Study on the structural design and performance of novel braid-reinforced and thermostable poly(m-phenylene isophthalamide) hollow fiber membranes

Abstract

Novel braid-reinforced (BR) and thermostable poly(m-phenylene isophthalamide) (PMIA) hollow fiber membranes comprising reinforced braids and a separation layer were prepared by a dry-wet spinning process for the first time. The effects of PMIA concentration and the braid composition on the structure and performance of the BR PMIA hollow fiber membranes were investigated. Field emission scanning electron microscopy (FESEM) was used to observe the morphologies of the BR PMIA hollow fiber membranes. An increase in PMIA concentration resulted in an increase of the protein rejection rate and a decrease in the pure water flux. The higher flux recovery rate indicated that the BR PMIA membranes had excellent antifouling property compared to commercial PVDF membranes. In the BR PMIA membranes existed favorable interfacial bonding between the separation layer and the reinforced braids as the tensile strength of the BR PMIA membranes exceeded 170 MPa. Moreover, when the operating temperature was increased from 25 C to 90 C, the water flux increased more than two-fold with stable ink solution rejection, which showed an excellent thermal stability.

Ultra-strong polymeric hollow fiber membranes for saline dewatering and desalination

“…The burst pressure of the pipe structure can also be approximately estimated according to Barlow’s equation 29 , 30 , as shown below: where, P represents the burst pressure, x represents the wall thickness, T is the maximum tensile stress and F s is the safety factor (typically, F s = 1). Other membrane characterizations such as field emission scanning electron microscope (FESEM), physical and mechanical properties were presented in the Supplementary Information .…”

“…To improve the mechanical strength and the crush or burst pressure of hollow fiber membranes, numerous strategies were followed (1) adding woven 24 , carbon nanotubes 25 , and inorganic salts 26 , 27 ; (2) adopting dual-layer extrusion technology 28 , 29 ; (3) employing the braid reinforced elements 30 – 32 . However, to the best of our knowledge, the aforementioned hollow fiber membranes are not ideal or suitable for OARO because they are mechanically weak (e.g., having a burst pressure less than 35 bar).…”

Effective Parameters on Fabrication and Modification of Braid Hollow Fiber Membranes: A Review

“…These groups lead to creating strong electronegativity and superior hydrophilicity PMIA membranes. These properties are the main goal to improve the antifouling property [28].…”

“…The thin separation layer of the BHFM also contributed to the water flux enhancement because of lower thickness compared to self-support HFMs [24]. Chen et al [28] reported that the flux of braid PMIA-BHFMs was higher than the PMIA-HFMs. It is due to the PMIA-BHFMs containing an inner layer with a relatively porous structure that leads to a reduction in membrane resistance for water transfer.…”

Reinforced thin‐film composite nanofiltration membranes: Fabrication, characterization, and performance testing

“…When reinforced, HF fiber membranes can withstand hydraulic pressures typical for reverse osmosis (~12.5 MPa) . To our knowledge, there have been five reports (one conference paper, two patents, and two journal articles) on reinforced HF thin‐film composite (TFC) membranes and seven studies on reinforced HF UF membranes …”