National Engineering Research Center of Coal Preparation and Purification, China University of Mining and Technology, Xuzhou 221116, China.
School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, China.
Molecules. 2022 Jul 8;27(14):4392. doi: 10.3390/molecules27144392.
Fatty acids, which are enriched in vegetable oil, have attracted much attention in low-rank coal flotation because of their unique chemical structure. In this study, density functional theory calculations, molecular dynamics simulations, and atomic force microscopy were employed to investigate the adsorption structure and forces between collectors and hydrophilic surfaces. The results show that fatty acids can be easily adsorbed onto surfaces through hydrogen bonds, and can cover the oxygen sites. The existence of hydration film on hydrophilic surfaces prevented nonpolar molecules from being able to adsorb, while polar fatty acids could adsorb and expel water molecules. The adhesion force between the RCOOH-terminated probe and the surface appeared in the retraction process, which differed significantly from that of the RCH-terminated probe, indicating that polar fatty acids are more suitable as flotation collectors for low-rank coal than nonpolar hydrocarbon oil. The simulation and AFM test revealed the mechanisms of polar fatty acids, and can provide guidance for low-rank coal flotation applications.
脂肪酸在植物油中含量丰富，由于其独特的化学结构，在低阶煤浮选领域引起了广泛关注。本研究采用密度泛函理论计算、分子动力学模拟和原子力显微镜研究了捕收剂与亲水表面之间的吸附结构和作用力。结果表明，脂肪酸可通过氢键轻易吸附到表面上，并能覆盖氧位。亲水表面上的水化膜阻止了非极性分子的吸附，而极性脂肪酸则可以吸附并排出水分子。在回缩过程中，RCOOH 末端探针与表面之间出现了粘附力，这与 RCH 末端探针有显著差异，表明极性脂肪酸比非极性烃油更适合作为低阶煤浮选捕收剂。模拟和 AFM 测试揭示了极性脂肪酸的作用机制，可为低阶煤浮选应用提供指导。
