title: Direct Measurement of the Critical Pore Size in a Model Membrane.
abstract: We study pore nucleation in a model membrane system, a freestanding polymer film. Nucleated pores smaller than a critical size close, while pores larger than the critical size grow. Holes of varying size were purposefully prepared in liquid polymer films, and their evolution in time was monitored using optical and atomic force microscopy to extract a critical radius. The critical radius scales linearly with film thickness for a homopolymer film. The results agree with a simple model which takes into account the energy cost due to surface area at the edge of the pore. The energy cost at the edge of the pore is experimentally varied by using a lamellar-forming diblock copolymer membrane. The underlying molecular architecture causes increased frustration at the pore edge resulting in an enhanced cost of pore formation.
authors.affiliation: Department of Physics & Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada.
authors.forename: Mark
authors.initials: M
authors.lastname: Ilton
authors.affiliation: Department of Physics & Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada.
authors.forename: Christian
authors.initials: C
authors.lastname: DiMaria
authors.affiliation: Department of Physics & Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada.|Laboratoire de Physico-Chimie Théorique, UMR CNRS Gulliver 7083, ESPCI ParisTech, PSL Research University, 75005 Paris, France.
authors.forename: Kari
authors.initials: K
authors.lastname: Dalnoki-Veress
mesh_terms: D008566:Membranes; D018625:Microscopy, Atomic Force; D008962:Models, Theoretical; D011108:Polymers; D013499:Surface Properties
chemical_list: D011108:Polymers