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Title: Water-soluble polystyrene latexes as photoredox media. 1. Interfacial fluorescence quenching and triplet-state electron transfer from pyrene and 1-pyrenebutyric acid

Journal Article · · Journal of Physical Chemistry; (United States)
DOI:https://doi.org/10.1021/j100133a027· OSTI ID:6094611
;  [1]
  1. Univ. of Texas, Austin (United States)

Aromatic chromophores (pyrene and 1-pyrenebutyric acid) have been adsorbed on water-soluble polystyrene latex particles (commercially referred to as microspheres) from the aqueous phase. The fluorescence properties and quenching efficiencies of these chromophores have been measured using a zwitterionic viologen SPV (4,4[prime]-bipyridino-l,l[prime]-bis(propanesulfonate)). The quenching mechanism has been found to be diffusion controlled. The electron-transfer quenching of the triplet state by SPV was characterized. Triplet-state quenching does not occur for pyrene embedded in these polystyrene latexes in aqueous solution, which is attributed to the hydrophobic protection of the pyrene from the approach of water-soluble SPV. On the other hand, the efficiencies of charge separation for l-pyrenebutyric acid both in homogeneous aqueous solution and adsorbed on polystyrene latexes in aqueous solution were found to be high. It is proposed that the amphiphilic l-pyrenebutyric acid molecules prefer to reside at the aqueous interface of the latexes. These results demonstrate that [open quotes]compartmentalization[close quotes] of ion pairs, produced by redox quenching, can be achieved when l-pyrenebutyric acid molecules are located at these interfaces. This provides a strategy for more efficient utilization of excited-state redox processes. 17 refs., 9 figs., 5 tabs.

DOE Contract Number:
FG05-86ER13629
OSTI ID:
6094611
Journal Information:
Journal of Physical Chemistry; (United States), Vol. 97:31; ISSN 0022-3654
Country of Publication:
United States
Language:
English