A new method for measuring the surface energy of solids

Kendall, Kevin; Alford, N.McN.; Birchall, J. D.

doi:10.1038/325794a0

Cited by 93 publications

(61 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For these values, the surface energy of a monomer particle was calculated to be γ = 1.7×10 −2 J m −2 for the monodisperse and 2.0×10 −2 J m −2 for the polydisperse SiO 2 particles. These values are in very good agreement with 2.5×10 −2 J m −2 measured for silica powder by Kendall et al (1987) and 1.86×10 −2 J m −2 measured for ∼1 µm SiO 2 particles by Heim et al (1999). This confirms the validity of the scaling model developed in Weidling et al (2012).…”

Section: Estimation Of the Surface Energy Of Macroscopic Aggregatessupporting

confidence: 79%

Submillimetre-sized dust aggregate collision and growth properties

Brisset

Heißelmann

Kothe

et al. 2016

A&A

View full text Add to dashboard Cite

Context. In the very first steps of the formation of a new planetary system, dust agglomerates grow inside the protoplanetary disk that rotates around the newly formed star. In this disk, collisions between the dust particles, induced by interactions with the surrounding gas, lead to sticking. Aggregates start growing until their sizes and relative velocities are high enough for collisions to result in bouncing or fragmentation. With the aim of investigating the transitions between sticking and bouncing regimes for colliding dust aggregates and the formation of clusters from multiple aggregates, the Suborbital Particle and Aggregation Experiment (SPACE) was flown on the REXUS 12 suborbital rocket. Aims. The collisional and sticking properties of sub-mm-sized aggregates composed of protoplanetary dust analogue material are measured, including the statistical threshold velocity between sticking and bouncing, their surface energy and tensile strength within aggregate clusters. Methods. We performed an experiment on the REXUS 12 suborbital rocket. The protoplanetary dust analogue materials were micrometre-sized monodisperse and polydisperse SiO 2 particles prepared into aggregates with sizes around 120 µm and 330 µm, respectively and volume filling factors around 0.37. During the experimental run of 150 s under reduced gravity conditions, the sticking of aggregates and the formation and fragmentation of clusters of up to a few millimetres in size was observed. Results. The sticking probability of the sub-mm-sized dust aggregates could be derived for velocities decreasing from ∼22 to 3 cm s −1 . The transition from bouncing to sticking collisions happened at 12.7 +2.1 −1.4 cm s −1 for the smaller aggregates composed of monodisperse particles and at 11.5 +1.9 −1.3 and 11.7 +1.9 −1.3 cm s −1 for the larger aggregates composed of mono-and polydisperse dust particles, respectively. Using the pull-off force of sub-mm-sized dust aggregates from the clusters, the surface energy of the aggregates composed of monodisperse dust was derived to be 1.6×10 −5 J m −2 , which can be scaled down to 1.7×10 −2 J m −2 for the micrometre-sized monomer particles and is in good agreement with previous measurements for silica particles. The tensile strengths of these aggregates within the clusters were derived to be 1.9 +2.2 −1.2 Pa and 1.6 +0.7 −0.6 Pa for the small and large dust aggregates, respectively. These values are in good agreement with recent tensile strength measurements for ∼mm-sized silica aggregates. Conclusions. Using our data on the sticking-bouncing threshold, estimates of the maximum aggregate size can be given. For a minimum mass solar nebula model, aggregates can reach sizes of ∼1 cm.

show abstract

Section: Estimation Of the Surface Energy Of Macroscopic Aggregatessupporting

confidence: 79%

Submillimetre-sized dust aggregate collision and growth properties

Brisset

Heißelmann

Kothe

et al. 2016

A&A

View full text Add to dashboard Cite

show abstract

“…For particle diameters between 1 and 5 km, they found a linear relation between the pull-o † force (ranging from 50 to 250 nN) and the grain size in agreement with the predictions by the JKR model. As a result, Heim et al (1999) deduced a speciÐc surface energy of c \ 0.019 J m~2, which corresponds to the earlier value of c \ 0.025 J m~2 by Kendall et al (1987). In addition, an increased surface energy due to, e.g., adsorbed layers is not the cause of H 2 O the high capture velocity as indicated by the fact that the collision experiments using particles coated with a hydrophobic layer of silane showed no signiÐcant di †erence from those with noncoated surfaces.…”

Section: Discussionmentioning

confidence: 99%

“…The authors experimentally veriÐed their model with centimeter-sized objects. Applied to a 1 km silica sphere adhering to a Ñat silica surface and setting the surface energy of each surface to c \ 0.025 J m~2 (Kendall, Alford, & Birchall 1987), the separation force amounts to several 100 nN. Using a modiÐed atomic force microscope, Heim et al (1999) measured the separation forces between silica spheres of several diameters down to 1 km and smooth, Ñat, and curved surfaces.…”

Section: Previous W Ork On Small-particle Collisionsmentioning

confidence: 99%

Analogous Experiments on the Stickiness of Micron‐sized Preplanetary Dust

Poppe

Blum

Henning

2000

ApJ

208

189

View full text Add to dashboard Cite

In the early solar nebula, the formation of planetesimals and cometesimals is believed to be due to inelastic collisions of initially micron-sized grains. The collisions are caused by relative velocities due to size-dependent interactions with the surrounding dilute gas. The grain growth process is determined by the velocity-dependent sticking efficiency upon collisions. Therefore, we performed experiments with eight samples of micron-sized particles consisting of monodisperse silica spheres, of irregularly shaped diamond, enstatite, and silicon carbide grains, and of silicon carbide whiskers. We determined the sticking probability and the energy loss upon bouncing collisions by studying individual grain-target collisions in vacuum. We found a sticking probability higher than predicted by previous theoretical work. Grain size, roughness, and primarily grain shape, i.e., the di †erence of spherical versus irregular grain shape, is important for the collisional behavior, whereas the material properties are rather unimportant. Our results indicate that the preplanetary dust aggregation is more e †ective than previously thought.

show abstract

“…The surface tension of liquids has been understood and measured since the time of Young's and Laplace [91]. In 1884 van der Waals proposed a deep and elegant theory of the surface tension of liquids, which has since been rediscovered, and give important extensions, by Cahn and Hilliard [92].…”

Section: Liquids and Liquid/solid Interfacesmentioning

confidence: 99%

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

et al. 2006

View full text Add to dashboard Cite

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...

show abstract

A new method for measuring the surface energy of solids

Cited by 93 publications

References 22 publications

Submillimetre-sized dust aggregate collision and growth properties

Submillimetre-sized dust aggregate collision and growth properties

Analogous Experiments on the Stickiness of Micron‐sized Preplanetary Dust

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

Contact Info

Product

Resources

About