Search results for "Monodisperse"

showing 3 items of 3 documents

Tuneable multicoloured patterns from photonic cross-communication between cholesteric liquid crystal droplets

2014

Monodisperse droplets of planar-aligned cholesteric (N*) liquid crystal exhibit an intriguing capacity for photonic cross-communication, giving rise to colourful patterns that depend sensitively on the N* pitch, droplet positions and illuminated area. The phenomenon results from a combination of omnidirectional selective reflection of N* droplets—which thus act as spherically symmetric self-assembled photonic crystals—and total internal reflection at the continuous phase surface. We outline how the unique optical properties can be employed in numerous applications.

Total internal reflectionMaterials scienceCholesteric liquid crystalbusiness.industryPhysics::OpticsGeneral ChemistryPhysics::Fluid DynamicsOpticsLiquid crystalMonodisperse dropletsMaterials ChemistryOptoelectronicsSelective reflectionPhotonicsbusinessOmnidirectional antennaJ. Mater. Chem. C
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Syntheses of TiO2 anatase nanocrystals with controlled size distribution. Influence of the crystallites size on the Raman spectrum and investigation …

2006

The determination of the size and the size distribution of anatase TiO2 nanopowders using Raman spectroscopy is presented. Several synthesis methods (soft chemistry, water-in-oil microemulsion, continuous hydrothermal synthesis) are used in order to control the size (from 3 to 20 nm), shape, phase and size distribution. The shift and width of the anatase Eg peak are often used to obtain the nanoparticles size. Homever, this peak is also sensitive to nonstoichiometry and others parameters. Low-frequency Raman scattering does not suffer from this problem. Size distibutions obtained by Raman spectroscopy and MET micrographs are compared. Finally, in situ Raman spectroscopy is used to study the…

[CHIM.MATE] Chemical Sciences/Material chemistryWater adsorptionAnataseSpectroscopie RamanNanoparticulesChimie douceSpectroscopie Raman basses fréquencesContinuous hydrothermal synthesisMonodisperseIn situ Raman spectroscopyPropriétés de surfaceSoft chemistryLow-frequency Raman spectroscopySynthèse hydrothermale en continu[ CHIM.MATE ] Chemical Sciences/Material chemistryRaman spectroscopySurface propertiesNanoparticlesMonodispersityTiO2Adsorption d'eauSpectroscopie Raman in situ
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Synthesis of Monodisperse Spherical Nanocrystals

2016

Nanoparticles, small units of matter with dimensions in the range 1-100 nm, exhibit many advantageous size-dependent magnetic, electrical, chemical and optical prop- erties, which are not observed at the microscale or bulk. These properties are extremely sensitive to particle size, and thus the ability to produce monodisperse particles is critical. Due to its ease of use and flexibility, precipitation of nanoparticles from solution is one of the most widely used synthesis methods. The main disadvantage of this method is that the relationship between particle growth and system conditions is not fully understood. In practice, the optimal reaction conditions are usually ascertained empirically…

evolution of the nanoparticle size distributionOstwald ripeningFlexibility (engineering)Materials sciencenanoparticle growthPrecipitation (chemistry)Dispersitysize focussing and defocussingNanoparticleCrystal growthparticle sizemonodisperse particlessymbols.namesakeNanocrystalChemical physicssymbolsNanoparticlesParticle size
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