Isn't dread wax water proof? How can it be washed out? - Dreadlocks FAQ's
This short question requires a pretty long answer because you have to understand how solvents and solutes work and you have to understand how an emulsifier works. It's much quicker to confirm the science - Simply wash some wax off of your hands with hot water and an effective soap - (DreadHead Dread Soap is seriously one of the most effective you'll find so it's ideal for this experiment). You'll see that with plenty of soapy lather and hot water the wax washes off. Since the wax washes away as the soap emulsifies it, and since only the surface can be acted upon, you'll also notice that the more wax you start with the longer it takes for it to all wash away. Please give this a try. First try washing the wax off with no soap - just hot water. It's a no go. Then add the soap and see the difference. When you're ready we'll tackle the science behind why this works.
As you just confirmed, wax does not "mix" with plain water. This is because wax is a non-polar solute and water is a polar solvent.
- Non-polar solutes dissolve in non-polar solvents
DreadHead wax is a non-polar solute. It will only dissolve in non-polar solvents. WaxxOff is a combination of 3 non-polar solvent that dissolve dread wax very quickly.
- Dread wax will NOT dissolve in polar solvents such as water or ethanol.
- Polar solutes such as glucose (C6H12O6) or Salt will dissolve in polar solvents such as water.
Nearly all compounds fall into one of two categories: hydrophilic ('water-loving') and hydrophobic ('water-hating').Water and anything that will mix with water are hydrophilic. Waxes, Oils and anything that will mix with oil are hydrophobic. When water and oil are mixed they separate. Hydrophilic and hydrophobic compounds just don't mix.
The cleansing action of Dread Soap is comes from its polar and non-polar structures (that allow it to be an emulsifier) in conjunction with an application of solubility principles (the way polar and non-polar solutes and solvents are compatible). Very simply, the soap molecule as two ends, one that likes water and one that doesn't. The long hydrocarbon chain is non-polar and hydrophobic (repelled by water). The "salt" end of the soap molecule is ionic and hydrophilic (water soluble).
When non-polar solutes are mixed with a soap / water solution, the soap molecules arrange themselves between the polar water molecules and non-polar solute molecules. Since soap molecules have both properties of non-polar and polar molecules the soap can act as an emulsifier. An emulsifier allows two substances to mix that wouldn't otherwise be able to. This is how wax, which doesn't naturally mix with water, can be removed by soap and water together. The little groups that the soap molecules arrange themselves in are called micelles. The wax is in the center with micelles attached all the way around it. The non-polar ends all face in, attaching to the non polar wax, while the opposite, polar ends all face out. Since the outward facing ends are all soluble in water, the micelle can be washed away.
And that is how soap can be used to wash away a non-polar, hydrophobic solute like DreadHead Wax.