Preparation of modified mesoporous MCM-41 silica spheres and its application in pervaporation

Mesoporous MCM-41 silica spheres were synthesized via modified Stöber method and modified by silylation. The MCM-41 pore structures, surface properties and morphological features before and after modification were examined by XRD, SEM, TEM, FT-IR, TGA, 29Si CP/MAS NMR and nitrogen adsorption–desorption. The results showed that the obtained MCM-41 silica had ordered mesoporous structure and spherical morphology. After silylation, the surface property of MCM-41 silica changed from hydrophilic to hydrophobic, whereas the MCM-41 framework and morphology were retained. The calcined and modified MCM-41 spheres were incorporated into a polydimethylsiloxane (PDMS) matrix, separately. It is clearly shown from the SEM image that modification of MCM-41 spheres greatly enhanced its interfacial adhesion with the polymer. The filled membrane was firstly used for pervaporation separation of dimethylcarbonate/methanol azeotropic mixture and displayed superior pervaporation performance than pure PDMS membranes.

Mesoporous MCM-41 silica spheres were synthesized and modified by silylation. The modified MCM-41 spheres were incorporated into a polydimethylsiloxane (PDMS) matrix. SEM image showed that modification of MCM-41 spheres could greatly enhance its interfacial adhesion with the polymer. The filled membrane displayed superior pervaporation performance.Figure optionsDownload as PowerPoint slideHighlights
► Mesoporous MCM-41 spheres were successfully synthesized and modified by silylation.
► Modified MCM-41/PDMS hybrid membranes were prepared as a new membrane material.
► The interfacial adhesion between MCM-41 and PDMS could be enhanced by silylation.
► Selectivity and flux of modified MCM-41/PDMS membrane can be raised simultaneously.