Fusionfire - 29-2-2012 at 01:08
Hi all,
I am looking for an article which lists many different types of hydrophilic materials and ranks them.
I've found a few articles that deal with individual substances but not a wide ranging comparison.
I'd be grateful for any input.
Thanks & have a great day!
[Edited on 29-2-2012 by ScienceSquirrel]
AJKOER - 29-2-2012 at 05:02
Start with a good definition, per Wikipedia:
"Hydrophile
From Wikipedia, the free encyclopedia
A hydrophile, from the Greek (hydros), meaning water, and φιλια (philia), meaning love, is a molecule or other molecular
entity that is attracted to, and tends to be dissolved by, water. A hydrophilic molecule or portion of a molecule is one that has a tendency to
interact with or be dissolved by water and other polar substances.[1][2] Hydrophilic substances can seem to attract water out of the air, the way
salts (which are hydrophilic) do. Sugar, too, is hydrophilic, and like salt is sometimes used to draw water out of foods.
This is thermodynamically favorable, and makes these molecules soluble not only in water but also in other polar solvents. There are hydrophilic and
hydrophobic parts of the cell membrane.
A hydrophilic molecule or portion of a molecule is one that is typically charge-polarized and capable of hydrogen bonding, enabling it to dissolve
more readily in water than in oil or other hydrophobic solvents. Hydrophilic and hydrophobic molecules are also known as polar molecules and nonpolar
molecules, respectively. Some hydrophilic substances do not dissolve. This type of mixture is called a colloid. Soap, which is amphipathic, has a
hydrophilic head and a hydrophobic tail, allowing it to dissolve in both waters and oils.
An approximate rule of thumb for hydrophilicity of organic compounds is that solubility of a molecule in water is more than 1 mass % if there is at
least one neutral hydrophile group per 5 carbons, or at least one electrically charged hydrophile group per 7 carbons.[3]"
To start your list, think of acidic or basic oxide that are attracted to and react with water to form the corresponding acid/base, or pair of acids.
Example of acidic oxides in this class: SO3, P2O5,... For basic oxides: Na2O, K2O,... . Also, the concentrated acids and bases associated with these
oxides: H2SO4, H3PO4,....,NaOH, KOH,....
Next look up deliquescence, again per Wiki:
"Deliquescence
Deliquescent materials are substances (mostly salts) that have a strong affinity for moisture and will absorb relatively large amounts of water from
the atmosphere if exposed to it, forming a liquid solution. Deliquescent salts include calcium chloride, magnesium chloride, zinc chloride, potassium
carbonate, potassium phosphate, carnallite, ferric ammonium citrate, potassium hydroxide, and sodium hydroxide. Owing to their very high affinity for
water, these substances are often used as desiccants, which is also an application for concentrated sulfuric and phosphoric acids. These compounds are
used in the chemical industry to remove the water produced by chemical reactions."
Next, do a general internet search on hydrates to expand your list. Most (not all) are deliquescent salts upon dehydration. Examples, cupric sulfate
pentahydrate (CuSO4.5H2O), sodium sulfate decahydrate (Na2SO4ยท10H2O),...
[Edited on 29-2-2012 by AJKOER]
LanthanumK - 29-2-2012 at 08:47
You must not confuse deliquescent substances with hygroscopic substances. Hygroscopic substances have an affinity for water, but do not dissolve in
that water to form a solution. This is the case with copper sulfate anhydrous; it is only hygroscopic but not deliquescent.
Fusionfire - 29-2-2012 at 11:12
Thanks. I was actually looking for hydrophilic polymers. Sorry, should have been more specific!
Hexavalent - 29-2-2012 at 14:36
Just out of curiosity FusionFire, what do you intend to use the list for? Or is it just one of those chemical curiosities that we all get?
Fusionfire - 1-3-2012 at 10:18
Mostly, it is a chemical curiosity 
Most acidic acid, highest energy density chemical substance, etc.
But here's my question. Suppose you have an impure aqueous solution consisting of every conceivable impurity - dissolved salts, organic matter and
pathogens.
If you have a very fine braid of a super-hydrophilic polymer, will pure water be selectively separated from the impurities by capillary action?
[Edited on 1-3-2012 by Fusionfire]