Dear all,
I'm performing colloidal syntheses of Si and Ge nano-particles (NPs).
Lately most of my result (XRD, EELS, Raman) are strongly effected by the presence of Nickel in my solution. The Ni come from the thermocouple i've been using.
I'm performing a standard hot injection synthesis protocol with a Schlenck line to work in oxygen-free atmosphere.
At first planning ahead of the problem we started the synthesis with a fretted glass jacket inserted in a 3 neck round bottom flask where to stick the TC in an inert solvent, but this has been troublesome for the accuracy of the temperature reading, given the different heat capacity of the 2 solvents.
Do any of you had a similar problem, how would you prevent the thermocouple to contaminate the synthesis?
Looking forward your answer and do not hesitate to contact me if interested.
Best
Bruno
Dear Abdullah Hasan Jabbar عبدالله حسن جبار ,
I just realize i forgot to mentio that the syntheses are carred out in the range 200-300°C
Dear Bruno,
and what's about Pt 100 sensor or something like that. There are many covers available.
I won't tell a the name of a special manufacturer here;
therefore please 'google' for "ceramic pt100 sensor".
Ceramic covered thermo couples are also available.
Please google for.
Good luck
Dear Gerhard Martens,
Thanks a lot for this suggestion!
It seems worthy to give these sensor a try.
Use glass (quartz) finger for thermocouple, and fill it with heat-transfer fluid ( silicon oil, for instance) . NS14 + Teflon sleeve is usual interface for bulb inlet.
Dear Andrei Rogoza,
Thanks for the answer.
we already had a glass finger, but it wasn't working that good, i'll try with ceramics sleeves.
Do you have any feedback on this?
Glass is some kind of ceramics so results will be similar for ceramic sleeves. Exclusion are rare : SiC and BeO for example, have much higher thermal conductivity
Air in finger is bad heat conductor, and TC have small contact surface. Thermal transfer fluid in finger allow to avoid such problem but temperature response time will be longer (~0.5-1s) rather than in the case of direct placement of TC in reaction media.
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