Sciencemadness Discussion Board

Why can't I make soft clay by mixing with oil rather than water?

Junk_Enginerd - 11-12-2022 at 12:49

I don't quite understand the reason. Dry clay, mixed with water turns into moist and malleable clay. No surprises there... But dry clay, mixed with oil, does not. Best case it turns into a gritty slurry, worst case it just stays a hard lump that is now wet with oil. It seems it is not dispersing/getting suspended properly. But why? Can something be added to encourage it?

DraconicAcid - 11-12-2022 at 12:52

Clays absorb water because they contain a bunch of ionic silicates. Ions don't attract non-polar oil molecules with the same enthusiasm.

CharlieA - 11-12-2022 at 14:32

@Draconic: A bit anthropomorphic, but right on!:D

DraconicAcid - 11-12-2022 at 14:53

Quote: Originally posted by CharlieA  
@Draconic: A bit anthropomorphic, but right on!:D

I explain hydration to my students with an enactment of water molecules saying, "Come play with us!" to the ions. Anthropomorphizing chemicals is a long-standing habit.

Σldritch - 11-12-2022 at 17:01

It is called plasteline though I don't know exactly what it contains. Maybe some surfactant, say, stearic acid or whatever.

Junk_Enginerd - 11-12-2022 at 21:33

Ohhh okay. I thought clay was simply tiny particles of sand basically. That makes sense. But that sort of implies that if you "wash" clay enough, it'll lose its water absorbing properties. Do you know whether that's the case?

Also anthropomorphising chemistry is definitely my jam. It's not wrong, and it makes it much easier to understand too.

DraconicAcid - 11-12-2022 at 21:52

No, washing clay won't make it lose it's water-absorbing qualities. Sand isn't SiO2 molecules, but a polymer with that formula. Adding water hydrates it, essentially turning one of the Os into two OHs. These are very hydrophilic.

Junk_Enginerd - 12-12-2022 at 09:07

Ah. It gets wet on a molecular level. Nothing water soluble needed, just easily transitioning between hydroxides and oxides. Welp, that's all I wanted to know. Thanks!

unionised - 12-12-2022 at 09:25

You may find this interesting.
https://en.wikipedia.org/wiki/Plasticine

Texium - 12-12-2022 at 11:32

Not to mention lots of insoluble calcium, magnesium, iron, etc silicates that are also present and provide ions for water to "hold on" to.

macckone - 12-12-2022 at 14:42

It is possible to modify clay with quaternary ammonium salts and make oil based clay. The following link has a procedure. It uses a decanoaic tri-methyl ammonium bromide and a non-ioninc surfacant. The ingredients do not seem too specific and other should work.
https://www.sciencedirect.com/science/article/abs/pii/S01691...

macckone - 12-12-2022 at 15:24

Ps. Lysol laundry sanitizer is the perfect product for this application.
It contains both non-ionic surfactants and the quantenary ammonium salt. Mix with bentonite clay, allow the water to evaporate. Powder and add oil should be all that is necessary according to the paper. After adding oil you need to mull the play to get the best consistency.

Lionel Spanner - 13-12-2022 at 14:23

Quaternium hectorites and bentonites are also commercially available pre-dispersed in suitable solvents, for cosmetic and industrial use. Elementis sell them under the trade name Bentone, but there are many generic versions available.

CharlieA - 14-12-2022 at 17:16

If I implied that there was something wrong with anthropomorphizing the behavior of chemical entities, I apologize. Whatever helps one to understand the behavior of invisible particles, especially in predicting their behavior is a good thing. I always described chemistry to my students as an "obscure" science in that it wasn't obvious why chemical "things" were doing what they were doing. My example: you mix two clear solutions together and get a red solution. You see what happened, but HOW, on the atomic/ionic/molecular level, did it happen?

DraconicAcid - 14-12-2022 at 21:55

Quote: Originally posted by CharlieA  
If I implied that there was something wrong with anthropomorphizing the behavior of chemical entities, I apologize. Whatever helps one to understand the behavior of invisible particles, especially in predicting their behavior is a good thing. I always described chemistry to my students as an "obscure" science in that it wasn't obvious why chemical "things" were doing what they were doing. My example: you mix two clear solutions together and get a red solution. You see what happened, but HOW, on the atomic/ionic/molecular level, did it happen?

That implication never crossed my mind. No apologies needed.

Junk_Enginerd - 23-12-2022 at 13:01

Quote: Originally posted by macckone  
It is possible to modify clay with quaternary ammonium salts and make oil based clay. The following link has a procedure. It uses a decanoaic tri-methyl ammonium bromide and a non-ioninc surfacant. The ingredients do not seem too specific and other should work.
https://www.sciencedirect.com/science/article/abs/pii/S01691...


I can't imagine ever finding such chemicals, but "quaternary ammonium salts" led me down a trail that ended at... Laundry softener. That I do have! Maybe I'll buy a non scented one before trying it though, lol

Junk_Enginerd - 2-1-2023 at 06:17

Well I'll be damned. Laundry softener did it. Soft supple clay, using paraffin oil as base. I did NOT, however, buy an unscented variety first, so it stinks. Still, mission accomplished!