Posted by Lelia on August 8, 2002 at 17:28:57:
: : hennotannic acid molecules which facilitates such fast and
: : dyeing of keratins?
: As far as I can tell (taking deep breath here, with a caveat the
: of a medium dog):
: Because lawsone is hydrophobic, it will dissolve readilly in a
: monoterpene alcohol, therefore you get far more of the lawsones
: available to penetrate and bind with the keratin. The acid breaks
: down the vegetal matter and faciliates dye release, then the
: monoterpene alcohol facilitates lawsone availability. Therefore,
: lawsone is made available to enter the skin cell.
: The monoterpene alcohol reacting with the lawsone within the skin
: cells contribute to more rapid and deeper level oxidation and
: darkening than can be achieved without monoterpenes under the same
: conditions of temperature and time. Perhaps the alcohols are
: evaporating and oxidizing the lawsones as they go. Therefore,
: henna gets darker than unterped henna, over the 72 hour period
: following application, and this is particularly visible in the upper
: layers of the stain.
: Contrary to prior perception, monoterpenes do not contribute to a
: shallow henna penetration. Unterped and terped henna stains in a
: comparison test disappered on the same day.
Laughing from me - my phtyochemistry teacher said the exact same
think - After giving her the squinty trying to process it into my
little bitty brain look she said "look - what's your skin cells bad
of." I reply - lipids (fats) she replys "good and what do we know
about e oils." I reply "They absorb readily into fats, oils ans into
lipid membranes." She say's all knowing and smiling "right - terpines
even more so..." I had my ah moment. Basically In a much less complex
and nifty sounding way, the terpines are facilitating a greater
amount of dye available to use AND making the molecules much more
hydrophobic and more lipid soluble then before. I'm definently not
science girl anymore and would have no idea on the metal ion things.
CCJ you rock!!! Lelia
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