Comparison of the Physicochemical Properties of Carboxylic and Phosphonic Acid Self-Assembled Monolayers Created on a Ti-6Al-4V Substrate

This study compared the tribological properties in nano- and millinewton load ranges of Ti‑6Al-4V surfaces that were modified using self-assembled monolayers (SAMs) of carboxylic and phosphonic acids. The effectiveness of the creation of SAMs with the use of the liquid phase deposition (LPD) technique was monitored by the contact angle measurement, the surface free energy (SFE) calculation, X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectroscopy (FTIR) measurements. The obtained results indicated that more stable and well-ordered layers, which were characterized by the lowest values of the coefficient of friction, adhesion, and wear rate, were obtained using phosphonic acid as a surface modifier. Based on the obtained results, it was found that the Ti-6Al-4V alloy modified by phosphonic acid would be the most advantageous for practical applications, especially in micro- and nanoelectromechanical systems (MEMS/NEMS).

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Mixed self-assembled monolayers of terminally functionalized thiols at gold surfaces characterized by angle resolved X-ray photoelectron spectroscopy (ARXPS) studies

Fresenius Journal of Analytical Chemistry ◽

10.1007/s002160051487 ◽

1999 ◽

Vol 365 (1-3) ◽

pp. 272-276 ◽

Cited By ~ 18

Author(s):

J. Heeg ◽

U. Schubert ◽

F. Küchenmeister

Keyword(s):

Photoelectron Spectroscopy ◽

Self Assembled Monolayers ◽

Gold Surfaces ◽

X Ray ◽

Assembled Monolayers ◽

Self Assembled

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X-ray spectroscopy characterization of self-assembled monolayers of nitrile-substituted oligo(phenylene ethynylene)s with variable chain length

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.3.2 ◽

2012 ◽

Vol 3 ◽

pp. 12-24 ◽

Cited By ~ 13

Author(s):

Hicham Hamoudi ◽

Ping Kao ◽

Alexei Nefedov ◽

David L Allara ◽

Michael Zharnikov

Keyword(s):

Chain Length ◽

Photoelectron Spectroscopy ◽

Self Assembled Monolayers ◽

Phenylene Ethynylene ◽

X Ray ◽

Molecular Length ◽

Assembled Monolayers ◽

Self Assembled ◽

Gold Thiolate

Self-assembled monolayers (SAMs) of nitrile-substituted oligo(phenylene ethynylene) thiols (NC-OPEn) with a variable chain length n (n ranging from one to three structural units) on Au(111) were studied by synchrotron-based high-resolution X-ray photoelectron spectroscopy and near-edge absorption fine-structure spectroscopy. The experimental data suggest that the NC-OPEn molecules form well-defined SAMs on Au(111), with all the molecules bound to the substrate through the gold–thiolate anchor and the nitrile tail groups located at the SAM–ambient interface. The packing density in these SAMs was found to be close to that of alkanethiolate monolayers on Au(111), independent of the chain length. Similar behavior was found for the molecular inclination, with an average tilt angle of ~33–36° for all the target systems. In contrast, the average twist of the OPEn backbone (planar conformation) was found to depend on the molecular length, being close to 45° for the films comprising the short OPE chains and ~53.5° for the long chains. Analysis of the data suggests that the attachment of the nitrile moiety, which served as a spectroscopic marker group, to the OPEn backbone did not significantly affect the molecular orientation in the SAMs.

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Interfacial Adhesion of Cu to Self-Assembled Monolayers on SiO2

MRS Proceedings ◽

10.1557/proc-695-l7.7.1 ◽

2001 ◽

Vol 695 ◽

Author(s):

G. Cui ◽

M. Lane ◽

K. Vijayamohanan ◽

G. Ramanath

Keyword(s):

Binding Energy ◽

Photoelectron Spectroscopy ◽

Interfacial Adhesion ◽

Adhesion Energy ◽

Binding Energies ◽

Self Assembled Monolayers ◽

Chemical Binding ◽

Barrier Materials ◽

Assembled Monolayers ◽

Self Assembled

ABSTRACTAs the critical feature size in microelectronic devices continues to decrease below 100 nm, new barrier materials of > 5 nm thickness are required. Recently we have shown that self-assembled monolayers (SAMs) are attractive candidates that inhibit Cu diffusion into SiO2. For SAMs to be used as barriers in real applications, however, they must also promote adhesion at the Cu/dielectric interfaces. Here, we report preliminary quantitative measurements of interfacial adhesion energy and chemical binding energy of Cu/SiO2 interfaces treated with nitrogen-terminated SAMs. Amine-containing SAMs show a ~10% higher adhesion energy with Cu, while interfaces with Cu-pyridine bonds actually show degraded adhesion, when compared with that of the reference Cu/SiN interface. However, X-ray photoelectron spectroscopy (XPS) measurements show that Cu-pyridine and Cu-amine interactions have a factor-of-four higher binding energy than that of Cu-N bonds at Cu/SiN interfaces. The lack of correlation between adhesion and chemical binding energies is most likely due to incomplete coverage of SAMs.

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Self-Assembled Monolayers of 12-Mercaptododecylphosphonic Acid on Titania Particles; Application to the Extraction of Heavy Metals

MRS Proceedings ◽

10.1557/proc-847-ee13.29 ◽

2004 ◽

Vol 847 ◽

Author(s):

Sébastien Anthérieu ◽

Florence Brodard-Séverac ◽

Gilles Guerrero ◽

P. Hubert Mutin

Keyword(s):

Heavy Metals ◽

Chemical Analysis ◽

Phosphonic Acid ◽

Metal Extraction ◽

Self Assembled Monolayers ◽

Extraction Ability ◽

Self Assembled Monolayer ◽

Inorganic Hybrid ◽

Assembled Monolayers ◽

Self Assembled

ABSTRACTTitania particles (P25 DEGUSSA AG) were treated by a solution of 12-mercaptododecyl-phosphonic acid (MDPA) in toluene to obtain an organic-inorganic hybrid material with thiol functions at the surface. This material was characterized by chemical analysis, solid state 31P MAS NMR and FTIR spectroscopies, and XPS. Reaction of the phosphonic acid end of MDPA with the TiO2 surface led to the formation of a relatively dense and well-ordered self-assembled monolayer (SAM), with a density of about 3.9 SH functions per nm2. This material was tested for the extraction of mercury in water at pH 7, 9, and 11. Chemical analysis indicated no loss of SH functionality, even at pH 11. The best extraction results were obtained at pH 9 and 11, with a metal extraction ability between 85 and 90%.

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