title: Spacing of Seeded and Spontaneous Streaks during Convective Deposition.
abstract: Convective deposition is widely used to deposit a highly ordered and uniform layer of monosized particles from solution by drawing the particles into an advancing thin film that uses capillary forces to define their local orientation. This process is often plagued by the formation of streaks, the regions where particles accumulate due to a local flux inhomogeneity. Flow occurs in the direction orthogonal to the deposition direction and parallel to the substrate near the streaks due to enhanced evaporation where particles have accumulated. This study investigates the formation of streaks nucleated from seeds or defects having prescribed dimensions and spacing across the substrate. The formation and spacing of both seeded and spontaneous streaks are characterized and were observed to be roughly dictated by the suspending fluid capillary length. Thus, spontaneously forming streaks can be suppressed by reducing the spacing to less than twice the critical length. Likewise, the conditions for maximum density or minimal spacing of streaks are also shown.
authors.affiliation: Naperville North High School , 899 N. Mill Street, Naperville, Illinois 60563, United States.|Department of Chemical and Biomolecular Engineering, Lehigh University , 111 Research Drive, Bethlehem, Pennsylvania 18015, United States.
authors.forename: Jane M
authors.initials: JM
authors.lastname: Boettcher
authors.affiliation: Department of Chemical and Biomolecular Engineering, Lehigh University , 111 Research Drive, Bethlehem, Pennsylvania 18015, United States.
authors.forename: Midhun
authors.initials: M
authors.lastname: Joy
authors.affiliation: Department of Chemical and Biomolecular Engineering, Lehigh University , 111 Research Drive, Bethlehem, Pennsylvania 18015, United States.
authors.forename: Kedar
authors.initials: K
authors.lastname: Joshi
authors.affiliation: Department of Chemical and Biomolecular Engineering, Lehigh University , 111 Research Drive, Bethlehem, Pennsylvania 18015, United States.
authors.forename: Tanyakorn
authors.initials: T
authors.lastname: Muangnapoh
authors.affiliation: Department of Chemical and Biomolecular Engineering, Lehigh University , 111 Research Drive, Bethlehem, Pennsylvania 18015, United States.
authors.forename: James F
authors.initials: JF
authors.lastname: Gilchrist