title: Enhanced transport into and out of dead-end pores.
abstract: Dead-end micro- and nanoscale channels are ubiquitous in nature and are found in geological and biological systems subject to frequent disruptions. Achieving fluid flows in them is not possible through conventional pressure-driven mechanisms. Here we show that chemically driven convective flows leading to transport in and out of dead-end pores can occur by the phenomenon of "transient diffusioosmosis". The advective velocity depends on the presence of an in situ-generated transient ion gradient and the intrinsic charge on the pore wall. The flows can reach speeds of 50 μm/s and cause extraction of otherwise-trapped materials. Our results illustrate that chemical energy, in the form of a transient salt gradient, can be transduced into mechanical motion with the pore wall acting as the pump. As discussed, the phenomena may underlie observed transport in many geological and biological systems involving tight or dead-end micro- and nanochannels.
authors.affiliation: Department of Chemical Engineering, and ‡Department of Chemistry, The Pennsylvania State University , University Park, Pennsylvania 16802, United States.
authors.forename: Abhishek
authors.initials: A
authors.lastname: Kar
authors.forename: Tso-Yi
authors.initials: TY
authors.lastname: Chiang
authors.forename: Isamar
authors.initials: I
authors.lastname: Ortiz Rivera
authors.forename: Ayusman
authors.initials: A
authors.lastname: Sen
authors.forename: Darrell
authors.initials: D
authors.lastname: Velegol
mesh_terms: D057446:Hydrodynamics; D008962:Models, Theoretical; D058608:Nanopores; D012965:Sodium Chloride / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D014867:Water; D012965:Sodium Chloride
keywords: dead-end pore; diffusioosmosis; diffusiophoresis; mixing; transient ion gradient