Layer‐by‐layer self‐assembly of aramid nanofibers on nonwoven fabric for liquid filtration

Abstract

The composite ultrafiltration membranes were fabricated by self-assembling the aramid nanofibers (ANFs) on nonwoven fabric (NF) via layer-by-layer technique. Different numbers of ANFs layers (8, 10, 12) have been selfassembled on the NF. The surface morphology, surface wettability, tensile strength, and filtration performance of as-prepared composite membranes were investigated. The results demonstrated that the surface assembled NF with the deposition of ANFs could improve their hydrophilicity and mechanical properties. The filtration experiments indicated that the composite membranes could efficiently remove the nanoparticles from water system. When the number of ANFs layers reaches 12, 10 nm Au nanoparticles can be removed from the feed solution with a rejection rate above 90%. This work presents the feasibility of liquid filtration by using the ANFs selfassembled composite membranes, which exhibits a potential application in ultrafiltration. POLYM. COMPOS.,

Micro-fluid through aramid/cellulose nanocomposite membranes and its filtration efficiency

“…It has been reported that the ANF can be dispersed and ionized in negatively charged polar solutions [12]. Yuan et al [13] showed that the LBL self-assembly process can be used for the preparation of composite membranes. Therefore, the negatively charged ANF can selfassemble on the surface of CNF to form composite membranes.…”

Fabrication, Applications, and Prospects of Aramid Nanofiber

“…For instance, ANF has been employed as a coating on nonwoven fabric (NF) via the LBL technique to solve the issues of large pore sizes (>10 µm), low filtration efficiency and high difficulty in filtering out nanoparticles (<100 nm) faced by conventional nonwoven filter media. [ 12 ] The obtained NF@ANF ultrafiltration membrane not only showed improved hydrophilicity and mechanical properties, but also exhibited high filtration efficiencies for 100 nm Fe 3 O 4 nanoparticles and 10 nm Au nanoparticles, approaching values of 96.4% and 91.9%, respectively, as shown in Figure A. [ 12 ] Furthermore, ANF was casted onto a nonwoven fabric to prepare a 3D interconnected hydrogel structure, as shown in Figure 19B.…”

“…[ 12 ] The obtained NF@ANF ultrafiltration membrane not only showed improved hydrophilicity and mechanical properties, but also exhibited high filtration efficiencies for 100 nm Fe 3 O 4 nanoparticles and 10 nm Au nanoparticles, approaching values of 96.4% and 91.9%, respectively, as shown in Figure A. [ 12 ] Furthermore, ANF was casted onto a nonwoven fabric to prepare a 3D interconnected hydrogel structure, as shown in Figure 19B. Taking advantage of the high solvent resistance of ANF and the porous 3D ANF hydrogel networks as well as a polyamide selective layer, the ANF‐based membrane is expected to show excellent transport performance for molecular separation in various organic solvents.…”

“…Reproduced with permission. [ 12 ] Copyright 2016, Society of Plastics Engineers. B) ANF‐based membrane for molecular separation in organic solvents.…”

“…In addition, as seen in Figure 1B, studies on ANF have been conducted in different research areas, such as materials science, engineering, chemistry, and polymer science, which demonstrates the increasing attention of ANF has received from varied quarters. It is considered a promising nanoscale building block and has been extensively applied in composite reinforcement, [ 5–7 ] electrical insulating materials, [ 8–10 ] adsorption and filtration media, [ 11,12 ] battery separators, [ 13,14 ] flexible electrodes, [ 15–18 ] and biological tissue. [ 19–21 ]…”