'Sticky waves': Molecular interactions at the nanoscale - What's Mathis' take?

Post new topic   Reply to topic

View previous topic View next topic Go down

'Sticky waves': Molecular interactions at the nanoscale - What's Mathis' take?

Post by Cr6 on Sun Mar 13, 2016 11:16 pm

See these Mathis' papers on Van der Waal forces. He clearly states that this force invalidates electron bonding.  

228. MORE PROBLEMS WITH THE STRONG FORCE
http://milesmathis.com/strong2.html

Re-assigning Boltzmann's Constant
-also a re-assignment of Avogadro's constant

http://milesmathis.com/boltz.pdf
Mathis wrote:I will be told that by my velocity argument, faster molecules will also occupy more space in the same time, adding to density. That is true, but it doesn't explain the increase in speed. What is causing the molecules of gas to move faster when we raise the temperature? If we follow the current explanation, we have no mechanism for the increase in speed. If we want to increase my speed mechanically, we have to push me somehow. What is pushing the molecules to move faster? You see how the current answer is an answer without a mechanism. “Higher temperature causes molecules to move faster.” That is an answer with no physical content, since we aren't told how. But with my theory, we have a mechanical answer. If the molecules increase their speed, it is because we have added photons to the container. More photons means more collisions, more pushing, and higher speed for molecules. Heat is basically denser charge, either because we have added photons, or because the photons we already had are getting bigger (by stacking on new spins).

That is why I have both terms in my equation. We have to follow both the molecules and the photons. In upcoming papers, I will show how to expand my equation even more. To do that, we will have to rewrite all the so-called van der Waals corrections to the ideal gas law, using photon-molecule interactions. Hopefully you can already see how my field gives us many more degrees of freedom to play with, while keeping everything mechanical. We won't need any of the fudges currently used to extend the historical gas laws.

The Third Wave - Part VI
- A Redefinition of Gravity


http://www.milesmathis.com/third6.html
Mathis wrote:The reason that this unimportance of mass is curious is that molecules are not all the same. For example, a molecule of neon gas weighs five times more than a molecule of hydrogen gas. And yet in these equations they act the same. If both molecules have the same temperature, and therefore the same speed*, you would expect the molecules of neon to have five times the momentum. But they don’t. Or, if they do, this momentum somehow does not translate into pressure.
      Van Der Waals state equation differentiates the two molecules by volume, since a larger molecule will cause more unavailable volume, which will tend to increase both the temperature and the pressure. But, as we have seen, this correction will only make a difference at extremes. At more normal temperatures and pressures, the ideal gas law will work. This fact means that van der Waals correction cannot explain the full mechanics of the situation. The fact that there is any situation in which increased mass does not cause increased pressure is a sign of the limits of our knowledge. Other signs of this limit are the two new constants in the van der Waals equation of state, which are different for different gases and which can be determined only from experiment. That is, they are heuristic corrections, with no theoretical underpinning.

==============

March 10, 2016

'Sticky waves': Molecular interactions at the nanoscale

(more at link...)
By Tom Fleischman
Robert DiStasio/Alexandre Tkatchenko

An accurate description of the van der Waals forces between objects at the nanoscale must account for the electrostatic interactions between wavelike charge density fluctuations. These forces are ubiquitous in nature and influence the chemical and physical properties of systems throughout chemistry, biology, physics and materials science.

Robert DiStasio
DiStasio
Alexandre Tkatchenko
Tkatchenko

Like the gravitational forces that are responsible for the attraction between the Earth and the moon, as well as the dynamics of the entire solar system, there exist attractive forces between objects at the nanoscale.

These are the so-called van der Waals forces, which are ubiquitous in nature and thought to play a crucial role in determining the structure, stability and function of a wide variety of systems throughout the fields of biology, chemistry, physics and materials science.

“To put it simply, every molecular system and every material in nature experiences these forces,” said Robert A. DiStasio Jr., assistant professor of chemistry and chemical biology in the College of Arts and Sciences. “In fact, we are finding that their influence is quite extensive, and includes protein-drug interactions, the stability of the DNA double helix, and even the peculiar adhesion properties of the gecko’s foot.”

When compared with the covalent bond (which involves the sharing of electron pairs between atoms), van der Waals forces are relatively weak and arise from instantaneous electrostatic interactions between the fluctuating electron clouds that surround microscopic objects. However, these forces are still quantum mechanical in origin and have posed a substantial challenge for both theory and experiment to date.

In a paper in the March 11 issue of Science, DiStasio and collaborator Alexandre Tkatchenko of the University of Luxembourg and the Fritz Haber Institute have put forth a new proposition for describing van der Waals forces among objects at the nanoscale.

Generally speaking, there are two schools of thought regarding these forces. The prevailing description of van der Waals interactions among most chemists and biologists is the picture of two induced electric dipoles, similar to the N and S poles of a magnet, representing the uneven distributions of positive and negative charges. The picture espoused by many physicists, however, centers around the fact that wavelike vacuum fluctuations are responsible for the van der Waals interactions among larger macroscopic objects.

In their work, DiStasio and Tkatchenko demonstrate that these fundamental forces between nanostructures must also be described by the electrostatic interactions between wavelike (or delocalized) charge density fluctuations instead of the aforementioned particle-like (or local) induced dipoles. They believe their work could help to bridge the gap between these two belief systems, and help scientists understand and control the interactions between objects at the nanoscale.

Our work is demonstrating that there is a much wider variety of systems, such as nanostructured systems, where you have to think about the van der Waals force in terms of interactions between waves instead of interactions between particles,” Tkatchenko said.

Paul McEuen, the John A. Newman Professor of Physical Science and director of the Kavli Institute at Cornell for Nanoscale Science, sees the duo’s research as an important first step in a long, complicated journey to what McEuen half-jokingly characterized as “solving biology.”

“It sounds like a rather boring problem, but it’s actually a deeply important problem, the way biomolecules assemble and so on,” said McEuen. “It’s a hugely important problem, especially for someone like me, who’s a nano-guy, but it’s going to take time to solve.”

McEuen is excited about the work, and said he and DiStasio are expecting to collaborate on related research in the future.

“This work provides a conceptual framework, or common language, that biologists, chemists, physicists and materials scientists can use to describe van der Waals forces at the nanoscale,” DiStasio said. “It also provides a computational framework for accurately predicting how these ubiquitous interactions influence the physical and chemical properties of matter.”

This research was supported by grants from Cornell University, the European Research Council and the Deutsche Forschungsgemeinschaft.

https://www.news.cornell.edu/stories/2016/03/sticky-waves-molecular-interactions-nanoscale

Cr6
Admin

Posts : 676
Join date : 2014-08-09

View user profile http://milesmathis.the-talk.net

Back to top Go down

Re: 'Sticky waves': Molecular interactions at the nanoscale - What's Mathis' take?

Post by Cr6 on Thu Mar 17, 2016 2:50 am

Seems to be a big topic in the Nano-sizing space:

http://www.thenanoage.com/van-der-Waals-forces.htm

THE FORCE IS WEAK IN THIS ONE

The van der Waals' forces (or interactions), named after Dutch scientist Johannes Diderik van der Waals (November 23, 1837 - March 8, 1923), are the attractive or repulsive forces between atoms, molecules, (or between parts of the same molecule) and surfaces, other than those due to covalent bonds or electrostatic interactions between ions with themselves or neutral molecules. They differ from covalent and ionic bonding in that they are caused by correlations in the fluctuating polarizations of nearby particles (a consequence of quantum dynamics). The term includes forces between permanent dipole and a corresponding induced dipole, and instantaneous induced dipole-dipole forces (London dispersion force). "Van der Waals' forces" is also used loosely as a synonym for the totality of intermolecular forces. Compared with normal chemical bonds, van der Waals' forces are relatively weak, but play a fundamental role in diverse fields such as supramolecular chemistry, structural biology, surface science, polymer science, nanotechnology, and condensed matter physics.

There are three van der Waals' forces:
Dipole-Dipole forces occur in polar molecules (those that have unequal sharing of electrons around their atoms, leading to part of the molecule being more positively charged, and part being more electronegative.) In a solution where there are billions of molecules with a slight charge variance on each side, the negative part of one molecule will orient itself with the positive side of a neighboring molecule. These intermolecular forces cause the molecules to 'stick' together.

Dispersion forces exist between non-polar molecules where, on average, there is equal sharing of electrons. Electrons are not stationary, however, and their constant movement is probabilistic, meaning that at one particular instant there might be a small charge variance on one side of the molecule or the other. This temporary charge lasts only for an instant before disappearing as quickly as it formed, but while it exists, it creates a weak intermolecular dipole force.

Hydrogen bonding is exactly the same as a dipole-dipole force, just stronger*, so it gets a special name. Hydrogen bonds occur between any molecule having both hydrogen and either oxygen, fluorine, or nitrogen. H is extremely good at losing electrons, and O, F and N are extremely good at attracting electrons, so the hydrogen bond results in an extreme dipole situation, whereby the very positive side of one molecule will orient itself with the very negative side of another.

*All of the three van der Waals' forces are very weak, so the 'strong' hydrogen bond is only strong compared with the other two types.

-------

Open-science van der Waals interaction calculations enable mesoscale design and assembly

September 22, 2015
(more at link...)
http://phys.org/news/2015-09-open-science-van-der-waals-interaction.html

As molecular-level electronic, photonic and biological devices grow smaller, approaching the nanometer scale, chemists, physicists and materials scientists strive to predict the magnitude of the fundamental intermolecular interactions, and whether new hierarchical combinations of these material components will assemble and function as designed.

Scientists at Case Western Reserve University and collaborators at University of Massachusetts-Amherst and University of Missouri-Kansas City, unveil Gecko Hamaker, an open-source computational and modeling tool with a full-spectral optical web-service, highlighted on the cover of today's issue of the American Chemical Society's journal Langmuir.

Researchers can use this 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.

"We open a whole range of insights into deep physics and share it with the scientists who are working on new self-assembled materials," said Roger H. French, the F. Alex Nason Professor of Materials Science and Engineering and faculty director of the Applied Data Science Minor at Case Western Reserve. "The free distribution of the Gecko Hamaker source code and its optical spectra open-data has great utility for design and fabrication of new mesoscale systems."

French's team has been investigating optical properties and van der Waals interactions with funding from the U.S. Department of Energy, Basic Energy Sciences. Their latest research based on the Gecko-Hamaker project, is also reported in Langmuir: the calculations of van der Waals interactions between DNA, carbon nanotubes, proteins and inorganic materials.

Simply speaking, van der Waals forces are the intermolecular attractions between atoms, molecules and surfaces that control interactions at the molecular level. The stability of materials are governed by these forces in the meso- and nano-scales.

"In this work, we now provide the ability to determine both van der Waals forces and torques that arise from cylindrical shaped materials or optically anisotropic materials," French said. "Our methods don't only address simple geometries, but also non-isotropic, complicated shapes. Our methodology allows us to address orientation, which is more difficult than simply describing van der Waals forces."

With Nicole F. Steinmetz, assistant professor of Biomedical Engineering at Case Western Reserve and colleagues nationally, the lab developed a sophisticated theoretical approach for calculating Hamaker coefficients, interaction free energies, forces, and torques of a wide range of geometries, and have accumulated hundreds of experimental and computational optical data for inorganic and organic materials.

"The open-source project and database are helpful to scientists in a variety of fields," Steinmetz said "In biomolecular engineering, for example, it would be very interesting to run a Gecko Hamaker calculation to predict how virus-like nanoparticles would approach each other or form self-assembly in a medium."

The open-source Gecko Hamaker software project and its online spectral database web-service gives other scientists access to these computational approaches and the open-data of the materials.

As it was being developed, "Gecko Hamaker has been downloaded more than 3,000 times in the past three years," said Yingfang Ma, the CWRU doctoral student who made available the full spectral optical properties of more than 100 materials in the open-data webservice.

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

Cr6
Admin

Posts : 676
Join date : 2014-08-09

View user profile http://milesmathis.the-talk.net

Back to top Go down

Re: 'Sticky waves': Molecular interactions at the nanoscale - What's Mathis' take?

Post by Cr6 on Thu Mar 17, 2016 2:54 am

Van der Waals versus dipolar forces controlling mesoscopic organizations of magnetic nanocrystals

Y. Lalatonne1, J. Richardi1 & M. P. Pileni1

Abstract

The structure, thermodynamics and dynamics in many physical and chemical systems are determined by interplay of short-range isotropic and long-range anisotropic forces. Magnetic nanoparticles dispersed in solution are ideal model systems to study this interplay, as they are subjected to both isotropic van der Waals and anisotropic dipolar forces. Here we show from experiment an abrupt transition of maghemite nanocrystal organization from chain-like to random structures when nanoparticle solutions are evaporated under a magnetic field. This is explained by brownian dynamics simulations in terms of a variation of the strength of van der Waals interactions with the particle contact distance, which is tuned by the length of the molecules coating the particles. The weak dipole–dipole interactions between the maghemite particles are usually not sufficient to result in the chain formation observed here. However, due to the van der Waals interactions, when the nanocrystal contact distance is short enough, clusters of nanocrystals are formed during the evaporation process. These clusters exhibit large dipole moments compared with a single particle, which explains the formation of chain-like structures. Conversely, when the nanocrystal contact distance is too long, no nanocrystal aggregation occurs, and a random distribution of maghemite nanocrystals is obtained.

http://www.nature.com/nmat/journal/v3/n2/full/nmat1054.html

Cr6
Admin

Posts : 676
Join date : 2014-08-09

View user profile http://milesmathis.the-talk.net

Back to top Go down

Re: 'Sticky waves': Molecular interactions at the nanoscale - What's Mathis' take?

Post by Cr6 on Thu Mar 17, 2016 2:56 am

Gecko Hamaker

An Open-Science Software Tool

for the Calculation of

van der Waals-London Dispersion (vdW-Ld) Interactions

Based on algorithms developed by V. Adrian Parsegian1 and others, Gecko Hamaker calculates Hamaker coefficients, interaction free energies, forces, and torques for a wide range of geometries and materials, using the full Lifshitz theory for vdW-Ld interactions. Gecko Hamaker also provides a web service for the distribution of over 100 materials’ full spectral optical properties.

http://geckoproj.sourceforge.net/

Cr6
Admin

Posts : 676
Join date : 2014-08-09

View user profile http://milesmathis.the-talk.net

Back to top Go down

Re: 'Sticky waves': Molecular interactions at the nanoscale - What's Mathis' take?

Post by Cr6 on Sun Mar 20, 2016 9:09 pm

Description of the Gecko's foot:

http://www.livescience.com/47307-how-geckos-stick-and-unstick-feet.html

Cr6
Admin

Posts : 676
Join date : 2014-08-09

View user profile http://milesmathis.the-talk.net

Back to top Go down

View previous topic View next topic Back to top


 
Permissions in this forum:
You can reply to topics in this forum