Nematic order drives macroscopic patterns of graphene oxide in drying drops

We report on a series of experiments on large-area ordered patterns of graphene oxide on solid substrates deposited from aqueous dispersions by directed drop evaporation. The aqueous dispersion of graphene oxide exhibits phase transitions from isotropic to liquid crystalline nematic phases via a bip...

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Veröffentlicht in:Langmuir : the ACS journal of surfaces and colloids. - 1992. - 30(2014), 48 vom: 09. Dez., Seite 14631-7
1. Verfasser: Luo, Yanqi (VerfasserIn)
Weitere Verfasser: Braggin, Gregory A, Olson, Grant T, Stevenson, Alexandra R, Ruan, Wanda L, Zhang, Shanju
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2014
Zugriff auf das übergeordnete Werk:Langmuir : the ACS journal of surfaces and colloids
Schlagworte:Journal Article
Beschreibung
Zusammenfassung:We report on a series of experiments on large-area ordered patterns of graphene oxide on solid substrates deposited from aqueous dispersions by directed drop evaporation. The aqueous dispersion of graphene oxide exhibits phase transitions from isotropic to liquid crystalline nematic phases via a biphasic region with increasing concentration. In the single nematic phase, schlieren textures accompanied by oriented bands are frequent. Drying of drops in each phase results in deposition covering the whole drop base. The dynamic process of drop drying is analyzed based on the weight loss, radius change, and texture change over time. It is found that the radial bands develop in the nematic drops in the vicinity of the receding of the contact line and subsequently transform into birefringent stripes after drying. Study into the structure and morphology of the stripes reveals anisotropic wrinkling of graphene oxide sheets. The nature of stripe orientation is strongly dependent on the local nematic order at the dewetting water front. Various macroscopic patterns with different stripe orientations including radial spokes, spider webs, and parallel stripes have been generated by tuning the nematic order of drops
Beschreibung:Date Completed 02.07.2015
Date Revised 09.12.2014
published: Print-Electronic
Citation Status PubMed-not-MEDLINE
ISSN:1520-5827
DOI:10.1021/la503670e