I'm having trouble finding the source of contamination on glass. FTIR
showes silicone rubber along with other spikes. One possibility is
that some cleaning agents used on our gloves are causing it.
I'd like to know if either isopropyl alcohol or triethylene chloride
could attack the polymer of some rubber gloves ("natural rubber" says
the manufacturer, I suspect a blend with nitrile and/or silicone) and
cause it to break down. I've searched Google, however no helpful links
Thanks in advance for any info on this.
Silicone is a notorious contaminant. Nearly all
silicones contain cyclic penta- and hexa-dimethylsiloxanes
(called cyclic D5 and cyclic D6, in the business),
as well as higher cyclic siloxanes. These undergo
a ring-opening polymerization reaction, which puts
down a very thin contaminant layer which is almost
impossible to remove. The disk drive industry hates
silicones, because these contaminant layers play
havoc with the head-disk interface. Note that certain
cosmetics such as lipstick and solid stick antiperspirants
contain cyclic siloxanes as major ingrediants. That's
a problem because production line workers may be
Silicone may infiltrate a production process through
a variety of ways. In the disk drive industry,
it has been learned through cruel experience that
the syringes used to dispense adhesives (for example
to attach the disk head to the actuator arm) can
contain troublesome amounts of silicone originating
in the silicone-based mold release agents used to
make the syringes. Even when non-silicone mold
release agents are specified for your syringes,
there can be cross-contamination through the air
from silicone mold release agents used on
neighboring production lines in the same facility.
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