INTERNATIONAL JOURNAL OF MINERAL PROCESSING
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2017
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IF 1.561
An Liu,Min-qiang Fan,Zhi-hong Li,Jin-chuan Fan
In this paper, in order to study the interaction mechanism of non-polar oil assisted dodecylamine (DDA) flotation of quartz, the particle-oil drops system were treated the same as the hydrophobic particles system. Pure dodecane was chosen as research object, the interfacial interactions between quartz particle and oil drop were investigated through calculation of the extended Derjaguin-Landau-Verwey-Overbeek (EDLVO) potential energy profile. Based on the calculations of the van der Waals attractive interaction potential, hydrophobic interaction potential, hydrocarbon chain association potential, and electrostatic interaction potential, the results indicated that the mineral particle and oil drop attachment state was mainly dominated by hydrophobic interaction potential. In the modification of oil agglomeration flotation process, the adsorption of DDA on the dodecane/water interface presented significant effects on the interfacial interactions between quartz particle and oil drop. It was found that the adsorption of DDA at dodecane/water interface changed the zeta potential value of oil drop from negative to positive. In this case, the attachment of the particles would occur spontaneously, which was due to the contribution of electric double layer attractive interaction. On the contrary, in the traditional oil agglomeration flotation process, a mechanical agitation was required to overcome a potential barrier due to the existence of electric double layer repulsive interaction between the negatively charged oil drops and mineral particles. This study was focus on the theoretical level, and provided some insights into mechanism of oil agglomeration flotation.
研究领域:
矿物加工工程
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界面化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
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2022
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IF 10.383
Ping Wen,Qianqian Yan,Rui Dong,Yunyan Han,Ran Fang,Mingjin Fan
Severe competition between nanolubricant additives and polar lubricating oil molecules for the formation of lubricant films has been hindering the progress of green and advanced lubricants. In this work, based on the tautomerism of cyanuric acid molecule (trione and triol configurations), two kinds of triazine-based covalent–organic frameworks (COFs), that is, Ton-COFs and Tol-COFs, were synthesized as additives of the polar PEG 400 oil, realizing compromise between them by providing delicate interactions. The triazine matrix bonding with intense polar groups in the framework of additives offers more powerful interactions to competitively form the adsorbed lubricant film on the surface of the metal substrate over PEG 400 oil and also bolts PEG 400 oil molecules by the hydrogen bonding inside the pore of the framework to cooperatively bear against the load. Molecular quantum chemical calculations further confirm that Ton-COFs can produce a more intense interaction with Fe atoms in the form of coordination and ions···π than Tol-COFs, far beyond PEG 400, and the cross-sectional profile of the worn surface definitely exhibits a protective lubricant film only composed of Ton-COFs. Consequently, at the low concentration of 0.3 wt %, the excellent friction reduction (41.2%) and antiwear property (97.4%) are achieved for the Ton-COFs compared to pure PEG 400 oil; moreover, 28.6% and 79.0% for Tol-COFs at the essential concentration of 0.7 wt % are achieved. This finding provides a novel insight from molecules to materials into guiding the development of additives for advanced lubricants.
研究领域:
材料科学
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润滑工程
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量子化学
✓ 已验证
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
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2025
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IF 6.9
Xiaoqiang Liu,Rong Liu,Guangping An,Shunjiang Guo
It still is a challenge for the most of base oils to reach the superlubricity at macroscale because of their intrinsic viscosity. Hybrid lubrication that combines the polymer coatings with liquid lubricants, has proven to be a successful approach to achieve superlubricity for viscous oils. However, the molecule structural effects of oil lubricants on the hybrid lubrication performance as well as the synergistic lubrication mechanisms of the oils on polymer coatings still are unclear. In this work, the molecular structural effects on the superlubricity behaviors on epoxy resin coatings were investigated by the comparative lubrication performance of linear and branched polar oils. The results showed that linear polar oils provided superior hybrid lubrication performance on epoxy resin coatings compared to the branched polar oils, even achieving robust superlubricity at the high rotary speeds. The superlubricity disappearance of branched oils at low rotary speeds could be related to the absence of epoxy resin transfer layers and weak hydroxylation of the counter ball surface. While the adsorption behaviors of the different polar oils on the epoxy resin coatings, investigated through molecular dynamics simulations, are the main responsibility for the lubrication failure of branched oils at high rotary speeds.
研究领域:
材料科学
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润滑工程
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表面科学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF MINERAL PROCESSING
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2017
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IF 1.561
An Liu,Min-qiang Fan,Zhi-hong Li,Jin-chuan Fan
It is well accepted that non-polar oils can be used as collector extender in oil agglomeration flotation of many different types of mineral. In this paper, in order to study the influences of oil structures on the non-polar oil assisted dodecylamine (DDA) flotation of quartz, the research focuses on the interaction of DDA (collector) and non-polar oil (collector extender) in aqueous phase. In this work, saturated hydrocarbon dodecane and cyclohexane , unsaturated hydrocarbon dodecene, aromatic hydrocarbon dimethylbenzene and 1-methylnaphthalene were chosen as researched subjects, and the influences of oil structures on interfacial activity of oil–DDA–water ternary models were investigated by experimental and theoretical methods. The flotation results demonstrated that the collecting capability of the oil and DDA combination follows the order of 1-methylnaphthalene > dimethylbenzene > dodecene > cyclohexane > dodecane. Moreover, molecular dynamic (MD) simulation is performed to investigate the interfacial property of these five non-polar oil-DDA-water systems, and five parameters, radial distribution functions, interaction energy, density distribution, interfacial thickness and self-diffusion coefficient are proposed to reveal the influence mechanism of molecular structure on interfacial activity of the ternary oil-DDA-water systems. The same trends are obtained from the parameters described above, aromatic hydrocarbon dimethylbenzene and 1-methylnaphthalene performance better than saturate hydrocarbon and unsaturated hydrocarbon. The researched results indicate the interaction between non-polar oil and DDA hydrophobic alkyl tail would enhance the mobility of oil component, which induce significant change of interfacial thickness and diffusivity . Additionally, the interaction between DDA hydrophilic head group and water molecules via strong hydrogen bonds , van der Waals interactions and weak electrostatic attraction would lead to water molecules penetrate through DDA monolayer and adsorb on oil surface. The researches enable us to obtain a deeper microscopic-level understanding of the interaction between oil-DDA-water ternary components, and maybe have some references for designing of oil-assisted flotation agent.
研究领域:
矿物加工工程
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物理化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）