ساخت و مشخصه يابي غشا هوشمند پاسخگوي دوگانه به pH براي جداسازي داروي ضد سرطان از پساب سنتزي

Preparation an‎d characterization of dual pH-responsive membrane for separation of anticancer drugs from synthetic wastewater

مهندسي شيمي

In this study, a dual-responsive pH-sensitive nanocomposite membrane was developed to remove anticancer pollutants such as doxorubicin, methotrexate, an‎d fluorouracil. For this purpose, pH-sensitive polymers were employed: polyvinyl pyridine (P4VP) with an open-gate mechanism in the substrate an‎d polyacrylic acid (PAA) with a closed-gate mechanism in the selec‎tive layer. Additionally, pH-sensitive SiO2 nanoparticles were incorporated into the substrate. SiTj membranes (i representing P4VP concentration an‎d j representing PAA concentration) were utilized for filtering synthetic wastewater. The successful fabrication of these membranes was confirmed using various characterization analyses, including FTIR, FE-SEM, EDS, AFM, an‎d degree of grafting. Furthermore, their surface an‎d structural properties were characterized through contact angle measurements, porosity, zeta potential analysis, nitrogen adsorption-desorption, flux recovery, MWCO, DLS, an‎d PZC. By analyzing the results from the screening experiments, polysulfone (PSF) membranes incorporating SiO2 nanoparticles an‎d varying concentrations of P4VP (0–10%) in the membrane matrix, along with PAA (65–94%) on the surface, were selec‎ted. The membraneʹs filtration performance was eva‎luated through flux an‎d pollutant rejection tests, as well as the assessment of fouling types an‎d levels under different pH an‎d pollutant concentrations. The results revealed that, at a constant pH an‎d pollutant concentration, increasing the P4VP concentration in the S5T3 membrane resulted in flux values of 2.61, 59, an‎d 6.73 LMH/bar for doxorubicin, methotrexate, an‎d fluorouracil, respectively, while rejection reached 3.73%, 3.53%, an‎d 45%. Additionally, total fouling was observed to increase with higher P4VP concentrations. Conversely, increasing the PAA concentration at a constant pH an‎d pollutant concentration enhanced the drug flux for doxorubicin, methotrexate, an‎d fluorouracil. For the S3T1 membrane, flux values increased from 2.43, 2.38, an‎d 5.46 LMH/bar to 3.60, 9.56, an‎d 6.61 LMH/bar in the S3T5 membrane. The drug rejections decreased from 4.75%, 6.42%, an‎d 4.30% to 3.91%, 5.60%, an‎d 3.50%, respectively. Additionally, total fouling decreased with increasing PAA concentration. To assess the membraneʹs pH responsiveness, the S3T3 membrane was tested at pH values of 9, 8, 7, 4, 3, an‎d 10. As the pH increased, the surface gates closed, improving drug removal, while the substrate gates opened, increasing drug flux. At pH 10, the drug fluxes of doxorubicin, methotrexate, an‎d fluorouracil reached 63.7, 63.2, an‎d 65 LMH/bar, respectively, with corresponding rejections of 94.7%, 66.4%, an‎d 62.9%. The membrane demonstrated remarkable performance in responding to pH changes an‎d effectively self-adjusting its pores, resulting in high flux values while maintaining desirable pollutant rejection.

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