TY - JOUR
T1 - Optically probing nanoemulsion compositions
AU - Zhu, Xiaoming
AU - Fryd, Michael M.
AU - Huang, Jung Ren
AU - Mason, Thomas G.
PY - 2012/2/21
Y1 - 2012/2/21
N2 - Many types of colloids, including nanoemulsions, which contain sub-100 nm droplets, are dispersed in molecular and micellar solutions, especially surfactant solutions that confer stability. Since it would be desirable to measure the droplet volume fraction and surfactant concentration C of a nanoemulsion non-destructively, and since the droplet and surfactant structures are significantly smaller than the shortest wavelengths of visible light, optical refractometry could provide a simple and potentially useful approach. By diluting a silicone oil-in-water nanoemulsion having an unknown and C with pure water, measuring its refractive index n(,C) using an Abbé refractometer, and fitting the result using a prediction for n that treats the nanoemulsion as an effective medium, we show that and C can be deduced accurately over a relatively wide range of compositions. Moreover, we generalize this approach to other types of nanoemulsions in which a molecular constituent partitions in varying degrees between the dispersed and the continuous phases.
AB - Many types of colloids, including nanoemulsions, which contain sub-100 nm droplets, are dispersed in molecular and micellar solutions, especially surfactant solutions that confer stability. Since it would be desirable to measure the droplet volume fraction and surfactant concentration C of a nanoemulsion non-destructively, and since the droplet and surfactant structures are significantly smaller than the shortest wavelengths of visible light, optical refractometry could provide a simple and potentially useful approach. By diluting a silicone oil-in-water nanoemulsion having an unknown and C with pure water, measuring its refractive index n(,C) using an Abbé refractometer, and fitting the result using a prediction for n that treats the nanoemulsion as an effective medium, we show that and C can be deduced accurately over a relatively wide range of compositions. Moreover, we generalize this approach to other types of nanoemulsions in which a molecular constituent partitions in varying degrees between the dispersed and the continuous phases.
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U2 - 10.1039/c2cp23007k
DO - 10.1039/c2cp23007k
M3 - Article
C2 - 22249645
AN - SCOPUS:84863012140
VL - 14
SP - 2455
EP - 2461
JO - Physical Chemistry Chemical Physics
JF - Physical Chemistry Chemical Physics
SN - 1463-9076
IS - 7
ER -