Hair conditioners are often used in hair care alongside shampoo, to improve the texture and appearance of human hair.

Hair consists of approximately 97% of a protein called keratin. The surface of keratin contains negatively-charged amino acids. Hair conditioners therefore usually contain cationic surfactants, which don't wash out completely, because their hydrophilic ends strongly bind to keratin. The hydrophobic ends of the surfactant molecules then act as the new hair surface.

Conditioning agents include moisturizers, oils and lubricants (e.g., some fatty alcohols, panthenol, dimethicone, etc.). They also inlcude antistatic agents, and sequestrants for better function in hard water. Other additional chemicals are preservatives.

Conditioners are frequently acidic, as low pH protonates the amino acids, providing the hair with positive charge. This allows better forming of hydrogen bonds between the keratin scales, giving the hair a more compact structure. Citric acid, or other organic acids, is the usual component maintaining acidity.

An easy and inexpensive way to condition one's hair and improve the health of one's scalp is to mix 2 tablespoons (30ml) of apple cider vinegar or lemon juice (but not both) with 1 cup (250ml / 8 fl oz.) of water and use in small amounts after shampooing. While this mixture does not foam or feel like a traditional conditioner, the positive changes to one's hair will be apparent after the first or second wash.

Types

There are several groups of hair conditioners, differing with composition and main functionality aspects:

• Moisturizers, whose role is to hold moisture in the hair. Usually these contain higher proportion of humectants.
• Reconstructors, usually containing hydrolyzed protein. Their role is to penetrate the hair and strengthen its structure through polymer crosslinking.
• Acidifiers, acidity regulators which maintain the conditioner's pH at about 2.5–3.5. In contact with acidic environment, the hair's somewhat scaly surface tightens up, as the hydrogen bonds between the keratin molecules are strengthened.
• Detanglers, which modify the hair surface by pH as acidifiers, and/or by coating it with polymers, as glossers.
• Thermal protectors, usually heat-absorbing polymers, shielding the hair against excessive heat, caused by, e.g., blow-drying or curling irons or hot rollers.
• Glossers, light-reflecting chemicals binding to the hair surface. Usually polymers, usually silicones, e.g., dimethicone or cyclomethicone.
• Oils(E.F.A.'s - essential fatty acids), If you have dry hair, you need to add oil to your hair. The scalp produces a natural oil called sebum. EFA's are the closest thing to natural sebum (sebum contains EFA'S). EFA's can take very dry and porous hair and transform it into soft pliable hair.

Other aspects in which conditioners differ are^*:

• Pack conditioners, heavy and thick, with high content of surfactants able to bind to the hair structure and "glue" the hair surface scales together. These are usually applied to the hair for longer time. The surfactants are based on long straight aliphatic chains similar to saturated fatty acids. Their molecules have tendency to crystallize easily, giving the conditioner higher viscosity, and they tend to form thicker layers on the hair surface.
• Leave-in conditioners, thinner, containing different surfactants, adding only a little material to the hair. They are based on unsaturated chains, which are bent rather than straight. This shape makes them less prone to crystallizing, making a lighter, less viscous mixture and providing significantly thinner layer on the hair. The difference between leave-in and pack conditioners is similar to the difference between fats and oils.
• Ordinary conditioners, combining some aspects of both pack and leave-in ones.
• Hold conditioners, based on cationic polyelectrolyte polymers, holding the hair in a desired shape. These have both the function and the composition similar to diluted hair gels.

External links

• Conditioner Manufacture
• How Is Hair Breakage Measured? The Beauty Brains
• How Conditioners Work