title: Formation of defect-free latex films on porous fiber supports.
abstract: We present here the creation of a defect-free polyvinylidene chloride barrier layer on the lumen-side of a hollow fiber sorbent. Hollow fiber sorbents have previously been shown to be promising materials for enabling low-cost CO(2) capture, provided a defect-free lumen-side barrier layer can be created. Film experiments examined the effect of drying rate, latex age, substrate porosity (porous vs nonporous), and substrate hydrophobicity/hydrophilicity. Film studies show that in ideal conditions (i.e., slow drying, fresh latex, and smooth nonporous substrate), a defect-free film can be formed, whereas the other permutations of the variables investigated led to defective films. These results were extended to hollow fiber sorbents, and despite using fresh latex and relatively slow drying conditions, a defective lumen-side layer resulted. XRD and DSC indicate that polyvinylidene chloride latex develops crystallinity over time, thereby inhibiting proper film formation as confirmed by SEM and gas permeation. This and other key additional challenges associated with the porous hollow fiber substrate vs the nonporous flat substrate were overcome. By employing a toluene-vapor saturated drying gas (a swelling solvent for polyvinylidene chloride) a defect-free lumen-side barrier layer was created, as investigated by gas and water vapor permeation.
authors.affiliation: School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 778 Atlantic Drive NW, Atlanta, Georgia 30332-0100, United States. ryan.lively@chbe.gatech.edu
authors.forename: Ryan P
authors.initials: RP
authors.lastname: Lively
authors.forename: Joshua A
authors.initials: JA
authors.lastname: Mysona
authors.forename: Ronald R
authors.initials: RR
authors.lastname: Chance
authors.forename: William J
authors.initials: WJ
authors.lastname: Koros
mesh_terms: D000327:Adsorption; D002152:Calorimetry, Differential Scanning; D002245:Carbon Dioxide / Q000737:chemistry; D057927:Hydrophobic and Hydrophilic Interactions; D007840:Latex / Q000737:chemistry*; D011143:Polyvinyl Chloride / Q000031:analogs & derivatives / Q000737:chemistry; D016062:Porosity; D014961:X-Ray Diffraction
chemical_list: D007840:Latex; D002245:Carbon Dioxide; C029547:polyvinylidene chloride; D011143:Polyvinyl Chloride