Sacrificial bonds and hidden length: unraveling molecular mesostructures in tough materials.
Sacrificial bonds and hidden length in structural molecules and composites have been found to greatly increase the fracture toughness of biomaterials by providing a reversible, molecular-scale energy-dissipation mechanism. This mechanism relies on the energy, of order 100 eV, needed to reduce entropy and increase enthalpy as molecular segments are stretched after being released by the breaking of weak bonds, called sacrificial bonds. This energy is relatively large compared to the energy needed to break the polymer backbone, of order a few eV. In many biological cases, the breaking of sacrificial bonds has been found to be reversible, thereby additionally providing a "self-healing" property to the material. Due to the nanoscopic nature of this mechanism, single molecule force spectroscopy using an atomic force microscope has been a useful tool to investigate this mechanism. Especially when investigating natural molecular constructs, force versus distance curves quickly become very complicated. In this work we propose various types of sacrificial bonds, their combination, and how they appear in single molecule force spectroscopy measurements. We find that by close analysis of the force spectroscopy curves, additional information can be obtained about the molecules and their bonds to the native constructs.
Fantner
Georg E
GE
Department of Physics, University of California at Santa Barbara, Santa Barbara, California 93106, USA. fantner@physics.ucsb.edu
Oroudjev
Emin
E
Schitter
Georg
G
Golde
Laura S
LS
Thurner
Philipp
P
Finch
Marquesa M
MM
Turner
Patricia
P
Gutsmann
Thomas
T
Morse
Daniel E
DE
Hansma
Helen
H
Hansma
Paul K
PK
D053674:Aggrecans; D000538:Aluminum Silicates / Q000737:chemistry; D001696:Biomechanical Phenomena; D011508:Chondroitin Sulfate Proteoglycans / Q000737:chemistry*; D003198:Computer Simulation; D016326:Extracellular Matrix Proteins / Q000737:chemistry*; D005983:Glutens / Q000737:chemistry*; D006820:Hyaluronic Acid / Q000737:chemistry*; D006860:Hydrogen Bonding; D037181:Lectins, C-Type / Q000737:chemistry*; D008956:Models, Chemical
D053674:Aggrecans; D000538:Aluminum Silicates; D011508:Chondroitin Sulfate Proteoglycans; D016326:Extracellular Matrix Proteins; D037181:Lectins, C-Type; D005983:Glutens; D006820:Hyaluronic Acid; C011934:mica