Abstract
The pore size of micelle-templated mesoporous silicates (MTS) is thermodynamically controlled, while their grain size is kinetically controlled. The pore size is affected by all parameters which modify the size of micelles; hydrocarbons can be used as swelling agents and co-surfactants as shrinking agents. In a typical example, alcohol co-surfactants decrease the pore size of amine-templated silica (HMS) by increasing the distance between polar heads in the rim of the micelle. The size of MTS particles depends on the ratio between their nucleation and growth rates. Rapid aggregation of silica and surfactant leads to the formation of small grains, while a low concentration of ionized silica allows the growth of large particles of MTS mesophases. The ionic strength and the pH affect particle size and wall thickness through their effect on the rates of hydrolysis and condensation of the silicate species, as shown by syntheses of MCM-41 in the system cetyltrimethylammonium–tetraethylorthosilicate.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.