Birefringent and rheologic properties of milling yellow suspensions

Abstract

Aqueous suspensions of Milling Yellow dye have been found to lie useful for engineering flaw studies by employing established birefringent techniques. In the present work, the basic birefringent and rheologic properties of Milling Yellow suspensions wore measured for a range of deformation rates important to the engineering applications. A concentric‐cylinder polariscope was used to measure the amount of birefringence and the angle of extinction for ten Milling Yellow suspensions at 25°C. varying in concentration from 1.25 to 1.46% dye by weight. The optical properties exhibited by these suspensions are similar to those of a number of colloidal suspensions as reported by past investigators. Rheologic data for Milling Yellow suspensions in the same concentration range were measured at 25°C. for deformation rates of 50–10 sec.−1 by means of a capillary viscometer. Over the complete range of deformation rates the rheologic data are accurately described with the Powell‐Eyring relationship for pseudo‐plastic materials.

Birefringent properties of aqueous cellulose nanocrystal suspensions

“…A rather sharp increase at low shear rates and a levelling off at higher velocity gradients has been similarly found for Xanthan gum solutions (Chow and Fuller 1984;Lane et al 2021). Birefringence of Milling Yellow suspensions has been reported to be proportional to the shear rate at low shear rates but also shows a levelling off at higher shear rates (Peebles et al 1964). The studied CNC suspensions display birefringence of magnitude 1e-5 and are in the same order as Xanthan gum (Lane et al 2021) and Milling Yellow (Peebles et al 1964).…”

“…Birefringence of Milling Yellow suspensions has been reported to be proportional to the shear rate at low shear rates but also shows a levelling off at higher shear rates (Peebles et al 1964). The studied CNC suspensions display birefringence of magnitude 1e-5 and are in the same order as Xanthan gum (Lane et al 2021) and Milling Yellow (Peebles et al 1964). Hence CNC suspensions appear as an attractive alternative for flow visualization studies due to their stability, ease of preparation and low cost.…”

Examination of flow birefringence induced by the shear components along the optical axis using a parallel-plate-type rheometer

“…Also represented in Fig. 5, it has been well reported that birefringence generally increases nonlinearly as the shear rate is increased 26,43,48,49 . This trend remains unchanged when organized by invariant, and the increase in birefringence per invariant decreases with decreasing gradient at higher invariants.…”

Birefringent Properties of Aqueous Cellulose Nanocrystal Suspensions

“…A rather sharp increase at low shear rates and a levelling off at higher velocity gradients has been similarly found for Xanthan gum solutions (Chow and Fuller 1984;Lane et al 2021). Birefringence of Milling Yellow suspensions has been reported to be proportional to shear rate at low shear rates but also shows a levelling off at higher shear rates (Peebles et al 1964). The studied CNC suspensions display birefringence of magnitude 1e-5 and are hence in the same order as Xanthan gum (Lane et al 2021) and Milling Yellow (Peebles et al 1964).…”

“…Birefringence of Milling Yellow suspensions has been reported to be proportional to shear rate at low shear rates but also shows a levelling off at higher shear rates (Peebles et al 1964). The studied CNC suspensions display birefringence of magnitude 1e-5 and are hence in the same order as Xanthan gum (Lane et al 2021) and Milling Yellow (Peebles et al 1964). Hence CNC suspensions appear as an attractive alternative for ow visualization studies due to their stability, ease of preparation and low cost.…”