PIP/TMC Interfacial Polymerization with Electrospray: Novel Loose Nanofiltration Membrane for Dye Wastewater Treatment

Abstract

A loose nanofiltration (NF) membrane with excellent dye rejection and high permeation of inorganic salt is required to fractionate dye/salt mixture in dye wastewater treatment. In this study, we fabricated the loose NF membrane by using the electrospray interfacial polymerization (EIP) method. It is a novel and facile interfacial polymerization method, which controls the thickness of the poly(piperazine-amide) (PPA) layer in nanometers (1 nm/min) and changes cross-linking degree of PPA layer and pore size by varying the electrospray time; consequently, water permeance and dye/salt rejection ratio can be handled. The fabricated EIP membrane with an optimized fabrication condition (M30, electrospray time was 30 min) possessed excellent pure water permeance (20.2 LMH/bar), high dye rejection (e.g., 99.6% for congo red (CR)), and low salt rejection (e.g., 6.3% for NaCl). Moreover, the EIP membrane exhibited enhanced antifouling property than commercial NF membrane (NF90) with a high flux recovery rate (FRR) of 87.1% and low irreversible fouling (R ir ) of 12.9% after fouled by bovine serum albumin (BSA) due to its great smooth surface (average roughness (R a ) is 12.2 nm), hydrophilicity property, enhanced zeta potential, and low protein adsorption. The results indicate that the EIP loose NF membrane had a high potential for dye wastewater treatment.

Nanofiltration Membranes with Octopus Arm-Sucker Surface Morphology: Filtration Performance and Mechanism Investigation

“…Different from the PES support, the as-prepared TFC membranes had new peaks, indicating the successful polymerization of the (poly)­piperazine amide layer. The new peaks observed at 1440 and 1625 cm –1 were attributed to the stretching vibrations of OH and CO of amide I. , Furthermore, the broad peak band between 3200 and 3600 cm –1 belonged to the stretching vibration of OH of carboxyl groups. , …”

Novel Poly(ester amide) Membranes with Tunable Crosslinked Structures for Nanofiltration

“…The structure and property of resultant thin-film composite (TFC) membranes can be finely tailored by choosing appropriate monomers. − Typically, state-of-the-art polyamide NF membranes are obtained through IP of polyamines and acyl chloride, possessing highly crosslinked network structures with a narrow pore size. Due to the high nucleophilicity of amine groups, it is difficult to reduce the crosslinking density of polyamide membranes down to the range of loose NF membranes. , Recently, polyols or polyphenols with low reactivity have been employed for the preparation of loose NF membranes. ,, However, enhancing the crosslinking density of these polyester membranes to achieve efficient desalination remains a challenge due to the limited reactivity of hydroxyl groups. − Therefore, it is hard to achieve rational control of the crosslinking density of interfacial-polymerized membranes in order for them to be applied in specific applications. Inspired by the above-mentioned properties of polyamide and polyester membranes, we hypothesize that choosing the monomer with both hydroxyl and amine groups to prepare poly­(ester amide) (PEA) membranes may bridge the gap between polyamide and polyester membranes since this kind of monomer with moderate reactivity can render it feasible to tune the crosslinking density of obtained membranes.…”

Adsorption performances and electrochemical characteristics of methyl blue onto magnesium-zinc ferrites

“…With the development of human society, dyes were widely applied in textiles, paper, leather, and pharmaceutical industries, etc [1][2][3]. A large amount of dye wastewater was generated, which has caused serious environmental pollution problems and posed a serious threat to human health [4][5][6]. Therefore, there is an urgent need for economical and efficient dye wastewater treatment technology.…”