Recent Progress in the Membrane Distillation and Impact of Track-Etched Membranes

Abstract

Membrane distillation (MD) is a rapidly developing field of research and finds applications in desalination of water, purification from nonvolatile substances, and concentration of various solutions. This review presents data from recent studies on the MD process, MD configuration, the type of membranes and membrane hydrophobization. Particular importance has been placed on the methods of hydrophobization and the use of track-etched membranes (TeMs) in the MD process. Hydrophobic TeMs based on poly(ethylene terephthalate) (PET), poly(vinylidene fluoride) (PVDF) and polycarbonate (PC) have been applied in the purification of water from salts and pesticides, as well as in the concentration of low-level liquid radioactive waste (LLLRW). Such membranes are characterized by a narrow pore size distribution, precise values of the number of pores per unit area and narrow thickness. These properties of membranes allow them to be used for more accurate water purification and as model membranes used to test theoretical models (for instance LEP prediction).

Graft Polymerization of Stearyl Methacrylate on PET Track-Etched Membranes for Oil–Water Separation

“…The functionalization of pore surfaces by graft copolymerizing with polymers carrying special functions increases their use as thin film electrodes [ 14 ], as catalysts [ 15 ] and for a variety of separation needs [ 16 , 17 ]. The applicability of such membranes is quite wide and is used in the pharmaceutical and chemical industries; in microelectronics, as well as in the processes of ultra-, microfiltration and membrane distillation [ 18 , 19 , 20 , 21 ].…”

Desalination technologies, membrane distillation, and electrospinning, an overview

“…Electrospun polymer membranes feature a large surface area to pore volume ratio [ 174 ]. Various polymers have been used to create electrospun membranes, including PVDF [ 175 ], PVDF–SiO 2 [ 176 ], polystyrene (PS) [ 166 ], PTFE–polyvinyl acetate [ 177 ] and PVDF–HFP/SiNP [ 178 ]. It should be mentioned that electrospun membranes have been tested in a variety of configurations and are among the most widely used membranes.…”

“…It should be mentioned that electrospun membranes have been tested in a variety of configurations and are among the most widely used membranes. Kebria [ 178 ] and others suggested a technique for inserting dendritic patterns during electrospinning to increase the hydrophobicity of nanofiber PVDF membranes. By polycondensing the carboxyl groups of nitriloacetic acid and the hydroxyl groups of boehmite, dendritic structures were created.…”

“…The qualities of the material can be greatly enhanced and varied by membrane modification. Convenience, ease of hardware design, and cost-effectiveness all play a role in the modification technique selected [ 178 ].…”

Interphase Surface Stability in Liquid-Liquid Membrane Contactors Based on Track-Etched Membranes

“…Due to their properties, such membranes can be used as model membranes for the development and confirmation of theoretical mass, heat transfer, liquid entry pressure, and fouling. Track-etched membranes also have a wide range of applications in the ultrafiltration and microfiltration of liquids and gases; in the analytical control of substances; and in the food and pharmaceutical industries, microelectronics, and other areas of science and industry [39]. Both symmetric and asymmetric small-pore track-etched membranes are widely employed to study the ionic transport phenomena in nanoscale volumes, to build nanofluidic devices, such as molecular sensors, pumps and gates, and logical elements [38], and to develop various new processes, such as electro-baromembrane ion separation [40].…”