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Probing stress induced phase transformation in aspirin polymorphs using Raman spectroscopy enabled nanoindentation
Praveena Manimunda1, S A Syed Asif1, Manish Kumar Mishra2
1Bruker Nano Surfaces, Eden Prairie, Minneapolis, Minnesota, USA. praveena.manimunda@gmail.com.
Chemical Communications (Cambridge, England)
|July 17, 2019
Summary
Nanoindentation can induce stress-driven polymorphic transformations in molecular crystals like aspirin. This study reveals micro-domain formation in aspirin form II crystals during nanoindentation, uncovering new insights into crystal mechanical behavior.
Area of Science:
- Materials Science
- Crystallography
- Solid State Chemistry
Background:
- Nanoindentation is a standard technique for measuring mechanical properties of molecular crystals.
- The potential for stress-induced polymorphic transformations during nanoindentation remains largely uninvestigated.
Purpose of the Study:
- To investigate stress-induced polymorphic transformations in aspirin during nanoindentation.
- To explore the formation of micro-domains in aspirin polymorphs under indentation stress.
Main Methods:
- Utilized a spatially synchronized Raman spectroscopy and nanoindentation technique.
- Employed an accelerated property mapping technique to generate spatial hardness maps.
Main Results:
- Successfully probed indentation-induced polymorphic transformation in aspirin polymorphs.
- Observed the formation of micro-domains within aspirin form II crystals.
Conclusions:
- Nanoindentation can induce significant changes in the polymorphic structure of molecular crystals.
- The findings highlight the importance of considering stress-induced transformations in mechanical property measurements of crystalline materials.
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