Generating in-Plane Orientational Order in Multilayer Films Prepared by Spray-Assisted Layer-by-Layer Assembly
| Autor: | Tom Lindström, Rebecca Blell, Xiaofeng Lin, Matthias Pauly, Gero Decher, Olivier Felix, Mikael Ankerfors |
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| Rok vydání: | 2016 |
| Předmět: |
Surface (mathematics)
Yield (engineering) Materials science Birefringence Layer by layer Aucun General Engineering General Physics and Astronomy 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Spray nozzle Crystallography chemistry.chemical_compound chemistry parasitic diseases General Materials Science Cellulose Composite material 0210 nano-technology Anisotropy Nanoscopic scale |
| Zdroj: | ACS Nano. 11:84-94 |
| ISSN: | 1936-086X 1936-0851 |
| DOI: | 10.1021/acsnano.6b04191 |
| Popis: | We present a simple yet efficient method for orienting cellulose nanofibrils in layer-by-layer assembled films through spray-assisted alignment. While spraying at 90° against a receiving surface produces films with homogeneous in-plane orientation, spraying at smaller angles causes a macroscopic directional surface flow of liquid on the receiving surface and leads to films with substantial in-plane anisotropy when nanoscale objects with anisotropic shapes are used as components. First results with cellulose nanofibrils demonstrate that such fibrils are easily aligned by grazing incidence spraying to yield optically birefringent films over large surface areas. We show that the cellulosic nanofibrils are oriented parallel to the spraying direction and that the orientational order depends for example on the distance of the receiving surface from the spray nozzle. The alignment of the nanofibrils and the in-plane anisotropy of the films were independently confirmed by atomic force microscopy, optical microscopy between crossed polarizers, and the ellipsometric determination of the apparent refractive index of the film as a function of the in-plane rotation of the sample with respect to the plane of incidence of the ellipsometer. |
| Databáze: | OpenAIRE |
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