Journal of Colloid and Interface Science, Vol.389, 115-120, 2013
Mesoporous silica containing Si(CH2)(3)NHC(S)NHC2H5 functional groups in the surface layer
One-step synthesis technique of mesoporous SBA-15 type silica with thiourea Si(CH2)(3)NHC(S)NHC2H5 groups in the surface layer was developed. According to elemental analysis, the content of surface groups is 1.25 mmol/g, which is consistent with TGA data. FT-IR spectra of the obtained sample contain characteristic absorption bands of thiourea groups (-NH-C(S)-NH-), as well as polysiloxane network ( Si-O-Si ). The synthesized sample was studied by XRD, TEM, SEM, and adsorption method. It was demonstrated that the sample features porous microspheres similar to 0.5 mu m with well-ordered internal spatial structure of the hexagonal lattice type due to the usage of template P123 during synthesis. According to XRD and TEM, the diameter of pores is 4.2-5 nm and the wall thickness between them is 2.6 nm. These data are consistent with the structural-adsorption characteristics calculated from nitrogen adsorption-desorption isotherms: S-sp. = 510 m(2)/g, V-s = 0.47 cm(3)/g, and d = 4.3 nm. Equilibrium is established within 60 min during sorption of silver(I) and mercury(II) ions from acidified aqueous solutions for this sample, and with the complexes are formed 1.1/1 for Ag+ and 0.8/1 for Hg2+ at metal/ligand ratio. (C) 2012 Elsevier Inc. All rights reserved.