October 2008 Archives

There are a wide array of styles and textures available to today's salon clientele. With so many options, the ability to switch from one look to another has never been more important.

To answer the question--can relaxed hair be stripped?--it is necessary that we first understand the chemistry of the hair, as well as the lanthionization (relaxation) process.

When two or more polypeptides align themselves parallel to each other, and their cysteines (amino acid) combine with each other to form cystine or disulfide bonds across these polypeptides, a keratin fiber is created in the process.

Hair, or keratin according to chemical terminology, is made up of polypeptides. (Polypeptides are made up of amino acids -- the basic unit of protein.) Polypeptides are aligned in a parallel fashion and are cross linked with cystine bonds (also called disulfide bonds). Note that cystine bonds have two sulfur atoms.

When excessively curly hair is chemically straightened with hydroxide-based relaxers, (i.e., sodium, potassium, lithium, and guanidine hydroxide, etc.) approximately one-third of the cystine bonds are changed to lanthionine bonds. The lanthionine bond has only a single sulfur atom; one sulfur atom less than the cystine bond of virgin hair.

It has come to my attention that folks using Microsoft's Internet Explorer browser haven't been able to view the entire blog properly. I am currently working to have the problem resolved; however, I would like to strongly encourage some of you to experiment with superior browsers such as Mozilla's "Firefox", Opera, Google's new browser "Chrome", and Apple's "Safari" browser. Thankfully, the hair care industry is full of competition so it is impossible for Avlon to rest on its laurels.

I recently updated several blog entries by posting the original PDFs of the articles, via SlideShare. Scroll down to the end of Recent Advances in Treating Excessively Curly Hair, Correlating Porosity and Tensile Strength of Chemically Modified Hair, Chemical Terms that YOU should know, Irritation Potential of Lye & No-Lye Relaxers, Study on physical properties of African American Hair, and Shelf Life and Storage of Salon Products to view the original PDF articles. You will have to view them in fullscreen mode.

With that said, I will be in Brasil for the next couple of weeks, so I will be a little busier than normal. Do not hesitate to comment or ask questions, and as always, I will do my best to respond to your questions or comments.

Lastly, I would like to leave you all with an interesting, somewhat unrelated, website that I recently stumbled upon called Wordle. It generates word clouds based on inputted text or URLs. The other day I inputted the URL of this site, www.dralisyed.com, and I got this:

wordle_dralisyed.jpg















It appears that I am in luck, and the word "hair" was the most prominent word on the main page at the time, so I must be blogging about the right subject.

Tchau obrigado

The folks at Nalco Company (Yin Hessefort, Brian Holland, and Richard Cloud) published an interesting study that appeared in the July/August issue of the Journal of Cosmetic Science, where they studied the porosity characteristics of damaged hair.

The study used the gas sorption method to determine the total pore volume, adsorption pore-size distribution, and the surface volume of the damaged hair. The two types of damaged hair they looked at were bleached hair and hair that had been exposed to UV rays.

What they found was that bleached hair nearly tripled in surface area during the first minute of bleaching due to an increase in the number of pores, followed by a sudden drop after 10 minutes of bleaching, suggesting that smaller micropores (< 2 nm) break down into larger macropores (> 50 nm). In contrast, they found that UV damaged hair showed an immediate loss in surface area during the first 200 hours of exposure and a gradual increase as exposure time continued, which they theorized was caused by a fusion of cuticle cells followed by an increase in pores or cracks.

roller_coaster.jpgWith the state of the current US financial markets the way that they are, many should be getting accustomed to wild swings in daily performance. I figured that now would be an apt time to discuss the pH of hair during relaxing. The pH of the hair goes through considerable changes during the relaxing process and it is appropriate to discuss these changes because such changes can be made to play a positive role in the art and science of relaxing hair. The following events take place before, during, and after relaxing with respect to the pH of the hair, swelling of the hair, and the state of cuticles:


  1. The pH of the untreated hair is in the range of 4.5 to 6.5 and the cuticles are considered closed, as the hair isn't swollen in the dry state.

  2. The pH of cream relaxers is around 13.0. When the relaxer is applied to the hair, the pH of the hair increases to 13.0 and the hair diameter swells as much as 60 - 80 percent of its original size. Also, the cuticles become wide open while the relaxer is on the hair. This is the best opportunity to condition the hair because the cuticles are open to the widest possible degree.

    Unfortunately, most conditioners are not stable at the pH of 13; especially the single molecules of quaternary ammonium compounds-- conditioning agents used in most conditioners. However, there a select few cationic polymers that remain stable at a high pH, and condition the hair while it is simultaneously being straightened by the relaxer. These conditioning agents are able to penetrate deep into the cortex of the hair and condition the hair more permanently than conventional conditioners. Since the molecular weight of these conditioners is around 1 million, they get stuck in the cortex of the hair when the cuticles start to close during rinsing of the relaxer. Also, these conditioners can stay in the cortex of the hair upto 4 shampooing treatments.

  3. After 13 to 18 minutes of relaxer treatment, the excessively curly hair generally becomes straight and at that stage, the relaxer is rinsed from the hair with tepid warm water for 4 to 5 minutes. The pH of the hair drops down to about 10 and the hair isn't as swollen as when the relaxer was on the hair. The cuticles are about 30 percent open at this stage. This is the second best opportunity to condition hair in the relaxing process. Since the cuticles are about 30 percent open, the conditioners such as high molecular weight cationic polymers are able to penetrate deep into the cortex of the hair and condition hair from the inside out. This penetration of conditioning agents is less than the penetration of conditioners during relaxing process.

  4. After rinsing the post-relaxer conditioner with water, the hair is then shampooed with Neutralizing/Normalizing shampoo of pH 4.5 to 6.5. Generally, a high quality neutralizing shampoo contains cationic polymers, mild detergents, organic acids (like citric acid or lactic acid), and color indicators to signal the neutralization of alkaline residue derived from relaxers. The hair acquires the pH of the neutralizing shampoo, that is, it comes back to its natural pH balance while the cuticles close back down to a level that is close to the original state.