Electric Response of CuS Nanoparticle Lubricant Additives: The Effect of Crystalline and Amorphous Octadecylamine Surfactant Capping Layers

Liu, Chenxu; Friedman, Ofir; Li, Yuanzhe; Li, Shaowei; Tian, Yu; Golan, Yuval; Meng, Yonggang

doi:10.1021/acs.langmuir.9b01714

Cited by 21 publications

(13 citation statements)

References 27 publications

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“…As well as adsorption of surfactants, the adsorption of charged nanoparticles on tribological surfaces can also be controlled using applied potential. Liu et al studied the friction behaviour of nanoparticles dispersed in diethyl succinate in a ZrO 2 /Cu contact and found that applied negative potential could promote adsorption and reduce friction of positively charged CuS nanoparticles [114], while positive potential could promote adsorption and thereby reduce friction of negatively charged MoS 2 nanoparticles [115].…”

Section: Charge-promoted Adsorptionmentioning

confidence: 99%

Triboelectrochemistry: Influence of Applied Electrical Potentials on Friction and Wear of Lubricated Contacts

Spikes

2020

Tribol Lett

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Research on the effects of applied electrical potential on friction and wear, a topic sometimes termed “Triboelectrochemistry”, has been reviewed. Historically, most such research has focussed on aqueous lubricants, whose relatively high electrical conductivities enable use of three-electrode electrochemical kinetic techniques, in which the electrode potential at a single electrode | fluid interface is controlled relative to a suitable reference electrode. This has led to identification of several different mechanisms by which applied electrode potentials can influence friction and wear. Of these, the most practically important are: (i) promotion of adsorption/desorption of polar additives on tribological surfaces by controlling the latters’ surface charges; (ii) stimulation or suppression of redox reactions involving either oxygen or lubricant additives at tribological surfaces. In recent years, there has been growing interest in the effects of applied electrical potentials on rubbing contacts lubricated by non-aqueous lubricants, such as ester- and hydrocarbon-based oils. Two different approaches have been used to study this. In one, a DC potential difference in the mV to V range is applied directly across a thin film, lubricated contact to form a pair of electrode | fluid interfaces. This has been found to promote some additive reactions and to influence friction and wear. However, little systematic exploration has been reported of the underlying processes and generally the electrode potentials at the interfaces have not been well defined. The second approach is to increase the conductivity of non-aqueous lubricants by adding secondary electrolytes and/or using micro/nanoscale electrodes, to enable the use of three-electrode electrochemical methods at single metal | fluid interfaces, with reference and counter electrodes. A recent development has been the introduction of ionic liquids as both base fluids and lubricant additives. These have relatively high electrical conductivities, allowing control of applied electrode potentials of individual metal | fluid interfaces, again with reference and counter electrodes. The broadening use of “green”, aqueous-based lubricants also enlarges the possible future scope of applied electrode potentials in tribology. From research to date, there would appear to be considerable opportunities for using applied electrical potentials both to promote desirable and to supress unwanted lubricant interactions with rubbing surfaces, thereby improving the tribological performance of lubricated machine components. Graphical Abstract

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Section: Charge-promoted Adsorptionmentioning

confidence: 99%

Triboelectrochemistry: Influence of Applied Electrical Potentials on Friction and Wear of Lubricated Contacts

Spikes

2020

Tribol Lett

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“…Nanoparticles of metals such as Ni, Cu, , Ag, , and Pd and metal salts such as oxides ZrO 2, , ZnO, , and CeO 2; sulfides MoS 2, , WS 2, Ag 2 S, and CuS; selenides VSe 2 and Bi 2 Se 3 ; and halides like LaF 3 have been extensively investigated as components of nanolubricants. , Their composites with graphene, such as copper, silver, , Mn 3 O 4, ceria, zirconia, boron nitride, and WS 2 , are well documented in the literature for enhanced tribological performance. Some graphene-based nanocomposites were also investigated by performing superlubricity (COF less than 0.01). , A titanium dioxide-reinforced boron nitrogen-codoped graphene nanocomposite was reported from our laboratory for excellent tribological activity .…”

Section: Introductionmentioning

confidence: 99%

Superlubricity of Nanocomposites of Polyaniline-Functionalized Reduced Graphene Oxide with Yttrium and Vanadium-Codoped Zinc Oxide Nanoparticles

Verma,

Prajapati,

Sahu

et al. 2024

ACS Appl. Eng. Mater.

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The surface modifications of reduced graphene oxide (rGO) nanosheets have been achieved by a conducting polymer, polyaniline (PANI), in an emeraldine state to yield PANI–rGO, which has hydrogen bonding, electrostatic interactions, and π–π interactions between PANI and rGO nanosheets. For the advancement of the tribological properties of PANI–rGO, its nanocomposite was prepared with yttrium, vanadium-codoped zinc oxide nanoparticles (Y–V–ZnO). The resulting nanocomposite (Y–V–ZnO/PANI–rGO) shows improved tenacity to the tribo-surfaces, enhanced dispersibility in the base oil, and enormously reduced agglomerating and restacking tendencies. The effect of these modifications can be adjudged by the optimized concentrations required for maximum antiwear efficiency. The optimized concentration (% w/v) reduces drastically for Y–V–ZnO/PANI–rGO, Y–V–ZnO (0.25), PANI–rGO (0.0125), and Y–V–ZnO/PANI–rGO (0.005). The anchored Y–V–ZnO nanoparticles on PANI–rGO have led to superlubricity, as is visibly seen by the tribological properties established from ASTM D4172 and ASTM D5183 tests on a four-ball tester. Specifically, a very small value of the coefficient of friction, 0.0087, supports superlubricity. The tribological properties of the well-characterized additives (by FTIR, p-XRD, HR-SEM, TEM, and XPS) improved in the following order: rGO < PANI < ZnO < PANI–rGO < Y–ZnO (4%Y) < V–ZnO (4%V) < Y–V–ZnO (1%Y and 3%V) < Y–V–ZnO/PANI–rGO. The morphological studies by SEM and AFM of the wear scar surface have corroborated the abovementioned order. The nanoparticles have reinforced the composite and separated the nanosheets to avoid their repiling. On the contrary, nanosheets have averted agglomeration of the nanoparticles. Doping in ZnO nanoparticles by yttrium and vanadium in different oxidation states has ameliorated the tribological properties by introducing more defects. Thus, all the components of the composite have assisted mutually in the upgradation of tribological behavior.

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“…13,14 Nano lubricants' tribological behavior is also affected by their viscosity, which rises as the concentration of nanoparticles rises. 15 Various kinds of nanoparticles that have been used as additives in base lubricant can be categorized as metals, 9,16 metallic oxides, 8,17 nonmetallic oxides, 13,18 sulfides, 19,20 fullerene, 21,22 and other carbon materials. 23−26 More specifically, 2D layered-structured materials have attracted attention as lubrication nanoadditives because of their excellent tribological characteristics.…”

Section: ■ Introductionmentioning

confidence: 99%

“…Moreover, the smaller the particle, the more likely it is to interact with the friction pair and reduce the coefficient of friction (CoF) and wear. , Nano lubricants’ tribological behavior is also affected by their viscosity, which rises as the concentration of nanoparticles rises . Various kinds of nanoparticles that have been used as additives in base lubricant can be categorized as metals, , metallic oxides, , nonmetallic oxides, , sulfides, , fullerene, , and other carbon materials. − More specifically, 2D layered-structured materials have attracted attention as lubrication nanoadditives because of their excellent tribological characteristics. The typical examples of such 2D materials are graphene, hexagonal boron nitride, black phosphorus, natural hydrate clay minerals (i.e., layered vermiculite), silicene, and MXenes. , For lubricity in industrial applications, e.g., drilling fluids, suspensions containing organic and inorganic nanoparticles ranging in diameter from 1 to 100 nm in the base fluids, such as water, oil, paraffin, glycerol, etc., are usually investigated. , The incorporation of these particles into the base fluid alters its rheology and lubricity .…”

Section: Introductionmentioning

confidence: 99%

Tribological and Rheological Study of Thixotropic Gels of 2D Nanoparticles

Kumar,

Joshi

et al. 2024

Langmuir

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A thixotropic colloidal gel constituting an aqueous dispersion of synthetic clay Laponite with varying concentrations of salt has been studied for its rheological and tribological performance as a lubricant. We observed that the incorporation of NaCl induces notable enhancements in the colloidal gel's relaxation time, elastic modulus, and yield stress. Although an increase in NaCl concentration decreases the material's relaxation time dependence on waiting time (t w ), overall, the strength of its thixotropic character has been observed to increase with an increase in salt concentration. The analysis of friction and wear indicated that the utilization of a thixotropic colloidal gel of Laponite with a higher concentration of NaCl resulted in progressively greater reductions in both the coefficient of friction and specific wear rates under various load-speed conditions. Severe abrasive wear on disc surface under dry test, gradually mitigated upon the introduction of these lubricants. Two simultaneous lubricating mechanisms, first, the smooth sliding of the friction pair, facilitated by the alignment of Laponite particles in the direction of shear forces, and second, the stable structure of Laponite, coupled with the addition of NaCl, enabling continuous replenishment of the wear track with lubricant, are attributed to lubrication effectiveness.

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Electric Response of CuS Nanoparticle Lubricant Additives: The Effect of Crystalline and Amorphous Octadecylamine Surfactant Capping Layers

Cited by 21 publications

References 27 publications

Triboelectrochemistry: Influence of Applied Electrical Potentials on Friction and Wear of Lubricated Contacts

Triboelectrochemistry: Influence of Applied Electrical Potentials on Friction and Wear of Lubricated Contacts

Superlubricity of Nanocomposites of Polyaniline-Functionalized Reduced Graphene Oxide with Yttrium and Vanadium-Codoped Zinc Oxide Nanoparticles

Tribological and Rheological Study of Thixotropic Gels of 2D Nanoparticles

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