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Shampoos, Harsh, Mild and Otherwise

I've examined a number of shampoos (those that I had, I did not buy any for this project) to test the notion that certain detergents (surfactants) are harsh and others are not. I did this through examination of hairs in the shampoo under a transmitted light microscope, in comparison to those hairs dry or in distilled water. When hair is well-saturated with water, it swells. But different hair swells different amounts. Hair treated with coconut oil doesn't swell as much. Fine hair doesn't swell as much. Undamaged hair without many porosities swells less than damaged hair. I measured some hairs, dry vs. wet and found quite a difference in the amount of swelling in water.

Pufferfish, all puffed up.

Pufferfish, not yet puffed up.

Never the less, water alone makes hair swell and in so doing, causes the normally-flat cuticle to lift and this creates porosities for things to leak out or diffuse in. Wetting hair alone has a "damaging" quality. Think of a pufferfish to get the right image of what happens to the cuticle when the hair swells.

Some shampoos dramatically increase this swelling. Detergents are "wetting agents" they make water - which dissolves so many things, even more "wet" and allow more things to be washed away by water. That's an oversimplification, but it's good enough for now because the pictures are the feature of this post. Detergents also can remove oils and soils. Some detergents are very good degreasing agents and some are not. The latter are the ones you want for your skin and hair. Clean is good, but too clean is irritating!

Now the fun part:
These hairs are mostly normal porosity or not porous - not chemically treated but have some damage from sun/heat from the sun, combing and brushing and daily life. I have placed them in what some people call a "sulfate shampoo" (see below).

sulfate shampoo

sulfate shampoo, arrows show raised cuticle

Yikes!

Green/yellow stripes from shampoo uptake

Shampoo with ammonium lauryl and laureth sulfate. Do you see the frilly and ragged edges? You might not want to do this too often. The picture directly to the right is a white hair which has actually held on to the color of the shampoo after rinsing (it was green). These are very effective degreasing detergents.

This is a shampoo with decyl glucoside, lauryl glucoside and cocamidopropyl betaine - Burt's Bees Super Shiny shampoo. Very little visible change taking place. The "glucosides" are regarded as mild - not strong degreasers but good "wetting agents." You can see the cuticles appear to lie smoothly and the edges do not look ragged or frilly.

Burt's Bees

Soap bar

This is hair in the "suds" or lather of a soap bar. The non-porous, very fine hair (at left) fared worse than the coarser (thicker) hair shown below. The pH of soap and shampoo bars is high because of the reaction of oils and fats with lye or another hydroxide (strong base) which is how you get oils/fats to turn into soap. This is harsh to hair. Rinsing will immediately begin to restore the hair to its own pH and the hair begins to look normal again. An acidic rinse will speed that process (though both acids and bases can damage hair), and also help remove soap scum which accumulates when oils in soap bond to minerals in hard water.

soap bar

Dilute C12-14 olefin sulfonate

To the right are hairs in a shampoo containing olefin sulfonate, which can be a strong detergent under some circumstances. It removes oils and soil quite well. This particular shampoo, however, has conditioning agents added and a low concentration of detergent, so you don't see much happening. Concentration matters as much as the actual "harshness" or effectiveness of a detergent.

Concentrated C12-14 olefin sulfonate - see edges
of hair for raised cuticles due to swelling. This is
an ordinary concentration for shampoo.

At left is a hair in a shampoo with a higher concentration of olefin sulfonate which contained a small amount of oil, but not enough to mitigate the shampoo's harshness. Again you can see the ragged edges at left and "lifted" cuticle at right.

Concentrated "mild" shampoo

Above, right is a hair in a "gentle" baby shampoo with decyl glucoside. The detergent may be gentle, but it is concentrated shampoo with a high percent of detergent and you can see the ragged edges showing in the hair's cuticle. Below is a shampoo with the same detergent, but it has been diluted (and thickened, which causes a slightly cloudy appearance). There is little apparent change in the hair in the diluted shampoo. The dilution or reduced concentration makes a harsh detergent less harsh. Even so-called mild detergents can be harsh if they are not diluted properly in a shampoo formula.

Dilute mild shampoo

I don't mean to give the impression that shampoo is all bad! It cleans the scalp and hair more effectively than just water. Dilute shampoos with mild detergents are not very damaging to hair (visibly, anyhow) and do a good job of cleaning soils and excess oils. Even one of the harsh shampoos can be diluted at a rate of 1-2 teaspoons of shampoo in a cup of water (or halve that if it's too much volume) for a shampoo that won't cause as much stress. If you shampoo your hair daily or every other day, you might consider diluting your shampoo or choosing a mild one. The same applies to colored (dyed) hair, chemically treated hair, curly or wavy hair, or hair which gets a lot of sun or heat styling. If you want healthy, strong hair, wash it less often. Washing with a gentle or a diluted shampoo should put less stress on the hair, leading to less damage. Even an occasional wash with a full-strength detergent with good degreasing properties isn't going to "ruin" already healthy hair.

Wavy Pride

What defines wavy hair?©Science-y Hair Blog 2013

Let’s start with this warning. Lots of us who must go online to learn how to care for our hair encounter a hair typing system. On the surface, it can help us understand what we have. But let me say now that I hate labels and categorizing. Remember the “blue eyes / brown eyes experiment?” Yeah, you get the picture. More on this later. First, some quick and dirty “bioengineering.”©Science-y Hair Blog 2013

Hair curls or waves because of the composition of proteins in the cortex of hair fibers and how the strands of proteins are arranged in the hair’s cortex (the mid-portion of the hair strand). There are cells in the cortex of some people’s hair called orthocortical cells, accompanied by paracortical cells, and mesocortical cells. How curly hair will be is determined by the proportion of these cells relative to each other, where they are located in the cortex, and what is the protein composition of the orthocortical cells.©Science-y Hair Blog 2013

This image is sourced from this website: http://www.slideshare.net/dralisyed/1-structureof-hair-euro-july-08 "The Structure of Hair," Sayed and Askar.

If you have curly (or wavy) hair but you are not of African descent, then you have a thin layer of orthoroctical cells, especially if your hair is also fine (small in diameter). A person with coarse (thick stranded) and very curly hair who is of African descent has far more orthocortical cells in their hair’s cortex, and a person with straight hair has no orthocortical cells.

This seems to be the best-supported hypothesis so far. And certainly a sample which covers a greater breadth of human geography would tell us more.©Science-y Hair Blog 2013

So here we have a structural and chemical difference to begin with between straight and curly and wavy hair.©Science-y Hair Blog 2013

Now throw away any notions about “hair typing” for a moment (if you have even heard of it). It’s best to avoid classification systems which can lead to value judgments and self-comparison to others. That’s just bad for self-confidence. Seriously. Hearing people wonder if their hair is curly enough to be called “curly” or just wavy or is it 2c or 3a, or looking askance at somebody’s self-declaration of their hair type – give me a break.

Curly hair is an especially robust wave pattern and wavy hair is relaxed wave pattern. It’s all a wave pattern, looser or tighter. You don’t look at the ocean at sunset and think, “Gee, it’s too bad these waves aren’t curly.” The visual difference is the bounce. Even if your wavy hair can make curls and waves that bounce back 2, 3, 4 inches, it still tends to stay near the scalp, waving and/or curling downward in soft waves and spirals. It’s not engineered to bounce more than that. More bounce would mean that those curls would spring outward, not down. So are loose curls really waves? Are tight or spirally waves really curls? It doesn’t matter. What matters is that you understand the medium.

Get to know your wavy hair!©Science-y Hair Blog 2013

Does your wavy hair have straight ends or ends that flip or curl?

What is your wavelength? The distance from the crest of one wave to the next? Is it different when your hair is styled?

Do your waves have amplitude? Is there much depth in between waves?

Are there areas which wave together next to other areas which also wave together (share a wave pattern)? How many areas like this are there?

How is your hair different in spring, summer, fall, winter?

Visual Aid:

I love visual aids but I don’t draw well with a mouse. So you get some green decorative ribbon.

On the left, you see what you’d call a curl. It has robust 3-dimensionality which it holds. Next you see a looser wave pattern, nearly smooth on top, curling near the bottom. You’ve seen hair like this! Next to that is a stretched-out curl or a “spiral.” It has a flatter profile in 3-D. If you have wavy hair, you may know this shape well, whether you can coax it out on demand or not. On the right is a lovely (backwards) S-shaped wave. Big and loose and bouncy.

And another:

Left: curly, next to that, a very loose wave, then the "smooth on top" wave, the loose spiral, and lastly the big, loose S-shaped wave. I like the profile shot because it shows better how these wave patterns "wear" in real life. This set of photos was taken with ribbon of the exact same length. Two were placed higher than the others due to canine interference during photography.

These three are just some forms that wavy hair can take on. There are variations, like wavier on the outer layers (canopy) of hair and straighter on the underlayers (understorey – borrowing a term from biology/ecology). Or the other way around. Or curly in front and wavy in back (or vice versa). If you have wavy hair, you may have a mix of all these hairs on your head (I do). Then the median takes over.

Curly hair can often be "molded" - you can wrap it around your finger either wet or dry to shape or "set" a curl. Wavy hair rarely does this - the spirals are much softer. If you press a wavy spiral upwards, you might get a coil of an inch in diameter (or more or less) but when you let go, the diameter decreases. Wavy curls don't have the determined springy bounce and preservation of diameter of curly curls. And that's perfectly okay, they have graceful, flowing movement unique to waves. I'm just trying to describe the behavior and motion of the fiber, not put a value on it.©Science-y Hair Blog 2013

"Wavy" seem to be a very misunderstood hair texture – often mistaken for un-brushed, unruly “straight” hair or hair which needs to be “fixed” (curled or straightened), leading many wavy-haired people to never learn to make the most of their locks and never allowing them to feel that this important aspect of visual appearance which belongs to them is good enough for public viewing. Your waves and curls are not broken and they don’t need fixing. They just need to be understood, empathized with, given care and encouragement. Hey, don’t we all!

Sources: ‪Chemical and Physical Behavior of Human Hair 4^th Ed.

Clarence R. Robbins, Springer Verlag 2002

Mysteries of Hydrolyzed Proteins

I have been researching various proteins used in hair products. Claims that this or that protein are high or low molecular weight and therefore good for this or that fell short of an adequate explanation. And some people can use one type of protein, but not another. Some proteins are lauded as being good for certain hair concerns. Okay, why?

The weight of the protein does play a role, and it makes sense if you compare proteins. I converted all weights to the unit “Daltons.” Smaller numbers are easier to deal with, reducing them to Kilodaltons gave some numbers which seemed a bit misleading.

Click to enlarge! Hydrolyzed protein weights (from various sources).

Each hydrolyzed protein may have amino acids and peptides in the solution as well (smaller molecules).

My sources are varied and so some are showing a range, including peptides (very small “protein” fragments) some show only an average. You can see that some proteins have a broader range of “protein sizes” which refers more to the methods used to identify the protein’s constituents and what I could find reported for that protein.

What is means for your hair: Low-weight hydrolyzed “proteins” are less than 1000 daltons. They’re not whole proteins anymore! Very small molecules (250 to 500 daltons) can penetrate the hair beyond the cuticle. Any and all of these proteins may contain smaller constituents that may penetrate. Penetrating into the hair can help improve elasticity of hair and moisturize deeply.

“Heavy” weights greater than 10,000 (or 80,000 depending on which source you consult) daltons are thought to be good film-formers for shine, body, helping fill in porosities in the cuticle. They are acting at the cuticle, forming a moisture-holding, protective coating and also having the potential to improve hair’s elasticity and strength.

Medium weight protein hydrolysates (1000 to 5000 daltons) are substantive to hair (bond to hair, don’t rinse off readily). This helps reduce friction (tangling, difficulty combing) which ultimately reduces hair breakage.

If you want a maximum protein boost, choose a mixture of proteins.

If your hair reacts badly to, say, wheat protein but not to keratin, you may have your answer – the wheat is forming a film on your hair, first and foremost whereas some of the keratin is also penetrating the deeper cuticle layers and possibly into the hair fiber.

Some hair will respond well to only certain proteins, or only in certain amounts. Light and medium weight proteins help keep hair hydrated by preserving water in and around the hair. Heavy-weight proteins help keep hair hydrated also by forming an invisible film (like a "glaze") over your hair.

Damaged (porous) hair may appreciate a broad range of proteins, amino acids and peptides to fill in the gaps of damaged cuticles, moisturize, and bond to the hair for ease of combing.

Proteins (top molecules) heated in an acid,
in the presence of water breaking into smaller "pieces"
thus a hydrolyzed protein.
Image from: http://www.chemguide.co.uk/organicprops/aminoacids/proteinhydrolysis.html

Proteins are used as humectants in cosmetics. But they're not humectants like glycerin or sorbitol or propylene glycol which are more "sugary" in nature. In fact - I think a food analogy is good here. If you put some wet brown sugar and some raw egg white on a plate and wait to see which evaporates first - the sugar dries faster. The proteins in the egg white do not release their water as easily. And as you may know - raw egg white dries to a very stiff film. I'm not advocating putting raw eggs in your hair. The proteins are too large to be useful. But you get the idea.

Hydrolyzed proteins in your hair products do the same thing - as humectants they attract and hold water and as protein-based humectants they lose that water slowly. Unlike glycerin or sorbitol or propylene glycol. Because water is what keeps hair hydrated and well-hydrated hair is strong and flexible, this is a wonderful benefit! Proteins or amino acids are ideal for silky or soft hair which is weighed down easily by oils and conditioners. Or for hair that snaps when you run your fingers through it.

There is a list of protein-containing shampoos and conditioners in the "Products By Category" page on this blog.

Deep Conditioning

Sounds so nice – deep conditioning for your hair. And yet it seems impossible because hair is not living tissue. You wouldn’t try to deep condition a damaged, old wool sweater, would you? But then we don’t subject our woolens to the same handling we subject our hair.©Science-y Hair Blog 2013

Deep conditioning hair really means several things: softening the hair, bonding compounds to the damaged areas to make hair “hydrophobic” or water-repelling like healthy hair. Deep conditioning is meant to maximize those things which conditioner does for your hair: reducing friction to prevent tangles and resulting breakage from combing and other mechanical damage, sealing in moisture, adding flexibility and softness.

There are several aspects of deep conditioning: product distribution, substantivity (ingredients bond to your hair rather than rinsing off), product penetration into the hair, duration (time of treatment) and use of heat.©Science-y Hair Blog 2013

Distribution: To thoroughly condition your hair, you need good product distribution which means combing or scrunching in a conditioner. When people use shower caps or plastic wraps, they are also improving distribution. Like painting a wall, the coating needs to be both even and thick.

Bonding: Cationic ingredients and proteins bond to your hair, filling in the gaps (porosities) caused by damage and daily handling, also creating a thin layer of lubrication so that your hair is less prone to tangling, easier to comb, and aligns with the neighboring fibers better - which is key to having lustrous (shiny) hair that feels soft.©Science-y Hair Blog 2013

Penetration into hair: Some ingredients have the potential to penetrate into the hair (beyond the outer, cuticle layers) such as coconut oil and Cetrimonium bromide. Another which I do not have research data for, but which has low enough molecular weights (short enough carbon chain) is Cetrimonium chloride. So if your conditioner has any of these ingredients, it already has greater potential to be a “deep” conditioner.©Science-y Hair Blog 2013

Duration of conditioning treatment: I’ve read that cosmetics chemists (those who design hair products) maintain that a product will not do more good if you leave it on longer than stated on the bottle. And yet I find information to contradict this. It’s probably not a good idea to leave conditioner on your hair for hours or overnight because these are products meant to be rinsed off and you may not want some of these ingredients to have contact with your skin for an extended period. That being said, the longer a hydrolyzed protein, a conditioning polymer such as polyquaternium-4 or quaternium-26 or cationic surfactant such as Cetrimonium bromide stays in contact with your hair, the more is adsorbed to the hair and, where possible, penetrated into the hair. So if you prefer to condition for longer than a few minutes, you may benefit. Or you may end up with limp hair. But it will be soft, limp hair! There is a point at which the hair has bound all the proteins and/or conditioners it can and cannot "use" any more. ©Science-y Hair Blog 2013

Heat: Do products which are not designed to be used with heat, work better with application of heat? Possibly.
1) Heat liquefies ingredients somewhat and this improves distribution, allowing oils (especially "solid" oils like coconut oil or shea butter) to spread and penetrate if they can. If you’re adding heat, you’ve probably wrapped your hair all up, also improving distribution.
2) Heat speeds up reactions; when ingredients are bonding to your hair, it is a chemical reaction. Heat also creates a very moist environment, all that moisture is there while the hair is swollen from having been wetted, from being in the presence of a wetting agent (conditioner) – so the humidity created by adding (moist) heat is probably beneficial, protecting the hair from water loss during the process.
You can add heat by putting on a heat wrap or wearing a shower cap or plastic covering over your hair, or you can warm your conditioner first. But don't zap it in the microwave - heat some water in a dish and then set your conditioner in a smaller dish, in that bowl of water to heat gently and evenly.

References:

Journal of Cosmetic Science, 56, 323-330 (September/October 2005)

Penetrationon of Cationic Conditioning Compounds into Hair Fibers: A TOF-SIMS Approach

S. B. RUETSCH and Y. K. KAMATH, TRI/Princeton

Journal of the Society of Cosmetics Chemistry, 43, 259-273 (September/October 1992)

Assessment of the Substantivity of Cationic Quaternary Compounds to Hair by Potentiometric Titration Using the Surfactant Electrode

NGHI VAN NGUYEN, DAVID W. CANNELL, ROGER A. MATHEWS, and HANS H. Y. OEI, Redken

What's Cooking This Week (8-13-11)

Flaxseed curl cream! If you like "all in one" products or are just looking for something new to try without actually shelling out cash, mix up some of this curl cream. The recipe is also at the bottom of the "Recipes and Projects" page.
©Science-y Hair Blog 2013
Flaxseed Curl Cream:

Combine:
1 tablespoon thick, rich conditioner (use less for fine hair) - add a few drops of canola oil or whatever oil you like if the conditioner has no oil in it
2 tablespoons flaxseed gel (with protein added if your hair likes it)
1 tablespoon strong hold hair gel
optional: 4 drops honey or agave nectar ( or 1/8 teaspoon or more - this is meant to add more "hold")
©Science-y Hair Blog 2013
Apply fairly liberally, style as you usually do.
This gives great curl definition and "clumps," controls frizz, enhances curls and feels soft in the hair. For the hair gel, use whatever feels like "strong hold" to you - whatever you have on hand. You can always use more honey or agave if you need more hold.
©Science-y Hair Blog 2013
Cut the batch! (Trial size) Use:
1 teaspoon of conditioner
2 teaspoons of flaxseed gel
1 teaspoon of strong hold hair gel
(optional) 1-2 drops honey or agave - not as good in high humidity.

The ratio of ingredients if you want an even smaller batch is:
2 parts flaxseed gel
1 part strong-hold gel
Anywhere from a drop to 1 part conditioner
1-3 drops oil (optional)
1-4 drops agave or honey (optional - not good in high humidity)

Shampoos, Harsh, Mild and Otherwise

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Wavy Pride

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Mysteries of Hydrolyzed Proteins

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Deep Conditioning

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What's Cooking This Week (8-13-11)

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