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Recent Developments in Rubber Research Using Atomic Force Microscopy
Published in Anil K. Bhowmick, Current Topics in ELASTOMERS RESEARCH, 2008
Up to here, the discussion has seemed to assume that viscosity η2 determined by dynamic nanofishing is due to solvent friction, an idea that is not groundless. To verify this assumption, the dependence of η2 on solvent temperature and quality was investigated. There is a well-accepted concept to describe polymer solution viscosity, intrinsic viscosity [η]. Values have been accumulated for different polymer species, solvent qualities, and temperatures by conventional techniques such as light scattering and osmotic pressure. () [η]=limc→0ηspc=KMα
Viscometers–Laboratory
Published in Béla G. Lipták, Analytical Instrumentation, 2018
The Mark-Houwink equation expresses the relationship between intrinsic viscosity and molecular weight: ) [μI]=KMwa or, in logarithmic form: ) log [μI]=logK+alogMw
Microscopic Structure of the Membrane and the State of the Permeant
Published in Takeshi Matsuura, Synthetic Membranes and Membrane Separation Processes, 2020
The intrinsic viscosity, [η](volume of solvent/weight of polymer), is a measure of the extension of a polymeric molecule in a solvent at infinite dilution. It is defined as () [η]=limg→01g(ηη0−1)
The response surface optimization of exopolysaccharide produced by Saccharomyces cerevisiae Y3 and its partial characterization
Published in Preparative Biochemistry & Biotechnology, 2022
Lina Liu, Jiaju Xu, Renpeng Du, Wenxiang Ping, Jingping Ge, Dan Zhao
Intrinsic viscosity [η] is an important viscosity index of polymer materials in solutions and is closely related to the conformation, molecular weight and relative volume of polymer materials. According to the Huggins and Kraemer formulas, the intrinsic viscosity of Y3 EPS was 306.58 mL/g at 25 °C and 200.91 mL/g at 35 °C (Figure 2), respectively. It could be seen that intrinsic viscosity was related to temperature, the higher of temperature, the lower of viscosity. Although the viscosity decreases, it was still lower than bacteria EPSs, such as EPS from Weissella confusa XG-3 was 409.7 mL/g,[38] also lower than plant sources polysaccharide, such as galactomannan from Astragalus gombo 860 mL/g.[39] Therefore, Y3 EPS had a lower viscosity and was easier to separate and purify. The results revealed that the viscosity of yeast EPSs was positively correlated with its molecular weight,[40] the low viscosity, the structure more stable. The EPSs are easier to absorb and diffuse, and play a biological activity.
Evaluation of the impact of guar gum applied to chemical enhanced oil recovery on produced water treatment using a SDBS-Chitosan flocculant system
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2022
Allan S. Santos, Anny Marry T. Marques, Luiz Carlos M. Palermo, Claudia R. E. Mansur
The viscometric molar masses determination of guar gum and chitosan were carried out using a Cannon-Ubbelohde capillary viscometer, number 1 C595, to measure the flow times of both guar gum and chitosan. The flow times measures were performed with the Ubbelohde viscometer immersed on a water bath of 25°C. The methodology to obtain the intrinsic viscosity is well known in the literature, first calculating the relative viscosity by the ratio between flow time of the diluted polymer solution and the solvent solution, then calculating intrinsic viscosity [η], by extrapolating reduced viscosity to concentration zero (Robert and Peter 2011). The intrinsic viscosity is related to the hydrodynamic volume of a polymer chain, which is empirically related to the molar mass of the polymer. The average viscosity molar mass (Mv) can be calculated using the Mark-Houwink-Sakurada equation (Lucas, Soares, and Monteiro 2001), as can be seen on equation 1:
The response surface optimization of exopolysaccharide produced by Weissella confusa XG-3 and its rheological property
Published in Preparative Biochemistry & Biotechnology, 2020
Dan Zhao, Lina Liu, Jing Jiang, Shangxu Guo, Wenxiang Ping, Jingping Ge
Intrinsic viscosity is a critical parameter which closely relates to solution property of microbial EPS.[3,7,11,40] The intrinsic viscosity, a measure of a hydrodynamic volume occupied by XG-3 EPS was 409.7 mL g−1 at 25 °C (Figure 3(A)) and 201.7 mL g−1 at 35 °C (Figure 3(B)), respectively. It could be concluded that the intrinsic viscosity was irrelevant to concentration and positive related to temperature. A higher intrinsic viscosity value is usually relates to a more extended structure and smaller molecular weight. Despite temperature, intrinsic viscosity value of XG-3 EPS was much lower than most plant sources polysaccharide such as galactomannan from Astragalus gombo 860 mL g−1[41] and higher than fungus Ganoderma atrum EPS 90 mL g−1.[42]