Sciencemadness Discussion Board

Spreading a film

silvergrahm - 27-11-2012 at 19:38

Hello,

I want to spread a thin but even film of fructose over a flat, smooth horizontal silica tile.

I began by simply dissolving in water and applying. The solution beaded up horribly as I expected. So, I'm looking for a wetting agent or surfactant that will allow the solution to spread across the surface in one unbroken, unbeaded sheet--as well as evaporate along with the water, leaving mostly fructose.

I am not a chemist but my understanding is I need an additive or a whole new liquid (in which fructose if soluble) that will lower the contact angle and lower the surface tension.

Thank you

elementcollector1 - 27-11-2012 at 20:36

Soap?
Preferably dish soap?

watson.fawkes - 27-11-2012 at 20:40

Quote: Originally posted by silvergrahm  
I am not a chemist but my understanding is I need an additive or a whole new liquid (in which fructose if soluble) that will lower the contact angle and lower the surface tension.
What kind of impurities can you tolerate in an additive? If you don't know, what's the application? (So folks here can get an idea of what won't work.)

And how thin is thin? Like 2 mm? Or a few microns?

bahamuth - 27-11-2012 at 20:43

Variable amounts of an alcohol might do the trick. Isopropanol works wonders as a "surfactant" in certain applications. n-butanol is also a good alternative.

silvergrahm - 27-11-2012 at 20:56

I'd like evrything to evaporate. Much thinner than 2mm, more like .5mm in the wet film, when dried, who knows, i dont have a way to measure such a thing. I've been doing some more research and it looks like methanol might be an easily accessible chem. though bahamuth I'm going to check out isopropanol and n-butanol.

phlogiston - 28-11-2012 at 01:43

How about preheating the tile, in a dry state, and then spraying it while hot with a fine mist of fructose solution. The droplets should evaporate nearly instantly whenthey land on the surface, and by using very fine droplets, a dilute solution and even spraying you should be able to make pretty homogenous coatings.