Unusually Large Young's Moduli of Amino Acid Molecular Crystals. Issue 46 (16th September 2015)

• Record Type: Journal Article
• Authors: Azuri, Ido; Meirzadeh, Elena; Ehre, David; Cohen, Sidney R.; Rappe, Andrew M.; Lahav, Meir; Lubomirsky, Igor; Kronik, Leeor
• Is Part Of: Angewandte Chemie international edition. Volume 54:Issue 46(2015)
• Page Start: 13566
• Page End: 13570
• Publication Date: 2015-09-16
• Subjects: amino acids -- crystallography -- density functional calculations -- mechanical properties -- Young's modulus; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201505813
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Young's moduli of selected amino acid molecular crystals were studied both experimentally and computationally using nanoindentation and dispersion‐corrected density functional theory. The Young modulus is found to be strongly facet‐dependent, with some facets exhibiting exceptionally high values (as large as 44 GPa). The magnitude of Young's modulus is strongly correlated with the relative orientation between the underlying hydrogen‐bonding network and the measured facet. Furthermore, we show computationally that the Young modulus can be as large as 70–90 GPa if facets perpendicular to the primary direction of the hydrogen‐bonding network can be stabilized. This value is remarkably high for a molecular solid and suggests the design of hydrogen‐bond networks as a route for rational design of ultra‐stiff molecular solids. Abstract : Exceptionally stiff amino acid crystals : Young's moduli of five prototypical amino acid crystals were determined using a combination of computational and experimental studies. The simple molecular solids possess surprisingly large Young's moduli, suggesting that the mechanical stiffness of the crystals may be determined by the orientation of the intermolecular hydrogen bond networks.