Contrasting relationship between macro- and microviscosity of the gelatin- and starch-based suspensions and gels

Abstract

The problem of correlation between rheological properties in macroand micro-scales of media with biopolymers of polypeptide (gelatin) and polysaccharide (starch) nature is investigated. The viscosity of the biopolymer solutions with concentrations 0.5-5 wt% was estimated by standard rotational rheometry technique and with fluorescent molecular rotor at 15-50°C. Opposite trends were observed for relationship between microviscosity g m and macroviscosity g for two biopolymers: g m \ \ g for gelatin and g m [ [ g for starch solutions. The temperature dependence of g m followed the monoexponential decay law in all samples over the whole temperature range indicating insensitivity of microviscosity to gel mesh melting under heating. The dissimilarity of macro-and micro-rheological properties of gelatin and starch-containing media is discussed in terms of difference in architecture of the gels.

Micro- and macro-viscosity relations in high concentration antibody solutions

“…where denotes the thermal energy, RH is the hydrodynamic radius of the fluorescently labelled tracer. Being able to use the GSE requires knowing how to relate the microviscosity h' to the macroviscosity h [13], [14] [15]. It is common to define a retardation factor, r' in terms of the relative diffusion coefficient ( ′ ) ⁄ ⁄…”

Thermal Inactivation of Butyrylcholinesterase in Starch and Gelatin Gels

“…Nevertheless, the activation energies of thermal inactivation calculated in this study suggest the stabilizing effect of the gelatin medium on BChE. It seems likely that within the temperature range studied here, this stabilizer prevents unfolding processes, as the overall viscosity of the gelatin solution was certainly reduced with the temperature rise [34].…”

Comparative Analysis of Methods for Enhancement of the Photostability of CdTe@TGA QD Colloid Solutions

“…Since the QD photodegradation rate depends on the presence of free oxygen in a solution, 34,35 decrease of its diffusion rate allows reduction of both the rate of collisions between QDs and oxygen molecules and the rate of oxygen transfer from the ambience to a solution. Addition of, e.g., 1% gelatin to the buffer solution is shown 36 to increase its viscosity by 2.3, leading to a 2.3-fold decrease of the oxygen diffusion rate. In our experiment, 10-fold photoluminescence quenching occurs during 165 min of illumination of CdTe QDs in the buffer solution.…”