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

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    Member foreveryours's Avatar
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    Default Measuring the water content of hair (I thought this was interesting)

    scalp > SL > MBL > WL > TBL > FTL > LHC > ???

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

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

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

    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

    Log in or Subscribe for FREE to read the full story.
    I'll have a go at finding an accessible source and post back here if I can. Sorry
    scalp > SL > MBL > WL > TBL > FTL > LHC > ???

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

    I could only see the beginning of the article too, but I really enjoyed the sentence:
    'while consumers profess a desire for ďmaximum moisturization,Ē the high humidity conditions that induce this state represent the very definition of a bad hair day.'
    Last edited by DropStitches; October 10th, 2021 at 04:44 PM. Reason: removed random asterisk
    Growing out a buzzcut since September 2019

    buzz -- shaggy pixie-ish mess -- chin -- SL -- CBL+ -- APL -- MBL -- waist -- hip

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

    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?

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

    Quote Originally Posted by Finda View Post
    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?
    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.
    scalp > SL > MBL > WL > TBL > FTL > LHC > ???

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

    Quote Originally Posted by foreveryours View Post
    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 canít read the article so Iím 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). Is that what the article is saying?

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

    Sorry if thatís too many questions!
    Last edited by Lady Stardust; October 13th, 2021 at 02:07 PM.

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    Member foreveryours's Avatar
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    Default Re: Measuring the water content of hair (I thought this was interesting)

    Quote Originally Posted by Lady Stardust View Post
    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). [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!

    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.
    Last edited by foreveryours; October 13th, 2021 at 05:54 PM.
    scalp > SL > MBL > WL > TBL > FTL > LHC > ???

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

    Quote Originally Posted by foreveryours View Post
    Use Firefox!

    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!

    Iím a big fan of pre-wash oiling. My hair is quite fragile so itís 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.

    Iím 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 youíre 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.

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

    Quote Originally Posted by Lady Stardust View Post
    Thank you so much for taking the time for this foreveryours!

    Iím a big fan of pre-wash oiling. My hair is quite fragile so itís 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.

    Iím 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 youíre 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 ďdryĒ feel and produce a pronounced improvement in hair quality that is described by consumers as ďmoisturization.Ē
    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.

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