How surface interactions freeze polymer molecules at room temperature: a single molecule approach

Brazil MRS Meeting 2014

Araújo, F.L.^1 ; Valente, G.T.^1 ; Faria, R.M.^1 ; Guimarães, F.E.G.^1

São Carlos Institute of Physics, University of São Paulo, C.P. 369, 13560-970 São Carlos, SP, Brazil^1

关键词: Confocal fluorescence microscopy;    Interacting molecules;    Interchain interactions;    Photophysical process;    Planar conformations;    Poly(9 ,9-dioctylfluorene);    Polymer conformation;    Surface interactions;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/97/1/012003/pdf
DOI  :  10.1088/1757-899X/97/1/012003

来源: IOP

【 摘 要 】

The planar conformation assumed by polyfluorenes is used as a model system to investigate how solid surfaces interact with an individual polymer chain as well as to access the effects of substrates and interchain interactions on the polymer conformation. We demonstrate that confocal fluorescence microscopy is very sensitive to characterize photophysical processes associated to conformation assumed by a single conjugated unit of poly (9,9 dioctylfluorene) or PFO. Emissions from interacting molecules have been resolved for the first time between the energies of the planar (β phase) and the non-planar (amorphous) phase that were associated to perturbations of the primary chain conformation. But we have found the planar conformation is assumed by single PFO molecules due to strong interactions with the hydrophilic quartz surfaces. This PFO conformation persists frozen even at room temperature, although emission lines are significantly broadened due to interactions with vibrating substrate atoms.