Development of novel nanoporous hexagonal tungsten oxide membrane for separation of water/acetic acid mixtures via pervaporation

Synthesis of C-Plane Oriented Hexagonal Tungsten Oxide Membranes on Tubular Substrates and Their Acetic Acid/Water Separation Performances

“…Even after repeated testing for more than 500 h, the separation factor was maintained almost constant. Both water and CH3COOH permeance decreased by about 20% from the first test to the second test; however, the permeance was still high compared to our previous report [26] and maintained nearly constant thereafter for more than 300 h. This indicated that the h-WO3 membrane is durable against acidic solvents and that its performance can be maintained even during a long-term-separation test. [26]; the cross marks indicate performances of conventional polymeric membranes reported in references [29][30][31]; the triangle marks indicate performances of conventional inorganic membranes reported in references [32,33]; the diamond marks indicate the conventional zeolite membranes reported in reference [9,12,14,20,34,35].…”

“…Even after repeated testing for more than 500 h, the separation factor was maintained almost constant. Both water and CH3COOH permeance decreased by about 20% from the first test to the second test; however, the permeance was still high compared to our previous report [26] and maintained nearly constant thereafter for more than 300 h. This indicated that the h-WO3 membrane is durable against acidic solvents and that its performance can be maintained even during a long-term-separation test. So far, several zeolite membranes have been evaluated using long-term separation tests [10][11][12][13]15,17].…”

“…This means that the pathway for only water molecules increased. As we have revealed in our previous study, the separation mechanism of h-WO 3 membranes is based on molecular sieving [26]. Because the pores of h-WO 3 is running along the c-axis of h-WO 3 crystals and the water-permeable pores are smaller than CH 3 COOH molecules, the higher c-plane orientation must have resulted in more pathways for water molecules without increasing those for CH 3 COOH molecules.…”

“…Moreover, the performances of the developed membranes seem to be higher than conventional polymeric membranes [29][30][31] and are becoming closer to those of conventional inorganic membranes [9,12,14,20,[32][33][34][35], including zeolite membranes [9,12,14,20,34,35], which are expected to be promising candidate membranes for separating CH 3 COOH/water mixtures. [26]; the cross marks indicate performances of conventional polymeric membranes reported in references [29][30][31]; the triangle marks indicate performances of conventional inorganic membranes reported in references [32,33]; the diamond marks indicate the conventional zeolite membranes reported in reference [9,12,14,20,34,35]. )…”

A novel study of tungsten oxide nanocrystallites as fuel additive for diesel oil

“…Because of the large surface area, flexible gap, high chemical stability, nontoxicity, cheapness, abundance, high photocatalytic activity and corrosion resistance properties of WO 3 nano-semiconductors at nano level, numerous articles have been published. It is evident that nano-semiconductors are now being used in different fields due to its unlimited applications include solar cells [10,11], gas sensors [12][13][14], drug delivery [15], fuel additives (current work), dye degradation [16], water treatment [17][18][19], Li-ion batteries [20,21], fuel cells [22,23], supercapacitors [24], corrosion [25], dye sensitized solar cells [26], antimicrobial activity [27], fire packing and resistance [28], cancer cell treatment [29], paint and coating industry [30], bone tissue engineering [31], nano-printing [32], etc. On the basis of these facts, this is being expected that various products based on aforementioned properties will be commercially available soon.…”