Gated Materials for On-Command Release of Guest Molecules

Multidisciplinary research at the forefront of the field of hybrid materials has paved the way to the development of endless examples of smart devices. One appealing concept in this fertile field is related to the design of gated materials. These are constructed for finely tuning the delivery of chemical or biochemical species from voids of porous supports to a solution in response to predefined stimuli. Such gated materials are composed mainly of two subunits: (i) a porous inorganic support in which a cargo is loaded and (ii) certain molecular or supramolecular entities, generally grafted onto the external surface, which can control mass transport from pores. On the basis of this concept, a large number of imaginative examples have been developed. This review intends to be a comprehensive analysis of papers published until 2014 on hybrid mesoporous gated materials. The molecules used as gates, the opening mechanisms, and controlled release behavior are detailed. We hope this review will not only help researchers who work in this field but also may open the minds of related ones to develop new advances in this fertile research area.