Synthesis of dicationic symmetrical and asymmetrical ionic liquids and their tribological properties as ultrathin films

Yu, Guanlong; Yan, Shan; Zhou, Feng; Liu, Xuqing; Liu, Weimin; Liang, Yong‐Min

doi:10.1007/s11249-006-9167-8

Cited by 90 publications

(88 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…represent a new generation of amphiphilic molecules [16]. The new structures have demonstrated special properties and the potential for use in materials science; for example, in the formation of liquid crystals [17,18], metal coatings [19], and high temperature lubricants [20,21]. Consequently, a deeper knowledge of the aggregation process of dicationic ILs is essential in order to allow the rational design of ILs for specific applications.…”

Section: Introductionmentioning

confidence: 99%

Anion effect on the aggregation behavior of the long-chain spacers dicationic imidazolium-based ionic liquids

Frizzo

Bender

Gindri³

et al. 2015

Colloid Polym Sci

View full text Add to dashboard Cite

This work reports the study of the anion effect on the aggregation behavior of the long-chain spacers of dicationic imidazolium-based ionic liquids (ILs) in a 4.75 % (v/ v) ethanol-water solution as well as in ethanol (95 %). The anions studied were Br − , NO 3 − , BF 4 − , SCN − and NTf 2 − .Aggregation behavior was investigated by differential scanning calorimetry (DSC), conductivity, surface tension, and fluorescence. In the ethanol-water solution, the critical aggregation concentration (CAC), free energy aggregation (ΔG°a), and the ionization degree (α) all significantly decreased with the increase in anion hydrophobicity. In ethanol, the CAC and ΔG°a values also decreased with the increase in anion size and hydrophobicity. The free energy adsorption (ΔG°a ds ) data showed that the dicationic ILs have good surfactant activity, and this property improved with the decrease in the hydration radius of the anions. The anion volumes calculated also showed a good correlation with the CAC values for aggregation in ethanol-water solution and ethanol.

show abstract

Section: Introductionmentioning

confidence: 99%

Anion effect on the aggregation behavior of the long-chain spacers dicationic imidazolium-based ionic liquids

Frizzo

Bender

Gindri³

et al. 2015

Colloid Polym Sci

View full text Add to dashboard Cite

show abstract

“…To date, there are brief reports on the tribological properties of R 4 P-derived RTILs [13,[20][21][22][23][24][25]. In this work, we focused on the relationship between the chemical structure and tribological properties of RT-ILs.…”

Section: Introductionmentioning

confidence: 99%

Tribo-Chemistry of Phosphonium-Derived Ionic Liquids

et al. 2010

View full text Add to dashboard Cite

The tribological properties of room temperature ionic liquids containing tetraalkylphosphonium cations were evaluated on the basis of the chemical structure of their salts. The tribochemistry of these ionic liquids was discussed on the basis of the results of tribo-tests and surface analyses. The tribological properties of the tetraalkylphosphonium salts examined in this work were observed to be better than those of 1,3-alkylimidazolium salts. The structure of the alkyl group in the phosphonium cation also has a slight effect on the tribological properties of the salts. During a friction test carried out under lowload conditions, the phosphonium cation was oxidized to phosphate to form a boundary film. This film inhibited the reaction of the bis(trifluoromethanesulfonyl)amide anion that yielded metal fluoride on the rubbed surfaces. The combination of the phosphonium cation with a phosphate anion or thiophosphate anion resulted in a better lubricant than 1,3-alkylimidazolium bis(trifluoromethanesulfonyl)amide. The reactions of the phosphate anion and thiophosphate anion yielded a phosphate boundary film that exhibited better tribological properties than those of the fluoride boundary film.

show abstract

“…They attributed the excellent tribological properties of these ionic liquid films to their strong adsorptions to the interface and the good transfer film-forming abilities on the counterpart surfaces. Yu et al [19,20] synthesized several kinds of novel ionic liquids and tested their tribological properties as thin films. They found that asymmetrical bis-substituted ionic liquids have the best tribological properties among the tested lubricants, i.e., PFPE, corresponding ionic liquids with single cation, and symmetrical bis-substituted ionic liquids, and the anti-wear life of these films increased with the increment of chain length.…”

Section: Introductionmentioning

confidence: 99%

Effect of the Anion on the Tribological Properties of Ionic Liquid Nano-Films on Surface-Modified Silicon Wafers

Zhu

Yan

et al. 2008

Tribol Lett

View full text Add to dashboard Cite

The films of three kinds of 3-butyl-1-methylimidazolium base ionic liquids with thickness of 2 nm were prepared on hydroxyl-terminated and amino-terminated Si substrates by dip-coating method. As anions, tetrafluoroborate, hexafluorophosphate, and adipate, respectively, were chosen. The tribological performances of these thin films were examined by the determination of the film durability and friction coefficient by means of a UMT-2MT tribometer using a steel ball as counterpart. The morphologies of worn surfaces were investigated by a non-contact interferometric microscope. The findings showed that 3-butyl-1-methylimidazolium hexafluorophosphate having the poorest hydrophilicity of the ionic liquids exhibited the best tribological properties on aminated Si surface at 0.4 N and 4 Hz.

show abstract

Synthesis of dicationic symmetrical and asymmetrical ionic liquids and their tribological properties as ultrathin films

Cited by 90 publications

References 34 publications

Anion effect on the aggregation behavior of the long-chain spacers dicationic imidazolium-based ionic liquids

Anion effect on the aggregation behavior of the long-chain spacers dicationic imidazolium-based ionic liquids

Tribo-Chemistry of Phosphonium-Derived Ionic Liquids

Effect of the Anion on the Tribological Properties of Ionic Liquid Nano-Films on Surface-Modified Silicon Wafers

Contact Info

Product

Resources

About