Membrane Distillation Research Paper

Membrane separation technologies are among the most promising processes in water purification regarding their low energy consumptions. Membrane distillation (MD) is a thermally driven separation process in which liquid feed is evaporated at the feed/membrane interface and is transported through a hydrophobic microporous membrane[1–4]. The hydrophobic character of the membrane allows only volatile components to enter the pores. The differences of the vapour pressures across the membrane is the driving force of the process[5,6].
In comparison with other conventional technologies, membrane distillation benefits from low operational temperature and pressure and therefore low energy requirements. In this process a lower energy is required due to working temperatures below the feed normal boiling point, so waste heats or other alternative energies including geothermal and solar energy are also applicable[7–10]. In addition, since there is no need to apply pressure difference between two sides of the membrane, membrane fouling as one of the most serious problems in pressure-driven membrane processes is less significant[11].
The membranes in MD process are required to have hydrophobic properties i.e. low surface energies. In most studies, commercial porous hydrophobic membranes including polypropylene, polyvinylidene fluoride (PVDF), and

Among the wide variety of possible precursors for plasma-polymerization, organosilicon monomers particularly hexamethyldisiloxane (HMDSO) are preferred since they are non-toxic, non-flammable, and inexpensive[45]. Plasma deposition of HMDSO is highly investigated for production of thin silicon oxide films in different atmospheres mainly including Ar, N2, and O2[40,46–48]. However, only few authors report the hydrophobic deposition using HMDSO by atmospheric pressure