Zygimantas Gricius has submitted the following academic thesis as part of the doctoral work at the Norwegian University of Science and Technology (NTNU):
Design of Pickering Emulsions for Photocatalytic Applications
Assessment Committee
The Faculty of Natural Sciences has appointed the following Assessment Committee to assess the thesis:
Associate Professor Nina Lock
Aarhus University
Denmark
Senior Research Scientist Wilhelm R. Glomm
SINTEF Industry
Norway
Associate Professor Brian A. Grimes
Department of Chemical Engineering, NTNU
Associate Professor Brian A. Grimes has been appointed Administrator of the Committee. The Committee recommends that the thesis is worthy of being publicly defended for the PhD degree.
Supervisors
The doctoral work has been carried out at the Department of Chemical Engineering, where Professor Gisle Øye has been the candidate’s supervisor. Professor Magnus Rønning has been the candidate’s co-supervisor.
Public trial lecture
Time: 12th of May at 10:15
Place: S1, Sentral Building 1, NTNU Gløshaugen
Prescribed subject: Interfacial mass transfer mechanisms in Pickering emulsions: State-of-the-Art and Challenges
Public defence of the thesis
Place: S1, Sentral Building 1, NTNU Gløshaugen
Zoom Meeting: https://NTNU.zoom.us/j/98552900464?pwd=aTq0O7arIZVyjsZAysfA1ew0pXuc82.1
Meeting ID: 985 5290 0464
Passcode: 248196
Summary of thesis
Modern wastewater is full of organic pollutants — from pesticides to pharmaceuticals — that are difficult to remove with traditional treatment methods. This PhD research addresses that challenge with a creative solution: using sunlight and carefully engineered oil droplets, stabilized by light-activated particles, to break down harmful chemicals in water.
These droplets, known as photocatalytic Pickering emulsions, act like tiny chemical microreactors. They are stabilized by nanoparticles, such as titanium dioxide (TiO₂), that sit at the oil-water interface. There, they absorb sunlight and trigger reactions that break down harmful organic pollutants.
The thesis explored how to fine-tune these emulsions to make them more effective, stable, and reusable:
· Embedding TiO₂ into hydrogels created more robust droplets that could be reused without losing performance.
· Coating TiO₂ particles with polymeric stabilizers like poloxamers helped resist changes in water chemistry but could slightly reduce cleaning efficiency.
· Particle surface modifications using silane chemistry allowed better control over droplet formation and pollutant interaction.
· Gold-doped titania particles improved light absorption and performance — especially under visible light — while also enhancing droplet stability.
This thesis not only expands the science of photocatalytic emulsions but also kickstarts new ways of thinking about sustainable water treatment. It shows that combining photocatalysis with smart material design can overcome long-standing challenges in the field — offering a low-cost, reusable, and scalable approach to cleaning contaminated water.