title: Effects of polar solvents on the mechanical behavior of fish scales.
abstract: Fish scales are unique structural materials that serve as a form of natural armor. In this investigation the mechanical behavior of scales from the Cyprinus carpio was evaluated after exposure to a polar solvent. Uniaxial tensile and tear tests were conducted on specimens prepared from the scales of multiple fish extracted from near the head, middle and tail regions, and after exposure to ethanol for periods from 0 to 24h. Submersion in ethanol caused instantaneous changes in the tensile properties regardless of anatomical site, with increases in the elastic modulus, strength and modulus of toughness exceeding 100%. The largest increase in properties overall occurred in the elastic modulus of scales from the tail region and exceeded 200%. Although ethanol treatment had significant effect on the tensile properties, it had limited influence on the tear resistance. The contribution of ethanol to the mechanical behavior appears to be derived from an increase in the degree of interpeptide hydrogen-bonding of the collagen molecules. Spatial variations in the effects of ethanol exposure on the mechanical behavior arise from the differences in degree of mineralization and lower mineral content in scales of the tail region.
authors.affiliation: Department of Materials Science and Engineering, University of Washington, Seattle, WA, USA.
authors.forename: Sandra
authors.initials: S
authors.lastname: Murcia
authors.affiliation: School of Electrical Engineering and Automation, Anhui University, Hefei, China.
authors.forename: Guihua
authors.initials: G
authors.lastname: Li
authors.affiliation: Department of Materials Science and Engineering, University of Washington, Seattle, WA, USA.
authors.forename: Mobin
authors.initials: M
authors.lastname: Yahyazadehfar
authors.affiliation: Department of Mechanical Engineering, University of Maryland Baltimore County, Baltimore, MD, USA.
authors.forename: Mikaela
authors.initials: M
authors.lastname: Sasser
authors.affiliation: School of Engineering, Universidad Eafit, Medellín, Colombia.
authors.forename: Alex
authors.initials: A
authors.lastname: Ossa
authors.affiliation: Department of Materials Science and Engineering, University of Washington, Seattle, WA, USA. Electronic address: darola@uw.edu.
authors.forename: D
authors.initials: D
authors.lastname: Arola
mesh_terms: D000825:Animal Structures / Q000737:chemistry*; D000818:Animals; D002347:Carps; D000431:Ethanol / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry*
chemical_list: D012997:Solvents; D000431:Ethanol
keywords: Cyprinus carpio; Fish scales; Fracture resistance; Mechanical behavior; Polar solvents