A Refractive Index- and Density-Matched Liquid–Liquid System Developed Using a Novel Design of Experiments

Refractive index and density matching are essential for optical measurements of neutrally buoyant liquid–liquid flows. In this study, we proposed a design experiments (DoE) to develop refractive systems, including objective setting, candidates screening, sampling fitting, detailed process. Candidates screening criteria based on the ranges aqueous organic phases were used. Using DoE, system with ternary phase potassium thiocyanate (KSCN)/ammonium (NH4SCN) solution m-dichlorobenzene/tripropionin as achieve tuning RI simultaneously. Empirical correlations respect concentration temperature three mixtures obtained by combining Latin hypercube binary polynomial fitting. Correlations validated existing data in literature found align deviations low 4×10−4 2×10−3 g⋅cm−3 density. correlations, indices phase, device materials matched be equal. Density was performed well. index- density-matched recipes could wide range temperatures (15–65 °C) (PMMA, borosilicate glass, quartz, silica gel). These provide options measurement required neutralize buoyancy.