Effect of chain length on the surface properties of ω-carboxy alkanethiol self-assembled monolayers

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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Chain length effect of alkanethiol self-assembled monolayers on the maximum spreading ratio of impacting water droplets

Colloids and Surfaces A Physicochemical and Engineering Aspects ◽

10.1016/j.colsurfa.2005.03.015 ◽

2005 ◽

Vol 260 (1-3) ◽

pp. 255-263 ◽

Cited By ~ 7

Author(s):

Yu-Wen Chang ◽

Chijioke Ukiwe ◽

Daniel Y. Kwok

Keyword(s):

Chain Length ◽

Self Assembled Monolayers ◽

Water Droplets ◽

Length Effect ◽

Assembled Monolayers ◽

Self Assembled ◽

Maximum Spreading

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Surface vibrations in alkanethiol self-assembled monolayers of varying chain length

The Journal of Chemical Physics ◽

10.1063/1.1643353 ◽

2004 ◽

Vol 120 (8) ◽

pp. 3880-3886 ◽

Cited By ~ 19

Author(s):

A. W. Rosenbaum ◽

M. A. Freedman ◽

S. B. Darling ◽

I. Popova ◽

S. J. Sibener

Keyword(s):

Chain Length ◽

Self Assembled Monolayers ◽

Assembled Monolayers ◽

Surface Vibrations ◽

Self Assembled

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Chain-Length-Dependent Vibrational Resonances in Alkanethiol Self-Assembled Monolayers Observed on Plasmonic Nanoparticle Substrates

Nano Letters ◽

10.1021/nl062283k ◽

2006 ◽

Vol 6 (11) ◽

pp. 2617-2621 ◽

Cited By ~ 40

Author(s):

Carly S. Levin ◽

Benjamin G. Janesko ◽

Rizia Bardhan ◽

Gustavo E. Scuseria ◽

Jeffrey D. Hartgerink ◽

...

Keyword(s):

Chain Length ◽

Self Assembled Monolayers ◽

Plasmonic Nanoparticle ◽

Assembled Monolayers ◽

Self Assembled ◽

Vibrational Resonances

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The Potential of a Nanostructured Titanium Oxide Layer with Self-Assembled Monolayers for Biomedical Applications: Surface Properties and Biomechanical Behaviors

Applied Sciences ◽

10.3390/app10020590 ◽

2020 ◽

Vol 10 (2) ◽

pp. 590 ◽

Cited By ~ 3

Author(s):

Wen-Chien Lan ◽

Ta-Sen Huang ◽

Yung-Chieh Cho ◽

Yueh-Tzu Huang ◽

Christopher J. Walinski ◽

...

Keyword(s):

Titanium Oxide ◽

Surface Properties ◽

Contact Stiffness ◽

Substrate Surface ◽

Stress Shielding ◽

Shielding Effect ◽

Self Assembled Monolayers ◽

Nanostructured Titanium ◽

Assembled Monolayers ◽

Self Assembled

This study investigated the surface properties and biomechanical behaviors of a nanostructured titanium oxide (TiO) layer with different self-assembled monolayers (SAMs) of phosphonate on the surface of microscope slides. The surface properties of SAMs were analyzed using scanning electron microscopy, X-ray photoemission spectroscopy, and contact angle goniometry. Biomechanical behaviors were evaluated using nanoindentation with a diamond Berkovich indenter. Analytical results indicated that the homogenous nanostructured TiO surface was formed on the substrate surface after the plasma oxidation treatment. As the TiO surface was immersed with 11-phosphonoundecanoic acid solution (PUA-SAM/TiO), the formation of a uniform SAM can be observed on the sample surface. Moreover, the binding energy of O 1s demonstrated the presence of the bisphosphonate monolayer on the SAMs-coated samples. It was also found that the PUA-SAM/TiO sample not only possessed a higher wettability performance, but also exhibited low surface contact stiffness. A SAM surface with a high wettability and low contact stiffness could potentially promote biocompatibility and prevent the formation of a stress shielding effect. Therefore, the self-assembled technology is a promising approach that can be applied to the surface modification of biomedical implants for facilitating bone healing and osseointegration.

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