the gas separation performance of commercial ceramic titania and hybrid silica (hybsi®) membranes was assessed using the gas permeation and permporometry methods. results indicated that the hybsi® membranes have a hybrid surface containing regions covered by a polymeric matrix and others with inorganic pores. these membranes have high h2 selectivity, which increases significantly with temperatu...

Textural evolution (porosity reduction, pore and crystallite growth) in titania-alumina composite membranes has been studied using thermal analysis, X-ray diffraction, field emission scanning electron microscopy and N, physisorption techniques. The presence of alumina in the membranes improved the thermal stability of the porous texture by retarding the anatase-to-rutile phase transformation a...

The gas separation performance of commercial ceramic Titania and hybrid silica (HybSi®) membranes was assessed using the gas permeation and permporometry methods. Results indicated that the HybSi® membranes have a hybrid surface containing regions covered by a polymeric matrix and others with inorganic pores. These membranes have high H2 selectivity, which incre...

Mesoporous titania networks consisting of interconnected anatase nanowires have been synthesized by using unique bacterial cellulose membranes as natural biotemplates; the titania networks exhibit enhanced photocatalytic activity compared with titania microfiber networks.

Textural evolution in sol-gel derived nanostructured unsupported titania membranes has been studied using differential scanning calorimetry (DSC), differential thermal analysis (DTA), thermal gravimetry (TG), X-ray diffraction (XRD) and N, adsorption. The anatase-to-rutile phase transformation kinetics were studied using the Avrami model. The precursor gel had a surface area of ca. 165 m2 g-', ...

Measurements of the mechanical and electrical properties of Nafion and Nafion/titania composite membranes in constrained environments are reported. The elastic and plastic deformation of Nafion-based materials decreases with both the temperature and water content. Nafion/titania composites have slightly higher elastic moduli. The composite membranes exhibit less strain hardening than Nafion. Co...

Parameters and/or processes responsible for the stability of catalyst supports and ceramic membranes are discussed. Two major parameters/processes were identified which are responsible for the stabiliv of sol-gel derived nanostmctured oxides at elevated temperatures. They are metastable-to-stable phase transformation and structure and packing of primary particles within the aggregate. Based on ...

This work investigates the structural formation and analyses of titania membranes (TM) prepared using different vacuum exposure times for molecular weight (MW) cut-off performance and oil/water separation. Titania membranes were synthesized via a sol-gel method and coated on macroporous alumina tubes followed by exposure to a vacuum between 30 and 1200 s and then calcined at 400 °C. X-ray diffr...