Selective functionalization of the mesopores of SBA-15

• Reloading as-synthesized SBA-15 with additional surfactant protects internal surfaces.
• Reloaded materials can be selectively grafted on the exterior.
• SSNMR and porosimetry were highly effective to interrogate surface functionalization.
• Stability of the silyl layer to hot ethanol was found to be remarkably high.

A method has been developed that permits the highly selective functionalization of the interior and exterior surfaces of the ubiquitous mesoporous material, SBA-15. The key step is reloading the as-synthesized material with structure-directing agent, Pluronic® P123, prior to selective functionalization of the external surface with a silylating agent. This new approach represents a significant improvement over literature procedures. Results from physisorption analyses as well as solid-state NMR permit a detailed, quantitative assessment of functionalized SBA-15. This work also provides insight into the stability of the silyl layer during extraction procedures – an issue often neglected in other studies but of significant importance as decomposition of this layer could result in the introduction of new silanols and reduce the effectiveness of any selective grafting procedure.

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