title: Gas barrier properties of bio-inspired LAPONITE®-LC polymer hybrid films.
abstract: Bio-inspired LAPONITE® (clay)-liquid crystal (LC) polymer composite materials with high clay fractions (>80%) and a high level of orientation of the clay platelets, i.e. with structural features similar to the ones found in natural nacre, have been shown to exhibit a promising behavior in the context of reduced oxygen transmission. Key characteristics of these bio-inspired composite materials are their high inorganic content, high level of exfoliation and orientation of the clay platelets, and the use of a LC polymer forming the organic matrix in between the LAPONITE® particles. Each single feature may be beneficial to increase the materials gas barrier property rendering this composite a promising system with advantageous barrier capacities. In this detailed study, LAPONITE®/LC polymer composite coatings with different clay loadings were investigated regarding their oxygen transmission rate. The obtained gas barrier performance was linked to the quality, respective LAPONITE® content and the underlying composite micro- and nanostructure of the coatings. Most efficient oxygen barrier properties were observed for composite coatings with 83% LAPONITE® loading that exhibit a structure similar to sheet-like nacre. Further on, advantageous mechanical properties of these LAPONITE®/LC polymer composites reported previously give rise to a multifunctional composite system.
authors.affiliation: University of Konstanz, Physical Chemistry, Universitätsstraße 10, D-78457 Konstanz, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Tritschler
authors.forename: Igor
authors.initials: I
authors.lastname: Zlotnikov
authors.forename: Peter
authors.initials: P
authors.lastname: Fratzl
authors.forename: Helmut
authors.initials: H
authors.lastname: Schlaad
authors.forename: Simon
authors.initials: S
authors.lastname: Grüner
authors.forename: Helmut
authors.initials: H
authors.lastname: Cölfen
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry*; D000818:Animals; D040761:Biomimetic Materials / Q000138:chemical synthesis*; D000077215:Clay; D004058:Diffusion; D005740:Gases / Q000737:chemistry; D008422:Materials Testing; D060734:Nacre / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry*; D010539:Permeability; D011108:Polymers / Q000737:chemistry*; D016062:Porosity; D017640:Silicates / Q000737:chemistry*
chemical_list: D000538:Aluminum Silicates; D005740:Gases; D060734:Nacre; D011108:Polymers; D017640:Silicates; C422409:liquid crystal polymer; C524813:laponite; D010100:Oxygen; D000077215:Clay