Thermosensitive Cation-Selective Mesochannels: PNIPAM-Capped Mesoporous Thin Films as Bioinspired Interfacial Architectures with Concerted Functions.

Rational design and elaborate modular construction of interfacial architectures in which molecular transport is mediated by responsive/adaptive nanostructures has become a growing and fertile field of research in supramolecular materials chemistry. This work presents, for the first time, the use of PNIPAM-capped mesoporous silica thin films as thermosensitive cation-selective mesochannels. Thus far, this feature has only been observed in thermosensitive biological channels. The interfacial architecture created here accomplishes its specific functions through the concerted or simultaneous action of spatially addressed subunits with temperature response and ion exclusion capabilities. The thermo-perm-selectivity effect stems from the synergistic interplay between the pH-dependent electrostatic characteristics of the silica scaffold and the thermo-controlled steric effects introduced by the capping brush layer. It is hoped that the "nanoarchitectonic" approach presented here will provide new routes toward the generation of heterosupramolecular nanosystems displaying addressable transport properties similar to those encountered in biological ion channels.