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Aug. 18, 2008 -- Blame it on the hair force.
Bad hair days grow out of interactions between individual hairs as they fly in a breeze or squish under your hat or on your pillow.
These hair-to-hair meetings result in "subtle forces" -- chemical, electrical, and mechanical energies -- that make your hair rough and unmanageable, notes Eva Max, a chemistry doctoral student at the University of Bayreuth, Germany.
Max and colleagues at BASF Care Chemicals Division aren't taking bad hair lying down. They've invented "single hair force spectroscopy," using electron microscopy to analyze nanoscale hair behavior.
"The system will allow scientists to explore how different hair-care products affect hair-to-hair interactions so that these products can be optimized in a more systematic fashion," Max says in a news release.
Despite the $60 billion spent worldwide on hair-care products, researchers still don't fully understand why hair conditioners give hair that smooth and silky feel -- and why they don't always help hair that's been tortured to force it into fashionable colors and shapes.
Using their new technique, Max and colleagues looked at hair samples from volunteers whose hair had been bleached blond. They found two reasons why hair becomes rough and unmanageable.
They found that mechanical damage to hair raises scaly projections on individual hairs. These scales jut out sideways from the hairs, creating friction as they slide past other hairs. The result: hair that's rough to the touch and hard to comb.
To cut back this problem, they say, hair products must contain ingredients that smooth out the scales.
The researchers also found that when hair fibers interact, they build up negative electrical charges. Same charges repel one another, making hair literally repulsive. Again friction results, making hair rough and hard to comb.
Rinsing out this problem will mean adding positively charged polymers to hair products to neutralize the negative charges.
But BASF scientist Claudia Wood, PhD, says it's not going to be easy to solve the bad-hair-day problem. Lots of other things contribute to hair problems, including humidity, the water content of each hair, and hair stickiness.
Max presented the findings at the American Chemical Society's 236th National Meeting, held Aug. 17-21 in Philadelphia.