Am looking for suggestions for system of ca. 100-300 um-sized microspheres in an aqueous system such that the refractive indices of microspheres and liquid are identical (i.e. microspheres disappear).
For example some plastic microspheres, perhaps made of CYTOP ™, have a refractive index close to water. If I then added sodium iodide or even sucrose to the water, could I adjust the liquid's refractive index to render spheres invisible?
Does anyone know of a combination of materials already designed to these specs? Is there a non-toxic additive to water that would increase its RI to the 1.40-1.52 range of most glass microspheres?
Need this as part of a digital microscopy system to image extremely small museum specimens.
Secondly, what is the formula for the refractive index of a mixture of two liquids when the RI's of the two components are known?
Thanks!