Synthesis and characterization of urea bridged hybrid periodic mesoporous organosilica materials

Urea bridged organic–inorganic hybrid mesoporous SiO2 materials (U-BSQMs) were synthesized through a sol–gel procedure by co-condensation of bis(triethoxysilyl propyl) urea (BSPU) under basic conditions using cetyltrimethylammonium bromide (CTAB) as organic template. X-ray diffraction (XRD) and transmission electron microscopy (TEM) confirmed the mesoporous structure of the sample. Fourier-transform infrared spectroscopy (FT-IR), solid state CP-MAS NMR spectroscopy of 29Si (29Si CP-MAS NMR) and 13C (13C CP NMR) indicated that most of the Si–C bonds are unbroken during the synthesis process. The N2 adsorption–desorption results revealed that these hybrid mesoporous SiO2 materials have bimodal distribution of pores with pore diameters of 2.4 and 3.8 nm, respectively. Thermogravimetric analysis (TG) demonstrated that about 16% Si–C bonds have been broke during the synthesis progress. This kind of material is expected to find possible application in ion supporting, drug delivery and catalysis.