Deformation and adhesion of elastomer poly(dimethylsiloxane) colloidal AFM probes.
We report on the synthesis and characterization of elastomer colloidal AFM probes. Poly(dimethylsiloxane) microparticles, obtained by water emulsification and cross-linking of viscous prepolymers, are glued to AFM cantilevers and used for contact mechanics investigations on smooth substrates: in detail cyclic loading-unloading experiments are carried on ion-sputtered mica, the deformation rate and dwell time being separately controlled. We analyze load-penetration curves and pull-off forces with models due respectively to Zener; Maugis and Barquins; and Greenwood and Johnson and account for bulk creep, interfacial viscoelasticity, and structural rearrangements at the polymer-substrate interface. A good agreement is found between experiments and theory, with a straightforward estimation of colloidal probes' material parameters. We suggest the use of such probes for novel contact mechanics experiments involving fully reversible deformations at the submicrometer scale.
Buzio
Renato
R
Nanomed Labs, ABC-Advanced Biotechnology Center, Largo R. Benzi 10, Genova, Italy. buzio@fisica.unige.it
Bosca
Alessandro
A
Krol
Silke
S
Marchetto
Diego
D
Valeri
Sergio
S
Valbusa
Ugo
U
D000268:Adhesiveness; D003102:Colloids; D004129:Dimethylpolysiloxanes / Q000737:chemistry*; D020724:Elastomers / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D008956:Models, Chemical
D003102:Colloids; D004129:Dimethylpolysiloxanes; D020724:Elastomers