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Updated: Sep 29, 2026

Investigating Single Molecule Adhesion by Atomic Force Spectroscopy
Published on: February 27, 2015
Gradient separation of polymers at critical point of adsorption
1DuPont Central Research and Development, Experimental Station, Wilmington, DE 19880-0228, USA. yefim.brun@usa.dupont.com
Abstract:
Theoretical and experimental analysis of interaction polymer chromatography revealed a new mode of polymer separation: gradient elution at the critical point of adsorption (the eluent composition where size-exclusion and adsorption interactions completely compensate each other). This mode allows for molecular-mass-independent separation by chemical composition and/or other structural differences between macromolecules. The isocratic and gradient elution of narrow polydispersity polystyrenes and poly(methylmethacrylates) on reversed- and normal-phase columns confirmed all basic theoretical assumptions and conclusions. The gradient separation of poly(alkylmethacrylate) and poly(alkylacrylate) blends, as well as styrene-butadiene copolymers provided further experimental verification of the theory.
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