title: Microstructures of superhydrophobic plant leaves - inspiration for efficient oil spill cleanup materials.
abstract: The cleanup of accidental oil spills in water is an enormous challenge; conventional oil sorbents absorb large amounts of water in addition to oil and other cleanup methods can cause secondary pollution. In contrast, fresh leaves of the aquatic ferns Salvinia are superhydrophobic and superoleophilic, and can selectively absorb oil while repelling water. These selective wetting properties are optimal for natural oil absorbent applications and bioinspired oil sorbent materials. In this paper we quantify the oil absorption capacity of four Salvinia species with different surface structures, water lettuce (Pistia stratiotes) and Lotus leaves (Nelumbo nucifera), and compare their absorption capacity to artificial oil sorbents. Interestingly, the oil absorption capacities of Salvinia molesta and Pistia stratiotes leaves are comparable to artificial oil sorbents. Therefore, these pantropical invasive plants, often considered pests, qualify as environmentally friendly materials for oil spill cleanup. Furthermore, we investigated the influence of oil density and viscosity on the oil absorption, and examine how the presence and morphology of trichomes affect the amount of oil absorbed by their surfaces. Specifically, the influence of hair length and shape is analyzed by comparing different hair types ranging from single trichomes of Salvinia cucullata to complex eggbeater-shaped trichomes of Salvinia molesta to establish a basis for improving artificial bioinspired oil absorbents.
authors.affiliation: Karlsruhe Institute of Technology, Institute of Microstructure Technology, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Zeiger
authors.forename: Isabelle C
authors.initials: IC
authors.lastname: Rodrigues da Silva
authors.forename: Matthias
authors.initials: M
authors.lastname: Mail
authors.forename: Maryna N
authors.initials: MN
authors.lastname: Kavalenka
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Barthlott
authors.forename: Hendrik
authors.initials: H
authors.lastname: Hölscher
mesh_terms: D059001:Aquatic Organisms / Q000648:ultrastructure*; D029064:Araceae / Q000648:ultrastructure; D052918:Environmental Restoration and Remediation / Q000379:methods*; D029624:Ferns / Q000648:ultrastructure*; D057927:Hydrophobic and Hydrophilic Interactions; D031653:Nelumbo / Q000648:ultrastructure; D059392:Petroleum Pollution; D018515:Plant Leaves / Q000737:chemistry / Q000648:ultrastructure*; D014783:Viscosity; D014867:Water; D014876:Water Pollution
chemical_list: D014867:Water