[socalfusions]

I was unsure of where to post this topic so heres a link to the originating thread: http://www.chemicalforums.com/index.php?topic=42477.0

[billnotgatez]

alumina hydrate combined with kaolin is used in pottery as something that will resist melting.
also it resists glaze adhering

we paint it on suspended in water

maybe Epsom salts would assist in dissolving.

[socalfusions]

alumina hydrate combined with kaolin is used in pottery as something that will resist melting.
also it resists glaze adhering

we paint it on suspended in water

maybe Epsom salts would assist in dissolving.

What characteristic of Epsom salts would lead you to believe it would dissolve the mixture? After a quick look up on wikipedia I couldn't exactly find why it would but perhaps its the epsom salts ability to raise the specific gravity in high concentration when placed in water?

Or perhaps it's this characteristic: "Anhydrous  magnesium sulfate is commonly used as a desiccant  in organic synthesis due to its affinity for water. During work-up, an organic phase is saturated with magnesium sulfate until it no longer forms clumps. The hydrated solid is then removed with filtration or decantation. Other inorganic sulfate salts such as sodium sulfate and calcium sulfate may also be used in the same way."

Thanks for your input  

[Biopolmonkey]

Maybe a dispersant. There are a fair few knocking around, but the one I worked with was poly(acrylic acid) + derivatives. There's quite a bit of literature on this topic, because kaolin is so heavily utilised in industry.

[billnotgatez]

Epsom salts are used in pottery glazes to prevent settling out of the solids.

I thought this might be a cheap way to assist in dissolving.

Try the experiment and let us know.

[socalfusions]

Maybe a dispersant. There are a fair few knocking around, but the one I worked with was poly(acrylic acid) + derivatives. There's quite a bit of literature on this topic, because kaolin is so heavily utilised in industry.

Is this because in a water solution at neutral ph the side chains of PHH will lose their protons and acquire a negative charge (taken from wiki)? Can you elaborate on what you mean by derivatives. I appreciate the feedback!

Epsom salts are used in pottery glazes to prevent settling out of the solids.

I thought this might be a cheap way to assist in dissolving.

Try the experiment and let us know.

Oh ok so the epsom salts could possibly dissolve the kaolin/alumina hydrate mix by preventing it from staying in a solid state? It sounds like a great idea, I'll test it and let you know how the results went!

[Biopolmonkey]

Socialfusions, I do not know how much you already know, so apologies if this is too basic for you.

Kaolin is found in the form of hexagonal plates with the formula Al2Si2O5(OH)4. At pH <8, the edges of the plates are positively charged, whilst the faces are negative. As pH increases, the polarity of the edges reverses and plate-plate interactions weaken.

By introducing PAA, a polyanion, we are trying to mimic the effect that occurs when you take the pH above 8. There is evidence that suggests the PAA interacts with the Al within the kaolin (PAA adsorption density onto alumina 10x that then on kaolin). We therefore infer that the PAA is adsorping at the plate edges + hinders plate-plate interactions.

When I referred to derivatives, basically I played around with the chain length and end groups. My funding died before I actually got to test any samples in clay, though.

[408]

A concentrated hot acid or base should take care of it.

[billnotgatez]

408 -

i am not sure that would be applicable as far as satety for the work site

socalfusions-

are you prepared to work with hot base or acid

[socalfusions]

Socialfusions, I do not know how much you already know, so apologies if this is too basic for you.

Kaolin is found in the form of hexagonal plates with the formula Al2Si2O5(OH)4. At pH <8, the edges of the plates are positively charged, whilst the faces are negative. As pH increases, the polarity of the edges reverses and plate-plate interactions weaken.

By introducing PAA, a polyanion, we are trying to mimic the effect that occurs when you take the pH above 8. There is evidence that suggests the PAA interacts with the Al within the kaolin (PAA adsorption density onto alumina 10x that then on kaolin). We therefore infer that the PAA is adsorping at the plate edges + hinders plate-plate interactions.

When I referred to derivatives, basically I played around with the chain length and end groups. My funding died before I actually got to test any samples in clay, though.

I have very little knowledge on the subject, I appreciate all explanations 

So PAA will take the ph level above 8 8and therefore start breaking down the kaolin + alumina? I'm assuming that working with PAA and related ingredients are quite expensive?

A concentrated hot acid or base should take care of it.

Are there certain hot acids I should be looking at that won't harm any metal on the glass or the glass itself? I'm unfamiliar with bases, could you explain what they are? Thanks for your response.

408 -

i am not sure that would be applicable as far as satety for the work site

socalfusions-

are you prepared to work with hot base or acid

I am prepared to work with them although I don't have adequate knowledge at the moment, I am willing to quickly learn it. Is it possible to test hot acids / bases with little to no equipment or are you required to buy a large setup.

How dangerous is it to work with hot acids and bases? Is this something that someone with no knowledge on the subject can quickly learn by a simple reading of directions?

I'm really looking to use it to dissolve the kaolin + alumina mixture inside of a lampwork bead without damaging the glass or metallic ingredients that are often mixed into the bead without a incredible amount of equipment, if that's possible. I appreciate the feedback!