Park, in general absent a means to repel each other, such as the use of an
electrolyte to defloculate, particles will tend to aglomerate. So while I
can't give you specifics on the particular dispersion you are seeking I can
point out that generally speaking nature does not want to accomodate your
desire for a suspension in pure DI. You can test the theory by using a
small quantity of a defloculent electrolyte.  Gary

Gary Hillman
Service Support Specialties, Inc.

-----Original Message-----
From:   sokwon Paik [SMTP:sokwonnp@yahoo.com]
Sent:   Thursday, October 06, 2005 11:28 PM
To:     mems-talk@memsnet.org
Subject:        [mems-talk] Nano particle dispersion

Can anybody confirm if 47nm Al2O3 dispersion be done with 30 min of
sonication in DI water?

My co-worker insist that 30 min of sonication be good enough for the
dispersion but as far as I know, 30 min of sonication couldn't be any close
to the dispersion.

Am I right?

Can anybody suggest for the better dispersion method for this? I want to
disperse without any surfactant. I want to disperse AL2O3 into pure DI
water with the dilution of 0.5%, 1% ...

Please suggest whatever method you know.