I’ve just put a 50/50 mix in my water bottle. Shook it to mix. Had a definate foam.
The surface tension of water is 73 dynes per centimeter, and that of alcohol is 22 (Surface-tension values - Wikipedia ) so It makes sense that alcohol would break up the surface tension of water which is essentially a surfactant. Surfactant - Wikipedia
It sure is. Every time I drink it, I wind up on a surface.
Surfactants act on phase boundaries. Alcohol is miscible in water – no liquid phase boundaries there. And the liquid-air interface surface tension would be that of the alcohol-water mix, so it hasn’t changed.
Small amounts of contaminants can create foam, though. Flavoring in the alchol and/or water, or simply residue in a re-used water bottle.
The problem with using liquor as a disinfectant or cleaning agent is that it will leave behind all manner of sugars, which will attract future bacterial growth.
Vodka has sugars? :dubious:
Chimera was talking about using alcohol as a disinfectant or cleaning agent – using it to remove something (presumably, to remove sticky sugars). Probably the alcohol wouldn’t solubilize the sugars, so they get left behind.
But the water in vodka would.
Well, if you and Chimera want to use your vodka for household cleaning tasks, I’m not going to stop you. Personally, if I drop a cinnamon bun, my first instinct isn’t to reach for the peppermint schanapps, you know?
The surface tension is between the alcohol-water mix and the air. A water-alcohol mix will have lower surface tension than pure water as noted by Sigene, so it is easier for bubbles to form even without other contaminants. You are correct that any contaminants can assist bubble formation even more.
I took Chimera’s to mean that any liquor had sugars, which might be true for some liqueurs but not vodka. If he’s talking about cleaning up some sugary mess with liquor, then vodka won’t work as well as plain water, but the water in it will still do a descent job dissolving sugar. If you’re talking about cleaning with schnapps (which includes a lot of added sugars), then obviously that’s a bad idea.
Unflavored vodkas shouldn’t have any sugars. Some people do use it, or Everclear, as a household cleaning agent, and in addition to being miscible with water, it’s an excellent co-solvent. In other words, things that don’t dissolve in water may dissolve in alcohol, which then dissolves in water. That’s the REAL reason why cough syrups contain a nominal amount of alcohol.