Dilution can not be enough I think, because I'm not sure whether it is obtained accurate results or not that colloidal particules exist in the medium.
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DLS methods are good at measuring dispersions, where the Brownian motion of nanoparticles is well manifested. These are usually dilute sols. Lyotropic liquid crystals are not studied by this method. These are not 3D, but 2D nanoobjects. They are studied by small-angle X-ray scattering. For example,
Article Small-angle X-ray scattering of the gadolinium triacetate–un...
Thank you for your support. We use that technic for determination of crystallographic structures i.e cubic, hexagonal or lamelar. Maybe Sem analysis works better to measure particle size.
DLS measurements are based in the diffusion of particles and it will be hindered in very packed systems, so it will show a bigger calculated size than it would be in a diluted system (hindered diffusion means apparent slower particles, so bigger radious as per Stokes-Einstein relation). Also most DLS systems wont be able to measure anything in very packed systems due to too much scattering.
SR-DLS (Spatially Reoslved DLS) can actually circumvent quite a lot of the particle number concentration limits, so you would get the hindered diffusion measurements (which can be useful on itself and/or calibrated against the free diffusing particle size). See the NanoFlowSizer (www.inprocess-lsp.com) as the only SR-DLS in the market nowadays for more info on the technique.
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