Originally Posted By: JHZR2
Originally Posted By: alternety
You arguing about this because you are "inclined to believe". Respectfully, I don't understand why you don't just go and study the technology instead.
I have studied particle stability and means of stabilizing fine particles after milling and to retain fine structure when put into other solutions. Ive done the experiments, made the calculations, and we see a sharp agglomeration after particles reduce to sub 500nm because of the surface energetics.
Im not trying to pick a fight with you, but it still doesnt make sense to say that there is some molecule that is 70nm, or that the particles stay that small - have SEM/TEM to prove this? Why not give the proof rather than saying its out there to believe but not citing?
Please reread what I have said. I have repeatedly said the 60-70nm structure is NOT a molecule. Review the definition of a Bucky Ball or Buckminsterfullerenes (the original Carbon structure is a Buckminsterfullerene (C60)). A simple search of Wikipedia will explain this to you http://en.wikipedia.org/wiki/Fullerene. It is a structure constructed (occurring) in a pseudo spherical form, sometimes created by humans. Being carbon based, it is referred to as an organic Fullerene. It was once thought that this form could only be attained with Carbon. Not so much. Hence the IF (Inorganic Fullerene like) prefix to IF WS2. The individual components of this structure are much smaller. Probably single digit nm. I have not really paid attention to that point. But really isty bitsy teeny weeny.
I have not provided references because they are readily available with Google. I am not going to go back and reread this thread, but I suspect there are some hints about references; maybe not. No one has really questioned the reality.
Sorry, Im really not fighting, I just dont believe it. Particularly based upon first hand R&D experience (with other nanoparticle systems, now WS2) and my quick review of the literature.
A C60 Fullerene is around 1.1nm at the longest dimension.
A C60 Fullerene does not, by definition, have a longest dimension. I believe you are confusing this with a Carbon nanotube. And that feels like a diameter.
Qiao, Rui; Roberts, Aaron P.; Mount, Andrew S.; Klaine, Stephen J.; Ke, Pu Chun. "Translocation of C60 and Its Derivatives Across a Lipid Bilayer". Nano Letters. Retrieved 4 September 2010.
A WS2 nanotube with 4-7 walls thickness is less than 20nm
Scheffer, L., Rosentzveig, R., Margolin, A., Popovitz-Biro, R., Seifert, G., Cohen, S. R., & Tenne, R. (2002). Scanning tunneling microscopy study of WS2 nanotubes. Physical Chemistry Chemical Physics, 4(11), 2095-2098.
Again, nanotubes. Not the discussion.
Here they found 120nm fullerenic WS2 nanoparticles but they were found to be allomerates of multi-layer sheets.
Moshkovith, A., Perfiliev, V., Lapsker, I., Fleischer, N., Tenne, R., & Rapoport, L. (2006). Friction of fullerene-like WS2 nanoparticles: effect of agglomeration. Tribology Letters, 24(3), 225-228.
These structures in that size are multiwall or multi-arranged in this trigonal prismatic structure.
So how "a" fullerene of WS2 is 70nm when the atoms and bonds are on the order of pm (and a C60 fullerene, with no dimension that different is on the order of 1nm) is beyond me.
Again, I believe there is a mix of Bucky balls and nanotubes in play here. THEY ARE NOT NANOTUBES!
A simple wikipedia search yields an SEM with bundles of nanotubes (5-8 wall typically) that together make bunches of ca. 20nm.
Interesting, but Fullerenes are not nanotubes.
Again, agglomerated. I have no doubt the "nano" particle is somewhere around 70nm, but it cannot exist in that size regime by itself due to external electronic forces of various types, or a LOT of stabilizing chemistry. So the subcomponents (which consist of thousands or millions or billion of WS2 molecules) may be 70nm in their "particle", but that particle agglomerates with others so it exists stabily in a particle of 500nm or more.
That's all Im saying.
Im happy to be wrong and learn something new - but until Ive seen actual peer-reviewed basis for claims, and preferably the reports from calibrated analytical equipment and SEM/TEM, its difficult to believe any claims...
OK. Here is what I am saying. You do not believe they exist. Sort of like elves and pixies. Fine. You may purchase these non-existent structures from Apnano. With real cash; they are not particularly inexpensive. This reference has, I am fairly certain, been made in this thread.
Has anyone run WS2 in oil through a particle scan in a UOA at least?
I have no idea what that means. I am not an oil person. Tests - yes. Look around. Apnano, Millers Oils, etc.