Bulk results and question
Questions
Can we use the anisotropy phase change in solution sample to check the results? film?
why the 60% ethanol chloroform mixture would have absorption in long range, but the change is not linear, why?
might caused by the conformation of liquid crystal
Ma, T., Song, N., Liu, B., Ren, J., Zhang, H., & Lu, D. (2019). Effect of External Electric-Field on Poly [(9, 9-dioctylfuorenyl-2, 7-diyl)-alt-co-(bithiophene)](F8T2) Chain Orderness, Morphology and Carrier Mobility in Different Condensation Process. The Journal of Physical Chemistry C.
why the conformation is a relative stable? why it does not change by shaking? if it is caused by different distance? then, what is the repulsion of the chain comes from???
If measure the average molecular size in the solvent, it might increase then decrease again.
the spectrum comparison between cryogenic and room temperature on MeTHF and Chloroform is different, it seems that it barely show J aggregate form under 400 nm excitation or chloroform situation
why the film with similar spectrum as hexane dissolved sample show super short lifetime that even shorter than the solvent situation?
similar to the lifetime trend in P3HT
It may from efficient(ultrafast) interchain exciton dissociation with eventual contribution of singlet-singlet annhilation.
Alternatively, aggergates could provide phonon modes capable of substantially increasing internal conversion, which cause the strong fluorescence quenching in film. (something as twistng motion of the molecular chain)
Ferreira, B., da Silva, P. F., Seixas de Melo, J. S., Pina, J., & Maçanita, A. (2012). Excited-state dynamics and self-organization of poly (3-hexylthiophene)(P3HT) in solution and thin films. The Journal of Physical Chemistry B, 116(8), 2347-2355.
polymer dissolved in hexane
Hex 400 nm fit
Hex 488 nm fit
compare with other bad solvent
abs with air blank
film
fluo 488 77K
Fluo 488
solvent
Chloroform and ethanol
cryogenic and room temperature control
lifetime
normalized
not normalized
Chloroform and Hexane
Lifetime
concentration dependent
wavelength dependent
Franck condon analysis
CH 400 nm fit
QY without correction
488 nm
400 nm
PLE
Fluo
488 77K
488 rm
400
ABS
