Ibpointless2 Crystal Cells

[triffid]

Solidification and Ordering during Directional Drying of a Colloidal Dispersion.[/size][/b]
Lucas Goehring, William J Clegg, Alexander F Routh
Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge, United Kingdom, CB2 3QZ.
During drying, colloidal dispersions undergo processes such as solidification, cracking, and the draining of interstitial pores. Here we show that the solidification of polystyrene and silica dispersions, during directional drying, occurs in two separate stages. These correspond to the initial ordering and subsequent aggregation of the colloidal particles. Transitions between these stages are observed as changes in transparency and color that propagate as distinct fronts along the drying layer. The dynamics of these fronts are shown to arise from a balance between compressive capillary forces and the electrostatic and van der Waals forces described by DLVO theory. This suggests a simple method by which the maximum interparticle repulsion between particles can be measured through the optical inspection of the dynamics of a drying dispersion, under a microscope.
Keywords: solidification; dispersion; dry; colloidal dispersion; colloidal; dure directional; directional; order dure; particle; front; force; crack; dlvo; dure; capillary force;

[triffid]

Drying and cracking mechanisms in a starch slurry.[/size][/b]
Lucas Goehring
BP Institute for Multiphase Flow, Madingley Rise, Madingley Road, Cambridge CB3 0EZ, United Kingdom.
Starch-water slurries are commonly used to study fracture dynamics. Drying starch cakes benefit from being simple, economical, and reproducible systems, and have been used to model desiccation fracture in soils, thin-film fracture in paint, and columnar joints in lava. In this paper, the physical properties of starch-water mixtures are studied, and used to interpret and develop a multiphase transport model of drying. Starch cakes are observed to have a nonlinear elastic modulus, and a desiccation strain that is comparable to that generated by their maximum achievable capillary pressure. It is shown that a large material porosity is divided between pore spaces between starch grains, and pores within starch grains. This division of pore space leads to two distinct drying regimes, controlled by liquid and vapor transport of water, respectively. The relatively unique ability for drying starch to generate columnar fracture patterns is shown to be linked to the unusually strong separation of these two transport mechanisms.
Keywords: starch; slurry; fracture; dry; crack; pore; starch grain; cake; desiccation; pore space; grain; transport; columnar; lava; soil;

[triffid]

 compressive capillary forces  now thats a mouthfull.That be the reason why water drips out of our cells sometimes.triffid

[Peanutbutter29]

I found a good page that shows reactions with Magnesium.  It doesn't contain everything of course (like known acid reactions) but does include some that we may be using with cells.

http://www.marz-kreations.com/Chemistry/Cation-ID/162m-Magnesium.html

Also, watching over at energeticforum (not a forum type person so not making an account there)  I see there has been mention of toothpaste, as I'd considered (shortly) this before. I've looked over the stuff already.  I'm not sure if anyone from there reads this thread, but maybe it can save those here some time.

Ingredients in toothpaste:
water 20-40%
Abrasives 50%
*Aluminum Hydroxide - reactive - Y - MgOH
*Calcium Carbonate - reactive - N  - (unless a chloride is free)
*Other Phosphates and silicates - reactive - ? - (very possible with potential of dissimilar plates)

Fluorides 1000 - 1500ppm (tiny)
Sodium Fluoride most common - reactive - N - no reaction see link above
If ,by chance, a potential or reaction would free sodium from fluoride;  it would react first with Calcium Carbonate = Calcium Fluoride

Primary advantage (other than a conductor) of toothpaste.  Single replacement of Aluminum with Magnesium hydroxide (electrolyte)

Another note with electrode potentials (if you look at those) they are referenced to H2 and some materials will show different potentials relative to other compounds.  E.G. carbon has a varying electrode potential based on a metal pairing.


I think I can categorize clearly (after reading up on all the designs) the styles that have been made so far.  A good way to generalize them at least....

Volta Pile - Metal touching Metal with a porous separator (paper, cloth, cardboard, plaster, leather etc) soaked in a salt electrolyte of any type reactive. (short life okay current)

Duluc Pile - Metal touching Metal with a porous separator (paper, cloth, cardboard, plaster, leather etc) soaked in only water (longer life, best if sealed, low current)

Zamboni Pile - various designs used;  metal touching metal with a porous separator (paper, cloth, cardboard, plaster, leather etc) of 2 distinct varieties.
--Early, barely damp (water only) porous separator, highly sealed (2 year life max, dead but low corrosion, very low current)
--Late, no moisture in porous separator, highly sealed (one from 1840 still running....life from 2-150yrs, current accepted to be piccoamps, eg. nil)

Galvanic Cell - Many designs; metal separate from metal in a fully liquid salt electrolyte of any type reactive (short life, days.  good -great current) 2 distinct varieties.
--Early, metal separate from metal only in an electrolyte and water, no separators  (one electrode had to be removed)
--Late, metal separate from metal with 2 electrolytes and a porous separator (ceramic, leather) dividing 2 electrolytes. (no electrodes had to be removed)

Dry Cell - Many designs;  metal separate from metal by a porous separator.  several varieties
--First, metal separate from metal with a thick porous separator of plaster or inert paste.  Electrolyte of 2 -3 salts that are either reactive to each other or metals.  (medium life medium current)
--Second, metal separate from metal with a thinner porous separator of inert paste.  Electrolyte of 1 salt that is reactive (long life medium current)
--Alkaline, metal powder separated with an Alkaline electrolyte (not acidic) and a thin separator film; last a metal powder and metal case. (longer life, lower current, but less corrosive to environment)
--Ni-Cd and Ni-mH; metal film, next to a thin film of electrolyte, next to a thin film separator , next to a metal film, next to a case / grid.  (rechargeable, good current, higher in Ni-Cd)
--Li Ion, a graphite film, next to 2 electrolytes (carbonate and lithium salt), next to a thin film separator, next to a lithium metal oxide, next to a case / grid. (rechargeable, higher storage in smaller space, decent current (less than Ni-Cd), life span variable highly)
--Mg/Mn, a magnesium alloy powder or film, next to an electrolyte (usually perchlorate), next to a separator, next to Mn02, next to a case or grid.  (used for military applications only, long pre-use storage and good current with small size)

I think that about covers all of the general styles so far.  Looking at those, there are just a few things overall to change. (e.g. modern dry cells are most closely related to the first volta piles but with a separator and alkaline).  But these can be generalized further to just, fully submerged, hydrated inert suspension of salts, thin hydrated salt, thin non-hydrated salt and thin non-salt hydrated.  Only 3 variations in design.  Metal touching metal, metal separate from metal, and metal separated from metal by a porous inert material.

Seems like what they were trying to find in the 1800's is still not found. That being, a completely non reactive system using only the properties of dissimilar metals.  I imagine that too would have low current, but no clue.  So as they quested for a perfect semiconductor in 1800;  I suppose that could still apply today.  A material that would allow movement of electrons from one metal to another, without any interaction in it's function or reversal of direction.  Anyone work at Intel? maybe grown crystals of silicon (grown in a mag field perpendicular or E field opposing intended flow) a few microns in thickness, then doped for enhanced polarity with electro-deposition with germanium;  could then couple with another metal and allow current flow.
Lol, not something I could ever have access to trying.

Sorry to be long as usual, but I hope there is good information here to help.
Thanks

[triffid]

I am considering biological materials such as wet wood which is conductive.Silica from grasses( up to 15%dry weight).Maybe a rock for an electrode.So a rock and a piece of wet wood?Could be electrodes?If we could get away from metals for electrodes that might be one answer.In the future it might be a conductive piece of plastic?Just thinking out loud here.triffid