SBA-15 silicas containing sucrose
Chemical, structural, and thermal studies
Introduction During the last 20 years, a significant progress has been achieved in the field of ordered mesoporous silicas (OMSs) [ 1 – 3 ]. OMSs constitute an exciting field in materials chemistry due to many potential
influence of silica on the nucleation and crystallization behaviors of PET has received considerable attention [ 12 , 13 ]. Experimental results show that in non-isothermal crystallization, silica particles in contact with the PET matrix can induce a
Abstract
The prepared amorphous γ-ZrP\SiO2 composite had a complicated composition, since a part of γ-ZrP is converted to α-form during the exfoliation of it. The γ-ZrP\SiO2 composite have specific surface area of 421 m2g–1. The acidic P–OH groups of the lamellae species placed on the surface (it is ≈1.0 meq g–1), do not destroy until the temperature of 1030 K. During the thermal treatment the total mass loss of 7.79% was found. This value corresponds to 0.42 mole of H2O per molecule unit. The water loss process was found very slow, because of the placing of bilamellar species in the composite.
platinum-aluminum alloy (PtAl 3 ) also deactivates platinum catalysts. Silica has various advantages as a support for platinum in terms of chemical inertness to sulfur and platinum, easy processing and high thermal stability. However, the weak
– 3 ]. However, metal nanoparticles have a tendency to agglomerate and are quite difficult to recover because of their small size. To avoid the above-mentioned drawbacks, they are usually deposited on inorganic porous supports, such as silica, which
and adsorptive, shape and size of pores, etc. Aristov et al. [ 8 ] obtained sorption behavior of water vapor on Fuji RD silica gels which have 820 m 2 g −1 BET surface areas and particle size between 0.3 and 1.0 mm using CAHN 2000 thermo
Abstract
The reaction between SiO2 and MgO at temperatures up to 1500°C was studied using thermal analysis, with X-ray diffraction being used to identify reaction products. The reaction is slow and results in the formation of Mg2SiO4 and MgSiO3, with minor amounts of SiO2·nH2O and residual amounts of unreacted SiO2 and MgO. Complete reaction of the starting materials to form Mg2SiO4 can only be achieved by maintaining the mixture at 1500°C for extended periods of time (>1 h).
]. Improving the mechanical and thermal properties of polymeric materials can be achieved by introduction of fillers, in particular highly dispersed silicas [ 8 , 9 ]. It is well known that chemical modification of the silica surface allows one to improve the
, such as fumed silica nanoparticles. Due to its fractal structure and its high specific area, fumed silica is prone to self-aggregation and can consequently form a network of connected or interacting particles in polymer matrices [ 29 ]. It has been
