Role of relative humidity in atomic force microscopy imaging

Thundat, Thomas; Zheng, Xingrong; Chen, G.Y.; Warmack, R. J.

doi:10.1016/0167-2584(93)91119-9

Cited by 29 publications

(31 citation statements)

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“…While others have observed a similar transition point ( maximum of adhesion) on mica [69,211]. Thundat et al [194], observed a flat response in force at relative humidity less than 20%, followed by a pronounced increase which did not level off at humidity up to 80%. Salmeron and et al found a virtually flat response in adhesion force on mica at relative humidity less than 20%, an increase near 20%, and a maximum at 25-30%, followed by a gradual decrease and found that the structure and height of the water layer on mica as a function of relative humidity [68].…”

Section: Meniscus Force On Hydrophilic Surfacesmentioning

confidence: 86%

“…Water condenses into the gap at the contact region between hydrophilic particles. This is with AFM [69,119,[190][191][192][193][194][195][196][197][198]. Many experiments showed a significant dependency of the adhesion force on the relative humidity [40,52,54,56,57,183].…”

Section: Influence Of Humidity On Adhesionmentioning

confidence: 99%

“…Many experiments showed a significant dependency of the adhesion force on the relative humidity [40,52,54,56,57,183]. A continuous increase humidity was, for example, observed for the interaction of a silicon nitride tip with mica [194], between silica particles [199], a silica particle and a silicon wafer [200], or between a silicon nitride tip and molybdenum trioxide [201]. The adhesion force between particles or particle surface by using AFM colloidal probe technique depending on relative humidity [190,202,203].…”

Section: Influence Of Humidity On Adhesionmentioning

confidence: 99%

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On the Adhesion between Fine Particles and Nanocontacts: An Atomic Force Microscope Study

et al. 2006

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To optimize the handling of fine powders in industrial applications, understanding the interaction forces between single powder particles is fundamental. The forces between colloidal particles dominate the behavior of a great variety of materials, including paints, paper, soil, and many industrial processes. With the invention of the atomic force microscope (AFM), the direct measurement of the interaction between single micron-sized particles became possible. The adhesional contact between a particle and a substrate is a parameter for analyzing pull-off force data generated by AFM. The aim of this study was to understand surface interactions between fine particles. I measured the adhesion forces between AFM tips or particles attached to AFM cantilevers and different solid samples. Smooth and homogeneous surfaces such as silicon wafer, mica, or highly oriented pyrolytic graphite (HOPG), and more rough and heterogeneous surfaces such as iron particles or patterns of TiO 2 nanoparticles on silicon wafer were used. First, I addressed to the wellknown issue that AFM adhesion experiment results show wide distributions of adhesion forces rather than a single value. My experimental results show that variations in adhesion forces comprise fast (i.e., from one force curves to the next) random fluctuations and slower fluctuations, which occur over tens or hundreds of consecutive measurements. Slow fluctuations are not likely to be the result of variations in external factors such as lateral position, temperature, humidity, and so forth because those were kept constant. Even if two solid bodies are brought into contact under precisely the same conditions (same place, load, direction, etc.) the result of such a measurement will often not be the same as for the previous contact. The measurement itself will induce structural changes in the contact region which can change the value for the next adhesion force measurement.In the second part I studied the influence of humidity on the adhesion of nanocontacts. Humidity was adjusted relatively fast to minimize tip wear during one experiment. For hydrophobic surfaces, no signification change of adhesion force with humidity was observed. Adhesion force-versus-humidity curves recorded with hydrophilic surfaces either showed a maximum or continuously increased. I demonstrate that the results can be interpreted with simple continuum theory of the meniscus force. The meniscus force is calculated based on a model that includes surface roughness and takes into account different AFM tip (or particle) shapes by a two-sphere-model.Experimental and theoretical results show that the precise contact geometry has a critical influence on the humidity dependence of the adhesion force.Changes of tip geometry on the sub-10-nm length scale can completely change adhesion force-versus-humidity curves. Our model can also explain the differences between earlier AFM studies, where different dependencies of the adhesion force on humidity were observed.Keywords: Atomic force microscopy (AFM), cantile...

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Section: Meniscus Force On Hydrophilic Surfacesmentioning

confidence: 86%

Section: Influence Of Humidity On Adhesionmentioning

confidence: 99%

Section: Influence Of Humidity On Adhesionmentioning

confidence: 99%

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On the Adhesion between Fine Particles and Nanocontacts: An Atomic Force Microscope Study

et al. 2006

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“…Ces expériences sur les modifications de surface demandent un très bon contrôle de la composition chimique de l'interface pointe-échantillon. Ainsi, plonger la tête du microscope dans un gaz neutre permet de réduire considérablement les problèmes dus à la contamination des échantillons à l'air [10,11]. L'unité principale du microscope est donc placée dans une boîte à gant en plexiglass, qui est ensuite purgée avec un gaz d'azote pur, pendant au moins 12 heures.…”

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“…1). Ce flux d'azote saturé en eau est obtenu en faisant passer, à température ambiante, de l'azote pur dans un récipient contenant de l'eau désionisée [11]. Le Fig.…”

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Nano-écriture sur couche d'or

Lebreton

Wang

1994

Microsc. Microanal. Microstruct.

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Robust deposition of lambda DNA on mica for imaging by AFM in air

Cervantes

Gutiérrez–Medina

2014

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Long DNA molecules remain difficult to image by atomic force microscopy (AFM) because of their tendency to entanglement and spontaneous formation of networks. We present a comparison of two different DNA deposition methods operating at room temperature and humidity conditions, aimed at reproducible imaging of isolated and relaxed λ DNA conformations by AFM in air. We first demonstrate that a standard deposition procedure, consisting in adsorption of DNA in the presence of divalent cations followed by washing and air-drying steps, yields a coexistence of different types of λ DNA networks with a only a few isolated DNA chains. In contrast, deposition using a spin-coating-based technique results in reproducible coverage of a significant fraction of the substrate area by isolated and relaxed λ DNA molecules, with the added benefit of a reduction in the effect of a residual layer that normally embeds DNA strands and leads to an apparent DNA height closer to the expected value. Furthermore, we show that deposition by spin-coating is also well-suited to visualize DNA-protein complexes. These results indicate that spin-coating is a simple, powerful alternative for reproducible sample preparation for AFM imaging.

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Role of relative humidity in atomic force microscopy imaging

Cited by 29 publications

References 14 publications

On the Adhesion between Fine Particles and Nanocontacts: An Atomic Force Microscope Study

On the Adhesion between Fine Particles and Nanocontacts: An Atomic Force Microscope Study

Nano-écriture sur couche d'or

Robust deposition of lambda DNA on mica for imaging by AFM in air

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