title: Equilibrium interaction of solid surfaces across a polymer melt.
abstract: Forces across polymer melts are poorly understood despite their importance for adhesion and fabricating composite materials. Using an atomic force microscope (AFM), this interaction was measured for poly(dimethyl siloxane) (PDMS). The structure of the polymer at the surface changed during the first approximately 10 h. Afterward, short-range attractive forces were observed with short-chain PDMS (M(w) = 4200 g/mol). Using PDMS with a molecular weight (M(w) = 18 000 g/mol) above the entanglement limit, we measured a monotonically decaying repulsive force, which indicates that a quasi-immobilized layer had formed at the solid surface. Due to the small radius of curvature of the tip, forces could be measured in equilibrium.
authors.affiliation: Max-Planck-Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany.
authors.forename: Gexiao
authors.initials: G
authors.lastname: Sun
authors.forename: Michael
authors.initials: M
authors.lastname: Kappl
authors.forename: Tadeusz
authors.initials: T
authors.lastname: Pakula
authors.forename: Kurt
authors.initials: K
authors.lastname: Kremer
authors.forename: Hans-Jürgen
authors.initials: HJ
authors.lastname: Butt
mesh_terms: D004129:Dimethylpolysiloxanes / Q000737:chemistry*; D018625:Microscopy, Atomic Force / Q000379:methods; D008970:Molecular Weight; D012680:Sensitivity and Specificity; D013499:Surface Properties
chemical_list: D004129:Dimethylpolysiloxanes