Introducing Distinctly Different Chemical Functionalities onto the Internal and External Surfaces of Mesoporous Materials

摘要

There is currently considerable interest in mesoporous materials for a diverse range of applications, such as catalysis, filtration and separation, molecular collection and storage, nanofluidics, medical imaging, drug delivery, and sensors. To instill functionality into the raw materials, there is often a need for modifying the outside differently than the inside (e.g. targeted drug delivery: external antibodies for cell targeting, internal therapeutics for delivery). Recently, Cheng and Landry demonstrated spatial chemical selectivity on mesoporous silica by exploiting the slow diffusion in the nanoscale pores to ensure that the exterior is modified preferentially to the interior. This technique is a significant advance but does not ensure complete separation of the external modification layer from the internal modification layer. Thus, a need still exists for a general, material-independent methodology that will allow the interior of mesoporous materials to be modified with a specific chemistry while allowing a completely different, well-controlled chemical landscape on the external surface.