Modulating the Emission Intensity of Poly-(9,9-bis(6‘-N,N,N-trimethylammonium)hexyl)-Fluorene Phenylene) Bromide Through Interaction with Sodium Alkylsulfonate Surfactants

Abstract

The interaction between the cationic HTMA-PFP (Poly-(9,9-bis(6′-N,N,N-trimethylammonium)hexyl-fluorene phenylene) bromide) and oppositely charged sodium n-alkyl sulfonate surfactants of different chain lengths has been studied in DMSO-water solutions (4% v/v) by UV-visible absorption, fluorescence spectroscopy, fluorescence lifetimes, electrical conductivity, and 1 H NMR spectroscopy. Polymer-surfactant interactions lead to complex spectroscopic behaviors which depends on surfactant concentration. At low surfactant concentrations, the observed strong static fluorescence quenching of fluorescence seems to be associated with formation of aggregates between polymer chains neutralized through interaction with surfactants. This is supported by conductivity and by analysis of absorption spectra deconvoluted at each surfactant concentration using an adapted iterative method. In contrast, above the surfactant critical micelle concentration, there is a strong fluorescence enhancement, leading in some cases to higher intensities than in the absence of surfactants. This is attributed to the transformation of the initially formed aggregates into some new aggregate species involving surfactant and polymer. These changes in HTMA-PFP fluorescence as a function of n-alkyl sulfonate concentration are important for the general understanding of polymer-surfactant interactions, and the aggregates formed may be important as novel systems for applications of these conjugated polyelectrolytes.

Singlet Excitation Energy Harvesting and Triplet Emission in the Self‐Assembled System Poly{1,4‐phenylene‐[9,9‐bis (4‐phenoxy‐butylsulfonate)]fluorene‐2,7‐diyl} copolymer/tris(bipyridyl)ruthenium(II)in Aqueous Solution

“…Poly-(9,9-bis(6 0 -N,N,N-trimethylammonium)-hexyl-fluorene phenylene) bromide (HTMA-PFP) was a kind gift from Dr. Ricardo Mallavia (Universidad Miguel Hernández, Alicante, Spain). The synthesis and characterization have been described elsewhere [27]. C 12 E 5 (Fluka) and tris(2,2 0 -bipyridyl)ruthenium(II) chloride hexahydrate (Alrich) were of the purest grade available, and were used without further treatment.…”

Photophysics and rotational relaxation dynamics of a β-carboline based fluorophore in cationic alkyltrimethylammonium bromide micelles

“…Hence study of the binding interaction of numerous fluorophores with micelles is highly significant [4,[9][10][11]. Recent studies on a variety of drugs and dyes with various surfactants enlighten our understanding of the probe-micelle binding interaction and the distribution and/or localization of the probes within the micellar environments [12,13]. Micelles are characterized as organized assemblies with three distinct regions: a nonpolar core containing hydrocarbon chains of the surfactants, micelle-water interface containing polar head groups, and a wider Gouy-Chapman layer containing the counterions [2].…”

Conformation Control of a Conjugated Polymer through Complexation with Bile Acids Generates Its Novel Spectral and Morphological Properties

“…We consider, therefore, that at the high SDS concentration, lithocholate in PT-1/lithocholate complex is totally replaced with SDS and PT-1 aggregates in the SDS micellar structure. [54] The difference between lithocholate and SDS indicates that the bulkiness and the rigidity characteristic of bile acids are indispensable for elongation of the PT-1 main-chain.…”