Xanthan is an extracellular polysaccharide of polyanionic nature widely used in industrial processes as flow modifier. Its characterization in dilute solutions is complicated by the strong tendency to aggregation. We explore the possibility to obtain dilute xanthan solutions without aggregates. We applied some steps of the sample preparation procedures from previous works on xanthan, such as ultrasonication, heating and micro filtration. The influence of this type of treatment on the observed properties of xanthan 0.1M NaCl aqueous solutions is studied. Renaturalization of xanthan solutions above the overlap concentration does not break the aggregates but, on the opposite, produces the ones that are more resistant to ultrasound. Ultrasonication breaks only large aggregates and at long sonication times brings the risk of the single chain degradation. The best results are provided by a procedure that combines a short ultrasonication time followed by micro filtration but it is impossible to obtain a solution completely free of small aggregates by conventional sample preparation methods. Nevertheless, a significant reduction of large aggregates results in a linear concentration dependence of xanthan reduced viscosity, which allows more confident determination of the intrinsic viscosity. Another advantage of large aggregates removal is a possibility of physical interpretation of xanthan molecular parameters by static light scattering, taking into account its association tendency.
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http://dx.doi.org/10.1016/j.ijbiomac.2017.07.110 | DOI Listing |
Int J Biol Macromol
January 2025
Advanced Membrane Technology Research Centre (AMTEC), Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor, Malaysia.
This study focuses on the development of an efficient membrane-based clarification process to enhance the performance of subsequent ultrafiltration and produce high-quality sweet lime juice. A range of casting solutions were prepared using a blend of pore-forming polymers, including polyvinylpyrrolidone (PVP), polyvinylidene fluoride (PVDF), and cellulose acetate (CA), dissolved in dimethylformamide (DMF) solvent through the phase inversion technique. To further enhance the membrane's performance, four biopolymers poly (lactic acid) (PLA), xanthan gum, chitosan, and gelatin were incorporated, with and without clay, to refine its structure, porosity, and surface properties.
View Article and Find Full Text PDFJ Colloid Interface Sci
January 2025
School of Engineering, University of Liverpool, Liverpool, L69 3GH, United Kingdom.
Hypothesis: We hypothesise that superhydrophobic surfaces can achieve effective interfacial slip and drag reduction even under non-Newtonian, shear-thinning fluid flows. Unlike Newtonian fluids, where slip is primarily influenced by viscosity and surface tension, we anticipate that the shear-thinning nature of these fluids may enhance slip length and drag reduction.
Experiments And Numerical Analysis: The superhydrophobic surfaces used in this study, featuring a dual-scale random topography, were fabricated via a spray coating process, and low-concentration xanthan gum solutions (50-250 ppm) were used as model shear-thinning fluids of low elasticity.
Nanomaterials (Basel)
January 2025
Department of Chemical Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada.
The interactions between cellulose nanocrystals and six different polymers (three anionic, two non-ionic, and one cationic) were investigated using rheological measurements of aqueous solutions of nanocrystals and polymers. The experimental viscosity data could be described adequately by a power-law model. The variations in power-law parameters (consistency index and flow behavior index) with concentrations of nanocrystals and polymers were determined for different combinations of nanocrystals and polymers.
View Article and Find Full Text PDFFood Chem X
January 2025
School of Food Science and Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China.
3D printing offers a promising solution for the increasing demand for visually appealing dysphagia diets. Xanthan gum (XG) is a critical component in various thickeners specialized for dysphagia diets, in which pyruvate group is important, but relative study remains scarce. This study tried to create 3D printed dysphagia diet using composite gels of pea protein (PPI) and XG with various pyruvate content (XG: 5.
View Article and Find Full Text PDFJ Air Waste Manag Assoc
January 2025
School of Emergency Management and Safety Engineering, China University of Mining and Technology (Beijing), Beijing, China.
Dust emissions from open-pit mining pose a significant threat to environmental safety and human health. Currently, the range of dust suppressants used in coal mining is limited, often failing to account for their suitability across various stockpiles. This oversight results in poor infiltration after application, leading to insufficient crust formation and reduced durability.
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