Sol-gel process is a method for producing solid materials from small molecules that is suitable for preparing different coatings (e.g., silicium and titanium oxides) on the surface of Ti-based materials. It involves conversion of small molecules (precursors) into a colloidal solution (sol) and then into an integrated network (gel) consisting of either discrete particles or network polymers. The sol-gel process involves four stages: (1) hydrolysis, (2) condensation/polymerization of monomers, (3) growth of particles, and (4) gel formation. These processes are influenced by several experimental parameters such as pH, temperature, concentration of the reactants, and presence of additives. Traditional precursors for sol-gel coatings are alkoxysilanes such as tetraethyl orthosilicate (TEOS) and tetramethyl orthosilicate (TMOS), but efforts are made in order to find less toxic and more environmental friendly precursors (Liana Maria Muresan, 2015).
The chemical solution deposition technique, sometimes called sol–gel method, has been used in a wide range of fields of materials science to prepare metal oxides in the form of nanoparticles. One advantage of the sol–gel technique is that it is an easy and very cheap process to prepare metal oxides and allows control over the doping process or addition of transition metals, as compared to other preparation techniques. Another advantage of the sol–gel process is that it can be controlled in order to obtain the required oxide with a high degree of homogeneity and purity. In addition, small quantities of dopants can be introduced in the chemical solution and incorporated into the required final product. This method is also distinguished by the fact that the desired metal oxide can be synthesized at lower temperatures, which makes it a favorable method. It is able also to obtain uniform and small sized powders. Consequently, it has now become a widespread technique with general acceptance in scientific research (Hassanien et al., 2018).
Chapter Chapter 17. Corrosion Protective Coatings for Ti and Ti Allo...
Sol-gel process is a method for producing solid materials from small molecules that is suitable for preparing different coatings (e.g., silicium and titanium oxides) on the surface of Ti-based materials. It involves conversion of small molecules (precursors) into a colloidal solution (sol) and then into an integrated network (gel) consisting of either discrete particles or network polymers. The sol-gel process involves four stages: (1) hydrolysis, (2) condensation/polymerization of monomers, (3) growth of particles, and (4) gel formation. These processes are influenced by several experimental parameters such as pH, temperature, concentration of the reactants, and presence of additives. Traditional precursors for sol-gel coatings are alkoxysilanes such as tetraethyl orthosilicate (TEOS) and tetramethyl orthosilicate (TMOS), but efforts are made in order to find less toxic and more environmental friendly precursors (Liana Maria Muresan, 2015).
The chemical solution deposition technique, sometimes called sol–gel method, has been used in a wide range of fields of materials science to prepare metal oxides in the form of nanoparticles. One advantage of the sol–gel technique is that it is an easy and very cheap process to prepare metal oxides and allows control over the doping process or addition of transition metals, as compared to other preparation techniques. Another advantage of the sol–gel process is that it can be controlled in order to obtain the required oxide with a high degree of homogeneity and purity. In addition, small quantities of dopants can be introduced in the chemical solution and incorporated into the required final product. This method is also distinguished by the fact that the desired metal oxide can be synthesized at lower temperatures, which makes it a favorable method. It is able also to obtain uniform and small sized powders. Consequently, it has now become a widespread technique with general acceptance in scientific research (Hassanien et al., 2018).
Chapter Chapter 17. Corrosion Protective Coatings for Ti and Ti Allo...