silver ion collisions

[Aussie]

Greetings all, hope you's don't object to my intrusion here, I'm a new member with a question for someone.

 

I'm involved with Silver Colloids and whilst I am no chemist or hold any academic degree or qualifications I am wondering if someone could confirm or deny if collisions of silver ions in solution generate heat?

 

This heating {if applicable} in all probability would require suitable instrumentation to detect {which is not my interest}but do you know if ionic collisions will generate *some* heating effect of either the solution itself, or the particle clusters which are formed.

 

My assumption is...if any form of collision occurs at the atomic state there would be friction involved, and this friction should/would? generate some heat, no matter how minute or relatively undetectable that heat may be.

 

Thanks.

[Mr Skeptic]

Friction works differently at the atomic scale, remember that energy is conserved. Anyhow, I think it would be more accurate to say that heat generates molecular collisions, unless you are shooting an ion beam at your solution or have some other source of energetic ions. Also, I don't think ions have much to do with colloids, other than that solid colloids are often made from ionic solutions.

[Aussie]

Friction works differently at the atomic scale, remember that energy is conserved. Anyhow, I think it would be more accurate to say that heat generates molecular collisions, unless you are shooting an ion beam at your solution or have some other source of energetic ions. Also, I don't think ions have much to do with colloids, other than that solid colloids are often made from ionic solutions.

 

 

Thanks for your reply.

 

I believe they are not specifically 'colloids' as such but rather the particle structures formed are 'clusters of atoms', resulting in a more crystal like structure and termed, possibly incorrectly in this context, as 'colloids'. I'm not sure if a true colloid exists at the nanoscale created by electrolysis, 'colloid' in this context may be more a term of convenience praps.

 

That being said, as ions are positively charged they are in constant motion by mutual repulsion {Zeta potential} but, as they move with considerable velocity while in solution some tend to collide with each other and break through the 'slipping plane' hence the collisions I speak of, and this action results in the formation of those crystaline structures.

 

I probly misquoted when I mentioned 'friction', the only 'friction?' activity would be when an ion breaks through the slipping plane causing it to adhere to another ion. It's that 'colliding' activity which prompted me ask the question regarding heat during the process of colliding. The force in which these collisions occur, or the force which is required for ions to 'adhere' to each other as a result of breaking through that 'slipping plane' encouraged me to think that some degree of heat would be evident in such an event. This is basically what I'm trying to determine.

 

Picking up on your 'energy' aspect, would this action of collision not be seen as 'energy'? ie; energy required by way of velocity of one ion to break through the slipping plane of another causing adhesion of that ion to the other, this then makes the original ion neutral in electrical charge and allows any/all other ions to have a clear pathway to enable that 'particle?' to become larger. This of course is happening throughout the solution many times over, and at nanoscale, but seemingly only until a point of stabilization in solution has been attained. This process of stabilization would determine an ionic solution over a more particulate solution, and by particulate I refer to atomic clusters {particles} as opposed to true colloidal particles. If one considers this collision occurring, and multiplying that many times over in the solution, would that not have *some?* temperature effect on the solution, or on the localised particle structure created?

 

You'll have to excuse my somewhat inadequate methods of explanation and enquiry, and praps my lack of chemistry knowledge makes my query null and void.

[Mr Skeptic]

Well, you have to think of it in terms of the laws of thermodynamics. The first is conservation of energy, and since thermal energy is a form of energy, it can't just be continuously generated. The second law is that heat flows from hot objects to cold objects, so the ions could only heat up the solution if they started off more energetic than the solution, and in doing so they would lose said energy (after the first few collisions) due to the first law, until they are the same temperature as the solution.

 

Or if you really like, you can do this in terms of particles colliding elastically, but things would get complicated really quickly since there are so many particles.

[Aussie]

On reading through your reply I realised I omitted to say that any temperature change {if applicable} would possibly be measured in micro seconds only, as opposed to actually heating up the solution. An instant momentary 'flash' of heat if you like, generated by that collision. This I hypothesised could praps cause temperature of solution, or the aforesaid atomic clusters thus formed, to fluctuate over a given time frame. *IF* there were to be any momentary heat resulting from those collisions, I realise it would take some fairly sophisticated measuring equipment to detect this in the scheme of things. I just wanted to know if it were possible or feasable that's all.

 

I get the impression that the velocity of ion activity as they move about in solution rusulting in those 'collisions', combined with the 'G' forces applied which would be needed to break through that slipping plane, and considering the massive numbers involved all occurring at a similar time, and lessening over time, that this would not constitute 'energy' per saye. I was under the misguided belief praps that heat would be generated in general, or localised at the site of impact, as a result of those collisions, as momentary measured in milli/micro seconds as that heating effect may be.

 

Praps I'll go away for a while and do some research on 'thermodynamics' as you suggest. This subject is simple in concept, but extremely complex at the same time, and although there are those who are extremely knowledgable about this stuff there are still some areas of which is not fully understood. I'm probly pushing my understanding level further than I really need to, but that's the nature of an inquisitive mind I guess.

 

Thanks for your assistance, much appreciated.

[Mr Skeptic]

Oh, I think I see what you are getting at. Yes, on occasion collisions will result in one molecule being given a boost in energy, so that the molecules have varying energy and speeds. This is true for any molecule, not just ions. Upon collision, the energy can be used for a chemical reaction. This can be seen in activation energy, the energy barrier a reaction needs to overcome before it can occur and fall to a lower energy state, and how temperature affects the rate of a reaction.

[Aussie]

Very interesting.

 

You've actually prompted another query that's been rattling around in my head for some time. Your snipped quote: "...on occasion collisions will result in one molecule being given a boost in energy, so that the molecules have varying energy and speeds" end quote. This may be a clue as to why conductivity readings fall/drop fairly rapidly over...let's say 24-48 hours...before tapering off or slowing down until a point of solution stability {lower energy state} is reached.

 

Would I be right in assuming that as these molecular collisions occur, that variation of molecular energy and speed created after initial impact may in fact *increase the rate of further molecular collisions* over a short time frame due to that change in energy and speed? An exponential thing or chain reaction {chemical reaction?} over a relatively short term until the solution becomes more stable.

 

That energy barrier would in this case be what I termed the 'slipping plane', but would be more correctly termed the 'Nernst' layer, or double layer would it not?

 

If I have understood you correctly, those molecular collisions or impacts would NOT necessarily generate a momentary flash of heat then, but rather the temperature of...in this case...water would influence the effectiveness/success of overcoming or breaking through that energy barrier? If this is right it would also explain why some solutions drop in conductivity reading faster than other solutions in the first 24-48 hours...water temperature dependant.

 

The success, the rate, or the exponential or chain reaction of molecular impacts is governed by water temperature, and those impacts by themselves do not necessarily result in any heating effect, either of the solution in general OR localised at the site of each collision/impact...Yes/No?

[Aussie]

I've done further research and whilst it's difficult to get definitive answers I am satisfied Ag+ ion impacts WILL generate heat, but would only be detectable with suitable instrumentation {if that instrumentation exists}.

 

After due deliberation I believe it would not be the actual collision or impact of Ag+ ions that creates the heating effect, but rather the action of the Ag+ ion breaking through the Nernst layer, or double layer {energy barrier}, that would result in heating by way of friction as it breaks through that energy barrier, and that moment of friction would create a release of energy...which could only result in heat being generated. Once that barrier is broken the force of + and - natural attraction then automatically ensues as unlike poles attract each other.

 

In a roundabout way you have assisted me in making my own determination, Thanks for that.