||Surface energy of strained amorphous solids
Schulman, Rafael D. ,
Trejo, Miguel ,
Salez, Thomas ,
Raphael, ElieDalnoki-Veress, Kari
p.1711 , 2017-11-28 , Cornell University Library
Surface stress and surface energy are fundamental quantities which characterize the interface between two materials. Although these quantities are identical for interfaces involving only fluids, the Shuttleworth effect demonstrates that this is not the case for most interfaces involving solids, since their surface energies change with strain. Crystalline materials, e.g. metallic and ionic, are known to have strain dependent surface energies, but in amorphous materials, such as polymeric glasses and elastomers, the strain dependence is debated due to a dearth of direct measurements. Here, we utilize contact angle measurements on strained glassy and elastomeric solids in order to address this matter. We show conclusively that interfaces involving polymeric glasses exhibit strain dependent surface energies, and give strong evidence for the absence of such a dependence in the case of incompressible elastomers. The results provide fundamental insight into our basic understanding of the interfaces of amorphous solids, and demonstrate further that the polarity of the contacting liquid plays a crucial role.