Amphiphilic Azobenzenesulfonic Acid Anionic Surfactant for Water-Soluble, Ordered, and Luminescent Polypyrrole Nanospheres

Abstract

Self-organized micelles of new renewable resource amphiphilic azobenzenesulfonic acid anionic surfactant were utilized to prepare water-soluble, luminescent, and highly ordered polypyrrole nanomaterials. The micellar behavior of the reaction medium was precisely controlled by varying the composition of pyrrole/surfactant ratio from 3 to 100 (up to 100 times lower amount of surfactant with respect to pyrrole), and polypyrrole nanospheres of 150-800 nm were prepared. Dynamic light scattering (DLS) and viscosity techniques were employed as tools to trace the factors, which control the mechanism of polypyrrole nanomaterials formation. DLS studies confirmed that the surfactant exists as in the form of spherical micelles of 4.8 nm diameter in water. Specific viscosity measurement revealed that the pyrrole+surfactant complexes in water exist in the form of either aggregated or isolated micelles depending upon their composition in the feed. SEM and TEM analysis confirmed that the aggregated micellar templates produced coral-like morphology, whereas uniform polypyrrole nanospheres of 150-400 nm were obtained at low micellar concentration. The nanomaterials formation was unperturbed by the variation of the oxidation agents such as ammonium persulphate (APS) or ferric chloride (FeCl3). WXRD analysis of the nanomaterials indicates that the anionic surfactant effectively penetrates into the polypyrrole chains, and a new peak at 2theta = 6.3 degrees (d-spacing = 14 A) was observed corresponding to highly ordered polymer chains. UV-vis and FT-IR confirmed the highly doped state, and the conductivity of the samples was obtained in the range of 10(-1) to 10(-2) S/cm by four-probe conductivity measurements. The azobenzenesulfonic acid anionic surfactant is luminescent in water, and its grafting on the polypyrrole nanospheres enhances the luminescent intensity with the quantum yield in the range of 2 x 10(-3) to 3 x 10(-4).

A novel, rapid synthetic protocol for controllable sizes, conductivities and monomer units of soluble polypyrrole

“…For the other PPy materials too, the conductivities can be increased at higher concentrations of HNO 3 . The conductivities of PPy spheres synthesized here are lower than other studies [16,25]. The decrease in conductivity herein is ascribed to the lower extent of doping of nitrate ions and is interpreted on the basis of (i) the dopant concentration and (ii) the reaction time.…”

“…The chemical polymerization of pyrrole can be accomplished using dispersive polymerization [20], interfacial polymerization [21,22], seeding techniques [23,24], emulsion polymerization [25,26], etc. Surfactant-assisted emulsion techniques offer facile routes for synthesizing PPy whereby interesting optical, electrical and morphological properties can be achieved in conjunction with easy removal of templates.…”

Highly sensitive electrocatalytic biosensing of hypoxanthine based on functionalization of graphene sheets with water-soluble conducting graft copolymer

“…No absorption peak for RGO sample was observed in the wavelength range of 300-1300 nm (curve a) (Liu et al, 2009a). The UV-vis spectrum of PSSA-g-PPY (curve b) showed a bipolaron absorption at 450 nm and a free carrier tailing of anti-bipolaron absorption in the near-IR region with a maximum value at about 1110 nm, indicating that the copolymer was in a selfdoped state (Bae et al, 2005;Antony and Jayakannan, 2007). After integrating with RGO, the characteristic absorption peaks at 450 and 1110 nm arising from PSSA-g-PPY were blue shifted to 415 and 965 nm in the spectra of PSSA-g-PPY/RGO (curve c), and the absorption peak at 415 nm was more broaden.…”

Synthesis of polypyrrole/indium tin oxide nanocomposites via miniemulsion polymerization

“…Moreover, the polymerization yields of pyrrole monomer are comparable to polymerization yields of other works. [36][37][38].…”

“…The characteristics bands of 1261, 1556, and 3431 cm −1 can be seen among the FTIR peaks of PPy and its nanocomposites which are due to C-N, C=C, and N-H bands. [9,37,39] An appeared peak at 1700 cm −1 is related to the C=O groups of surfactant which is used for the synthesis of neat PPy and its nanocomposites. [34] The spectra of the PPy/ITO have almost identical peaks as those associated with the structure of neat PPy, which is due to the dominating phase of PPy in the formed nanocomposites.…”