Brad Sondahl on sun 14 sep 97
Hamer's Dictionary says in amounts over 15 %, Rutile and/or titannium
will cause phototrophism--a reversible darkening in reaction to light. I
imagine it's like eyeglasses that turn gray. Sounds fun--anyone have a
recipe?
--
Brad Sondahl
bsondahl@camasnet.com
http://www.camasnet.com/~asondahl
PO Box 96, Nezperce ID 83543
"When it comes to dabbling, I'm just a dilettante..."
Bill Aycock on mon 15 sep 97
The characteristic of Titanium, in chrystals in glazes or glasses to change
with light (particularly, Sunlight) has long been known. In a paper
presented to the pottery section of the British Ceramics Society,
W.O.Williamson discussed the phenomenon. - Rutiles containing appreciable
Iron dont do it as much. He didnt say how much. (in the review I saw)
This was reported in Ceramic Age, 37,(5) 160-161
In 1941.
LOTS of work has been done on this, since then- The earliest light
sensitive glasses used this trick. Some research into the glass trades
should show more information. (Karl ?)
At 12:35 PM 9/14/97 EDT, you wrote:
>----------------------------Original message----------------------------
>Hamer's Dictionary says in amounts over 15 %, Rutile and/or titannium
>will cause phototrophism--a reversible darkening in reaction to light. I
>imagine it's like eyeglasses that turn gray. Sounds fun--anyone have a
>recipe?
>--
>Brad Sondahl
>bsondahl@camasnet.com
>http://www.camasnet.com/~asondahl
>PO Box 96, Nezperce ID 83543
>"When it comes to dabbling, I'm just a dilettante..."
>
>
Bill Aycock --- Persimmon Hill --- Woodville, Alabama, US 35776
--- (in the N.E. corner of the State) ---
also -- W4BSG -- Grid EM64vr
baycock@hiwaay.net
Karl P. Platt on tue 16 sep 97
>Hamer's Dictionary says in amounts over 15 %, Rutile and/or titannium
>will cause phototrophism--a reversible darkening in reaction to light.
I
>imagine it's like eyeglasses that turn gray. Sounds fun--anyone have a
>recipe?
Just to make this clear, the mechanism is different, but the effects are
similar.
In fact, little is known about the phototropic effects seen in TiO2 rich
glazes.
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