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Publikācija: Counterintuitive Increase in Optical Scattering Efficiency during Negentropic Orientational Transition in Dilute ZnO Nanowire Suspensions

Publication Type Scientific article indexed in SCOPUS or WOS database
Funding for basic activity Unknown
Defending: ,
Publication language English (en)
Title in original language Counterintuitive Increase in Optical Scattering Efficiency during Negentropic Orientational Transition in Dilute ZnO Nanowire Suspensions
Field of research 2. Engineering and technology
Sub-field of research 2.5 Materials engineering
Authors Andris Šutka
Martin Timusk
Martin Järvekülg
Ardi Loot
Urmas Joost
Rünno Lõhmus
Kristjan Saal
Keywords ZnO Nanowires, solvothermal synthesis, Smart Window, PDMS, Colloids, suspension, composite materials
Abstract We demonstrate experimentally that the electrophoretic manipulation of a ZnO nanowire (NW) suspension in polydimethylsiloxane (PDMS) causes a remarkable change in optical scattering. Counterintuitively, as an electric field is applied to the suspension and a negentropic orientational transition from a chaotically oriented state to a partially ordered (aligned) state is induced, the geometrical cross-section of the particles decreases whereas the scattering efficiency increases significantly, indicating an increase in the scattering cross-section. The alignment of the longer axis of oblong ZnO nanoparticles in the direction of incident light unexpectedly resulted in up to a 40% decrease in transmittance in the middle of the visible spectral range in the case of 150 mm thick composite films with below 0.1 vol% NW concentration. A prepared prototype smart window device exhibited spontaneous restoration of transmittance, persistent electro-optical performance (0% change in contrast after more than 10 cycles), and temporal stability against nanoparticle sedimentation and agglomeration.
DOI: 10.1039/C5RA22448A
Hyperlink: http://pubs.rsc.org/en/content/articlelanding/2015/ra/c5ra22448a#!divAbstract 
Reference Šutka, A., Timusk, M., Järvekülg, M., Loot, A., Joost, U., Lõhmus, R., Saal, K. Counterintuitive Increase in Optical Scattering Efficiency during Negentropic Orientational Transition in Dilute ZnO Nanowire Suspensions. RSC Advances, 2015, Vol.5, pp.104149-104154. Available from: doi:10.1039/C5RA22448A
Additional information Citation count:
ID 21582