i am working on a project related to nanocomposite coatings, one of the compositions we are concentrating on is rich in cadmium content. The problem arised when we tried to stir the solution of nanocomposite, we observed the solution to be liquid free with increase in stirring time. what could be the possible reasons for this?
Hello
For my knowledge, you should check the physical properties of each component in the solution you are stirring. In fact, at a constant stirring speed, increasing the stirring time could cause some friction effect that could cause local temperature increase. This local temperature increase could be the reason of liquid loss in your solution. Also note that increasing the stirring speed could also affect the solution state.
Best of luck
Regards
Loraine
Hello Imad Disher,
Yes i mean a suspension as i am using a mixture of nanoparticles & i am using ethanol as solvent with a binder.
You have a suspension of nanoparticles suspended in ethanol and are strirring it in an open beaker?
Ethanol has a relatively high vapor pressure and is therefore prone to rapid evaporation in an open system. Stirring would increase the rate of evaporation. I would suggest using a wide-neck sample jar instead.
I'm not sure if foil would be "air tight." Do you have any parafilm?
Is there any apparent change in the nanoparticles? Do you form a mass/conglomerate? or does it just seem like the "solvent" has evaporated?
I have seen references suggesting that cadmium rich nanoparticles will bind to polyvinyl alcohol via interaction with -OH. Could it be possible for your nanoparticles to adsorb the alcohol?
Sir,
From what I have observed, there is a change in amount of solvent remained with stirring time. For 24hrs of stirring ,there is no trace of solvent remained.
Glad to hear a new version related to adsorption, how can I know whether the alcohol is adsorbed.
Do you have access to FTIR or FTIR-ATR? I would assume that you'd be able to see the alcohol via the IR. I would also be fairly confident that IR would give you some information about the interactions between the OH and nanoparticle surface.
Have you determined if there is a mass difference before and after stirring? If the mass of the beaker/contents doesn't change, then the solvent would still have to be in the beaker, otherwise you are simply seeing evaporation.
Sir,
If there is chance of evaporation ,will it be visible at the foil surface.
If it was water I'd say definitely- but alcohol (I assume you mean ethanol or methanol?) maybe not.
I would really encourage you to monitor the mass of the system during the course of the experiment- simplest measurement in the lab. Measure the beaker, particles, stir-bar, solvent and foil at beginning and every couple of hours. If you observe a mass loss = initial solvent mass then it's simple evaporation and you need to find a better way of covering the beaker. If mass loss = zero, then you've got a mystery to solve. But first find out if it IS a mystery.
Dear Narasimha Kalyan,
you might be interested to replace your beaker with a simple, and low cost, canning[1] preserve glass (or similar, with an optional parafilm[2], airtight ones).
1. As a example, see: Glass Mason Jars Canning Preserve w/ Lids https://www.ebay.com/itm/12-Wide-Mouth-Quart-32oz-Glass-Mason-Jars-Canning-Preserve-w-Lids-New-Ball-Kerr/172810202061?hash=item283c4a6bcd:g:edcAAOSwwmlZh4Vl
2. Parafilm M Laboratory Film 2" wide 10' Long ( 5cm wide 305cm long) https://www.ebay.com/itm/Parafilm-M-Laboratory-Film-2-wide-10-Long-5cm-wide-305cm-long/142604540835?hash=item2133e49ba3:g:4QEAAOSw3fZaHbqk
Sir,
The previous answers are totally concentrating on the solvent ethanol. But , when I did the same for lead rich composite, there is presence of solvent.
My question is " why there is no trace of solvent in case of cadmium rich composite".
Thanking you.
Dear Narasimha Kalyan,
remake both tests using some new (proposal) "canning preserve glassware" (same quality); then reform your question. I presume that it will be not the same(?) question, as the last question.
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