The goal of this paper was to design several sodium carboxymethylcellulose hydrogels containing a BCS class II model drug and to evaluate their flow and thixotropic properties. The rheological measurements were performed at two temperatures (23 °C and 37 °C), using a rotational viscometer. The hydrogels were stirred at different time intervals (10 s, 2, 5, 10 and 20 min at 23 °C, and 10 s, 2 an...

Abstract Mixing and homogenization in anaerobic digesters are affected by the flow curve of sludge. The aim this study is to mathematically express dense anaerobically digested sludge behaving as thixotropic pseudoplastic fluids. Time-dependent changes two parameters, i.e., consistency index ( µ p ) n ), shear modeled using a second-order kinetic equation with coefficient that includes power fu...

The in vitro fluoride uptake by dental enamel from two conventional acidulated phosphate fluoride gels was compared to a thixotropic acidulated phosphate fluoride gel. The fluoride concentration and enamel biopsy depths were determined using an acid-etch biopsy method based on calcium determinations. A significant fluoride uptake by dental enamel from a thixotropic topical fluoride agent follow...

Yield stress fluids have proven difficult to characterize, and a reproducible determination of the yield stress is difficult. We study two types of yield stress fluids (YSF) in a single system: simple and thixotropic ones. This allows us to show that simple YSF are simply a special case of thixotropic ones, and to pinpoint the difference between static and dynamic yield stresses, one of the maj...

Thixotropy is one of the oldest documented rheological phenomenon in colloid science and may be defined as an increase of viscosity in a state of rest and a decrease of viscosity when submitted to a constant shearing stress. This behavior has been exploited in recent years to prepare injectable hydrogels for application in drug delivery systems. Thixotropic hydrogels may be profitably used in t...

Thixotropic properties are one of the low temperature rheology behaviors of gelled waxy crudes. In order to study the thixotropic behavior of gelled waxy crudes oil under cyclic loading of linear increasing and decreasing of shear rate, three different types of waxy crude oil were studied experimentally by using MARSIII rheometer. It is found that hysteresis loop area could represent strength o...

Maybe viscosity in drilling fluid is the most important parameter because cutting removal from well are task of viscose fluid. If viscosity of fluid is less than particular value, cutting will settle down in well and drilling operation will be stopped. In this study, synthesis of Alumina/Polyacrylamide nanocomposite through solution polymerization method was performed. Rheological behavior of m...