Low-fouling membrane surfaces by using thin coating technologies

Juha Nikkola, Hanna-Leena Alakomi, Chuyang Tang

Research output: Contribution to conferenceConference articleScientificpeer-review

Abstract

Among others hydrophilicity and low surface roughness are the key factors in the development of low-fouling surfaces for thin-film-composite reverse osmosis (TFC RO) membranes. The main focus of the recent study was to develop and evaluate different thin coating technologies which could have potentiality to introduce low-fouling performance on commercial TFC RO membrane surface. Furthermore, it was aimed to improve the mechanical and chemical resistance of the TFC RO membrane surface. The selected thin coating technologies, including inorganic-organic sol-gel and inorganic ALD (atomic layer deposition) thin films and also antibacterial polymer films, were studied. Typical sol-gel coating consisted of organically modified siloxanes whereas aluminium oxide (Al2O3) thin film was applied by the ALD method. In addition, different active agents, such as zinc oxide (ZnO) and carbon nanotube (CNT), were used to functionalise the polyvinyl alcohol (PVA) thin coatings. Commercial DOW LE membrane was used as a substrate for the coating applications. The coating thickness varied from 5 nm to 200 nm depending on the applied thin coating method. The surface chemistry and structure of the coated surfaces were characterised by using ATR-FTIR, AFM and SEM-EDS. Based on the surface analysis all the applied coatings decreased the roughness of the membrane surface. Contact angle measurement was used to determine the hydrophilicity and hydrophobicity as well as to calculate the surface energy of the coated surfaces. Some of the applied coatings were clearly more hydrophilic compared to the uncoated membrane surface. The bacteria attachment test with a flow was carried out to evaluate the anti-fouling performance of the surfaces. In the particular method the coated samples were contacted with Pseudomonas aeruginosa cells for 24 hours in modified standard seawater (ASTM D1141-98 (2008)) in room temperature (130 rpm orbital shaker) and after 24 h bacterial exposure the number of adhered cells on the surface was analysed. In general it was seen that less bacteria was attached to hydrophilic surface, but on the other hand it was noticed that the low surface roughness decreased the bacteria attachment even the surface was relatively hydrophobic. Furthermore it is suggest that some of the functional chemical groups also decrease the bacteria attachment. The flux and salt rejection test was performed for the selected samples to evaluate the membrane's filtration performance. As expected all the tested coatings showed lower flux compared to unmodified TFC RO membrane.
Original languageEnglish
Publication statusPublished - 2012
EventAdvanced Membrane Technology V: Membranes for sustainable water, energy and the environment - , Singapore
Duration: 14 Oct 201219 Oct 2012

Conference

ConferenceAdvanced Membrane Technology V
CountrySingapore
Period14/10/1219/10/12

Fingerprint

Membrane fouling
Coatings
Osmosis membranes
Reverse osmosis
Thin films
Bacteria
Fouling
Membranes
Atomic layer deposition
Surface roughness
Composite materials
Hydrophilicity
Sol-gels
Fluxes
Siloxanes
Zinc Oxide
Polyvinyl Alcohol
Carbon Nanotubes
Chemical resistance
Aluminum Oxide

Keywords

  • TFC PA membrane
  • anti-fouling
  • thin films

Cite this

Nikkola, J., Alakomi, H-L., & Tang, C. (2012). Low-fouling membrane surfaces by using thin coating technologies. Paper presented at Advanced Membrane Technology V, Singapore.
Nikkola, Juha ; Alakomi, Hanna-Leena ; Tang, Chuyang. / Low-fouling membrane surfaces by using thin coating technologies. Paper presented at Advanced Membrane Technology V, Singapore.
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title = "Low-fouling membrane surfaces by using thin coating technologies",
abstract = "Among others hydrophilicity and low surface roughness are the key factors in the development of low-fouling surfaces for thin-film-composite reverse osmosis (TFC RO) membranes. The main focus of the recent study was to develop and evaluate different thin coating technologies which could have potentiality to introduce low-fouling performance on commercial TFC RO membrane surface. Furthermore, it was aimed to improve the mechanical and chemical resistance of the TFC RO membrane surface. The selected thin coating technologies, including inorganic-organic sol-gel and inorganic ALD (atomic layer deposition) thin films and also antibacterial polymer films, were studied. Typical sol-gel coating consisted of organically modified siloxanes whereas aluminium oxide (Al2O3) thin film was applied by the ALD method. In addition, different active agents, such as zinc oxide (ZnO) and carbon nanotube (CNT), were used to functionalise the polyvinyl alcohol (PVA) thin coatings. Commercial DOW LE membrane was used as a substrate for the coating applications. The coating thickness varied from 5 nm to 200 nm depending on the applied thin coating method. The surface chemistry and structure of the coated surfaces were characterised by using ATR-FTIR, AFM and SEM-EDS. Based on the surface analysis all the applied coatings decreased the roughness of the membrane surface. Contact angle measurement was used to determine the hydrophilicity and hydrophobicity as well as to calculate the surface energy of the coated surfaces. Some of the applied coatings were clearly more hydrophilic compared to the uncoated membrane surface. The bacteria attachment test with a flow was carried out to evaluate the anti-fouling performance of the surfaces. In the particular method the coated samples were contacted with Pseudomonas aeruginosa cells for 24 hours in modified standard seawater (ASTM D1141-98 (2008)) in room temperature (130 rpm orbital shaker) and after 24 h bacterial exposure the number of adhered cells on the surface was analysed. In general it was seen that less bacteria was attached to hydrophilic surface, but on the other hand it was noticed that the low surface roughness decreased the bacteria attachment even the surface was relatively hydrophobic. Furthermore it is suggest that some of the functional chemical groups also decrease the bacteria attachment. The flux and salt rejection test was performed for the selected samples to evaluate the membrane's filtration performance. As expected all the tested coatings showed lower flux compared to unmodified TFC RO membrane.",
keywords = "TFC PA membrane, anti-fouling, thin films",
author = "Juha Nikkola and Hanna-Leena Alakomi and Chuyang Tang",
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Nikkola, J, Alakomi, H-L & Tang, C 2012, 'Low-fouling membrane surfaces by using thin coating technologies' Paper presented at Advanced Membrane Technology V, Singapore, 14/10/12 - 19/10/12, .

Low-fouling membrane surfaces by using thin coating technologies. / Nikkola, Juha; Alakomi, Hanna-Leena; Tang, Chuyang.

2012. Paper presented at Advanced Membrane Technology V, Singapore.

Research output: Contribution to conferenceConference articleScientificpeer-review

TY - CONF

T1 - Low-fouling membrane surfaces by using thin coating technologies

AU - Nikkola, Juha

AU - Alakomi, Hanna-Leena

AU - Tang, Chuyang

N1 - Project code: 72487

PY - 2012

Y1 - 2012

N2 - Among others hydrophilicity and low surface roughness are the key factors in the development of low-fouling surfaces for thin-film-composite reverse osmosis (TFC RO) membranes. The main focus of the recent study was to develop and evaluate different thin coating technologies which could have potentiality to introduce low-fouling performance on commercial TFC RO membrane surface. Furthermore, it was aimed to improve the mechanical and chemical resistance of the TFC RO membrane surface. The selected thin coating technologies, including inorganic-organic sol-gel and inorganic ALD (atomic layer deposition) thin films and also antibacterial polymer films, were studied. Typical sol-gel coating consisted of organically modified siloxanes whereas aluminium oxide (Al2O3) thin film was applied by the ALD method. In addition, different active agents, such as zinc oxide (ZnO) and carbon nanotube (CNT), were used to functionalise the polyvinyl alcohol (PVA) thin coatings. Commercial DOW LE membrane was used as a substrate for the coating applications. The coating thickness varied from 5 nm to 200 nm depending on the applied thin coating method. The surface chemistry and structure of the coated surfaces were characterised by using ATR-FTIR, AFM and SEM-EDS. Based on the surface analysis all the applied coatings decreased the roughness of the membrane surface. Contact angle measurement was used to determine the hydrophilicity and hydrophobicity as well as to calculate the surface energy of the coated surfaces. Some of the applied coatings were clearly more hydrophilic compared to the uncoated membrane surface. The bacteria attachment test with a flow was carried out to evaluate the anti-fouling performance of the surfaces. In the particular method the coated samples were contacted with Pseudomonas aeruginosa cells for 24 hours in modified standard seawater (ASTM D1141-98 (2008)) in room temperature (130 rpm orbital shaker) and after 24 h bacterial exposure the number of adhered cells on the surface was analysed. In general it was seen that less bacteria was attached to hydrophilic surface, but on the other hand it was noticed that the low surface roughness decreased the bacteria attachment even the surface was relatively hydrophobic. Furthermore it is suggest that some of the functional chemical groups also decrease the bacteria attachment. The flux and salt rejection test was performed for the selected samples to evaluate the membrane's filtration performance. As expected all the tested coatings showed lower flux compared to unmodified TFC RO membrane.

AB - Among others hydrophilicity and low surface roughness are the key factors in the development of low-fouling surfaces for thin-film-composite reverse osmosis (TFC RO) membranes. The main focus of the recent study was to develop and evaluate different thin coating technologies which could have potentiality to introduce low-fouling performance on commercial TFC RO membrane surface. Furthermore, it was aimed to improve the mechanical and chemical resistance of the TFC RO membrane surface. The selected thin coating technologies, including inorganic-organic sol-gel and inorganic ALD (atomic layer deposition) thin films and also antibacterial polymer films, were studied. Typical sol-gel coating consisted of organically modified siloxanes whereas aluminium oxide (Al2O3) thin film was applied by the ALD method. In addition, different active agents, such as zinc oxide (ZnO) and carbon nanotube (CNT), were used to functionalise the polyvinyl alcohol (PVA) thin coatings. Commercial DOW LE membrane was used as a substrate for the coating applications. The coating thickness varied from 5 nm to 200 nm depending on the applied thin coating method. The surface chemistry and structure of the coated surfaces were characterised by using ATR-FTIR, AFM and SEM-EDS. Based on the surface analysis all the applied coatings decreased the roughness of the membrane surface. Contact angle measurement was used to determine the hydrophilicity and hydrophobicity as well as to calculate the surface energy of the coated surfaces. Some of the applied coatings were clearly more hydrophilic compared to the uncoated membrane surface. The bacteria attachment test with a flow was carried out to evaluate the anti-fouling performance of the surfaces. In the particular method the coated samples were contacted with Pseudomonas aeruginosa cells for 24 hours in modified standard seawater (ASTM D1141-98 (2008)) in room temperature (130 rpm orbital shaker) and after 24 h bacterial exposure the number of adhered cells on the surface was analysed. In general it was seen that less bacteria was attached to hydrophilic surface, but on the other hand it was noticed that the low surface roughness decreased the bacteria attachment even the surface was relatively hydrophobic. Furthermore it is suggest that some of the functional chemical groups also decrease the bacteria attachment. The flux and salt rejection test was performed for the selected samples to evaluate the membrane's filtration performance. As expected all the tested coatings showed lower flux compared to unmodified TFC RO membrane.

KW - TFC PA membrane

KW - anti-fouling

KW - thin films

M3 - Conference article

ER -

Nikkola J, Alakomi H-L, Tang C. Low-fouling membrane surfaces by using thin coating technologies. 2012. Paper presented at Advanced Membrane Technology V, Singapore.