Automatic laser refractometer

On Total Internal Reflection Investigation of Nanoparticles by Integrated Micro-Fluidic System

“…The dependence of the ERI, n , on the concentration, c , and the value of their specific RI Increment (SRII), dn/dc , of all dispersions used here have been reported in a recent work . These measurements are made with an automatic refractometer implementing the method of the disappearing diffraction pattern. − It is a modified critical-angle method, which is feasible for dense scattering and turbid media . The precision of the refractometric data is 2 × 10 -4 .…”

“…21 These measurements are made with an automatic refractometer implementing the method of the disappearing diffraction pattern. [21][22] It is a modified critical-angle method, which is feasible for dense scattering and turbid media. 22 The precision of the refractometric data is 2 × 10 -4 .…”

“…[21][22] It is a modified critical-angle method, which is feasible for dense scattering and turbid media. 22 The precision of the refractometric data is 2 × 10 -4 . The effective absorption index (EAI) of the dispersions is measured by a light transmission from a 5 µm thick cell.…”

“…The integrated sensor response is defined and measured as the relative DE change δη ) (ηη 0 )/η 0 , where η is the zeroth order DE for a given dispersion and η 0 corresponds to the DE for the carrier liquid. The sensitivity of the integrated detector to the microfluidic RI variation is calibrated using aqueous solutions of sucrose, which have a linear dependence of their RI, n, on concentration c: ∆n ) 1.45 × 10 -3 c. 22 The calibration is made at the critical angles and δ's relevant for each type of nanoparticle dispersions studied. The calibration results for the response δη, plotted versus the RI increment ∆n ) nn 0 are shown in Figure 3.…”