Vulcanized Ethene-PMO: A New Strategy to Create Ultrastable Support Materials and Adsorbents

A periodic mesoporous organosilica (PMO) functionalized with sulfur units between the organic bridges has been successfully synthesized by a postsynthetic cold vulcanization treatment performed on an ethenylene-bridged PMO material (ethene-PMO). The results of X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and nitrogen adsorption/desorption porosimetry show that the resultant materials have well-ordered hexagonal mesoporous structures with narrow pore size distributions. Moreover, 13C CP/MAS NMR, 29Si MAS NMR, X-ray photoelectron spectroscopy (XPS), and elemental analysis prove the cross-linking between the organic moieties through additional sulfur bridges. Besides the incorporation of a new functionality to this PMO, the vulcanization treatment, reminiscent of that applied to rubber, improves the thermal and hydrothermal stabilities of the material. The vulcanized materials were employed as mercury adsorbents able to be reused without loss of their capacity in repetitive adsorption tests.