Abstract:
In the last few decades, tremendous advances have been made in synthesis of
ordered porous solids with controlled pore size, shape and regularity of the pores.1-5
Among them, ordered mesoporous silica stands out due to their high surface area, ease
of synthesis and chemical modifications, high thermal stability and bio-compatibility.6-
10 Mesoporous silica is generally synthesized via organic-inorganic assembly of
amphiphilic surfactants and silicate species (produced by base or acid catalysed
hydrolysis of silane precursors, tetraalkoxysilane). The amphiphilic surfactants act as
structure directing agents or templates. After the condensation of silicates species around
the superstructures formed by surfactant molecules (template), the solid mesoporous
silica can be obtained by removing the template (via calcination or ion exchange or
simple washing).11-12
The term surface engineering in the context of mesoporous silica is primarily
associated with controlling the parameters like pore structure, pore philicity and surface
charge. Since, these parameters define the mass transport through the mesopores, it is
necessary to optimise them for their applications in drug delivery10, 13-16, sensing17,
catalysis18-19, bio-mimetic channels20-21 etc. This chapter highlights various strategies
adopted such as gating, incorporation of receptor molecules, philicity and surface charge
modifications to regulate the mass transport in mesoporous silica.
