Fabrication of polydimethylsiloxane membrane and modification of its properties by TiO2 nanoparticles for water and ethanol separation in pervaporation process

removal of volatile organic compounds is one of the most challenging issues according to the new environmental policies. considering the disadvantages of these compounds and the important effects on the environment and life of organisms, proper treatment and prevention of these compounds to the environment is important. in this research, separation of ethanol as a volatile organic compound using PDMS pure membrane and PDMS/ TiO2 nanocomposite membranes with different percentages of nanoparticles during pervaporation permeation was investigated. the effect of temperature, ethanol concentration and the effect of increasing the percentage of nanoparticles on pervaporation performance was studied. scanning electron microscopy (SEM) was used to study the structure and morphology of membranes, CA analysis (contact angle) to evaluate the membrane hydrophobicity, TGA analysis to investigate the thermal resistance of membranes and FTIR analysis to observe the membranes 'and chemical bonds. according to the results, increasing the temperature leads to increase in the movement and molecular mobility followed by increase in total flux. by increasing the flux of water ، the separation factor is reduced. on the other hand, separation factor is a function of feed concentration and the separation factor decreases considerably by increasing the amount of ethanol in feed. by adding nanoparticles to the membrane, at first, we see increase in membrane selectivity and then decrease it. this can be due to agglomeration of nanoparticles at high concentration. in general, nanocomposite membranes containing 0.1 % of nanoparticles with selectivity of 11.2 % and permeate flux 1230 showed the best selectivity.