Chemical Engineering / Kimya Mühendisliği

Permanent URI for this collectionhttps://hdl.handle.net/11147/14

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  • Article
    Citation - WoS: 14
    Citation - Scopus: 16
    Facile Fabrication of Anti-Biofouling Polyaniline Ultrafiltration Membrane by Green Citric Acid Doping Process
    (Elsevier, 2021) Güngörmüş, Elif; Alsoy Altınkaya, Sacide
    This study aimed to enhance the anti-biofouling property of the polyaniline (PANI) based ultrafiltration (UF) membrane by utilizing its self-acid doping ability. A naturally derived biodegradable agent, citric acid, was doped to the membrane by filtering at 1 bar. Acid doping increased the hydrophilicity, made the surface nearly electroneutral, and imparted biocidal characteristics to the membrane. Biofouling was simulated by filtering a suspension of E.coli and S.aureus through the membranes. Most fouling on the doped membrane was reversible and easily removed by simple washing, leading to a high flux recovery ratio. The SEM images taken after filtration and washing steps showed that the modified membrane surface was free of bacteria while many bacteria accumulated on the pristine membrane surface. The doped membrane was stored in 1 M NaCl solution for up to five months. A tiny amount of citric acid was lost from the membrane, and at the end of storage, the flux, rejection, and antibacterial activity values did not change, demonstrating the antibacterial agent's stability. The protocol proposed in this study is fast, simple, facile, and easily scalable for large-scale production. Using a green antibacterial agent and its loading with a one-step process without consuming chemicals or functionalizing the support makes the proposed method environmentally friendly.
  • Article
    Citation - WoS: 50
    Citation - Scopus: 51
    A Facile Route To the Preparation of Antibacterial Polysulfone-Sulfonated Polyethersulfone Ultrafiltration Membranes Using a Cationic Surfactant Cetyltrimethylammonium Bromide
    (Elsevier, 2020) Cihanoğlu, Aydın; Alsoy Altınkaya, Sacide
    Cetyltrimethylammonium bromide (CTAB), a cationic surfactant, is known to have strong bactericidal potential. In this study, we report a facile approach for preparing CTAB-containing polysulfone-sulfonated polyethersulfone (PSF-SPES) based ultrafiltration membranes with antibacterial properties. The CTAB was added in gelation medium at three different concentrations and made an electrostatic interaction with SPES at the polymer/bath interface during phase inversion. The successful incorporation of the CTAB in the membrane structure was confirmed by attenuated total reflectance Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The CTAB-containing membranes had higher contact angle, lower pure water permeability (PWP) and molecular weight cut-off than the pristine membrane. The membranes prepared at critical and above critical micelle concentration (CMC) of the CTAB showed excellent antibacterial activity on both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria. On the other hand, the PWP of the membrane decreased from 93 +/- 1.6 to 39.3 +/- 3.2 L/m(2) h bar upon increasing the CTAB concentration from 10(-3) M (=CMC) to 10(-2) M, consequently, CMC was chosen as the optimal concentration. The membrane prepared at the CMC displayed almost 100% flux recoveries after dynamic bacteria filtration followed by simple rinsing with PBS solution. Leaching experiments continued up to 30 days demonstrated that 96% of the CTAB remained in this membrane. Furthermore, at the end of 1 month of storage in 1 M NaCl solution, no change was observed in the antibacterial activity of this membrane compared to fresh membrane. These findings emphasize the potential of the facile approach proposed in this study to develop antibacterial ultrafiltration membranes in a single step.