title: Enhanced Barrier Performance of Engineered Paper by Atomic Layer Deposited Al2O3 Thin Films.
abstract: Surface modification of cellulosic paper is demonstrated by employing plasma assisted atomic layer deposition. Al2O3 thin films are deposited on paper substrates, prepared with different fiber sizes, to improve their barrier properties. Thus, a hydrophobic paper is created with low gas permeability by combining the control of fiber size (and structure) with atomic layer deposition of Al2O3 films. Papers are prepared using Kraft softwood pulp and thermomechanical pulp. The cellulosic wood fibers are refined to obtain fibers with smaller length and diameter. Films of Al2O3, 10, 25, and 45 nm in thickness, are deposited on the paper surface. The work demonstrates that coating of papers prepared with long fibers efficiently reduces wettability with slight enhancement in gas permeability, whereas on shorter fibers, it results in significantly lower gas permeability. Wettability studies on Al2O3 deposited paper substrates have shown water wicking and absorption over time only in papers prepared with highly refined fibers. It is also shown that there is a certain fiber size at which the gas permeability assumes its minimum value, and further decrease in fiber size will reverse the effect on gas permeability.
authors.affiliation: Department of Chemical and Biological Engineering, University of British Columbia , 2360 East Mall, Vancouver, British Columbia V6T1Z3, Canada.
authors.forename: Mehr Negar
authors.initials: MN
authors.lastname: Mirvakili
authors.affiliation: Department of Chemical Engineering, Delft University of Technology , Julianalaan 136, 2628 BL Delft, The Netherlands.
authors.forename: Hao
authors.initials: H
authors.lastname: Van Bui
authors.affiliation: Department of Chemical Engineering, Delft University of Technology , Julianalaan 136, 2628 BL Delft, The Netherlands.
authors.forename: J Ruud
authors.initials: JR
authors.lastname: van Ommen
authors.affiliation: Department of Chemical and Biological Engineering, University of British Columbia , 2360 East Mall, Vancouver, British Columbia V6T1Z3, Canada.
authors.forename: Savvas G
authors.initials: SG
authors.lastname: Hatzikiriakos
authors.affiliation: Department of Chemical and Biological Engineering, University of British Columbia , 2360 East Mall, Vancouver, British Columbia V6T1Z3, Canada.
authors.forename: Peter
authors.initials: P
authors.lastname: Englezos
keywords: Al2O3 ALD; cellulose paper; hydrophobicity; plasma-assisted atomic layer deposition; pulp refining; water vapor transmission rate