Sciencemadness Discussion Board - DIY magic filter papers - a video demonstration

DIY magic filter papers - a video demonstration

peach - 7-10-2010 at 09:58

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mr.crow - 7-10-2010 at 14:24

Why is it private?

not_important - 7-10-2010 at 14:36

How about a text version for us bandwidth-limited folks?

Ozone - 7-10-2010 at 15:14

No workee.

peach - 7-10-2010 at 21:38

Whoops!

I set them to private to make sure it uploads properly and doesn't go crazy, and then forgot to unclick it.

ldanielrosa - 7-10-2010 at 23:51

Nice! Lacking a sep funnel, I'll use that for CHCl3.

peach - 8-10-2010 at 00:28

Quite.

I can imagine a lot of people without sep funnels could have fun with this, and save some cash if they're not regular funnel users.

Example of a fun home experiment:
Wash paint stripper with water to remove the polymer gunk, run it through a magic paper, harvest the semi-cleaned up DCM, redistill if you like (not necessarily in glass, it usually comes in metal cans and DCM boils around 40C), add some carbonate from the kitchen, water coffee and stir, extract with the DCM, split the DCM from the coffee solution with another magic paper, evaporate, caffeine. Recrystalize from E.Acetate nail polish remover for pretty crystals (they are real pretty, clusters of syringe like needle stars).

It can be used to split tiny or gigantic volumes, not needing specific funnel volumes.

And I wonder if the haloform could be run above one of these to have the chloroform drop out of the bottom?

[Edited on 8-10-2010 by peach]

Picric-A - 8-10-2010 at 00:39

I have used these many time before. They are called Hydrophobic Frits.
Another benefit of them is they dry the organic solvent fairly well aswell... not dry enough for grignards ect... but dry enough for extrctions non the less.

Ps. Great work Peach on inventing a OTC alternative to commercial Frits.
Are you sure some silicon compound does not dissolve in the organic solvent?

[Edited on 8-10-2010 by Picric-A]

peach - 8-10-2010 at 00:53

I should point out
I'm now on a big mission to circumnavigate the idea that you need to pay the famous brand names $......k to do something similar or better for very little or nothing. The goal being, to get people spending money on ability over names (which even university labs DO do; see rotovaps on rotary vanes) and to make it easier for people in poorer regions or the third world, who want to learn, to get access to the things they need; e.g. vacuums, liquid air products, flash columns made from syringes, these papers and so on. Another e.g. People are still finding near miracle drugs in the rain forests (things that will save a lot of cancer patients and so on). The people who live around there are extremely poor, and the R&D rate is strongly set by the lack of equipment and money, when it needn't always be so.
Pointed

Lacking a spectroscope of any sorts or NMR, I'm not 100%. Whatman are almost certainly not using something far off what's in the cans.

The can doesn't list what else is in it, but the dry paper has no strange additions that I can sense or see straight off. There's no perfume, dyes or sparkly bits added for a start, which is good.

I'm guessing there is a large component of volatile carrier in there. It's very easy to saturate the papers with the spray and it sinks in incredibly well, there is no doubt it's fully penetrating (the paper will be nearly transparent immediately after spraying). The companies, of coarse, design the spray to do that, as it needs to sink in well for thick, outdoor fabrics, meaning it goes into the filter paper super easy.

The effect is quite impressive to see. Once it's dry, the paper looks and feels like an ordinary paper. But you can clearly see the paper is not only not whetting, even on the inside, but the meniscus is upside down and the water is beading off the surface. I've left one full of water for a while and it doesn't change.

As to the silicon going through. The only way I can try to determine that would be to try soaking one in organic for a day or something like that, then testing it with water again. I think it may hold up well.

Even if some of the silicone does go through, as a trace, it's used as grease for the tapers on the majority of lab glass anyway.

If you're worried about trace carrier over, when they're dry, give them a spray with your solvent / pH of choice first, to rinse out anything that the sample will pick up on the way through.

What really interests me is, it looks like the silicone is actually getting down to the individual fibres of the paper. If so, a pack of them could be sprayed, chopped up and then blended to mush in an organic solvent. The mush could then go into a column and organic put through to get the water out.

I'm curious to know just how dry a mush column could get it. As solvent stills and commercial SPS systems are way beyond the safety and price levels most at homers can deal with.

The pure alumina for the SPS method isn't cheap or easy to get either. So, even if the paper mush doesn't do a good enough job on it's own, it'd mean a significantly smaller amount of pure alumina could be used as the final layer.

I might try a pipette column and whip out some water tests. That'd be amazing if it worked, a little bank of columns all made from cheap pipettes doing each solvent, on your desktop at home, quietly, safely, easily. <----- there goes the patent rights and ability to charge $15k for a station of them.

I do have four sinter funnels, but resisted the urge to spray them and show that too due to the cleaning up involved. As you probably know, they can be quite ?fun? to thoroughly clean.

One of mine had already been used in a lab. It looked pure white when I was given it, then I dumped some piranha through and it immediately turned brown / black.

I'm passing on the sinter spraying challenge to you Picric.

I'm sure it'll work just as well, but it may mess with the other uses of the funnel if you can't find some way to easily get it 100% back out of the pores; meaning it'd probably be better to designate that a hydrophobic funnel.

Maybe you've got some spec / NMR gear at uni / work that you could give it a run through to see what it's like.

Curly arrow is using it for his NMR samples, and says the branded papers don't show a line for water.

I wonder if it could be used as a permeable membrane concentration method over distillation and such. E.g. Splitting alcohol to water & ethanol. <---- more invalid patent applications.

[Edited on 8-10-2010 by peach]

aonomus - 8-10-2010 at 03:53

I'd be more interested to see some more research into what solvents the DWR sprays (durable water repellancy) use as a solvent, and whether they actually crosslink or bond to the hydrophilic surfaces, or, just sit on the surfaces and can eventually be either dissolved or worn off.

Usually these RP filter papers are made by silanizing the heck out of hydrophilic surfaces using stuff like C18 silanes. They are durable enough to withstand a tiny bit of handling, and I wonder if these will be the same.

Peach: can you do any tests to see whether certain solvents degrade the water repellancy, and whether some protic organic solvents like alcohols can make it through? What if they are miscible with water?

[Edited on 8-10-2010 by aonomus]

peach - 8-10-2010 at 03:56

I've just tried putting a miscible mix through and it most certainly does not split them.

I'm skeptical that they're actually crosslinking like silicon from a gun, but then, I have seen it peeling back off things, like my school bag, as a film after years of battering.

The solvent isn't a standard volatile, or at least there's no a lot of one in there. I can't smell any strong smell that I recognize (DCM, acetone, acetate etc) and it takes too long to boil off compared to the really volatile ones.

I suspect the solvent is some oily organic minus a halogen, alcohol, acetate or aldehyde, possibly something from the petrochemicals.

I've put them in a bath of xylene and will leave them for a while to see how they hold up to a good soak.

{edit}I used to constantly get rained on and walked back and forth from school four times a day, sometimes between buildings down a road as well, so I ended up caking my school bag with the stuff to stop my books getting soaked.

[Edited on 8-10-2010 by peach]

spong - 8-10-2010 at 04:00

Great idea Peach

The column of papers is great too, especially for ethanol and water. Have you tried running any 95% ethanol through one of the papers yet?

peach - 8-10-2010 at 04:05

I've tried splitting fermented alcohol, it doesn't work. It needs to be a miscible boundary.

What I suspect is happening is that the boundary is getting caught in the microscope pores, the same way you'd see water caught in the gaps in a sieve doing some pasta. The surface tension is enough to catch pockets of water in the sieve, even though the gaps are orders of magnitude bigger than the water molecules.

When it's a miscible solution of the two solvents, the surface tension effect doesn't work.

Also, if I put fermented alcohol through, both the water and alcohol go through, indicating the miscible ethanol is helping carry the water through.

But it still works where you have a boundary producing mix.

I'm not sure, yet, how it works with dissolved water content, where it's in solution with the water. E.g. DCM will produce a boundary with water, but it also crosses over to a small extent; it's not a perfect boundary.

I made a video of the ethanol example. Now I'm soaking the paper in an organic to see if the silicone will wash back off over time when submerged.

I'll post it up tonight or tomorrow.

[Edited on 8-10-2010 by peach]

aonomus - 8-10-2010 at 04:08

I'm curious as to whether the hydrophobicity only works when it isn't wetted. Under pressure in a column water might force its way through. Can you maybe load a syringe with a frit of paper and make an emulsion or just shake up a mix of water + immiscible solvent?

peach - 8-10-2010 at 04:10

I was thinking that as well.

I think it will work, but the question would be to what degree. And it'll change with the liquids being used.

If my surface tension thinking is correct, the pressure the effect stops working at will correspond to the surface tension needed to keeping the pockets intact at the pores.

I do have genuine, ultra fine grade papers and activated carbon. If the effect is related to surface tension and pore size, using one of those over the coffee filter may allow for better splits at increased pressure.

Vacuum filtration would be another one to investigate. Does it work as is? Does it need a layer of sprayed activated carbon on top of the paper / sinter?

As I say, I'm already busy videoing ethanol and soaking them, but then I'll try to look at vacuum filtration as well, which would correspond to flash chromatography; the pressure SPS is usually run at.

[Edited on 8-10-2010 by peach]

spong - 8-10-2010 at 04:18

Ahh damn, is there a cutoff point in water percentage where it will refuse to pass through the paper? Not that would be any real use though I suppose, it would have to be pretty dilute ethanol.

Rogeryermaw - 8-10-2010 at 04:34

this smacks of creative genius! thank you for sharing. this little technique is going to find its way into the lineup of nearly every home chemist out there. whether you invented this or not you have done us a huge service. now that's a peachy trick! are there any organics we should be aware of that will dissolve the silicone layer allowing the water through? any particular brand of silicone spray that is better than others? ready to have a go with this one! (licking chops)

peach - 8-10-2010 at 07:31

@spong

Concentrating ethanol... I was hopeful it'd work, because I have 10l of it sat around from raw sugar, and I've had 210l of it in a huge shipping drum at one point. Being able to knock the percentage up would be a big help in getting the rest of it with desktop sized glass; close to anhydrous when vacuum distilled. Then you'd have an easy source of dry ethanol. And, ethanol is a great feedstock for other processes, it can be catalytically converted to the aldehyde by blowing it over hot copper. Some guys on here have already shown that works at home and that it works very well. That can then go on to feed other things. For example, the various one pot, do it in a bucket, pyridine syntheses.

But alas, it doesn't. It all went through. But the paper was still dry, so the layer is there, but the organic ethanol is helping the water through with them both in solution.

More over getting drunk very quickly, is my wondering about how the water dissolved in the organic is behaving. Is that going through too? And just leaving the bulk behind when it hits the true phase boundary? Probably if the ethanol example is a universal.

I need to sort out an easy test to check how much is getting through. The most precise thing I have is the 0.1mg balance, so it'll probably be something involving a mass change, like how an anhydrous salt changes in mass as I drop the results of a magic paper split on it. I can easily remove the solvent from the sample afterwards under vacuum, leaving behind the water of crystallization, and look at that on the balance.

I now have lots of papers upside down and black activated carbon, drenched in it, drying off under vacuum.

@Roger

I used Fabsil Gold, but only because it was the first can I could find lying around the house. It's probably the case that the cheaper it is, the better, since it'll be closer to silicone, a carrier and not a lot else.

In terms of compatibility, contact time is always an issue when thinking about that. Even those $3k HazMat suits designed for handling ultra toxic waste don't work if you go for an hour long swim in the stuff. It'll depend on how much is being filtered and how long it takes to get through. Which, if it's a simple mix, won't be long at all; 30s?

If in doubt, as DuPont themselves say, you need to give them a spray with your weapon of choice first and see if the layer is affected in your time scale.

Also note that the compatibility results are often not very descriptive. It may be that the silicone is only swelling, it's permeable, or it's falling apart, or chemically burning to a cinder. There's no real dimension to them other than a rough warning of ones to watch. {edit} Actually, I'll add a note about that at the end of the list

Anyway, with that said, here is the entire list of compatibilities Cole Parmer are aware of for silicone. I thought about picking the obvious ones out, but then thought that would inevitably end up with people not seeing the one they were after. And I thought about just adding a link, but then figured people looking at this thread might find it easier if it's right here as a guide. Helpfully, it's alphabetic. Scroll or clicka-da-searcha edit / find button combo.

{edit}I notice xylene has a severe effect on there. I have some of the papers sat, submerged in xylene now. I'll have a look at them tonight and see if the layer's died over 9h or so.

-------------------------------------

Acetaldehyde A-Excellent
Acetamide B-Good
Acetate Solvent C-Fair
Acetic Acid C-Fair
Acetic Acid 20% B-Good
Acetic Acid 80% B-Good
Acetic Acid, Glacial B-Good
Acetic Anhydride C-Fair
Acetone D-Severe Effect
Acetyl Bromide N/A
Acetyl Chloride (dry) C-Fair
Acetylene B-Good
Acrylonitrile D-Severe Effect
Adipic Acid N/A
Alcohols:Amyl D-Severe Effect
Alcohols:Benzyl N/A
Alcohols:Butyl B-Good
Alcohols

iacetone D-Severe Effect
Alcohols:Ethyl B-Good
Alcohols:Hexyl B-Good
Alcohols:Isobutyl A-Excellent
Alcohols:Isopropyl A-Excellent
Alcohols:Methyl A-Excellent
Alcohols:Octyl B-Good
Alcohols

ropyl A-Excellent
Aluminum Chloride B-Good
Aluminum Chloride 20% B-Good
Aluminum Fluoride B-Good
Aluminum Hydroxide N/A
Aluminum Nitrate B1-Good
Aluminum Potassium Sulfate 10% A-Excellent
Aluminum Potassium Sulfate 100% A-Excellent
Aluminum Sulfate A-Excellent
Alums A1-Excellent
Amines B-Good
Ammonia 10% N/A
Ammonia Nitrate N/A
Ammonia, anhydrous C-Fair
Ammonia, liquid N/A
Ammonium Acetate N/A
Ammonium Bifluoride N/A
Ammonium Carbonate C-Fair
Ammonium Caseinate N/A
Ammonium Chloride C-Fair
Ammonium Hydroxide A-Excellent
Ammonium Nitrate C-Fair
Ammonium Oxalate N/A
Ammonium Persulfate D-Severe Effect
Ammonium Phosphate, Dibasic A-Excellent
Ammonium Phosphate, Monobasic A-Excellent
Ammonium Phosphate, Tribasic A-Excellent
Ammonium Sulfate A-Excellent
Ammonium Sulfite N/A
Ammonium Thiosulfate N/A
Amyl Acetate D-Severe Effect
Amyl Alcohol D-Severe Effect
Amyl Chloride D-Severe Effect
Aniline B-Good
Aniline Hydrochloride D-Severe Effect
Antifreeze C-Fair
Antimony Trichloride N/A
Aqua Regia (80% HCl, 20% HNO3) D-Severe Effect
Arochlor 1248 B-Good
Aromatic Hydrocarbons D-Severe Effect
Arsenic Acid A-Excellent
Arsenic Salts N/A
Asphalt D-Severe Effect
Barium Carbonate N/A
Barium Chloride A-Excellent
Barium Cyanide N/A
Barium Hydroxide A-Excellent
Barium Nitrate B-Good
Barium Sulfate A-Excellent
Barium Sulfide A-Excellent
Beer A-Excellent
Beet Sugar Liquids A-Excellent
Benzaldehyde D-Severe Effect
Benzene D-Severe Effect
Benzene Sulfonic Acid D-Severe Effect
Benzoic Acid B-Good
Benzol D-Severe Effect
Benzonitrile A1-Excellent
Benzyl Chloride D-Severe Effect
Bleaching Liquors B-Good
Borax (Sodium Borate) B-Good
Boric Acid A-Excellent
Brewery Slop N/A
Bromine D-Severe Effect
Butadiene D-Severe Effect
Butane D-Severe Effect
Butanol (Butyl Alcohol) B-Good
Butter B-Good
Buttermilk A-Excellent
Butyl Amine B1-Good
Butyl Ether D-Severe Effect
Butyl Phthalate A1-Excellent
Butylacetate D-Severe Effect
Butylene D-Severe Effect
Butyric Acid D-Severe Effect
Calcium Bisulfate C-Fair
Calcium Bisulfide C-Fair
Calcium Bisulfite A-Excellent
Calcium Carbonate A-Excellent
Calcium Chlorate N/A
Calcium Chloride A-Excellent
Calcium Hydroxide A-Excellent
Calcium Hypochlorite B-Good
Calcium Nitrate B1-Good
Calcium Oxide A-Excellent
Calcium Sulfate N/A
Calgon A-Excellent
Cane Juice A-Excellent
Carbolic Acid (Phenol) D-Severe Effect
Carbon Bisulfide N/A
Carbon Dioxide (dry) B-Good
Carbon Dioxide (wet) B-Good
Carbon Disulfide N/A
Carbon Monoxide A2-Excellent
Carbon Tetrachloride D-Severe Effect
Carbon Tetrachloride (dry) D-Severe Effect
Carbon Tetrachloride (wet) D-Severe Effect
Carbonated Water N/A
Carbonic Acid A-Excellent
Catsup N/A
Chloric Acid N/A
Chlorinated Glue N/A
Chlorine (dry) D-Severe Effect
Chlorine Water D-Severe Effect
Chlorine, Anhydrous Liquid D-Severe Effect
Chloroacetic Acid D-Severe Effect
Chlorobenzene (Mono) D-Severe Effect
Chlorobromomethane D-Severe Effect
Chloroform D-Severe Effect
Chlorosulfonic Acid D-Severe Effect
Chocolate Syrup N/A
Chromic Acid 10% C-Fair
Chromic Acid 30% C-Fair
Chromic Acid 5% C-Fair
Chromic Acid 50% C-Fair
Chromium Salts N/A
Cider B1-Good
Citric Acid A-Excellent
Citric Oils N/A
Cloroxr (Bleach) N/A
Coffee A-Excellent
Copper Chloride A1-Excellent
Copper Cyanide A-Excellent
Copper Fluoborate N/A
Copper Nitrate N/A
Copper Sulfate >5% A-Excellent
Copper Sulfate 5% A-Excellent
Cream N/A
Cresols D-Severe Effect
Cresylic Acid D-Severe Effect
Cupric Acid A1-Excellent
Cyanic Acid A1-Excellent
Cyclohexane D-Severe Effect
Cyclohexanone D-Severe Effect
Detergents A-Excellent
Diacetone Alcohol D-Severe Effect
Dichlorobenzene D-Severe Effect
Dichloroethane N/A
Diesel Fuel D-Severe Effect
Diethyl Ether D-Severe Effect
Diethylamine B-Good
Diethylene Glycol B1-Good
Dimethyl Aniline D-Severe Effect
Dimethyl Formamide C-Fair
Diphenyl D-Severe Effect
Diphenyl Oxide C-Fair
Dyes N/A
Epsom Salts (Magnesium Sulfate) A-Excellent
Ethane D-Severe Effect
Ethanol B-Good
Ethanolamine B-Good
Ether D-Severe Effect
Ethyl Acetate B-Good
Ethyl Benzoate D-Severe Effect
Ethyl Chloride D-Severe Effect
Ethyl Ether D-Severe Effect
Ethyl Sulfate N/A
Ethylene Bromide D-Severe Effect
Ethylene Chloride D-Severe Effect
Ethylene Chlorohydrin C-Fair
Ethylene Diamine A-Excellent
Ethylene Dichloride D-Severe Effect
Ethylene Glycol A-Excellent
Ethylene Oxide D-Severe Effect
Fatty Acids C-Fair
Ferric Chloride B-Good
Ferric Nitrate C-Fair
Ferric Sulfate B-Good
Ferrous Chloride N/A
Ferrous Sulfate N/A
Fluoboric Acid N/A
Fluorine D-Severe Effect
Fluosilicic Acid N/A
Formaldehyde 100% B-Good
Formaldehyde 40% N/A
Formic Acid B-Good
Freon 113 D-Severe Effect
Freon 12 D-Severe Effect
Freon 22 D-Severe Effect
Freon TF D-Severe Effect
Freonr 11 D-Severe Effect
Fruit Juice N/A
Fuel Oils D-Severe Effect
Furan Resin D-Severe Effect
Furfural D-Severe Effect
Gallic Acid D-Severe Effect
Gasoline (high-aromatic) D-Severe Effect
Gasoline, leaded, ref. D-Severe Effect
Gasoline, unleaded D-Severe Effect
Gelatin A-Excellent
Glucose A-Excellent
Glue, P.V.A. A-Excellent
Glycerin A-Excellent
Glycolic Acid A-Excellent
Gold Monocyanide N/A
Grape Juice A-Excellent
Grease D-Severe Effect
Heptane D-Severe Effect
Hexane D-Severe Effect
Honey A-Excellent
Hydraulic Oil (Petro) B-Good
Hydraulic Oil (Synthetic) B-Good
Hydrazine B-Good
Hydrobromic Acid 100% D-Severe Effect
Hydrobromic Acid 20% D-Severe Effect
Hydrochloric Acid 100% D-Severe Effect
Hydrochloric Acid 20% D-Severe Effect
Hydrochloric Acid 37% B-Good
Hydrochloric Acid, Dry Gas N/A
Hydrocyanic Acid C-Fair
Hydrocyanic Acid (Gas 10%) D-Severe Effect
Hydrofluoric Acid 100% D-Severe Effect
Hydrofluoric Acid 20% D-Severe Effect
Hydrofluoric Acid 50% D-Severe Effect
Hydrofluoric Acid 75% D-Severe Effect
Hydrofluosilicic Acid 100% D-Severe Effect
Hydrofluosilicic Acid 20% D-Severe Effect
Hydrogen Gas C-Fair
Hydrogen Peroxide 10% A-Excellent
Hydrogen Peroxide 100% B-Good
Hydrogen Peroxide 30% B-Good
Hydrogen Peroxide 50% B-Good
Hydrogen Sulfide (aqua) C-Fair
Hydrogen Sulfide (dry) C-Fair
Hydroquinone N/A
Hydroxyacetic Acid 70% N/A
Ink N/A
Iodine N/A
Iodine (in alcohol) N/A
Iodoform N/A
Isooctane D-Severe Effect
Isopropyl Acetate D-Severe Effect
Isopropyl Ether D-Severe Effect
Isotane N/A
Jet Fuel (JP3, JP4, JP5) D-Severe Effect
Kerosene D-Severe Effect
Ketones N/A
Lacquer Thinners D-Severe Effect
Lacquers D-Severe Effect
Lactic Acid A-Excellent
Lard B-Good
Latex A-Excellent
Lead Acetate A-Excellent
Lead Nitrate B1-Good
Lead Sulfamate B-Good
Ligroin D-Severe Effect
Lime N/A
Linoleic Acid B1-Good
Lithium Chloride A1-Excellent
Lithium Hydroxide N/A
Lubricants D-Severe Effect
Lye: Ca(OH)2 Calcium Hydroxide A-Excellent
Lye: KOH Potassium Hydroxide C-Fair
Lye: NaOH Sodium Hydroxide A1-Excellent
Magnesium Bisulfate N/A
Magnesium Carbonate N/A
Magnesium Chloride A-Excellent
Magnesium Hydroxide A-Excellent
Magnesium Nitrate N/A
Magnesium Oxide N/A
Magnesium Sulfate (Epsom Salts) A-Excellent
Maleic Acid N/A
Maleic Anhydride N/A
Malic Acid B-Good
Manganese Sulfate A1-Excellent
Mash N/A
Mayonnaise N/A
Melamine C-Fair
Mercuric Chloride (dilute) N/A
Mercuric Cyanide A-Excellent
Mercurous Nitrate N/A
Mercury N/A
Methane D-Severe Effect
Methanol (Methyl Alcohol) A-Excellent
Methyl Acetate D-Severe Effect
Methyl Acetone N/A
Methyl Acrylate D-Severe Effect
Methyl Alcohol 10% A-Excellent
Methyl Bromide N/A
Methyl Butyl Ketone D-Severe Effect
Methyl Cellosolve D-Severe Effect
Methyl Chloride D-Severe Effect
Methyl Dichloride N/A
Methyl Ethyl Ketone D-Severe Effect
Methyl Ethyl Ketone Peroxide B-Good
Methyl Isobutyl Ketone D-Severe Effect
Methyl Isopropyl Ketone C-Fair
Methyl Methacrylate C-Fair
Methylamine N/A
Methylene Chloride N/A
Milk A-Excellent
Mineral Spirits D-Severe Effect
Molasses N/A
Monochloroacetic acid N/A
Monoethanolamine B-Good
Morpholine N/A
Motor oil N/A
Mustard N/A
Naphtha D-Severe Effect
Naphthalene D-Severe Effect
Natural Gas A-Excellent
Nickel Chloride A-Excellent
Nickel Nitrate N/A
Nickel Sulfate A-Excellent
Nitrating Acid (<15% HNO3) N/A
Nitrating Acid (>15% H2SO4) N/A
Nitrating Acid (S1% Acid) N/A
Nitrating Acid (S15% H2SO4) N/A
Nitric Acid (20%) D-Severe Effect
Nitric Acid (50%) D-Severe Effect
Nitric Acid (5-10%) C-Fair
Nitric Acid (Concentrated) D-Severe Effect
Nitrobenzene D-Severe Effect
Nitrogen Fertilizer N/A
Nitromethane D-Severe Effect
Nitrous Acid N/A
Nitrous Oxide N/A
Oils:Aniline D-Severe Effect
Oils:Anise N/A
Oils:Bay N/A
Oils:Bone N/A
Oils:Castor A-Excellent
Oils:Cinnamon N/A
Oils:Citric N/A
Oils:Clove N/A
Oils:Coconut A-Excellent
Oils:Cod Liver B-Good
Oils:Corn A-Excellent
Oils:Cottonseed A-Excellent
Oils:Creosote D-Severe Effect
Oils

iesel Fuel (20, 30, 40, 50) D-Severe Effect
Oils:Fuel (1, 2, 3, 5A, 5B, 6) C-Fair
Oils:Ginger N/A
Oils:Hydraulic Oil (Petro) B-Good
Oils:Hydraulic Oil (Synthetic) B-Good
Oils:Lemon N/A
Oils:Linseed A-Excellent
Oils:Mineral C-Fair
Oils:Olive D-Severe Effect
Oils:Orange D-Severe Effect
Oils

alm N/A
Oils

eanut A-Excellent
Oils

eppermint N/A
Oils

ine D-Severe Effect
Oils:Rapeseed D-Severe Effect
Oils:Rosin N/A
Oils:Sesame Seed N/A
Oils:Silicone C-Fair
Oils:Soybean A-Excellent
Oils:Sperm (whale) N/A
Oils:Tanning N/A
Oils:Transformer B-Good
Oils:Turbine D-Severe Effect
Oleic Acid D-Severe Effect
Oleum 100% D-Severe Effect
Oleum 25% D-Severe Effect
Oxalic Acid (cold) B-Good
Ozone A-Excellent
Palmitic Acid D-Severe Effect
Paraffin N/A
Pentane D-Severe Effect
Perchloric Acid D-Severe Effect
Perchloroethylene D-Severe Effect
Petrolatum D-Severe Effect
Petroleum D-Severe Effect
Phenol (10%) D-Severe Effect
Phenol (Carbolic Acid) D-Severe Effect
Phosphoric Acid (>40%) D-Severe Effect
Phosphoric Acid (crude) D-Severe Effect
Phosphoric Acid (molten) N/A
Phosphoric Acid (S40%) C-Fair
Phosphoric Acid Anhydride N/A
Phosphorus N/A
Phosphorus Trichloride N/A
Photographic Developer B-Good
Photographic Solutions A-Excellent
Phthalic Acid B1-Good
Phthalic Anhydride N/A
Picric Acid D-Severe Effect
Plating Solutions, Antimony Plating 130°F N/A
Plating Solutions, Arsenic Plating 110°F N/A
Plating Solutions, Brass Plating: High-Speed Brass Bath 110°F N/A
Plating Solutions, Brass Plating: Regular Brass Bath 100°F N/A
Plating Solutions, Bronze Plating: Cu-Cd Bronze Bath R.T. N/A
Plating Solutions, Bronze Plating: Cu-Sn Bronze Bath 160°F N/A
Plating Solutions, Bronze Plating: Cu-Zn Bronze Bath 100°F N/A
Plating Solutions, Cadmium Plating: Cyanide Bath 90°F N/A
Plating Solutions, Cadmium Plating: Fluoborate Bath 100°F N/A
Plating Solutions, Chromium Plating: Barrel Chrome Bath 95°F N/A
Plating Solutions, Chromium Plating: Black Chrome Bath 115°F N/A
Plating Solutions, Chromium Plating: Chromic-Sulfuric Bath 130°F N/A
Plating Solutions, Chromium Plating: Fluoride Bath 130°F N/A
Plating Solutions, Chromium Plating: Fluosilicate Bath 95°F N/A
Plating Solutions, Copper Plating (Acid): Copper Fluoborate Bath 120°F N/A
Plating Solutions, Copper Plating (Acid): Copper Sulfate Bath R.T. N/A
Plating Solutions, Copper Plating (Cyanide): Copper Strike Bath 120°F N/A
Plating Solutions, Copper Plating (Cyanide): High-Speed Bath 180°F N/A
Plating Solutions, Copper Plating (Cyanide): Rochelle Salt Bath 150°F N/A
Plating Solutions, Copper Plating (Misc): Copper (Electroless) N/A
Plating Solutions, Copper Plating (Misc): Copper Pyrophosphate N/A
Plating Solutions, Gold Plating: Acid 75°F N/A
Plating Solutions, Gold Plating: Cyanide 150°F N/A
Plating Solutions, Gold Plating: Neutral 75°F N/A
Plating Solutions, Indium Sulfamate Plating R.T. N/A
Plating Solutions, Iron Plating: Ferrous Am Sulfate Bath 150°F N/A
Plating Solutions, Iron Plating: Ferrous Chloride Bath 190°F N/A
Plating Solutions, Iron Plating: Ferrous Sulfate Bath 150°F N/A
Plating Solutions, Iron Plating: Fluoborate Bath 145°F N/A
Plating Solutions, Iron Plating: Sulfamate 140°F N/A
Plating Solutions, Iron Plating: Sulfate-Chloride Bath 160°F N/A
Plating Solutions, Lead Fluoborate Plating N/A
Plating Solutions, Nickel Plating: Electroless 200°F N/A
Plating Solutions, Nickel Plating: Fluoborate 100-170°F N/A
Plating Solutions, Nickel Plating: High-Chloride 130-160°F N/A
Plating Solutions, Nickel Plating: Sulfamate 100-140°F N/A
Plating Solutions, Nickel Plating: Watts Type 115-160°F N/A
Plating Solutions, Rhodium Plating 120°F N/A
Plating Solutions, Silver Plating 80-120°F N/A
Plating Solutions, Tin-Fluoborate Plating 100°F N/A
Plating Solutions, Tin-Lead Plating 100°F N/A
Plating Solutions, Zinc Plating: Acid Chloride 140°F N/A
Plating Solutions, Zinc Plating: Acid Fluoborate Bath R.T. N/A
Plating Solutions, Zinc Plating: Acid Sulfate Bath 150°F N/A
Plating Solutions, Zinc Plating: Alkaline Cyanide Bath R.T. N/A
Potash (Potassium Carbonate) N/A
Potassium Bicarbonate A1-Excellent
Potassium Bromide A1-Excellent
Potassium Chlorate B-Good
Potassium Chloride A-Excellent
Potassium Chromate N/A
Potassium Cyanide Solutions A-Excellent
Potassium Dichromate A-Excellent
Potassium Ferricyanide N/A
Potassium Ferrocyanide N/A
Potassium Hydroxide (Caustic Potash) C-Fair
Potassium Hypochlorite N/A
Potassium Iodide N/A
Potassium Nitrate A-Excellent
Potassium Oxalate N/A
Potassium Permanganate N/A
Potassium Sulfate A-Excellent
Potassium Sulfide A-Excellent
Propane (liquefied) D-Severe Effect
Propylene D-Severe Effect
Propylene Glycol A-Excellent
Pyridine D-Severe Effect
Pyrogallic Acid N/A
Resorcinal N/A
Rosins A-Excellent
Rum A-Excellent
Rust Inhibitors N/A
Salad Dressings N/A
Salicylic Acid N/A
Salt Brine (NaCl saturated) A1-Excellent
Sea Water A1-Excellent
Shellac (Bleached) N/A
Shellac (Orange) N/A
Silicone C-Fair
Silver Bromide N/A
Silver Nitrate A-Excellent
Soap Solutions A-Excellent
Soda Ash (see Sodium Carbonate) A-Excellent
Sodium Acetate D-Severe Effect
Sodium Aluminate N/A
Sodium Benzoate N/A
Sodium Bicarbonate A-Excellent
Sodium Bisulfate A-Excellent
Sodium Bisulfite A-Excellent
Sodium Borate (Borax) A-Excellent
Sodium Bromide N/A
Sodium Carbonate A-Excellent
Sodium Chlorate C-Fair
Sodium Chloride A-Excellent
Sodium Chromate N/A
Sodium Cyanide A-Excellent
Sodium Ferrocyanide N/A
Sodium Fluoride N/A
Sodium Hydrosulfite C-Fair
Sodium Hydroxide (20%) A2-Excellent
Sodium Hydroxide (50%) A1-Excellent
Sodium Hydroxide (80%) A1-Excellent
Sodium Hypochlorite (<20%) B-Good
Sodium Hypochlorite (100%) B-Good
Sodium Hyposulfate N/A
Sodium Metaphosphate A-Excellent
Sodium Metasilicate N/A
Sodium Nitrate D-Severe Effect
Sodium Perborate B-Good
Sodium Peroxide D-Severe Effect
Sodium Polyphosphate D-Severe Effect
Sodium Silicate A-Excellent
Sodium Sulfate A-Excellent
Sodium Sulfide A-Excellent
Sodium Sulfite A-Excellent
Sodium Tetraborate A-Excellent
Sodium Thiosulfate (hypo) A-Excellent
Sorghum N/A
Soy Sauce N/A
Stannic Chloride B-Good
Stannic Fluoborate N/A
Stannous Chloride B-Good
Starch N/A
Stearic Acid B-Good
Stoddard Solvent D-Severe Effect
Styrene D-Severe Effect
Sugar (Liquids) A-Excellent
Sulfate (Liquors) B-Good
Sulfur Chloride C-Fair
Sulfur Dioxide B-Good
Sulfur Dioxide (dry) B-Good
Sulfur Hexafluoride B-Good
Sulfur Trioxide B-Good
Sulfur Trioxide (dry) B-Good
Sulfuric Acid (<10%) C-Fair
Sulfuric Acid (10-75%) D-Severe Effect
Sulfuric Acid (75-100%) D-Severe Effect
Sulfuric Acid (cold concentrated) D-Severe Effect
Sulfuric Acid (hot concentrated) D-Severe Effect
Sulfurous Acid D-Severe Effect
Sulfuryl Chloride N/A
Tallow N/A
Tannic Acid B-Good
Tanning Liquors B-Good
Tartaric Acid A-Excellent
Tetrachloroethane D-Severe Effect
Tetrachloroethylene D-Severe Effect
Tetrahydrofuran D-Severe Effect
Tin Salts B-Good
Toluene (Toluol) D-Severe Effect
Tomato Juice N/A
Trichloroacetic Acid D-Severe Effect
Trichloroethane D-Severe Effect
Trichloroethylene D-Severe Effect
Trichloropropane N/A
Tricresylphosphate C-Fair
Triethylamine N/A
Trisodium Phosphate A-Excellent
Turpentine D-Severe Effect
Urea B-Good
Uric Acid N/A
Urine N/A
Varnish D-Severe Effect
Vegetable Juice B-Good
Vinegar A-Excellent
Vinyl Acetate D-Severe Effect
Vinyl Chloride N/A
Water, Acid, Mine B-Good
Water, Deionized N/A
Water, Distilled C-Fair
Water, Fresh B-Good
Water, Salt B-Good
Weed Killers A-Excellent
Whey N/A
Whiskey & Wines A-Excellent
White Liquor (Pulp Mill) A-Excellent
White Water (Paper Mill) N/A
Xylene D-Severe Effect
Zinc Chloride B-Good
Zinc Hydrosulfite N/A
Zinc Sulfate A-Excellent

{edit}Something that seriously pisses me off are those toxic symbols, and the word toxic it's self. In what sense? Is this thing going to sting when a breath it and little else? Or is a few ppb going to render me signed off to brain cancer?

Hydrogen Chloride is toxic, according to most datasheets. It'll certainly blister you, and hurts to breath, and will kill you if you get caught in a room of it; due to blistering of your lungs. But then, nitrogen will kill you if you get caught in a room of it, and it's 80% of the atmosphere.

That breaks it down to the blistering then. So, why no toxic symbol on the common acids?

Why is the same toxic sticker on a bottle of food additive I have also on the bottle of mercury chloride sat next to it? With the latter being on it's way towards nerve agents in terms of toxicity, accumulatively toxic, neurotoxic and very difficult to remove from the body.

I've tried making that point quite a few times, and editing wiki's to include the warning signs for potentially dangerous chemicals. I've then had my edit's reversed and them replaced with 'toxic'. Also noteworthy is that there are in depth discussions on there of the toxicity of relatively basic problems, and none for things like some of the really nasty phosphorus compounds.

What the shit is that going to do in terms of helping people avoid a.) genuinely toxic materials b.) know when something toxic has actually escaped?

They go on about wiki not being a guide or supplementing the MSDS, but if we're going down that route, it's not a reference either. So why not delete the entire project and just have a link to Google?

Wankers.

[Edited on 8-10-2010 by peach]

mr.crow - 8-10-2010 at 07:45

Thanks, I love your videos!

One thing though, DMSO is miscible with water so your little note doesn't really apply.

Maybe this can be used to fix emulsions with DCM?

peach - 8-10-2010 at 08:03

You're right, well spotted! I've changed the note.

Emulsions, I have an absolute beast of one in a bottle right now. The phase boundary is a joke, it's about 6" deep.

That might be up for a bashing with the paper as well.

[Edited on 8-10-2010 by peach]

smuv - 8-10-2010 at 08:57

You might be interested in concrete waterproofer as well; it is a mixture of siloxanes. You can find it at home improvement stores.

I think though xylene is not a great solvent to test the limits of this with. There is no way xylene is going to dissolve much silicone polymer, try it with more polar solvents like Ethyl acetate/Acetone/ethyl methyl ketone/DCM.

Also I am surprised the ethanol/water passed through? This makes be believe this process is a seperation based upon surface tension. Essentially the water beads up around the pores of the filter paper, add something which reduces the surface tension, and it can pass through. Why not add some soap to water and see if it passes through. Am I correct in assuming the ethanol was ca. 10% alcohol?

peach - 8-10-2010 at 11:18

Correct (10%), and the surface tension thing is how I suspect it's functioning as well.

My prediction is, there is a good chance it'll pull water through the paper when I try putting it under vacuum, as the pressure difference will overcome the tension holding it in the pores.

Solution to that, use finer grade paper, or some form of packing.

I have some concrete waterproofer. The 1,3-Butadiene stuff that stinks of new carpets. Spent a few days in the hottest summer in the UK rendering the entire garden with it and a plastering trowel, by hand. And the mix, by hand with a spade. Think that took about half a ton or more. My body didn't like me for that.

I've drenched a few tablespoons of activated carbon in the spray (until it was a liquid puddle), and now have that drying under vacuum to have a mess around with. The carbon takes lots longer to dry than the papers; surface area / volume of spray on it.

I'll have a look at other solvents as well. I need to get my freaky deekin' glassware sorted. My receiver bend is broken, other bits are chipped, so I can't redistill solvents at the moment, and some of the bottles are running dry as it is, with lots of it in flasks all over the place, waiting for attention. Obviously, rebuying all of the common ones could easily be toward £100 by the time the VAT and delivery is on that. I'm trying to get a VAT code as we speak to sort that, by officially becoming a charity case.

You're right about needing to try them. I chose xylene just because I had the can of paint thinner beside me, it's easy to get hold of and I have something like the CP cyclohexane for actual, careful chemistry - so I wasn't using up something I might need the next day.

Saying that, Cole Parmer lists xylene as D for compatibility with silicone, the lowest rating they give.

Experiments done thus far!
Gravity phase splitting - easy (curly arrow is using DCM in his, but his are also commercial papers)

Splitting miscibles - doesn't work

Suggested experiments to try!
Different solvents

Look at drying potential by the change in mass of an anhydrous

Investigate the film it's producing. My initial thought was, it may just be a particulate layer. Even if that's so, provided you don't scrumple the papers up and mess around with them, it'll work (HPLC columns are after all, particulates). But, as I've said, I've also seen it peeling back off normal fabrics after they're been abused or put through the wash, as a film like layer, suggesting it may actually be binding it's self by some method. I'll try spraying some onto a new ceramic tile and see if I can peel it back off.

What's in it? Hmmmm.... I guess I could try TLC'ering the liquid to see if there are any waxy remains in there. But my chromatography powers don't extend as far as HPLC or GC. I have been wondering about doing a Sauron and building my own HPLC system but, realistically, it's not worth it for now; those things, even using the absolute best bargains available, once all the parts are accounted for, cost a lot.

Hows about making the paper extremely hydrophillic? To do the opposite.

[Edited on 8-10-2010 by peach]

smuv - 8-10-2010 at 12:28

Hmm...this is pretty interesting, I have never heard of a separation process on the basis of surface tension (although I guess we have not confirmed it is surface tension). Probably in reality there are two factors at play, solubility in the stationary phase and surface tension of the liquid. Liquids soluble in the stationary phase do not bead up around the pores and can go right through them. Liquids insoluble in the stationary phase bead up and if the pores are sufficiently small, cannot pass through them.

Therefore, In theory (questionable theory that is) you need to either reduce the pore size, or increase the repulsion between water and the stationary phase. From a practical standpoint (without getting a new siloxane) this means finer filter paper.

Also, I wonder if you tune the pore size correctly, if you will recover enriched ethanol/water on the other side of the membrane, or if simply nothing will pass through the filter. I think it comes down to what is the probability that on a nano scale the local concentration of ethanol due to random distribution is high enough at a single point on the siloxane/solution interface to allow the ethanol to pass through?

So based on my completely unfounded, back-of-the-envelope theoretical mumbo jumbo, I think the separation would be so slow it would essentially not work. The reason being, surface tension is a bulk property of a solution; it requires many molecules to be repelled by a pore to form an aggregate of molecules at the interface (and stop flow). Therefore, the chances that the composition of this aggregate is much different than the bulk solution are very small.

[Edited on 10-8-2010 by smuv]

not_important - 8-10-2010 at 12:52

This is surface tension based, and doesn't separation miscible liquids. For such you need to use the related pervaporation - http://en.wikipedia.org/wiki/Pervaporation - which works by evaporating one (or more) of the liquids through a membrane impermeable to the other liquid(s).

Picene - 8-10-2010 at 12:56

Quote: Originally posted by peach

You're right, well spotted! I've changed the note.

Emulsions, I have an absolute beast of one in a bottle right now. The phase boundary is a joke, it's about 6" deep.

That might be up for a bashing with the paper as well.

[Edited on 8-10-2010 by peach]

How much liquid are you dealing with peach?

peach - 8-10-2010 at 13:12

@NI & smuv

Ar huh, it'll be surface tension.

There are permeable membranes that can do some fairly neat tricks with solutions.

Maybe a film of the silicone would work for alcohol and other miscibles?

Organics tend to soak into plastics. The halogenated solvents will do it with PTFE and the other fluoropolymers. Say I had some PTFE tubing and filled it with damp DCM, the PTFE would, to some extent, separate the two. I have a video on there were I'm replying to a guy a Saint Gobain about some tubing he sent me to try, and I explain how it swells up. They mention that on their site and the guy had already seen that happening, and I predicted it would happen. So it's a known effect and not random chance or unknown interactions. Obviously, there is the possibility a very thin film of PTFE, or one of it's friends, would work for that.

I am trying to produce a continuous film of just the silicone at the moment, so I'll have a look and see if it's done it tomorrow. If it has, I'll add that to the list of things to try.

Chemistry forums seem full of alky's trying to get drunk even faster.

@Picene

About 1.5, 1.75l, out of which I need around 150ml, stuck in the boundary.

I may see if I can get it through the washing machine in bottles and if the g's in a high speed spin cycle will be enough to help.

Tried salting it, and freezing. Not much luck.

I know there are emulsion busting additives available, but that means buying more bottles of things at the moment. Bottles which may not function for the mountain of gunk at the boundary.

I'm trying to extract nicotine from cigarette butts. Almost 200 of them. I washed with 5% NaOH to freebase it, then blended to get the filters smashed up; already having stripped the papers by hand. The blending and base seems to have been enough to digest the filters, which (combined with all the now saponified tars) is the mass of gunk at the boundary, trapping the xylene.

[Edited on 8-10-2010 by peach]

peach - 8-10-2010 at 13:45

I checked the xylene soaking papers. They've been in there, submerged, for 6-9h.

Let them dry, tried the water. Both let the water through, at a very slow rate.

However, I noticed the meniscus was still flipped, and the paper wasn't whetting normally. And that, when I messed with the paper, the rate shot up. Lifting the paper out, it seemed to be dripping only from the crimped seam at the bottom. As I had to fold the papers up to get them in the xylene, I figured I may have damaged the seam (where they usually break).

I cut swatches from the walls of the papers and am looking at water penetration for those. Thus far, ~45 minutes on, not a single drop has gone through.

Again, pretty predictable stuff. If you scrumple coffee filters up, bend them, fold them, the seam is going to start going with or without the spray. It's either the paper it's self opening to a point where normal capillaries have formed again due to the seam parting, or it's opened a little and broken a film of the silicone.

Whichever it is, it's not a problem. Unless you plan to soak for 6-9h in xylene and be folding / bending the papers in the process. These ones are reused as well.

I don't recommend spraying a normal flat disc, then fluting it, as you may damage the effect. Flute, then spray. With a flat filter paper, as you'd normally use in a Buchner, that's a lot less of an issue; kind of, not an issue at all, as there are no seams and it's not folded or bent.

There's ANOTHER test. Bend / fold up flat discs after spraying and see if they leak. If they do, it's a film of silicone breaking. If not, the coffee ones are the seam parting. Which will demonstrate whether the spray is penetrating to a fibre by fibre level or not.

See how they're doing tomorrow.

[Edited on 8-10-2010 by peach]

smuv - 8-10-2010 at 15:25

Quote: Originally posted by peach

@NI & smuv
Organics tend to soak into plastics. The halogenated solvents will do it with PTFE and the other fluoropolymers. Say I had some PTFE tubing and filled it with damp DCM, the PTFE would, to some extent, separate the two. I have a video on there were I'm replying to a guy a Saint Gobain about some tubing he sent me to try, and I explain how it swells up.

That's different, it swells because of solubility or the organic in ptfe; that is simply an extraction,the partition coefficient has nothing to do with how porous the pfte is (the kinetics do however), and is therefore a completely different system.

[Edited on 10-8-2010 by smuv]

aonomus - 8-10-2010 at 19:56

http://www.informaworld.com/smpp/content~db=all~content=a779... is an interesting note describing the use of phase separation paper in a vapor path. The authors note the eventual dissolution of the silicones over time with organics, as well as the potential for backpressure buildup.

I don't think that phase separation paper will work for a solvent drying system unfortunately since it can't remove trace dissolved amounts. You wouldn't pour solvent into a SPS that had visible immiscible water droplets in it anyway, so the best thing to do would be to use it to substitute separatory funnels to save time and glassware cleaning.

Because it uses wetting, vacuum filtration is probably out of the question as well.

I have some scotchgard spray which I might try impregnating onto some Whatman filter paper and drying, we'll see how that turns out.

food - 5-11-2010 at 22:44

hey

Quote: Originally posted by peach

.
Tried salting it, and freezing. Not much luck.
[Edited on 8-10-2010 by peach]

you didn't mention celite here

I'm curious; I'd read that read that vacuum filtering through celite (or diatomaceous earth for the $ challenged?) was an option for stubborn emulsions. I've never tried it, but I've a plastic bottle of diatomaceous earth ('Insectigone'; guarantee: silicon dioxide 80% available as diatomaceous earth ) just waiting to go. Any thoughts?

Hexagon - 6-11-2010 at 04:41

Quote: Originally posted by food

hey

Quote: Originally posted by peach

.
Tried salting it, and freezing. Not much luck.
[Edited on 8-10-2010 by peach]

I've heard that sticking a vibrating dildo to your separatory funnel does wonders on emulsions...

smuv - 7-11-2010 at 13:12

Quote:

I'm curious; I'd read that read that vacuum filtering through celite (or diatomaceous earth for the $ challenged?) was an option for stubborn emulsions. I've never tried it, but I've a plastic bottle of diatomaceous earth ('Insectigone'; guarantee: silicon dioxide 80% available as diatomaceous earth ) just waiting to go. Any thoughts?

It works. Simply filtering through fritted glass (I assume filter paper as well but don't have experience with that) helps break up emulsions.

spirocycle - 8-11-2010 at 18:32

I dont understand
what do you mean by "break up emulsions"

will one component go through first?
or will the whole lot go through, but be in two distinct layers in the collection vessel?

Mister Junk Pile - 9-11-2010 at 12:42

Some water repellent products use fluorinated surfactants to induce hydrophobicity. It is likely that these would be much more resistant to being dissolved by organics than regular siloxanes. In fact, at least one perfluoro acid salt is almost completely insoluble in at least 20 different types of organic solvents. This would be the potassium salt of perfluorooctanesulfonic acid.

If the acid could somehow be deposited on the paper as the potassium salt I believe it would last a VERY long time. I suspect the paper would begin to fall apart before that compound fully dissolved regardless of what solvent was passed through it.

Maybe the acid could be dissolved in a solvent and then a potassium base could be added to precipitate the salt on the paper somehow.

I know this isn't exactly "at-home" stuff (PFOS happens to be quite expensive but maybe a little bit would go a long way?), but it's interesting to think about.

[Edited on 11-9-2010 by Mister Junk Pile]

franklyn - 9-11-2010 at 17:35

Commonly available in pint to nearly quart size , a liquid dish soap plastic bottle
is an effective improvised separation funnel. The kind with a telescoping spigot
that snaps close serves well as a stopcock. A small hole in the base of the plastic
bottle just large enough to let the stem of a funnel to fit allows the pouring in of
the mixture. After standing and draining the lower phase one need only place a
finger over that hole to severely restrict the flow , concluding by just pressing
the spigot against the bench top to close it.
217527180.jpg - 18kB

Treating filter material to serve as a diaphragm in electrolysis separation is an area
wanting of experiment and development. The durability of the substrate is what
determines the limits of it's use. Paper is cellulose and must be regarded as such
in contemplating an intended application. There are other materials with attributes
more suited to harsh use , for example polyethylene ' paper '. See Tyvek here _
http://en.wikipedia.org/wiki/Tyvek
If you wonder what Tyvek is like , inspect the Express Mail envelope at the U.S. Post office
http://upload.wikimedia.org/wikipedia/en/thumb/f/f6/TyvekExp...

Quote: Originally posted by peach

Splitting miscibles - doesn't work

No reason why it could , pore size is in the micron range , an azeotrope requires
molecular scale openings to discriminate.

[Edited on 10-11-2010 by franklyn]

scientician - 15-5-2011 at 11:32

Sorry to keep digging this old shit up. I worked on this last night, both with a 25% solution of water in ethanol (everclear, bitches!) and some 5% vinegar.

The everclear just slipped through, albeit slowly. I was disappoint.

The vinegar seemed to be working well. I observed the same thing as peach, wondering if I hadn't ruined the seams. On closer inspection, I realized I was using the pre-fluted, seamless style of coffee filter.

It seems that if you crease or even bend the paper after the spray has dried, water can get through.

Not being one to be dissuaded, I whipped out my AeroPress coffee thinger (a great buy for the home scientist as a replacement for vacuum filtration in certain circumstances, IMHO. Have a butcher's; http://aerobie.com/products/aeropress.htm) I prepared one of the 2" diameter circular paper filters and dried it in the oven at 250 F.

Excitedly, I set it up to collect pure GLACIAL ACETIC ACID and poured some of my freeze distilled vinegar in. It promptly sat there and did nothing at all, smiling at me the whole time. I may as well have poured it into a cup.

After I finished throwing some of my glassware at the wall, I sat down and thought about it, and realized that although paper might not be ideal, there are these nylon, re-usable coffee filter thingers that might really work well. (The spray is designed for cloth, after all.) I'm going to play with this a while, and report back how it goes.

chemrox - 29-3-2016 at 14:57

what is phase separator paper? https://www.zoro.com/whatman-phase-separator-paper-150cm-pk1...

Is it only for vapor phase water removal and how would that be done? What is the use generally speaking? i.e. how would it be applied? I assume it's a fairly useful item as it is a Whatman product sold in packages. Anyway, "Zoro" is worth looking into. Some really high prices other reasonable and a wide range of products. Hint: use the backspace key rather than backing up on the listed pathways.

[Edited on 29-3-2016 by chemrox]

Dr.Bob - 29-3-2016 at 18:59

The phase separator papers are great for using in place of sep funnels, especially for small amounts. They work well in whatman type filter rigs, but they can be used inside a syringe barrel or other tube to allow you to quickly filter off DCM from water solutions. You can put a solution in a syringe, and add a squirt of DCM, which will have enough time to extract some material and then drip through. Over a few washes, you can extract a solution several times, and even do it in parallel or with an automated system. That is what makes them better than sep funnels. I have seen manifolds that do 8, 12, or 24 samples at once.

If some people want to test the Whatman ones out, I have a few boxes of them I found recently, I can provide a few samples or sell a box of them. I don't remember the exact sizes, but I think they are 90, 110, or 150 mm in diameter. I might even have some other forms of them, but I have no idea exactly what box they were in.

Bob

RogueRose - 24-5-2016 at 15:36

Can anyone explain what these papers are? The video shows an error when I try to view it.

Dr.Bob - 24-5-2016 at 18:32

They are a type of filter paper which has been treated to be hydrophobic, aka "water-hating". So water beads up on them, just like it would on chloroform or when mixed with grease. But hydrocarbons can still wet them, so they flow through. It is almost like a cell membrane, keeping water in, but letting some molecules pass through passively. They will only separate immiscible liquids, not miscible ones, like ethanol and water.

gatosgr - 6-6-2016 at 02:56

Vinylidene fluoride is hydrophobic, what is the process of the OP?

Dr.Bob - 6-6-2016 at 04:03

Quote: Originally posted by Mister Junk Pile

Some water repellent products use fluorinated surfactants to induce hydrophobicity. It is likely that these would be much more resistant to being dissolved by organics than regular siloxanes. In fact, at least one perfluoro acid salt is almost completely insoluble in at least 20 different types of organic solvents. This would be the potassium salt of perfluorooctanesulfonic acid.

If the acid could somehow be deposited on the paper as the potassium salt I believe it would last a VERY long time. I suspect the paper would begin to fall apart before that compound fully dissolved regardless of what solvent was passed through it.

Some of the hydrophobic frits and papers are or were made from perfluoroacids or sulfonic acids, most were actually activated as the acid chloride and then reacted with the paper, the hydroxyls in the cellulose react with the acid chloride to covalently attach the perfluoro material. For a while, there was a big fad in chemistry to use perfluoro materials for that. It has since died down a bit, due to costs and being overhyped. But the papers work well for some uses.

Waterless urinals also use a similar principle but different membrane to let urine flow through, but not let sewer gasses flow back.

Firmware21 - 8-6-2016 at 07:48

Not working for me ;(

Anyone got a link to the video ?

chemrox - 8-6-2016 at 09:28

was there a video somewhere? I didn't see one