Effect of surface properties of polysulfone support on the performance of thin film composite polyamide reverse osmosis membranes

Abstract

In this work, influence of initial conditions and surface characteristics of porous support layer on structure and performance of a thin film composite (TFC) polyamide reverse osmosis (RO) membrane was investigated. The phase inversion method was used for casting of polysulfone (PSf) supports and interfacial polymerization was used for coating of polyamide layer over the substrates. The effect of PSf concentrations that varied between 16 wt % and 21 wt %, and kind of the solvent (DMF and NMP) used for preparation of initial casting solution were investigated on the properties of the final RO membranes. SEM imaging, surface porosity, mean pore radius, and pure water flux analysis were applied for characterization of the supports. The substrate of the membrane, which synthesized with 18 wt % of PSf showed the most porosity and the synthesized RO membrane had the lowest salt rejection. In case of the solvents, the membranes synthesized with DMF presented better separation performance that can be attributed to their lower thickness and sponge-like structure. The best composition of support for TFC RO membranes reached 16 wt % PSf in DMF solvent.

Performance enhancement of thin‐film composite membranes in water desalination process by wood sawdust

“…Increasing the polymer solution viscosity tends to reduce penetration rates, thereby producing a slower demixing in the phase inversion process. Consequently, shorter and narrower macrovoids along with thick walls and sponge‐like structure in the substrate stemming from delayed phase inversion …”

“…Consequently, shorter and narrower macrovoids along with thick walls and sponge-like structure in the substrate stemming from delayed phase inversion. 1,6 It is expected that MSD and EWU increase by increasing the concentration of polymer. Because the amount of solid in the substrate as well as the membrane thickness increased by increasing the polymer concentration.…”

“…In particular, the PA film thickness, roughness, morphology, interfacial properties, and finally performance are significantly related to the morphology, physicochemical properties, overall porosity, pore size, and also wettability of substrate. [2][3][4] Several significant systematic investigations [1][2][3][4][5][6] have accordingly attempted to explain the relationship between substrate structure and final TFC membrane performance.…”

A Thin Film Nanocomposite Reverse Osmosis Membrane Incorporated with S‐Beta Zeolite Nanoparticles for Water Desalination

“…Due to relatively low energy consumption and simplicity of reverse osmosis (RO) membrane compared to the thermal‐based methods, RO membrane process is considered the most effective large‐scale water purification method in the 21 st century . The pressure‐driven RO technologies have been successfully used to treat salty water and industrial wastewater in many countries nowadays …”

“…[5] The pressure-driven RO technologies have been successfully used to treat salty water and industrial wastewater in many countries nowadays. [6,7] Thin film composite (TFC) membranes, which are used in RO process composed of three important layers, i. e., a top layer (selective layer) established on a middle layer (porous layer) supported by a nonwoven fabric. [8,9] The top surface (a crosslinked polyamide (PA) active layer) is usually made by interfacial polymerization of m-phenylenediamine (MPD) with trimesoyl chloride (TMC) while the middle layer is typically made of phase inversion technique.…”