Electrospun Al ₂ O ₃ hydrophobic functionalized membranes for heavy metal recovery using direct contact membrane distillation

Abstract

In this study, styrene-butadiene-styrene (SBS) was used to develop a novel functionalized electrospun membrane for the effective treatment of heavy metals in direct contact membrane distillation (DCMD) applications. Functionalization was achieved by the addition (doping) of the super hydrophobic Al 2 O 3 nanoparticles (Al NPs) within the matrix of the membrane during electrospinning. Neat (pristine nondoped) and doped SBS membranes were tested. The performance of the SBS membranes were also compared with fabricated polyvinylidene fluoride membranes with and without doping with Al NPs. The membrane characteristics were tested via Fourier transform infrared, scanning electron microscopy, pore size, and porosity investigations. The wettability of the membranes was investigated with respect to the liquid entry pressure (LEP) and contact angle. The performance of the membranes was tested in a DCMD setting for its ability to treat water containing salt (NaCl) and heavy metals (Cr (VI), Cd, Pb) in various concentration in a single and multicomponent systems. The SBS member exhibited excellent hydrophobicity characteristics such as a high LEP (16.87 psi) and contact angle (141 ± 2 ). It also had superior permeate flux rate compared to the other prepared membranes (54.4 LMH). The addition of the Al 2 O 3 nanoparticles enhance the performance of the membranes substantially.Slight decline in the flux was observed after 14 hours of continuous operating time that could be attributed to agglomeration, adsorption, or temperature polarization effects. The SBS AL NPs membranes also demonstrated excellent flux for saline solutions of varied concentrations with 99% salt rejection.

Computational analysis of atomic binding energy for organosilicon‐ low‐density polyethylene‐coated silica embedded in polyvinylidene fluoride composite membrane for membrane gas absorption

“…The contact angle also represents the hydrophobicity of the membrane. 47 The measured contact angles of all composite membranes are higher than 90.6 of neat membrane, at 99.1 , 100.8 , and 103.1 for LDPE/TS-530, LDPE/TS-610, and LDPE/TS-720 membranes, respectively, attributed to the incorporation of hydrophobic LDPE/f-SiNP. 9 However, the contact angle and hydrophobicity of the membranes are also influenced by the membrane structure and porosity.…”

“…These changes in structure, or lack thereof, are also reflected in the contact angle of the membrane. The contact angle also represents the hydrophobicity of the membrane 47 . The measured contact angles of all composite membranes are higher than 90.6° of neat membrane, at 99.1°, 100.8°, and 103.1° for LDPE/TS‐530, LDPE/TS‐610, and LDPE/TS‐720 membranes, respectively, attributed to the incorporation of hydrophobic LDPE/f‐SiNP 9 .…”

Membrane distillation: recent technological developments and advancements in membrane materials

“…& Styrene-butadiene styrene [118,119] & PS [120] To improve mechanical strength and mass transfer, duallayer ENMs have also been developed, e.g., with a polyacryl o n i t r i l e ( P A N ) s u p p o r t l a y e r u n d e r a P V D F / hexafluoropropylene active separation layer [121]. In another investigation, the PVDF ENM served as the separation layer and PS served as the support, and together, they showed superior performance in comparison to PVDF ENMs without PS support [122].…”

Desired properties and corresponding improvement measures of electrospun nanofibers for membrane distillation, reinforcement, and self‐healing applications

“…Khraisheh et al prepared a novel functionalized membrane by adding superhydrophobic Al 2 O 3 nanoparticles to styrene–butadiene–styrene. [ 102 ] The addition of nanoparticles improved the LEP and water contact angle, which contributed to a high flux, salt rejection, and heavy metal retention.…”