He, ShuHe, Shuai, et al. International Journal of Biological Macromolecules 263 (2024): 130193.ai, et al. International Journal of Biological Macromolecules 263 (2024): 130193.
Thermoviscosifying polymers are a class of smart materials that exhibit a responsive behavior to environmental stimuli, specifically an increase in solution viscosity with increasing temperature. The temperature-dependent behavior of thermoviscosifying polymers offers potential advantages for enhanced oil recovery (EOR) applications. However, there is limited research on the use of thermoviscosifying polymers for improving oil recovery in high-temperature, high-salinity reservoirs. To address this issue, this study investigated the use of Poly(2-ethyloxazoline)-modified Welan Gum as a thermally responsive moiety to enhance viscosity.
Modification of Welan Gum with PEOX-NH2
A mixture of Welan Gum (2.0 g) and amino-terminated poly(2-ethyl-2-oxazoline) (PEOX-NH2) (2.0 g) was added to a three-necked flask containing 1000 mL of deionized water. The pH of the solution was then adjusted to 7.2. Subsequently, 20 and 5 times the molar amount of PEOX-NH2 of N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC) (0.56 g) and 1-hydroxybenzotriazole hydrate (HOBT) (0.1 g) were added, respectively. After reacting at room temperature for 24 hours, the resulting solution was purified using anhydrous ethanol to remove any unreacted Welan Gum. The obtained white solid was dissolved in water, transferred to a dialysis bag with a molecular weight cutoff of 100,000 Da, and dialyzed against pure water. The product was then recovered by freeze-drying, with a yield of 90%.
Tian, Cong, et al. Construction and Building Materials 441 (2024): 137539.
Biopolymers are considered environmentally sustainable and play a crucial role in enhancing the performance of cementitious materials. This study focused on using Welan Gum (WG) as a bio-thickening agent to evaluate its effects on the rheological characteristics, anti-shrinkage cracking, and mechanical properties of cementitious materials. The results show that the addition of WG can improve the cohesiveness and stability of cementitious materials, while reducing their shear-thinning behavior. WG has a relatively small impact on cement hydration. However, WG may form agglomerates, leading to increased dewatering and drying shrinkage rates. High dosages of WG can reduce the dewatering rate caused by film formation, but excessive WG may introduce porosity and increase the drying shrinkage rate. WG exhibits the ability to delay the drying shrinkage cracking of cementitious materials, improving their deformability and crack resistance. Comprehensive analysis reveals that in cement paste with a water-to-cement ratio of 0.4, the optimal mass fraction of WG is 0.10%, which can enhance the cohesiveness, water retention, and anti-shrinkage cracking performance without compromising the mechanical properties.
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