A mild method to remove organic templates in periodic mesoporous organosilicas by the oxidation of perchlorates

A new method of ammonium perchlorate (AP) oxidation has been developed to remove organic templates of mesoporous materials at relatively low temperature (80-120 degrees C). Periodic mesoporous organosilicas (PMOs) with ethane-bridged prepared by using triblock copolymers P123 as a template are chosen as an example to demonstrate the AP treatment method. The resultant template-free PMO-80 products at 80 degrees C have a larger pore size (7.2 nm) and volume (1.40 cm(3)/g) compared to solvent-extracted sample (6.9 nm and 1.06 cm(3)/g). No framework shrinkage is observed based on XRD results. TEM images show that PMO-80 sample has a highly ordered mesostructure. This template removal strategy can be extended to prepare other nanoporous materials like pure mesoporous silicas. (C) 2008 Elsevier Inc. All rights reserved.