March 29, 2024, 05:27:51 AM
Forum Rules: Read This Before Posting


Topic: separation of substances  (Read 11255 times)

0 Members and 1 Guest are viewing this topic.

Offline levi0709

  • Regular Member
  • ***
  • Posts: 9
  • Mole Snacks: +0/-0
separation of substances
« on: September 08, 2009, 01:29:25 AM »
hello, i recently have been working with polyvinyl alcohol, and i was wondering, i mixed the polyvinyl alcohol with water that contained a dye that was water soluble, the polyvinyl alcohol hardened and it got painted with the dye, but now i want to separate the dye from the polyvinyl alcohol, i tried soaking it in water until the polyvinyl alcohol dissolved again, but now how can i separate the dye from the polyvinyl alcohol?
thanks for your time

Offline Gerard

  • Full Member
  • ****
  • Posts: 196
  • Mole Snacks: +13/-13
  • Gender: Male
  • "pressure makes diamond"
Re: separation of substances
« Reply #1 on: September 08, 2009, 02:20:45 AM »
I also experienced that situation in which i mixed a polyvinyl alcohol with a stained ionized water. check if the dye is also oil soluble or grease soluble, you can use this as a solvent to separate the dye from the PVA.
Try completely hydrolyzing the PVA before mixing in the oil or grease..
(DO NOT AT ALL COST EXPOSE YOUR PVA TO TEMPERATURE NEAR 200 DEGREES CENTIGRADE)
"Charles! Charles! That's it Mr. Charles Darwin get out of this room, I told you once and I told you twice not to tease your fellow Mr. Arrhenius!"

Offline levi0709

  • Regular Member
  • ***
  • Posts: 9
  • Mole Snacks: +0/-0
Re: separation of substances
« Reply #2 on: September 11, 2009, 11:04:17 AM »
hello, the dye is alcohol soluble, but not oil or grease soluble...
can anyone help me please?

Offline typhoon2028

  • Full Member
  • ****
  • Posts: 251
  • Mole Snacks: +18/-12
Re: separation of substances
« Reply #3 on: September 11, 2009, 03:21:58 PM »
Maybe try hexanol?

Offline levi0709

  • Regular Member
  • ***
  • Posts: 9
  • Mole Snacks: +0/-0
Re: separation of substances
« Reply #4 on: September 11, 2009, 03:58:50 PM »
you mean mix hexanol with the mixture already in water? or do i mix it in solid state?

Offline typhoon2028

  • Full Member
  • ****
  • Posts: 251
  • Mole Snacks: +18/-12
Re: separation of substances
« Reply #5 on: September 14, 2009, 09:29:26 AM »
Mix in the water.  Hopefully you will get phase separation between hexanol and water.  I'm not sure if PVA will also go into the hexanol phase.  Your yield may not be so good, but it might be worth a try.

Offline levi0709

  • Regular Member
  • ***
  • Posts: 9
  • Mole Snacks: +0/-0
Re: separation of substances
« Reply #6 on: September 14, 2009, 11:12:46 AM »
ok, ill try that and post the result as soon as posible.
really thanks for taking the time to answer my post and help me!!!!

Offline typhoon2028

  • Full Member
  • ****
  • Posts: 251
  • Mole Snacks: +18/-12
Re: separation of substances
« Reply #7 on: September 14, 2009, 01:10:32 PM »
if you have access to octanol, that might be better.

Offline Don Shelly

  • Regular Member
  • ***
  • Posts: 29
  • Mole Snacks: +2/-1
  • I am a professional in the SPE business.
    • UCT website
Re: separation of substances
« Reply #8 on: September 18, 2009, 04:49:44 PM »
Send the dye/alcohol solution through a gram or two of silica gel.  The dye will stick and the alcohol should pass through.  The more diluted it is with water the better this should work.

Offline levi0709

  • Regular Member
  • ***
  • Posts: 9
  • Mole Snacks: +0/-0
Re: separation of substances
« Reply #9 on: October 11, 2009, 05:47:48 PM »
greetings, as it turns out, the dye was water soluble, so i tried sticking the hardened mixture into the water and letting the polyvinyl alcohol dissolve, but when i tried to decant the dye from the blob of polyvinyl alcohol it just made a big mess, does anyone have a good method of getting rid of the polyvinyl alcohol and separating the dye?

Offline levi0709

  • Regular Member
  • ***
  • Posts: 9
  • Mole Snacks: +0/-0
Re: separation of substances
« Reply #10 on: October 17, 2009, 09:31:13 PM »
so, there is no way to separate the polyvinil alcohol from the dye stained water without making a mess?

Offline eugenedakin

  • Oilfield Consulting Chemist
  • Retired Staff
  • Full Member
  • *
  • Posts: 658
  • Mole Snacks: +88/-2
  • Gender: Male
  • My desk agrees with the law of entropy
    • Personal Website
Re: separation of substances
« Reply #11 on: October 21, 2009, 08:08:53 AM »
Hello levi0709,

When you said
Quote
when i tried to decant the dye from the blob of polyvinyl alcohol it just made a big mess
, could you please describe to the group what a 'big mess' is? Could you describe physical properties, colour, and any other description that may help the viewer understand what you are seeing.

Thanks for your help,

Eugene
There are 10 kinds of people in this world: Those who understand binary, and those that do not.

Offline levi0709

  • Regular Member
  • ***
  • Posts: 9
  • Mole Snacks: +0/-0
Re: separation of substances
« Reply #12 on: October 21, 2009, 08:46:00 AM »
of course, the polivynil alcohol/water mixture became almost the same color, clumps of polyvinil got loose on the water, it looked like a blob as it was completely saturated by the water, i tossed that experiment and tried another with smaller amounts of water to prevent it from becoming blobish, the polyvinyl alcohol clump could be seen as a whole, but smaller clumps became loose on the water, so to separate the dye i tried squeezing the bigger clump like squeezing the juice out of a fruit, some of the dye mixed with the water but most of it remained within the larger clump.
hope anyone can help me with this, and thanks for your reply!!!

Offline eugenedakin

  • Oilfield Consulting Chemist
  • Retired Staff
  • Full Member
  • *
  • Posts: 658
  • Mole Snacks: +88/-2
  • Gender: Male
  • My desk agrees with the law of entropy
    • Personal Website
Re: separation of substances
« Reply #13 on: October 25, 2009, 06:36:14 AM »
Hello levi0709,

Here is where some chemistry experience - and digging for some information - will help you out.

What you need to research, is to find a chemical (solvent?) that is soluble for your dye and is insoluble for PVA. You have already tried water (as the solvent) and realized that the dye and polyvinyl alcohol (PVA) are both soluble in water.

By either searching on the internet or looking in your favorite library, look up the solubilities of PVA and your dye. This information will help you select the solvent.

Best wishes,

Eugene
There are 10 kinds of people in this world: Those who understand binary, and those that do not.

Offline levi0709

  • Regular Member
  • ***
  • Posts: 9
  • Mole Snacks: +0/-0
Re: separation of substances
« Reply #14 on: October 25, 2009, 09:28:04 AM »
ok, i'll guess ill start testing the solvents;
i'll post the results when i have them;
thanks for answering my posts!!

Sponsored Links