|Michigan Tech's Open Sustainability Technology Lab.|
Background[edit | edit source]
There is a method of solar water disinfection (SODIS) that lets water be naturally heated by the sun's rays over a period of about six hours. When the amount of UV radiation has peaked, then the water is safe to drink. The water container is a recycled plastic water bottle, which is what makes this method so cheap. However, this is the least efficient method of solar water disinfection.
Purpose[edit | edit source]
Experimental research on the gaphchromic polymer will allow us to fabricate a polymer that will change color when the bottle has recieved the allowable amount of UV radiation that indicates pasteurization.
Materials[edit | edit source]
- Gaphchromic polymer
- UV retardant (sunscreen)
- UV filter
- Solar simulator
Procedure[edit | edit source]
The solar simulator is approximately 1 kW/sq meter when the sample is 35-40 centimeters away from the front of the lense of the solar simulator. Combine the gaphchromic polymer with the UV filter and sunscreen, and then leave the sample 35-40 centimeters away from the front of the lense. Take samples from the gaphchromic polymer every ten minutes for 6 hours.
Applying Sun Screen Layer[edit | edit source]
- Dissolve sunscreen in acetonitrile (ACN)
- Centrifuge to remove TiO2 Particles
- Collect superatant (This is solution that will be sprayed onto gaphchromic)
- Spray even, thin coat of ACN onto film, solvent dries leaving sunscreen
- Spray single film w/ gradient of different ACN/sunscreen components and expose to 1,000 W/sq meter to identify concentration. (need to appropriately attenuate energy/color change)