4, 8 x 10-³. Xerogel contain 30 % wt of LiBr (dry matter) was prepared and characterized by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Furier Transmittance Infra Red (FTIR), Energy Dispersive X-ray (EDX) and Thermal Gravimetry Analysis (TGA ) systems . The results obtained from SEM were shown the micrograph of LiBr on the silica matrix and chemical elemental analysis data was resulted by EDX. On the other hand, the TEM have confirmed average particle size of SiO2-LiBr about 50 nm and FTIR spectrum describes functional groups of nano composite. The thermal analysis of SiO2-LiBr nano composite was performed using TGA system and the results show that the suitable temperature for initial thermal treatment is about 200oC.

The silica xerogel is prepared using copper source; 0.02 mol of (Cu NO3)2 3H2O that has been added to 1 mol TEOS (tetraethyl orthosilicate). The copper ions are doped to silica matrix by the sol gel method and determination of total molar ratio of components with a reported molar ratio of H2O /TEOS(R)=6.2. In this method, the acidity the of reaction (pH) depends on the catalyst type in the hydrolysis step and the molar ratio of H2O /TEOS (R) that is studied with gelation time (tg). In this reaction, acidity varies between 2.4 and 3.5. Average size and molecular structure of this nanocomposite were analyzed using TEM, FTIR and XRD. Copper oxide can be produced from the decomposition of copper nitrate and is doped on the silica matrix by thermal treatment.