Date of Publication

2-15-2022

Document Type

Dissertation/Thesis

Degree Name

Doctor of Philosophy in Chemical Engineering

College

Gokongwei College of Engineering

Department/Unit

Chemical Engineering

Thesis Advisor

Arnel B. Beltran
Aileen H. Orbecido

Defense Panel Chair

Lawrence P. Belo

Defense Panel Member

Ramon Christian P. Eusebio
Blessie A. Basilia
Joseph L. Auresenia
Ely Anthony R. Ouano

Abstract/Summary

The preparation of an anti-biofouling membrane is the main focus of this study. This is achieved by incorporating copper (Cu) known for its’ antibacterial property in a polythiourea (PTU) membrane through a novel and facile simultaneous non-solvent induced phase separation (NIPS) and complexation induced phase separation (CIPS) process. This is possible due to the characteristics of PTU to instantaneously form a macromolecular-metal complex with Cu resulting in crosslinking of PTU with subsequent precipitation. The process strategically incorporates Cu in the membrane specifically at the PTU-non-solvent interface which ultimately forms the surface and pore walls of the membrane.

The polymerization process of 4,4-oxydianiline and p-phenylene diisothiocyanate for the synthesis of PTU was optimized in terms of molecular weight and processibility for membrane fabrication by phase separation. Characterization of the PTU using Fourier transform infrared (FTIR) spectroscopy, x-ray diffraction (XRD), and static light scattering for molecular weight (MW) determination confirm the polymerization reaction and the suitability of the polymer for the phase separation process and membrane application with MW of PTU around 451±17.59 kilodalton. Similarly, FTIR spectra of PTU-Cu membrane confirm the complexation reaction with the observed decline in the intensity of various functional groups responsible for complexation with an increase in Cu concentration.

The PTU-Cu membrane is relatively smoother and more hydrophilic compared to the pristine PTU membrane which indicates its antifouling potential. After filtering 5 grams/liter of a model foulant sodium alginate at 5 bars for 300 minutes, the flux ranges from 76% to 90% of the original flux for the PTU-Cu membrane while about 55% of the original flux for the PTU membrane. Both the surface of the PTU and PTU-Cu membrane showed antibacterial activity against E. coli.

Abstract Format

html

Language

English

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2022_Margarito_PreliminaryPages.pdf (1060 kB)
Preliminary Pages

2020_Margarito_PageswithSignature.pdf (399 kB)
Approval Sheet

2022_Margarito_Chapter1.pdf (436 kB)
Introduction

2022_Margarito_Chapter2.pdf (714 kB)
Review of Related Literature

2022_Margarito_Chapter3.pdf (1675 kB)
Theoretical Framework

2022_Margarito_Chapter4.pdf (700 kB)
Materials and Methodology

2022_Margarito_Chapter5.pdf (3626 kB)
Results and Discussions

2022_Margarito_Chapter6.pdf (135 kB)
Conclusions and Recommendations

2022_Margarito_ListofReferences.pdf (548 kB)
List of References

2022_Margarito_Appendix.pdf (5710 kB)
Appendix

Embargo Period

2-14-2022

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