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Atomic force microscopy investigation of the adhesion between a single polymer sphere and a flat surface

Journal Article


Abstract


  • Adhesional interaction forces between a single 5 μm radius polystyrene sphere and an atomically smooth mica surface have been measured using an atomic force microscope. The pull-off force was determined as a function of two factors: the contact time between the surfaces at a constantmaximum applied load and the applied load. Careful analysis of the data in the contact zone revealed that the polystyrene underwent significant non-elastic deformations when the contact times were more than 10 s. These data were rationalized on the basis of viscoelastic deformation of thesphere as the load was applied; the loads used here exceeded the elastic limit for polystyrene. It appears from the data that the exact modelling of the sphere deformation is a complex problem involving both surface asperities and bulk material collapse. The pull-off force was seen to increaseboth with increasing applied load and with longer contact time. Calculation of the applied forces indicated that plastic deformation was likely, at least at the slower loading rates, and the relationship between the pull-off force and the applied load (P) agreed with a P1/2 dependenceas suggested by Maugis and Pollock. It was concluded that at the applied loads used here, the surface asperities were effectively 'squeezed out' resulting in an apparent smooth sphere contact. © VSP 1998.

Publication Date


  • 1998

Citation


  • Biggs, S., & Spinks, G. (1998). Atomic force microscopy investigation of the adhesion between a single polymer sphere and a flat surface. Journal of Adhesion Science and Technology, 12(5), 461-478. doi:10.1163/156856198X00164

Scopus Eid


  • 2-s2.0-0031650923

Start Page


  • 461

End Page


  • 478

Volume


  • 12

Issue


  • 5

Abstract


  • Adhesional interaction forces between a single 5 μm radius polystyrene sphere and an atomically smooth mica surface have been measured using an atomic force microscope. The pull-off force was determined as a function of two factors: the contact time between the surfaces at a constantmaximum applied load and the applied load. Careful analysis of the data in the contact zone revealed that the polystyrene underwent significant non-elastic deformations when the contact times were more than 10 s. These data were rationalized on the basis of viscoelastic deformation of thesphere as the load was applied; the loads used here exceeded the elastic limit for polystyrene. It appears from the data that the exact modelling of the sphere deformation is a complex problem involving both surface asperities and bulk material collapse. The pull-off force was seen to increaseboth with increasing applied load and with longer contact time. Calculation of the applied forces indicated that plastic deformation was likely, at least at the slower loading rates, and the relationship between the pull-off force and the applied load (P) agreed with a P1/2 dependenceas suggested by Maugis and Pollock. It was concluded that at the applied loads used here, the surface asperities were effectively 'squeezed out' resulting in an apparent smooth sphere contact. © VSP 1998.

Publication Date


  • 1998

Citation


  • Biggs, S., & Spinks, G. (1998). Atomic force microscopy investigation of the adhesion between a single polymer sphere and a flat surface. Journal of Adhesion Science and Technology, 12(5), 461-478. doi:10.1163/156856198X00164

Scopus Eid


  • 2-s2.0-0031650923

Start Page


  • 461

End Page


  • 478

Volume


  • 12

Issue


  • 5