Silicon powder

*1: See particle size distribution of the original sample with our ANALYSETTE 22 NanoTec (meas. no. 596) on separate page.

*2: For grinding, we had to add 11,3g of (e.g. Fluka D200) silicon oil.

A grinding in alcohol is not recommended because of a chemical reaction (causes a formation of high pressure during grinding with lower carbon chained alcohols). A leakage will happen immediately.

*3: To avoid overpressure, we ground the sample in steps of 3 minutes, followed by 7 minutes of programmed pausing time.

A longer grinding didn’t lead to a better endfineness. So the grinding has been aborted after totally 30 minutes.

It has shown that a grinding with silicon oil is only sub optimal. Small particles use to flock without an additional use of a proper Tenside. Formally, we ground one sample of pure silicon with Octodecene to d50 < 100nm after 120min of grinding (see additionally attached grinding report / you can also find all the report on our homepage). By using this kind of solvent with a high boiling point (315°C) , the grinding process has been optimal.

*4: See particle size distribution after 15 minutes of grinding with our ANALYSETTE 22 NanoTec (meas. no. 596) on separate page. It has also been observed that a fine film of silicon was covering the glass surface. Eventually smaller particles as shown on the print out have been lost that way. This might be caused by the usage of a improper Tenside (we tried diluting with a drop of Tween 80 and Sympatens SHO 400).For dilution, Span 80 (not in our laboratory equipment anymore) should be better.