New chemicals

Mary Tang mtang at
Tue Aug 23 11:39:46 PDT 2005

Hi Sora --

Thanks, this is pretty much the info we need, in addition to MSDS for 
each of the chemicals.

Although your process is generally do-able, I would strongly recommend 
several changes. The octadecyltrichloroethoxysilane or methoxysilane 
versions of OTS are much safer and less chemically reactive than the 
trichlorosilane version. There are several good, documented processes 
for assembling monolayers using these (the process window is actually 
quite wide.) You don't need to control the moisture in the solvent as 
rigorously, and it lasts a lot longer (when you've opened the bottle of 
the trichlorosilane, you've pretty much ruined what's left.) Also, if we 
could avoid the use of chlorinated solvents (carbon tet and chloroform) 
it would be a lot safer. We don't typically allow chloroform in our lab 
because the TLV's is quite low. 90% ethanol (for the ethoxy- or 
methoxy-silane versions of OTS) works quite well for SAM's.

The safer versions of OTS are available through United Chemical 
Technologies. It's a little more expensive than the trichlorosilane, but 
a lot safer and more reproducible. If you would like to try out the 
safer protocols let me know and we can provide them. Or, you can contact 
UCT -- the technical service people are extremely knowledgeable about SAM's.

If you really need this specific version, let's discuss it.



Sora Kim wrote:

> Dear Mary,
> I am the student who asked how to bring in new chemicals from outside 
> last week.
> I am writing up a proposal, but I don ’ t know what kind of 
> information that I need to add for storage and disposal sections.
> Also, I don ’ t know how much I have to describe in detail.
> You are much more experienced than I am, so I want to ask you some help.
> Can I see you this afternoon? I am available from 1pm to 4:30pm . If 
> you let me know when you are free, I can drop by your office.
> Thanks!
> Sora Kim
> p.s. The attached file is the proposal that I am writing up.

Mary X. Tang, Ph.D.
Stanford Nanofabrication Facility
CIS Room 136, Mail Code 4070
Stanford, CA  94305
mtang at

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