Chulalongkorn University Theses and Dissertations (Chula ETD)
Other Title (Parallel Title in Other Language of ETD)
การหาสภาวะที่เหมาะสมที่สุดในการปรับสภาพเส้นใยนาโนอิเล็กโทรสปันด้วยโซเดียมไฮดรอกไซด์เพื่อเป็นชั้นรองรับแก่ฟิล์มบางคอมโพสิตเมมเบรนสำหรับรีเวอร์สออสโมซิส
Year (A.D.)
2022
Document Type
Thesis
First Advisor
Chalida Klaysom
Second Advisor
Ratthapol Rangkupan
Faculty/College
Faculty of Engineering (คณะวิศวกรรมศาสตร์)
Department (if any)
Department of Chemical Engineering (ภาควิชาวิศวกรรมเคมี)
Degree Name
Master of Engineering
Degree Level
Master's Degree
Degree Discipline
Chemical Engineering
DOI
10.58837/CHULA.THE.2022.1208
Abstract
Poly(acrylonitrile-co-methyl acrylate) (PAN-co-MA) was electrospun onto non-woven backing and used as the support for thin film nanofiber composite (TFNC) membranes. Post treatment via hydrolysis using NaOH solution was applied to the support layer. The effect of NaOH concentration, reaction temperature and reaction time on the support physicochemical properties, thin film morphology and surface chemistry, and membrane performances were investigated. Furthermore, the response surface methodology (RSM) – Box Behnken Design (BBD) experimental design was employed to find the optimal hydrolysis parameters condition and thus obtain the best NaCl rejection and pressure-normalized flux. The membrane characterizations, consisting of support pore size, chemical functional structure, PA morphology and hydrophilicity were carried out. The separation performances of TFNC membranes were evaluated using a cross-flow filtration module, where NaCl solution (2,000 ppm) was fed at 5 bars operating pressure. The result showed that the hydrolysis modification on the support layer played a significant role in the formation of PA selective layer. Hydrolysis could narrow support pore size that results in denser support with smaller open pores which contribute to the uniform formation of PA selective layer. It was found that support pore size significantly affects the PA morphology and surface chemistry properties of the prepared TFNC membranes. In addition, the developed models from the RSM optimization study successfully predicted the optimal NaOH concentration, reaction temperature, and reaction time at 1.65 M, 50oC, and 1.32 h, respectively. The best actual value of TFNC membrane prepared from the optimal condition was achieved at 96.19% NaCl rejection and 1.60 Lm-2h-1bar-1 pressure-normalized flux. Moreover, the optimal TFNC membranes fabricated could outperform the conventional TFC, commercial NF and RO membranes. The facile support modification through alkaline hydrolysis performed in this work could improve membrane performances by producing highly cross-linked and defect-free TFNC membranes.
Other Abstract (Other language abstract of ETD)
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Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Recommended Citation
Augusty, Anniza Cornelia, "Sodium hydroxide post treatment optimization for electrospun nanofiber as the support for thin-film composite membrane for reverse osmosis" (2022). Chulalongkorn University Theses and Dissertations (Chula ETD). 11880.
https://digital.car.chula.ac.th/chulaetd/11880