ScienceIML - 6-3-2013 at 00:10
Hello everybody,
I was recently trying to make a dssc with anthocyanins. So my titanium dioxide paste bonds wel when adhering. When I heated it on my hot pate it went
browny-yellow and then white again. Then I got the raspberry juice and left it on the TiO2 slide for 1 hr.
When I washed off the excess juice the titanium dioxide adhered really well and it didn't wash off. But the problem is that the TiO2 doesn't get
stained very much. It is supposed to be a pretty deep purple colour right? mine is sort of pale pink
any ideas?
Harristotle - 6-3-2013 at 04:20
Hi.
I am looking at dye sensitised cells too.
Possibly a problem is that titanium dioxide is so reactive a substance that the supplies of it used in health and makeup products may be coated with
something to make it more inert.
I will be trying to activate a very small quantity with H2O2/H2SO4 mixture to see if I can oxidise anything stuck to it.
Be careful, be safe - I have not yet tried this but I will need to for some students who will be trying to make dssc's next month.
Does anyone here actually know something (other than my speculation) about cosmetic grade TiO2 ? 
K12Chemistry - 6-3-2013 at 07:58
Well it's probably not that because it happens to me and I am using reagent grade (EXPENSIVE!!).
Maybe it's because I didn't let the slide cool completely, or because It wasn't dry??
Like ^^^ said, does anyone actually know?