Mesoporous silica containing Si(CH₂)₃NHC(S)NHC₂H₅ functional groups in the surface layer
2013
Nazarchuk, Galyna I. | Melnyk, Inna V. | Zub, I︠U︡. L. | Makridina, Olga I. | Vezentsev, Alexandr I.
One-step synthesis technique of mesoporous SBA-15 type silica with thiourea Si(CH₂)₃NHC(S)NHC₂H₅ groups in the surface layer was developed. According to elemental analysis, the content of surface groups is 1.25mmol/g, which is consistent with TGA data. FT-IR spectra of the obtained sample contain characteristic absorption bands of thiourea groups (NHC(S)NH), as well as polysiloxane network (SiOSi). The synthesized sample was studied by XRD, TEM, SEM, and adsorption method. It was demonstrated that the sample features porous microspheres ∼0.5μm 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 4.2–5nm and the wall thickness between them is 2.6nm. These data are consistent with the structural-adsorption characteristics calculated from nitrogen adsorption–desorption isotherms: Sₛₚ.=510m²/g, Vₛ=0.47cm³/g, and d=4.3nm. Equilibrium is established within 60min during sorption of silver(І) and mercury(ІІ) 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.
显示更多 [+] 显示较少 [-]