In situ and ex situ AFM investigation of the formation of octadecylsiloxane monolayers

Resch, R.; Grasserbauer, M.; Friedbacher, Gernot; Vallant, Th; Brunner, H.; Mayer, U.; Hoffmann, Helmuth

doi:10.1016/s0169-4332(98)00585-6

Cited by 47 publications

(36 citation statements)

References 30 publications

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“…Again SAM growth began with the initiation of submonolayer islands that grew and eventually coalesced, although a full monolayer was not reached. In 1999 Resch et al studied the self-assembly of octadecylsiloxane molecules from toluene onto mica using both in situ and ex situ AFM methods and concluded that the in situ approach was more suited to study SAM formation [29]. A similar study was carried out on silicon surfaces by Leitner and co workers [30].…”

Section: Background -Amphiphile Adsorption and In Situ Afmmentioning

confidence: 99%

In Situ Study of Model Organic Friction Modifiers Using Liquid Cell AFM: Self-Assembly of Octadecylamine

et al. 2015

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Liquid cell AFM has been applied to study in situ the formation and properties of selfassembled films formed on mica surfaces by octadecylamine from alkane solution.Mica surfaces immersed in hexadecane or dodecane at room temperature show no identifiable surface films. However when octadecylamine solution is injected into the cell a boundary film forms almost immediately. This film takes the form of irregular islands of mean diameter approximately 1 to 3 µm and thickness typically 1.5 nm when measured in contact mode. These islands are believed to correspond to patches of vertically-oriented but tilted octadecylamine or ammonium salt held together primarily by van der Waals forces between adjacent alkyl chains. These films are quite labile in that during scanning of the tip in both tapping and in contact mode changes to the shape of the islands takes place, including consolidation of the island density in the scanned region and depletion from around this area.In situ experiments in which the temperature of the cell is varied over time show that the initially-formed islands disappear at a temperature of ca. 35ºC but are reformed when the cell is re-cooled. Similar tests on samples that remain immersed in solution for extended periods show more stable films, with islands being lost only above about 50-60ºC.The work shows that liquid cell AFM has great promise for studying the formation and properties of the boundary films formed by organic friction modifiers.

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Section: Background -Amphiphile Adsorption and In Situ Afmmentioning

confidence: 99%

In Situ Study of Model Organic Friction Modifiers Using Liquid Cell AFM: Self-Assembly of Octadecylamine

et al. 2015

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“…5 Atomic force microscopy has proved to be a very valuable tool for the analysis of these organic films because the high lateral and depth resolution capability provides unique information on the morphology, size 6,7 and friction 8 -11 of the individual submonolayer structures.…”

Section: Introductionmentioning

confidence: 99%

Atomic force microscopy of thin organic films on silicon in ultrahigh vacuum and under ambient conditions

Reiniger

Basnar

Friedbacher

et al. 2002

Surface & Interface Analysis

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In this paper we investigate thin organic films on silicon oxide by different atomic force microscopy (AFM) techniques. For the preparation of the organic films we chose octadecyltrichlorosilane (OTS), which shows a strong tendency for self-assembly. As substrates we use silicon covered with a native silicon oxide. The self-assembled monolayers are deposited in solution to give octadecylsiloxane (ODS) islands. Island density and size vary, among other things, with the solution age, its concentration and the deposition time. Growth and structure are investigated in air as well as in ultrahigh vacuum (UHV) with AFM. The measurements are performed in contact, non-contact or tapping mode. We found that the ODS islands are 1.6 nm in height in UHV as well as under ambient conditions. From the length of the OTS molecules a height of 2.6 nm should be expected. We attribute the reduced height to a tilt of the alkyl chains. Damping maps show that the energy dissipation on the ODS islands is less than on the silicon oxide substrate.

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“…It should also be emphasized that not only different solids were used in our study, but also these solid surfaces had a signi cantly different pattern of heterogeneity. Yoon and co-workers [22,24] used silica and glass covered by varying amounts of silane reagents, which usually form patches, non-uniformly distributed on the silanized surface, instead of a uniform molecular pattern [28][29][30]. This type of heterogeneity was not present in the systems studied in this program, although heterogeneities associated with the complex composition of the toner substrate were present in our system, as discussed in the previous section.…”

Section: Long-range Attractive Forcesmentioning

confidence: 87%

Long-range attractive forces and energy barriers in de-inking flotation: AFM studies of interactions between polyethylene and toner

Drelich

Nalaskowski

Gosiewska

et al. 2000

Journal of Adhesion Science and Technology

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The interfacial forces between a polyethylene particle and a toner substrate in alkaline aqueous solutions were studied using an atomic force microscope colloidal probe technique. Measurements were taken at pH 9 in water and solutions of 5 £ 10 ¡4 M CaCl 2 , 1 £ 10 ¡4 M Na oleate, and 1 £ 10 ¡4 M Na oleate plus 5 £ 10 ¡4 M CaCl 2 in order to mimic the conditions present during de-inking otation. A polyethylene particle was used to represent the air bubble. The observed interaction forces were described by the extended DLVO theory. An energetic barrier caused by electrical double-layer repulsion was observed in water and Na oleate solutions but was greatly diminished in CaCl 2 solution. A long-range attractive force was found to be present in these systems and was described using a simple exponential function. The long-range attractive force was virtually the same in water and CaCl 2 solution but decreased signi cantly in Na oleate solution because of the reduced hydrophobicity of the interacting surfaces caused by the adsorbed carboxylate layer. However, in the presence of oleate and calcium ions the observed attraction was even stronger and of longer range than in water and CaCl 2 solutions. Moreover, no energetic barrier was observed. These results can be attributed to the presence of precipitated calcium oleates on the interacting surfaces.

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In situ and ex situ AFM investigation of the formation of octadecylsiloxane monolayers

Cited by 47 publications

References 30 publications

In Situ Study of Model Organic Friction Modifiers Using Liquid Cell AFM: Self-Assembly of Octadecylamine

In Situ Study of Model Organic Friction Modifiers Using Liquid Cell AFM: Self-Assembly of Octadecylamine

Atomic force microscopy of thin organic films on silicon in ultrahigh vacuum and under ambient conditions

Long-range attractive forces and energy barriers in de-inking flotation: AFM studies of interactions between polyethylene and toner

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