Measuring the water content of hair (I thought this was interesting)

[foreveryours]

https://www.cosmeticsandtoiletries.com/testing/invitro/Measuring-the-Water-Content-of-Hairpremium-246571251.html

[patchoulilove]

This is interesting. The article truncates for those who aren't part of that website tho, sadly.

[foreveryours]

Thankyou for that update. I use Firefox and I can see the entire article fine. I just checked using Chrome and indeed the article does not extend below


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I'll have a go at finding an accessible source and post back here if I can. Sorry

[DropStitches]

I could only see the beginning of the article too, but I really enjoyed the sentence:
'while consumers profess a desire for “maximum moisturization,” the high humidity conditions that induce this state represent the very definition of a bad hair day.'

[Finda]

I think it's a script blocker more than firefox on itself. I was also able to read the article, but when I switched off uMatrix it broke off as well, even using firefox.

Super interesting. It also cites the Davis and Stofel study and describes how the term moisturizing is used wrongly by customers.

Math is really not my strength. Does the article say oiling does not actually change moisture adsorption?

[foreveryours]

I think it's a script blocker more than firefox on itself. I was also able to read the article, but when I switched off uMatrix it broke off as well, even using firefox.

Super interesting. It also cites the Davis and Stofel study and describes how the term moisturizing is used wrongly by customers.

Math is really not my strength. Does the article say oiling does not actually change moisture adsorption?

https://forums.longhaircommunity.com/attachment.php?attachmentid=44460&d=1612945575 Finda, it must be a FF addon which allows you to see thru the paywall (I use similar, uBlock Origin and NoScript and never realized it may be an issue for others).

Yes, oiling does not change the water content of hair. So conclusions based upon naive measurements showing the contrary, by "ignoring" the fact that, for samples of identical weight, the treated sample contains less hair than the untreated sample, are unsound. While oiling may change the RATE of water absorption/desorption of water by hair with changing humidity, it does not change its water content at equilibrium which is dictated by RH.

[Lady Stardust]

https://forums.longhaircommunity.com/attachment.php?attachmentid=44460&d=1612945575 Finda, it must be a FF addon which allows you to see thru the paywall (I use similar, uBlock Origin and NoScript and never realized it may be an issue for others).

Yes, oiling does not change the water content of hair. So conclusions based upon naive measurements showing the contrary, by "ignoring" the fact that, for samples of identical weight, the treated sample contains less hair than the untreated sample, are unsound. While oiling may change the RATE of water absorption/desorption of water by hair with changing humidity, it does not change its water content at equilibrium which is dictated by RH.

I can’t read the article so I’m flying a bit blind here, bear with me! Is this talking about oiling before washing?

My understanding is that prepoo oiling is done to slow down the rate at which the water penetrates (going by what I have read on Science-y Hair Blog (http://science-yhairblog.blogspot.com/2014/03/managing-elasticity-and-porosity-in-hair.html)). Is that what the article is saying?

Is there any discussion about post wash oiling or use of humectants?

Sorry if that’s too many questions!

[foreveryours]

I can’t read the article so I’m flying a bit blind here, bear with me! Is this talking about oiling before washing?

My understanding is that prepoo oiling is done to slow down the rate at which the water penetrates (going by what I have read on Science-y Hair Blog (http://science-yhairblog.blogspot.com/2014/03/managing-elasticity-and-porosity-in-hair.html)). [1] Is that what the article is saying?

[2] Is there any discussion about post wash oiling or use of humectants?

Sorry if that’s too many questions!

Use Firefox! :D

My interest was drawn to the paper's Figure 1 (Water-hair adsorption isotherm) because I wanted to know the water content of my own hair. Typically it's about 6% by weight. I live in an arid climate. Would it behave better if I "moisturize"? Consumer rags say yes while science says no (MG Davis and S Stofel, Consumer perception versus single and bulk fiber technical measurements, Proc 16th International Hair Science Symposium, Weimer, Germany (2009)).

To address the issue, you need ways to measure actual water content which is what the paper is about.

[1] Your understanding appears essentially correct. The author argues that at equilibrium, water content of hair is independent of conventional hair treatments like "oiling". In the short term, by retarding the rate at which water enters the hair shaft, pre-wash oiling can reduce swelling of the fiber (damage).

[2] Post-wash oiling, again by retarding the rate at which water can leave the hairshaft, results in a higher pre-equilibrium water content. At equilibrium (reached in a day maybe?), the moisture-altering effect of oil is exactly zero. Though there is some mention of specific chemicals (e.g. phenol) able to alter the equilibrium amounts of water in hair in a measurable way, there is no discussion of humectants.

[Lady Stardust]

Use Firefox! :D

My interest was drawn to the paper's Figure 1 (Water-hair adsorption isotherm) because I wanted to know the water content of my own hair. Typically it's about 6% by weight. I live in an arid climate. Would it behave better if I "moisturize"? Consumer rags say yes while science says no (MG Davis and S Stofel, Consumer perception versus single and bulk fiber technical measurements, Proc 16th International Hair Science Symposium, Weimer, Germany (2009)).

To address the issue, you need ways to measure actual water content which is what the paper is about.

[1] Your understanding appears essentially correct. The author argues that at equilibrium, water content of hair is independent of conventional hair treatments like "oiling". In the short term, by retarding the rate at which water enters the hair shaft, pre-wash oiling can reduce swelling of the fiber (damage).

[2] Post-wash oiling, again by retarding the rate at which water can leave the hairshaft, results in a higher pre-equilibrium water content. At equilibrium (reached in a day maybe?), the moisture-altering effect of oil is exactly zero. Though there is some mention of specific chemicals (e.g. phenol) able to alter the equilibrium amounts of water in hair in a measurable way, there is no discussion of humectants.

Thank you so much for taking the time for this foreveryours!

I’m a big fan of pre-wash oiling. My hair is quite fragile so it’s good to give it a bit of extra protection. I also use a leave in conditioner to slow down the rate of the water leaving the hair.

I’m not quite sure where humectants come into it, which is why I wondered whether the article mentioned them. As far as I remember from Science-y Hair Blog, a film forming humectant can also slow down the rate at which the water leaves the hair. From what you’re saying about equilibrium, these things only really apply to wash day, but since I need to wash my hair every other day anyway, my hair hopefully benefits from this routine.

[Finda]

Thank you so much for taking the time for this foreveryours!

I’m a big fan of pre-wash oiling. My hair is quite fragile so it’s good to give it a bit of extra protection. I also use a leave in conditioner to slow down the rate of the water leaving the hair.

I’m not quite sure where humectants come into it, which is why I wondered whether the article mentioned them. As far as I remember from Science-y Hair Blog, a film forming humectant can also slow down the rate at which the water leaves the hair. From what you’re saying about equilibrium, these things only really apply to wash day, but since I need to wash my hair every other day anyway, my hair hopefully benefits from this routine.


I've also thought for a long time my hair is dry, I need to hydrate, but the article actually questions that water benefits the hair in any way.

This is a quote from the article:


Conventional conditioning treatments are widely seen by consumers as being effective in providing moisture even though technical measures show no actual change in water content. Therefore, other factors must be responsible for this perception. A likely explanation involves the lubrication delivered by products to mask a rough, coarse and “dry” feel and produce a pronounced improvement in hair quality that is described by consumers as “moisturization.”

Here is a quote from another chemist who blogs on Instagram:


"...but adding water isn't beneficial for the hair (you of course need it for the use of products like shampoo or conditioner). Water makes the hair swell, which can lead to damage. Wet hair (without conditioning agents) is more vulnerable and research has actually shown that hair containing higher percentages of water feels more dry/brittle/rough and hair with lower percentages is percieved as more smooth"
Quote by Sciencemeetscosmetics on Instagram, today

Concerning products who advertise hydration/moisture she says that they don't actually add water to the hair, they only work because they condition.

I think both authors reference the same study.

I wonder if this pertains to the loc method as well: that it works because it conditions and not because it keeps the water in the hair.

[Lady Stardust]

I've also thought for a long time my hair is dry, I need to hydrate, but the article actually questions that water benefits the hair in any way.

This is a quote from the article:



Here is a quote from another chemist who blogs on Instagram:



Concerning products who advertise hydration/moisture she says that they don't actually add water to the hair, they only work because they condition.

I think both authors reference the same study.

I wonder if this pertains to the loc method as well: that it works because it conditions and not because it keeps the water in the hair.

Thank you for those quotes, it’s very interesting!

According to the blog post I linked upthread from Science-y Hair Blog (if I’ve understood it correctly anyway) water is beneficial to the hair but problems occur if water penetrates the hair shaft too quickly, or evaporates from the hair too quickly.

The LOC method would help with the latter, slowing down the evaporation, but I agree that some benefit at least would be from the conditioning effect of the products, and from keeping the hair supple.

[Finda]

Thank you for those quotes, it’s very interesting!

According to the blog post I linked upthread from Science-y Hair Blog (if I’ve understood it correctly anyway) water is beneficial to the hair but problems occur if water penetrates the hair shaft too quickly, or evaporates from the hair too quickly.

The LOC method would help with the latter, slowing down the evaporation, but I agree that some benefit at least would be from the conditioning effect of the products, and from keeping the hair supple.

I just read the article you linked. I understood it in the same way you did. So it differs a bit from the view in the cosmeticsandtoiletries article in such a way as the author definitely sees some purpose in retaining water in the hairshaft. Although, using leave in conditioner, like you mentioned, will definitely protect the hair to an extend from mechanical damage as well I imagine. I use a silicone containing hair oil daily for this purpose.
I'll look for more information on this topic, I'm interested in finding a more definite answer ;-)