Warming up for mechanosynthesis - temperature development in ball mills during synthesis
Hannes Kulla1, Manuel Wilke, Franziska Fischer
1BAM Federal Institute for Materials Research and Testing, Richard-Willstätter-Str. 11, 12489, Berlin, Germany. franziska.emmerling@bam.de.
Chemical Communications (Cambridge, England)
|January 19, 2017
Summary
This study directly measured milling temperatures using Raman spectroscopy. Results show low mechanical heat but significant reaction heat, excluding high-temperature theories for soft matter synthesis.
Area of Science:
- Materials Science
- Chemistry
- Process Engineering
Background:
- Milling is a common technique for synthesizing materials.
- Understanding temperature evolution during milling is crucial for controlling reaction pathways and product properties.
- Previous theories suggested high temperatures (magma plasma, hot spot) might occur during milling.
Purpose of the Study:
- To directly measure temperature changes during soft matter milling.
- To differentiate temperature contributions from mechanical impact versus chemical reactions.
- To evaluate the validity of high-temperature theories in soft matter milling.
Main Methods:
- Direct temperature measurement using thermocouples.
- In situ Raman spectroscopy for chemical analysis during milling.
- Combined analysis of thermal and spectroscopic data.
Main Results:
- Mechanical impact resulted in a minor temperature increase.
- Significant temperature rises were observed, directly correlated with reaction exotherms.
- The measured temperature profiles do not support high-temperature phenomena like magma plasma or hot spots.
Conclusions:
- Soft matter milling involves distinct thermal contributions from mechanical and reaction processes.
- Reaction heat is the dominant factor for temperature increase in these syntheses.
- High-temperature theories are not applicable to the studied soft matter milling conditions.
