I posted this question over at basenotes



... I'm still trying to process the responses. Apparently diffusion through air is about 10,000 times faster than diffusion through water, but I don't know if this takes into account the rate of the sublimation process (the process of turning from solid to gas.)

Once the mones reach the boundary layer at the surface of the mixture between the mixture and the air, I think dexter is talking about how the weak forces between the mones and the mixture might affect how quickly the mones would fly out of the mixture?

This talks about the intermolecular forces affecting the boiling point : http://www.phs.d211.org/science/smithcw/...Forces.pdf

This talks about the considerations for boiling point and vapor point : http://www.nicearticles.net/reference-an...tance.html

Quote:For liquids in open containers, scientists define the boiling point as the temperature at which the vapor pressure of the liquid equals the atmospheric pressure. These pressures must be equal because liquid particles below the surface need to overcome both their intermolecular attractions and the external pressure above the liquid, which pushes the particles close together and prevents them from expanding into a vapor bubble. Heat increases the kinetic energy of the liquid particles and therefore the vapor pressure. When the vapor pressure of the liquid equals the external pressure, the particles beneath the surface have enough kinetic energy to separate into a vapor. At this point, the liquid begins to boil. At higher altitudes, such as on the top of mountains, the atmospheric pressure is lower than at sea level. In places such as these, the vapor pressure will equal the atmospheric pressure when the liquid is at a lower temperature. This is why the boiling point for a particular liquid is a lower temperature at higher altitudes.

I think this system needs to be modeled with the liquid phase (the mixture of mones and stuff) and the air phase being at body temp for the liquid and the air can vary depending on indoor/outdoor, geography, and season.

I wonder how much wind plays a role in this? I guess if you are standing in a good wind then the atmospheric pressure would really be lower since the movement of the air across your body would create low-pressure pockets in the eddies and swirls as it moves across you, but modeling that would be super-computer stuff.

(06-23-2012 9:13 AM)2Soon2Care Wrote:  This talks about the intermolecular forces affecting the boiling point : http://www.phs.d211.org/science/smithcw/...Forces.pdf

For reasons I don't understand, boiling point without some other consideration factored in doesn't seem relevant. Andreostenol, as mentioned, has a higher boiling point than androstenone, for instance. So there must be some other factor at play.

Why things are this way doesn't make the slightest bit of sense to me, so perhaps I'm missing something here.

I'm thinking along the same lines as Dexter. If you want something to diffuse slower, put it into a base of DPG/oil, or faster, in a base of alcohol. So wouldn't it just be a matter of layering your individual molecules on the skin using different bases for each to get an even distribution, if you truly required this precise of a diffusion rate?

I think we need to establish something for this thread, and I don't claim to be the expert, but right now I'll claim that I'm claiming something.

dexter's claims toward understanding pheromone diffusion:

1. no 'mones (standard steroid based) ever reach their boiling point while being used as a topically applied scent on human skin.
As such is the case, the boiling point of pheromone molecules is not a factor in their diffusion (unless their boiling point is significantly close to human body temperature (~95-105 F, ~35-40 C).

2. Pheromones are in the solid phase when airborn. They are not liquid phase they are not gas phase. They are very small molecules that are suspended in air, while maintaining their solid properties.

3. Smaller molecules do not evaporate/sublimate/diffuse faster because they are smaller. An example would be Water (H20) vs Ethanol/Ethyl Alchohol/ETOH (C2H6O, CAS# 64-17-5) ETOH evaporates much faster than water, even though water is a smaller molecule.



Support for claim #3 is based on the fact that water is a polar molecule. Which does not mean that water/ice is at the North Pole. It means that the shape of the H20 molecule has a dipole, where one side of the molecule has a net + charge, and the other side has a net - charge. Because of H20's shape it can orderly arrange itself as a liquid and solid in a way where one molecules + will orrient close to it's neighboring molecules -. This creates waters high surface tension, where you can float a metal paperclip on top of water, just by setting it there, due to surface tension.

ETOH is not a strong polar molecule, it has a much lower surface tension than water. The molecules can diffuse easier because they do not need to overcome the high surface tension forces that water has.

If the Pheromone molecule dissolves easily in the solvent, then you can have your 'mones as single molecules in suspension. If they do not, they may not dissolve completely and be clumped multiple molecules stuck together. This would impede diffusion and use, as you have a dirt clod or a bunch of 'mones instead of a single 'mone molecule.

If the Pheromone has a dipole or multiple dipoles, or areas where it has a high +/- charge, this will play into how the molecule pulls to the solvent and other molecules.

Not a CLAIM, but being said like one, sort of:
If the Pheromone attracts strongly to ETOH it will diffuse faster (which is hard because ETOH isn't polar), if it is non-polar like ETOH it may help in it's diffusion as it will not attract to the molecules on your skin and clothes and bond tightly with them. Some pheromones may have an attraction to other molecules used as cover scent, and ride them like a pony, using the diffusion properties of the cover scent to help spread the 'mones.

THE MAN OATH:
I'M A MAN, BUT I CAN CHANGE, IF I HAVE TO, I GUESS. (Red Green)

I should also throw in that temperature, on it's own, is a false metric. Temperature is an average of the kinectic energy of molecules. You can and do have wildly different energies from one molecule to the next. 2 molecules on your skin may have an average temperature, and be right next to each other, but individually they may be 80F and 120F, while maintaining an average temperature of 100F.

This can help in evaporation. Think of it as the balls in Newton's cradle. A molecule runs into another molecule, giving it some kinetic energy, and losing it's own, the other molecule now has enough energy to take off. But their average energy remains the same. This can help some molecules (due to their properties) become airborn because they do have a sudden increase in energy/temperature even though the average temp doesn't change.

I'm still pushing for looking at the diffusion rate of the carrier/fixatives and the pheromones ability to use the carrier properties. While the pheromones are always in the solid state.

I've talked to another friend with an advanced degree. She also pointed to melting point as being a good indicator of tendency to sublimate.

Quote:no 'mones (standard steroid based) ever reach their boiling point while being used as a topically applied scent on human skin.
As such is the case, the boiling point of pheromone molecules is not a factor in their diffusion

While I've given up on using boiling point and what you're saying is true, I think you're missing where I was going here. I was thinking that boiling point should be an indicator of attraction between the molecules of a liquid or solid. I was never trying to actually boil anything.

Alcohol, for instance, has a lower boiling point than water and also evaporates more readily. The same is true for most liquids that I'm aware of.

We're not actually melting mones either, but the point at which something melts may be useful info.

Quote:2. Pheromones are in the solid phase when airborn. They are not liquid phase they are not gas phase. They are very small molecules that are suspended in air, while maintaining their solid properties.

Seriously? You're saying we're not dealing with sublimation at all? Why do you believe that mones re-attach to one another in regular patterns when becoming airborne? I'm honestly curious here.

Quote:3. Smaller molecules do not evaporate/sublimate/diffuse faster because they are smaller. An example would be Water (H20) vs Ethanol/Ethyl Alchohol/ETOH (C2H6O, CAS# 64-17-5) ETOH evaporates much faster than water, even though water is a smaller molecule.

There are two big factors in evaporation of liquids. One is the size (or perhaps density) of the molecule and one is the intermolecular forces holding the stuff together in a liquid. So look at the relative boiling points of methane, ethane, propane, butane and pentane. The boiling point increases as you add to the alkane chain. So 'size does matter' to an extent. But most androstanes are of fairly similar weights, so weight is probably not the biggest factor differentiating them.

Water is, as you mention, highly polar, so it "sticks to itself" much more strongly than the non-polar alkanes, and therefore has a boiling point much higher than would be indicated by its size.

Quote:If the Pheromone molecule dissolves easily in the solvent, then you can have your 'mones as single molecules in suspension. If they do not, they may not dissolve completely and be clumped multiple molecules stuck together. This would impede diffusion and use, as you have a dirt clod or a bunch of 'mones instead of a single 'mone molecule.

I've looked at the solubility for a few mones. All the stuff we've used is used in small enough doses that it's well dissolved in the solvent in question.

I do need to look into solubility for 7-Keto-DHEA, however. I've come back to find some mixes with that stuff in it crystallized into a pretty little pattern that disappeared when I held the bottle in my hand.

(06-25-2012 2:35 PM)wiserd Wrote:  I've talked to another friend with an advanced degree. She also pointed to melting point as being a good indicator of tendency to sublimate.

Yes it may be an indicator into the diffusion process, but no the pheromones do not sublimate.

Quote:While I've given up on using boiling point and what you're saying is true, I think you're missing where I was going here. I was thinking that boiling point should be an indicator of attraction between the molecules of a liquid or solid. I was never trying to actually boil anything.
Alcohol, for instance, has a lower boiling point than water and also evaporates more readily. The same is true for most liquids that I'm aware of.
We're not actually melting mones either, but the point at which something melts may be useful info.

while melting point may show some points of correlation with diffusion, I think it is coincidental and not a hard rule. I agree with the boiling point showing to some extent the attraction between molecules of the solvent to themselves. But I don't think the boiling point of the 'mones helps because it is very dillute. The 'mones if dissolved will not be adjacent to each other in solution. The boiling point of 'mones will be irrelevent because it describes inter-molecular interactions between identical 'mones molecules. This just isn't the case when it is dissolved.

Quote:

Quote:2. Pheromones are in the solid phase when airborn. They are not liquid phase they are not gas phase. They are very small molecules that are suspended in air, while maintaining their solid properties.

Seriously? You're saying we're not dealing with sublimation at all? Why do you believe that mones re-attach to one another in regular patterns when becoming airborne? I'm honestly curious here.

yes, that is what I'm saying. I'm not saying that they crystalize in the air, forming clumps or multi-mone-molecule masses in the air. What I am saying is that a single 'mones molecule, airborn, exhibits properties of 'mones in solid form. It does not sublimate and exhibit properties of a molecule that has had it's energy raised to that of a gas phase.

Water can vaporize, that is where individual water molecules in the liquid phase diffuse into the air, but do not act as steam. I may need to double check, but in a quick web search, vaporization seemed to mean boil, but that isn’t what I remember. Steam is water in the gas phase, and is hot, it has the energy that makes it act like a gas phase water molecule. I may need to look up what the process is called when solids are suspended in gas, it may be vaporized, but it may be a different term, but it is not sublimation. Ok, it’s called a suspension, and there is a link to it in Wikipedia below.

Quote:

Quote:3. Smaller molecules do not evaporate/sublimate/diffuse faster because they are smaller. An example would be Water (H20) vs Ethanol/Ethyl Alchohol/ETOH (C2H6O, CAS# 64-17-5) ETOH evaporates much faster than water, even though water is a smaller molecule.

There are two big factors in evaporation of liquids. One is the size (or perhaps density) of the molecule and one is the intermolecular forces holding the stuff together in a liquid. So look at the relative boiling points of methane, ethane, propane, butane and pentane. The boiling point increases as you add to the alkane chain. So 'size does matter' to an extent. But most androstanes are of fairly similar weights, so weight is probably not the biggest factor differentiating them.

Water is, as you mention, highly polar, so it "sticks to itself" much more strongly than the non-polar alkanes, and therefore has a boiling point much higher than would be indicated by its size.
I've looked at the solubility for a few mones. All the stuff we've used is used in small enough doses that it's well dissolved in the solvent in question.

I think you are correct when looking at the patterns with methane thru pentane. But adding the groups to different carbons on a steroid backbone may be a very different problem. The different ‘mones aren’t a simple pattern, I’m sure there is a pattern out there, but it is a more convoluted equation than the number of C’s in a backbone.

Quote:I do need to look into solubility for 7-Keto-DHEA, however. I've come back to find some mixes with that stuff in it crystallized into a pretty little pattern that disappeared when I held the bottle in my hand.

This sounds like the 7-Keto is a polar molecule and is attracted to itself in solution, and forming a crystal structure. Perhaps increasing the content of a polar solvent like water would help to eliminate the recrystalization of the 7-Keto, which is falling out of solution.

Here is some info .
http://en.wikipedia.org/wiki/Suspension_(chemistry)

Quote:A suspension of liquid or fine solid particles in a gas is called an aerosol or particulate. In the atmosphere these consist of fine dust and soot particles, sea salt, biogenic and volcanogenic sulfates, nitrates, and cloud droplets.
Destabilisation phenomena of a dispersion
Creaming, Sedimentation – particles form and fall out or float
Flocculation, Coalescence, Coagulation –form from a suspension (wasn’t dissolved, it was suspended)

Quote:yes, that is what I'm saying. I'm not saying that they crystalize in the air, forming clumps or multi-mone-molecule masses in the air. What I am saying is that a single 'mones molecule, airborn, exhibits properties of 'mones in solid form. It does not sublimate and exhibit properties of a molecule that has had it's energy raised to that of a gas phase.

Water can vaporize, that is where individual water molecules in the liquid phase diffuse into the air, but do not act as steam. I may need to double check, but in a quick web search, vaporization seemed to mean boil, but that isn’t what I remember. Steam is water in the gas phase, and is hot, it has the energy that makes it act like a gas phase water molecule. I may need to look up what the process is called when solids are suspended in gas, it may be vaporized, but it may be a different term, but it is not sublimation. Ok, it’s called a suspension, and there is a link to it in Wikipedia below.

If you're arguing that mones diffuse in a suspension or as an aerosol, then you are arguing that they are clumps in the air. (maybe some mones are waxy rather than crystaline solids. I'm not sure. But either way, the same idea holds.)

I'm not sure what it means to have a 'single molecule solid' as a gas. If something is a solid, this describes its relation to other surrounding molecules. A single molecule floating in the air is a gas. Or you can have condensed droplets of a substance (say, water) in the air which float, as they do in clouds or in the visible portions of steam (the part of steam which has condensed and is no longer a gas.) If a single molecule in the air lacks enough energy, it might condense very readily into a liquid (or droplet in the air) given the opportunity. But it's still in gas phase till it does so.

You can also have tiny droplets of a solid or liquid that float in the liquid without dissolving, which is a colloid or colloidal suspension(solid in liquid) or emulsion(liquid in liquid) or particulate or aerosol (solid or liquid in air). But then we're back to clumps of stuff in the air or water.

Perhaps in water it's possible to have a single molecule of a solid which is either ionized or not... I don't think so, but I'm not sure. But in gas, this wouldn't make sense.

We agree that the amount of energy that a molecule in a liquid has can vary away from the average temperature. In a glass of water 50 Degrees C, a few molecules will have enough energy to be "boiling," effectively, and this "boiling at room temperature" is what we call evaporation. Its the same as boiling all the liquid, except that only a few molecules have enough energy to escape the liquid and become gas.

My point re: molecular weight is that weight does matter. While it may be hard to guess the impact of adding one carbon or hydroxyl group, doubling the molecular weight of a molecule, for example, will likely make it 'too big to fly.' So if we were writing an equation, weight is a factor. But it is one one which might be canceled out by other factors and is probably not be the largest factor.

Quote:while melting point may show some points of correlation with diffusion, I think it is coincidental and not a hard rule.

Sure. The goal would seem to be to gather up the various relevant factors and try to "add them up" so to speak. Right?

Quote:But I don't think the boiling point of the 'mones helps because it is very dillute.

If you mix alcohol and water and heat it, you'll get a temperature plateu at the boiling point of alcohol till all the alcohol boils off. This is true essentially regardless of the quantity of alcohol in the mix.

So for mixed liquids, the quantity of liquid doesn't seem to matter in regards to boiling point of the liquids within it. If it did, those plateus wouldn't be curved or slanted rather than flat.

Sublimation of non heterogenous solids (mix of fixative and seem to be different, which is what we're trying to figure out.) (Most mones work after the alcohol evaporates away, after all)

aaaarrrrrgh!

I just typed out a bonzer thesis of a reply and I accidentally hit the mousepad and it acted as a back button and took me to the last webpage. Of course losing all the stuff I was just about to hit the post button on.

Later I'll get it all typed out.

Groan!