Non-resonant light scattering in dispersions of 2D nanosheets.

ABSTRACT: Extinction spectra of nanomaterial suspensions can be dominated by light scattering, hampering quantitative spectral analysis. No simple models exist for the wavelength-dependence of the scattering coefficients in suspensions of arbitrary-sized, high-aspect-ratio nanoparticles. Here, suspensions of BN, talc, GaS, Ni(OH)₂, Mg(OH)₂ and Cu(OH)₂ nanosheets are used to explore non-resonant scattering in wide-bandgap 2D nanomaterials. Using an integrating sphere, scattering coefficient (?) spectra were measured for a number of size-selected fractions for each nanosheet type. Generally, ? scales as a power-law with wavelength in the non-resonant regime: ?(?)?[?/?L?]^-m, where ?L? is the mean nanosheet length. For all materials, the scattering exponent, m, forms a master-curve, transitioning from m?=?4 to m?=?2, as the characteristic nanosheet area increases, indicating a transition from Rayleigh to van der Hulst scattering. In addition, once material density and refractive index are factored out, the proportionality constant relating ? to [?/?L?]^-m, also forms a master-curve when plotted versus ?L?.

SUBMITTER: Harvey A 

PROVIDER: S-EPMC6212482 | biostudies-literature | 2018 Nov

REPOSITORIES: biostudies-literature