Re: sticky shower curtains

[Bernard Cleyet <anngeorg@PACBELL.NET>]

dry CuSO4 is white -- wet blu.     try a little in the water and see if after
supposedly dry, is.    Of course  JU's explanation might effectively remove the
water from the salt to bond with the vynil and porcelon.

bc

"Carl E. Mungan" wrote:

> I was wondering what makes wet shower curtains so sticky? I suppose the
> answer is that water adheres to both plastic and porcelain. But what seems
> curious to me is that the curtain continues to stick after the water
> evaporates, and yet I cannot get a dry shower curtain to adhere to the tub
> when I press it on. This suggests that plastic doesn't adhere directly to
> porcelain, but that even after all the evident water evaporates something
> has happened to the surface bonds of the plastic and porcelain.
>
> Two possibilities come to mind: Maybe there's a thin monolayer of water
> still left after the bulk evaporates (since water adheres so well) and
> that's like a thin glue between the curtain and tub. The counter to this is
> that even a "dry" curtain should then have about a monolayer of water left
> on it, so why shouldn't a "dry" curtain adhere to a tub when I rub my finger
> nail over it like I might do with a piece of scotch tape?
>
> The other possibility has to do with how the dangling surface bonds get
> passivated as the water between the curtain and tub evaporates, but I'm
> starting to get out of my league here.
>
> Curious mind invites comments (CMIC), Carl
> -----
> Carl E. Mungan, Asst. Prof. of Physics  410-293-6680 (O) -3729 (F)
>       U.S. Naval Academy, Stop 9C, Annapolis, MD 21402-5026
> mailto:mungan@usna.edu          http://usna.edu/Users/physics/mungan/