Preparation of Cationic Grafted‐Microfiltration Membrane of PSF‐g‐QPDMAEMA and Study on its Adsorption and Rejection Performance for Acid Dye

Abstract

Chloromethylated polysulfone (CMPSF) microfiltration membrane were first prepared by using immersion-precipitation phase transformation method, and then CMPSF membrane was modified into aminated PSF membrane (AMPSF membrane). A surface-initiating system of -NH 2 /S 2 O 8 2− was constituted at the interface between AMPSF membrane and a aqueous solution, in which monomer dimethylaminoethyl methacrylate (DMAEMA) and initiator ammonium persulfate were dissolved. The graft polymerization of DMAEMA was successfully realized on AMPSF membrane, resulting in the grafted membrane PSF-g-PDMAEMA. And then quaternization modification of the grafted membrane PSF-g-PDMAEMA was performed, resulting in the cationic microfiltration membrane of PSF-g-QPDMAEMA. The isothermal adsorption experiments of PSF-g-QPDMAEMA membrane for two acid dyes, reactive brilliant red (RBR), and reactive light yellow (RLY), were carried out, and the permeation experiments were also conducted. The experimental results show that PSF-g-QPDMAEMA membrane has strong adsorption ability for acid dyes by right of the electrostatic interaction between the quaternary ammonium cations on the surface of PSF-g-QPDMAEMA membrane and the sulfonate anions in the molecules of acid dyes as well as by right of cation-π interaction between the quaternary ammonium cations on PSF-g-QPDMAEMA membrane and the aromatic rings in the molecules of acid dyes. PSF-g-QPDMAEMA membrane displays excellent rejection and removing performance for acid dyes in water. POLYM. ENG. SCI., 60:900-908, 2020.

Soaking pretreatment of hydrogel adsorbent in distilled water to enhance efficiency of adsorption onto low concentration dye

“…The dynamic changes of adsorbate concentration in residual solution and swelling ratio of adsorbents were followed in literatures. [18][19][20] The ion releasing phenomena of hydrogels have been ignored during swelling and dye adsorption.…”