Oil Water Separation Using �Titania-Coated Filter

Team Lead: Hunter Ross

Ashton Foster

Brian Nguyen

Huyen Nguyen

Mike Patino

James Salud

Advisor: Dr. Mingheng Li

Introduction

Objectives

Figure 1.

A modified coated filter that repels oil while allowing seawater to pass through.

Current Methods

• The inspiration for this project comes from self-cleaning window coatings
• Self-cleaning refers to three critical properties that will be useful in filters
• Oleophobicity
• Hydrophilicity
• Photocatalysis

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Background

Methodology

Cost Optimization

Materials/Equipment

Treatment Methods

Sol-Gel Preparation

• Solution 1: Slowly add TTIP into 1-Butanol while mixing for 30 min
• Solution 2: Dropwise add acetic acid into Solution 1 while mixing for 120 min

Exothermic reaction. Conditions are under a fume hood or well-ventilated area at room temperature

Treatment Method: Microwave

Procedure:

• Microwave sol-gel coated substrate at 1000 W for 3 minutes
• Allow coated filter to dry at room temp for 24 hours

• Microwave heats the volume of solution evenly
• Reaction rate of process forming TiO₂ particles increases
• Produces high yield for the cost of materials

Treatment Method: Refrigeration

• A lower treatment temperature leads to a smaller crystalline size for TiO_2. 
• Lowest treatment temperature compared to other methods
• Smaller crystal size -> Larger surface area to volume ratio

Procedure:

• Immerse the filter completely in the sol-gel
• Store the immersed substrate in a refrigerator at 4°C for 24 hours
• Let the filter dry at room temp for 24 hours

Treatment Method: Sonication

• Cavitation creates temperatures >5000K and pressures >20 MPa in a localized area
• Enhances creation of metal oxide and nanoparticles
• Leads to the formation of crystalline titanium dioxide without additional heating

Procedure:

• Immerse beaker containing sol-gel into ultrasonic bath
• Sonicate for a total of 20 minutes
• Immerse substrates into sonicated solution
• Allow filters to dry at room temperature for 24 hours

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Timed Oil Filtration Test

Reasoning:

• Treated filters are expected to reduce volume of filtrate
• Gives quantifiable value to filtration capability
• Allows for the comparison of filtration efficiency between filters

Procedure:

• 50 mL of motor oil was poured onto the filter and allowed to run for 5 minutes
• Volume of oil pass-through measured in 30 second intervals

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Filtration ability of treated filters vs. control

LOWER = BETTER

% improvement in filtration capacity

HIGHER = BETTER

Static Contact Angle Test

Reasoning:

• Higher contact angle indicated enhanced oleophobicity
• The static contact angle for treated is expected to be higher than untreated
• Contact angle shows the filters resistance to being wetted with oil

Procedure:

• A macro video was recording, an oil droplet being placed onto the filter
• Image of the droplet on first contact with the filter is captured from video

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Static oil contact angle of oil droplet on filters

HIGHER = BETTER

Photocatalytic Analysis

• Methyl blue (MB) was applied to TiO₂ coated strips of the filter 
• Color of MB degrades under exposure to UV light in the presence of a photocatalyst
• Proof of photocatalysis confirms that the filter fulfills one of the self-cleaning properties

t = 0 hours

t = 10 hours

t = 20 hours

Conclusions

Future Work

• Pretreating fabric to improve titanium dioxide adhesion
• Improve practical implementation of the filter using additional layers of coated substrates
• Explore additional less porous substrates 

References

Chen, X., & Mao, S. S. (2007). Titanium dioxide nanomaterials: Synthesis, properties, modifications, and applications. ChemInform, 38(41). https://doi.org/10.1002/chin.200741216 ​

Salazar, J. M. G. de, Duduman, C. N., Gonzalez, M. J., Palamarciuc, I., Pérez, M. I. B., & Carcea, I. (2016, August 1). Research of obtaining TiO2 by sol-gel method using titanium isopropoxide TIP and tetra-n-butyl orthotitanate TNB. IOP Conference Series: Materials Science and Engineering. Retrieved January 8, 2021, from https://iopscience.iop.org/article/10.1088/1757-899X/145/7/072011 

Prasad, K., Pinjari, D. V., Pandit, A. B., & Mhaske, S. T. (2010). Phase transformation of nanostructured titanium dioxide from anatase-to-rutile via combined ultrasound assisted sol–gel technique. Ultrasonics Sonochemistry, 17(2), 409–415. https://doi.org/10.1016/j.ultsonch.2009.09.003 ​

Cesnovar, A., Paunovic, P., Grozdanov, A., & Makreski, P. (2012, January). Preparation of nano-crystalline TiO2 by sol-gel method using titanium tetraisopropoxide (TTIP). Research Gate. Retrieved December 15, 2021, from https://www.researchgate.net/publication/234164554_Preparation_of_nano-crystalline_TiO2_by_sol-gel_method_using_titanium_tetraisopropoxide_TTIP

U.S. National Library of Medicine. (n.d.). PubMed. National Center for Biotechnology Information. Retrieved April 15, 2022, https://pubmed.ncbi.nlm.nih.gov/ 

Sucio, R., Indrea, E., Silapas, D. T., & Dreve, S. (n.d.). TiO2 thin films prepared by sol – gel method. Research Gate. Retrieved January 15, 2022, from https://www.researchgate.net/publication/231058491_TiO2_thin_films_prepared_by_sol_-_gel_method 

Chaudhary, V., & Srivastava, A. (n.d.). On the sol-gel synthesis and characterization of titanium oxide nanoparticles. Research Gate. Retrieved January 18, 2022, from https://doi.org/10.1557/opl.2011.759

Wiener, J., Noman, T., et al. (2017, June 28). In-situ development of highly photocatalytic multifunctional nanocomposites by ultrasonic acoustic method. Ultrasonics Sonochemistry. Retrieved February 1, 2022 from https://doi.org/10.1016/j.ultsonch.2017.06.026

Sadr, F. A., & Montazer, M. (2014, March). In situ sonosynthesis of nano TiO2 on cotton fabric. Science Direct. Retrieved January 22, 2022, from https://www-sciencedirect-com.proxy.library.cpp.edu/science/article/pii/S1350417713002290 

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Special Thanks To

Questions?

Please feel free to email me your questions:

htross@cpp.edu

Our publication:

Filter Modified with Hydrophilic and Oleophobic Coating for Efficient and Affordable Oil/Water Separation

https://doi.org/10.3390/separations9100269