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Photopatterning Proteins and Cells in Aqueous Environment Using TiO2 Photocatalysis
Published on: October 26, 2015
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Photochromic TiO2/PEGDA organogels
Raivis Eglītis1, Andris Šutka2
1Faculty of Materials Science and Applied Chemistry, Institute of Materials and Surface Engineering, Riga Technical University, Paula Valdena 3/7, Riga, 1048, Latvia. raivis.eglitis_1@rtu.lv.
Summary
New photochromic gels using titanium dioxide (TiO2) quantum dots offer tunable light transmittance for energy-saving windows. These stable gels provide a practical alternative to liquid suspensions for advanced window applications.
Area of Science:
- Materials Science
- Nanotechnology
- Photochemistry
Background:
- Photochromic materials modulate light transmittance for privacy and energy savings.
- Titanium dioxide (TiO2) nanoparticles show promise but require liquid suspensions for optimal performance.
- Polymer composites lack sufficient hole scavenging for effective photochromic response.
Purpose of the Study:
- To develop a stable, gel-based photochromic material using TiO2 quantum dots.
- To overcome the limitations of liquid suspensions and less responsive polymer composites.
- To create a practical photochromic material for window applications.
Main Methods:
- Preparation of TiO2 quantum dot (QD)-based gels using polyethylene glycol diacrylate (PEGDA), N,N-Dimethylformamide (DMF), and ethanol (EtOH).
- Incorporation of TiO2 at 1-5 volume% into the gel matrix.
- Characterization of photochromic performance, including photodarkening time, transmittance change, and recovery time.
Main Results:
- TiO2 QD-based gels exhibited photochromic performance comparable to liquid suspensions.
- Photodarkening occurred within 30 minutes, with transmittance changes from 35.8% to 84.5% at 550 nm.
- Gels recovered initial transmittance within 3-8 hours and showed good stability over 10 cycles with <10% decrease.
Conclusions:
- TiO2 QD-based gels offer a viable, stable alternative to liquid suspensions for photochromic applications.
- The developed gels demonstrate potential for use in energy-saving photochromic windows.
- This research addresses the practical challenges of implementing photochromic materials in real-world devices.
