# gst: the strong impact on nanosheets by the weak van der Waals force

<< Van der Waals is a weak force that allows neutral molecules to attract one another through randomly fluctuating dipoles, depending on distance. Though small, its effects can be seen in the macro world, like when geckos walk up walls. >> 

<< Van der Waals forces are everywhere and, essentially, at the nanoscale everything is sticky, (..) When you put a large, flat particle on a large, flat surface, there's a lot of contact, and it's enough to permanently deform a particle that's really thin and flexible. >> 

Matt Jones. 

<< the ubiquitous, "weak" van der Waals force was sufficient to indent a rigid silver nanosheet. The phenomenon suggests possible applications in nanoscale optics or catalytic systems. >>

<< In further experiments, (..) nanospheres could be used to control the shape of the deformation, from single ridges when two spheres are close, to saddle shapes or isolated bumps when the spheres are farther apart. >> 

Mike Williams. Weak force has strong impact on nanosheets. Rice University. Dec 15, 2020. 

https://phys.org/news/2020-12-weak-strong-impact-nanosheets.html

Sarah M. Rehn, Theodor M. Gerrard-Anderson, et al. Mechanical Reshaping of Inorganic Nanostructures with Weak Nanoscale Forces. Nano Lett. doi: 10.1021/ acs.nanolett.0c03383. Dec 10, 2020. 

https://pubs.acs.org/doi/10.1021/acs.nanolett.0c03383  

Also

keyword 'van der Waals' in FonT

https://flashontrack.blogspot.com/search?q=van+der+Waals

# chem: Van der Waals' bonds: to measure the tensile strength and the force required to pull the crystal until it breaks

<< Van der Waals' are weak electric forces that attract atoms to one another through subtle shifts in the atom's electron configurations >>

AA << grew and compared three different types of crystals: one pure gallium selenide, one with 0.6 percent tellurium and one with 10.6 percent tellurium. To test the effect on the tellurium on interlayer bonding, [AA] invented the equivalent of a crystal sandwich opener. Their system is able to measure with exquisite detail the tensile strength, the force required to pull the crystal until it breaks >>

Opening the Van der Waals' Sandwich. Oct 31, 2017

https://publishing.aip.org/publishing/journal-highlights/opening-van-der-waals-sandwich

Tadao Tanabe, Shu Zhao, et al. Effect of adding Te to layered GaSe crystals to increase the van der Waals bonding force featured. Journal of Applied Physics  2017; 122 (16) doi: 10.1063/1.4986768

http://aip.scitation.org/doi/full/10.1063/1.4986768

# s-chem: weak van der Waals' bonds to self-assembly

Gecko Hamaker, a  open source << software to calculate van der Waals forces between molecules and meso/nanoscale units, predict molecular organization and evaluate whether new combinations of materials will stick together, thereby facilitating the design of meso/nanoscale self-assembly >>

http://m.phys.org/news/2015-09-open-science-van-der-waals-interaction.html

# s-gst-chem: weak long-range van der Waals interactions in self-assembly

<< The researchers found that weak long-range van der Waals (attractive or repulsive forces between molecules or atomic groups that do not arise from interactions due to a covalent bond or electrostatic force) yielded the largest contribution to the molecule-surface interaction >>

A self-assembling molecular nanoswitch
A possible future molecular memory device. January 18, 2016

http://www.kurzweilai.net/a-self-assembling-molecular-nanoswitch

<< We find that on both substrates, the adsorbate-substrate interaction is dominated by attractive van der Waals forces >>

Moritz Müller, Katharina Diller, et al. Interfacial charge rearrangement and intermolecular interactions: Density-functional theory study of free-base porphine adsorbed on Ag(111) and Cu(111). The Journal of Chemical Physics, 2016; 144 (2): 024701 DOI: 10.1063/1.4938259 (open access)

http://scitation.aip.org/content/aip/journal/jcp/144/2/10.1063/1.4938259

# gst: unusual properties of substances trapped in nanobubbles.

AA << modeled the behavior of nanobubbles appearing in van der Waals heterostructures and the behavior of substances trapped inside the bubbles. >>

<< The properties exhibited by substances inside the van der Waals nanobubbles are quite unusual. For example, water trapped inside a nanobubble displays a tenfold decrease in its dielectric constant and etches the diamond surface, something it would never do under normal conditions. Argon which typically exists in liquid form when in large quantities can become solid at the same pressure if trapped inside very small nanobubbles with a radius of less than 50 nanometers. >>

Substances trapped in nanobubbles exhibit unusual properties. Skolkovo Institute of Science and Technology. April 14, 2020.

https://phys.org/news/2020-04-substances-nanobubbles-unusual-properties.html

T. F. Aslyamov,  E. S. Iakovlev, et al. Model of graphene nanobubble: Combining classical density functional and elasticity theories. J. Chem. Phys. 152, 054705. Feb 3, 2020. 

https://aip.scitation.org/doi/10.1063/1.5138687

# s-gst: emerging mixed-dimensional weak heterostructures

<< The isolation of a growing number of two-dimensional (2D) materials has inspired worldwide efforts to integrate distinct 2D materials into van der Waals (vdW) heterostructures >>

<< the vdW heterostructure concept can be extended to include the integration of 2D materials with non-2D materials that adhere primarily through non-covalent interactions >>

Deep Jariwala, Tobin J. Marks & Mark C. Hersam.  Mixed-dimensional van der Waals heterostructures. Nature Materials 16, 170–181 (2017) doi:10.1038/nmat4703.

https://www.nature.com/nmat/journal/v16/n2/full/nmat4703.html

FonT

teoria dei sistemi prevede, senz'altro in prima approx, il trasferimento, l'esportazione di concetti e modelli tra differenti contesti, anche lontani tra loro ...

cfr:  Ludwig von Bertalanffy. General System Theory (1969). Teoria generale dei sistemi. Arnoldo Mondadori Editore SpA Milano (1983).

https://it.m.wikipedia.org/wiki/Ludwig_von_Bertalanffy

# s-chem: hydrogen bonding, the strength in the middle ...

<< Hydrogen bonds are much weaker than chemical bonds, but stronger than intermolecular van der Waals interactions >>

<< With this study, [AA] have opened up new ways to identify three-dimensional molecules such as nucleic acids or polymers via observation of hydrogen atoms >>

Hydrogen bonds directly detected for the first time. May 12, 2017

https://m.phys.org/news/2017-05-hydrogen-bonds.html

Shigeki Kawai, Tomohiko Nishiuchi, et al. Direct quantitative measurement of the C═O⋅⋅⋅H–C bond by atomic force microscopy. Science Advances. 12 May 2017:Vol. 3, no. 5, e1603258 DOI: 10.1126/sciadv.1603258

http://advances.sciencemag.org/content/3/5/e1603258

# gst: shuffling atomic layers like playing cards (almost like to compose a quasi-stochastic poetry)

<< Materials scientists can now shuffle layered compounds together, much like combining two different decks of cards. >>️

<< The technique, recently discovered (..), is leading to development of new materials with unusual electron transport properties that have potential applications in next-generation quantum technologies. >>️

<< The discovered technique has shown another unexpected and promising application in new materials design. The "reshuffling" approach can generate thermally stable three-dimensional (3D) heterostructures from layered transition metal dichalcogenides (TMDCs). These are van der Waals materials composed of metal nanolayers sandwiched between two other layers of chalcogens—sulfur, selenium, or tellurium. Similar to graphite, these compounds can be exfoliated into 2D layers, which display unique electron transport properties and quantum phenomena. >>

️

Scientists shuffle atomic layers like playing cards to make new quantum materials. Ames Laboratory. Jul 20, 2021. 

https://phys.org/news/2021-07-scientists-shuffle-atomic-layers-cards.html

Ihor Z. Hlova, Prashant Singh, et al. Incommensurate transition-metal dichalcogenides via mechanochemical reshuffling of binary precursors. 

Nanoscale Adv. 3: 4065-4071. doi: 10.1039/ D1NA00064K. Jun 7, 2021. 

https://pubs.rsc.org/en/content/articlelanding/2021/NA/D1NA00064K

Also

1836 - immillante sandwich. Notes. Nov 28, 2004 (quasi-stochastic poetry)

https://inkpi.blogspot.com/2004/11/1836-immillante-sandwich.html