In organic solar cell processing both Chloroform and Chlorobezene can be used to dissolve polymers (30,000 - 50,000 Mw for the polymer "PM6" for example) and small molecules (i.e. "Y6" or "ITIC"). As I'm not a chemist by trade my understanding of dissolving polymers with organic solvents is primarily based on "like for like".
Basically my question is how can CF and CB both dissolve these complex (aromatic) polymers despite their widely different structures (and therefore I'd assume different intramolecular forces) and further to this would this affect the crystallisation of the dissolved materials outside of different evaporation rates?
This is an important question to me because in all of literature regarding PM6:Y6 OPV systems CF is practically the only solvent used.
Any help would be greatly appreciated, thanks for your time.
Kind regard,
Matthew Smith
In inorganic solver such as water, the splitting of the solvated materials depends on the dielectric screening of the polarized water molecules. It is so that the positive water ions screens the negative ions of the solvated material while the negative water ions surround and screen the positive ions of the solvated materials. In this way the ions of the solvated materials gets spaced away from each other. Which means the ions of the solvated material become electrostatically screened by the water molecules.
Organic solvents do not work on the same concept.
I am an electrical engineer and not a chemist. It seems that the organic solvents have mostly covalent bonds inside the molecules and van der Waal forces.
How the dissolution occurs it seems that the similarity between the solvent and the solvated materials is the driving force for the dissolution process. At the end a mixture is formed where the overall potential energy gets lower. This concept is the ruling principle for the dissolution process.
Best wishes
Dear Matthew Smith, solubility is possible when solvent and solute have close solubility parameters. This is what is like dissolves like. These aromatic polymers have other sites where interactions with the solvent are possible, from here solubility starts. For the crystallinity, if it is existing it may be re-establushed (reformed) from solution. My Regards
In inorganic solver such as water, the splitting of the solvated materials depends on the dielectric screening of the polarized water molecules. It is so that the positive water ions screens the negative ions of the solvated material while the negative water ions surround and screen the positive ions of the solvated materials. In this way the ions of the solvated materials gets spaced away from each other. Which means the ions of the solvated material become electrostatically screened by the water molecules.
Organic solvents do not work on the same concept.
I am an electrical engineer and not a chemist. It seems that the organic solvents have mostly covalent bonds inside the molecules and van der Waal forces.
How the dissolution occurs it seems that the similarity between the solvent and the solvated materials is the driving force for the dissolution process. At the end a mixture is formed where the overall potential energy gets lower. This concept is the ruling principle for the dissolution process.
Best wishes
Dear Dr. Abdelhalim Zekry, what you have said is correct, just one remark about the last statement in your contribution. Solubilization is physical process and not a chemical one. My Regards
Okay, thank you Abdelkader BOUAZIZ ! Please see the last sentence after I reformulated it.
Best wishes
No change, still it is said : '.....chemical processes including the dissolution process.'. Again dissolution is a physical process.
Abdelkader BOUAZIZ and Abdelhalim abdelnaby Zekry
Thank you both for your insightful answers.
Kind Regards
one practical aspect, why chloroform is more used is its substantially lower boiling point, much easier to be removed by evaporation.
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