Be Safe

1
Be Safe!

• Rogers group meeting, June 05

www.drs.uiuc.edu
2
Chemicals and materials we use

• solvents
• hexanes, xylenes, toluene
• SU-8 developer
• acetone, alcohols

• poisonous corrosives
• HF
• µCP gold etch

• corrosives
• strong acids HNO3, H2SO4, HCl
• strong bases KOH
• halogens (Br, I)

• substrates
• semiconductors
• glass
• plastic

• nanos
• CNT
• µS-Sc
• particles

• silicones (PDMS)
• custom (gelest, etc.)
• Dow-Sylgard 184 and variants

3
HF
Exposure of less than 10 of the body can be
fatal, even with immediate medical treatment.
Highly concentrated solutions may lead to acute
hypocalcemia, followed by heart attack and death,
and may be fatal in as little as 2 body exposure
Inhalation Extraordinarily toxic, most likely
fatal in concentrations gt200ppm, non-fatal doses
can result in pulmonary edema.
CaF2 H2SO4 ? 2 HF CaSO4
250ºC

• etches SiO2 and many oxides
• reacts w/ Ca and Mg in the body
• targets heart, liver, kidneys, nerves, bones
• goes through latex glovesuse thick nitrile
  gloves

Source wikipedia.com
4
Corrosives (strong acids, bases, etc.)
they burn you
they are volatile and burn your lungs
Note fluorinated silane gives-off HCl
Note µCP Au etch KOH cyanide
Br and vapors
5
Nanomaterials
micro/nanowires
asbestos
They get stuck in your lungs and cause trouble.

• Examples
• CNT
• µS-Sc
• metal dust

6
Solvents

• Hexane, benzene, xylenes, etc.
• make you sick if you get too much exposure.
• absorbed through skin
• brain damage, reproductive trouble.
• keep in fume hood!

• acetone, alcohols
• make you sick if you get too much exposure.
• absorbed through skin
• methanol makes you blind and deadbreaks-down
  like ethanol does in liver, only faster, and
  produces formic acid and formaldehyde. fatal
  dose 4 fl oz.

7
Substrates
Hard substrates like glass and wafers break into
sharp piecesbig and tiny. Plastic is pretty safe.
8
Silicones
Gelest some of the components are in some
harmful solvents. Dont inhale them while mixing.
Regular 184 seems pretty safe. Just dont eat it.
9
Four basics

• Know your stuff. When in doubt, ask.
• Think and look before you act.
  (Take your time).
• Wear safety gear (glasses, gloves).
• Be considerate of others (labels, talk to them).

10
Careful how you mix them
Mix ammonium hydroxide and nitric acid, get
ammonium nitrate.

• Ammonium nitrate is a main component of some
  explosives. Detonations
• Texas City, 1947
• Oklahoma City, 1995

Lesson store and dispose of acids w/acids, bases
w/ bases, oxidizers (incl. HNO3) w/ oxidizers
not with each other.