Authors:Dorota Majda, Wacław Makowski, and Maria Mańko
Nanostructured materials have attracted substantial interest in many fields of science because of their potential application [ 1 ]. Among them the ordered mesoporous silicas, such as MCM-41 or SBA-15, exhibiting
Authors:Jenny Alongi, Claudio Colleoni, Giuseppe Rosace, and Giulio Malucelli
sustainability. Recent study within the sol–gel area has enabled phosphorus-silicon synergisms to be studied as alternatives [ 11 – 20 ]. Usually the success in such nanocomposite systems refers to the formation of silica nanoparticles (eventually doped with
Authors:M. Ştefănescu, M. Stoia, O. Ştefănescu, A. Popa, M. Simon, and C. Ionescu
Hybrid organic-inorganic materials,
silica – polyols (ethylene-glycol – EG; 1,2 propane diol –
1,2PG; 1,3 propane diol – 1,3PG and glycerol – GL), were prepared
by a sol-gel process starting from tetraethylorthosilicate (TEOS) and polyols,
in acid catalysis. The resulting materials were studied by thermal analysis
(in air and nitrogen), FTIR and solid state 29Si-NMR
spectroscopy. These techniques evidenced the presence of polyols in the silica
matrix both hydrogen bounded and chemically bounded in the silica network.
The thermal analysis proves to be the most appropriate technique to evidence
the organic chains linked in the matrix network and to follow the thermal
evolution of the gels to the SiO2 matrix.
In order to correlate the biological activity of silica to its surface properties, the analysis of surface sites on three kinds of silicas of different origins and textures has been performed by adsorption calorimetry.
Authors:Liying Song, Kaixiang Li, Xiaohong Li, and Peng Wu
functionalization, and of inorganic components such as excellent mechanical and thermal stability. Moreover, mesoporous carbon/silica nanocomposites can also facilitate thermal, chemical, conductive and mechanical properties. Confinement effects inside the mesopores
Authors:Wei Zhao, Baochun Ma, Yong Ding, and Wenyuan Qiu
polyoxotungstate [ 21 ], silica supported peroxotungstate [ 22 , 23 ] and triphasic phosphotungstate [ 24 ] were used in typical works. Especially, the methods of grafting or tethering of active species onto the inner walls of mesoporous molecular sieves were
Authors:J. Skubiszewska-Zięba, B. Charmas, R. Leboda, V. A. Tertykh, and V. V. Yanishpolskii
transition metals into the framework of such materials (especially titanium) gives additional special catalytic properties [ 3 – 11 ].
Silica-titania materials (STM) possessing different compositions and physico-chemical characteristics are widely
Authors:D. K. Sawant, H. M. Patil, D. S. Bhavsar, J. H. Patil, and K. D. Girase
silica gel so that a very slow reaction occurs with the formation of a sparingly soluble compound. When the concentration of this compound exceeds the solubility limits, crystals will be formed, while the main function of the gel is to control the flow of
Authors:M. S. Amin, S. A. Abo-El-Enein, A. Abdel Rahman, and Khaled A. Alfalous
, lowering heat of hydration, and thermal expansion [ 1 ]. Recently, the use of pozzolanic cement is increasing world-wide because it needs less energy for production.
Early hydration reactions of Portland cement–silica fume blends were studied and