Colloidal refractometry: meaning and measurement of refractive index for dispersions; the science that time forgot

Mohammadi, Mansur S.

doi:10.1016/0001-8686(95)00261-n

Cited by 55 publications

(38 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This method allows the probing of the structure of concentrated dispersions in their undiluted state. The values of n can provide a measure of the volume-average particle size [86].…”

Section: Colloidal Refractometrymentioning

confidence: 99%

On‐line Monitoring of Polymerization and Cure

Hergeth¹

1999

Sensors Update

View full text Add to dashboard Cite

“…This method allows the probing of the structure of concentrated dispersions in their undiluted state. The values of n can provide a measure of the volume-average particle size [86].…”

Section: Colloidal Refractometrymentioning

confidence: 99%

On‐line Monitoring of Polymerization and Cure

Hergeth¹

1999

Sensors Update

View full text Add to dashboard Cite

“…In the case of a transparent sample if the reflected intensity is plotted as a function of incidence angle, the critical angle manifests as a sharp transition between the regions where TIR occurs and where the light merely refracts through. A technique commonly used by researchers, [2][3][4][5][6] and by commercial TIR-based refractometers, 7 is to locate this transition by taking the derivative with respect to incident angle of the reflected intensity profile and associating the point of maximum slope (which, for transparent samples, coincides with the point at which the slope of the reflectance profile is discontinuous) with an "effective" critical angle. The differentiation method is popular because of its perceived "simplicity and technical maturity."…”

mentioning

confidence: 99%

Note: Refractive index sensing of turbid media by differentiation of the reflectance profile: Does error-correction work?

Goyal

Dong

Kane

et al. 2012

Review of Scientific Instruments

View full text Add to dashboard Cite

A widely used method for determining refractive index postulates that the derivative of the angular profile for light reflected from the sample is maximum at the critical angle for total internal reflection (TIR). It is well-known that in turbid media this "differentiation method" yields errors in refractive index. Unexplained anomalies in previous error-calculations are eliminated if one uses a recent model of TIR which departs from traditional Fresnel theory. However we find that, in practical situations, the refractive index obtained by differentiation even after error-correction is significantly different from the best estimate for the refractive index obtained by curve-fitting the reflectance data. Thus the differentiation method lacks scientific validity in turbid media.

show abstract

“…The differentiation algorithm is a representative and straightforward algorithm [8]. Mohammadi demonstrated the differentiation algorithm by defining the presentational critical angle as the maximum change of the slope of the relative reflective curve [9]. The threshold algorithm was introduced by Bail, who suggested the pixel point of 0.923 of the maximal reflective light intensity as the critical angle point [10].…”

Section: Introductionmentioning

confidence: 99%

Real part of refractive index measurement approach for absorbing liquid

Liu

Yang

et al. 2015

Appl. Opt.

View full text Add to dashboard Cite

An algorithm based on use of a reflected refractometer to measure the real part of the refractive index (RI) for an absorbing liquid is presented. The absorption of liquid will blur the division between bright and dark regions on a Fresnel reflective curve. However, the reflective ratio at some incident angles that are less than the critical angle have little sensitivity to absorbability. Unlike common methods that extract RI from reflectivity in critical angle vicinity, the presented method acquires the real RI from reflective ratio at a subcritical angle. Supported by the theoretical analysis and experimental results on a reflected refractometer, we have achieved accuracy better than 3×10(-4) RIU on ink samples with absorption coefficient around 300 cm(-1). Additional tests on Alizarin yellow GG solutions prove that the subcritical algorithm is feasible and of high accuracy.

show abstract

Colloidal refractometry: meaning and measurement of refractive index for dispersions; the science that time forgot

Cited by 55 publications

References 13 publications

On‐line Monitoring of Polymerization and Cure

On‐line Monitoring of Polymerization and Cure

Note: Refractive index sensing of turbid media by differentiation of the reflectance profile: Does error-correction work?

Real part of refractive index measurement approach for absorbing liquid

Contact Info

Product

Resources

About