Use of Self-Assembling Monolayers to Control Interface Bonding in a Model Study of Interfacial Fracture
The relationships between the extent of interfacial bonding, energy dissipation mechanisms, and fracture toughness in a glassy adhesive/inorganic solid joint are not well understood. We address this subject with a model system involving an epoxy adhesive on a polished silicon wafer containing its native oxide. The extent of interfacial bonding, and the wetting behavior of the epoxy, is varied continuously using self-assembling monolayers (SAMs) of octadecyltrichlorosilane (ODTS). The epoxy interacts strongly with the bare silicon oxide surface, but forms only a very weak interface with the methylated tails of the ODTS monolayer. We examine the fracture behavior of such joints as a function of the coverage of ODTS in the napkin-ring geometry. Various characterization methods are applied to the ODTS-coated surface before application of the epoxy, and to both surfaces after fracture. The fracture data are discussed with respect to the wetting of the liquid epoxy on the ODTS-coated substrates, the locus of failure, and the energy dissipation mechanisms. Our goal is to understand how energy is dissipated during fracture as a function of interface strength.
- Research Organization:
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sandia National Lab. (SNL-CA), Livermore, CA (United States)
- Sponsoring Organization:
- US Department of Energy (US)
- DOE Contract Number:
- AC04-94AL85000
- OSTI ID:
- 4261
- Report Number(s):
- SAND99-0558C; TRN: AH200113%%132
- Resource Relation:
- Conference: Annual Meeting of the Adhesion Society, Panama City, FL (US), 02/19/1999--02/24/1999; Other Information: PBD: 5 Mar 1999
- Country of Publication:
- United States
- Language:
- English
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