Raman Spectroscopic and Electrochemical Studies on the Doping Level Changes of Polythiophene Films during Their Electrochemical Growth Processes

Shi, Gaoquan; Xu, Jingkun; Fu, Mingxiao

doi:10.1021/jp013023o

Cited by 114 publications

(110 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The low frequency modes at 885 and 965 cm À1 are assigned to ring C-S stretching and ring-CH 3 rocking, respectively, in agreement with previous work on a methyl-substituted polythiophene. 61,62 Similar RR spectra have been reported for another polythiophene polyelectrolyte with an alkoxy cationic side chain, the cation being a tertiary amine. 63 Upon excitation at 473 nm, the RR spectrum of CPT in PBS significantly changes, with the C a QC b stretch band downshifted to 1487 cm À1 , and the relative intensity between the C a QC b and the C b -C b 0 stretch modes reversed with the latter being more intense at this wavelength (middle of Fig.…”

Section: Resonance Raman Studiessupporting

confidence: 68%

Salt-induced thermochromism of a conjugated polyelectrolyte

Peterhans

Alloa

Sheima

et al. 2017

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

We report here the photophysical properties of a water-soluble conjugated polythiophene with cationic side-chains. When dissolved in aqueous buffer solution (PBS, phosphate buffered saline), there is ordering of the polymer chains due to the presence of the salts, in contrast to pure water, where a random-coil conformation is adopted at room temperature. The ordering leads to a pronounced colour change of the solution (the absorption maximum shifts from 400 nm to 525 nm). Combining resonance Raman spectroscopy with density functional theory computations, we show a significant backbone planarization in the ordered phase. Moreover, the ratio of ordered phase to random-coil phase in PBS solution, as well as the extent of intermolecular interactions in the ordered phase, can be tuned by varying the temperature. Femtosecond transient absorption spectroscopy reveals that the excited-state behaviour of the polyelectrolyte is strongly affected by the degree of ordering. While triplet state formation is favoured in the random-coil chains, the ordered chains show a weak yield of polarons, related to interchain interactions. The investigated polyelectrolyte has been previously used as a biological DNA sensor, based on optical transduction when the conformation of the polyelectrolyte changes during assembly with the biomolecule. Therefore, our results, by correlating the photophysical properties of the polyelectrolyte to backbone and intermolecular conformation in a biologically relevant buffer, provide a significant step forward in understanding the mechanism of the biological sensing.

show abstract

Section: Resonance Raman Studiessupporting

confidence: 68%

Salt-induced thermochromism of a conjugated polyelectrolyte

Peterhans

Alloa

Sheima

et al. 2017

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

show abstract

“…The most intense line for the P3TMA spectra is identified at ca. 1480 cm -1 , which corresponds to the totally symmetric in-phase vibration of the thiophene rings spread over the polymer chains [38]. Raman spectra were recorded from three different spots of the PLA-P3TMA fibers (Figures 2c and 2d) as well as from P3TMA particles, which are clearly visible as dark spots inside the fibers (Figures 2c and 2e).…”

Section: Results and Discussion 31 Topography And Raman Analyses Ofmentioning

confidence: 99%

Semiconducting, biodegradable and bioactive fibers for drug delivery

Pérez‐Madrigal¹,

Llorens²,

Valle³

et al. 2016

Express Polym. Lett.

View full text Add to dashboard Cite

Abstract. In this work we present the drug release properties and morphological studies of fibers formed by mixing different ratios of poly(lactic acid) (PLA) and poly(3-thiophene methyl acetate) (P3TMA) loaded with four drugs (ciprofloxacin, chlorhexidine dihydrochloride, triclosan and ibuprofen sodium salt). Thus, the main aim of this study is to prove that the excellent cellular response of PLA-P3TMA biocompatible scaffolds can be successfully combined with essential applications as drug carrier and delivery systems. Atomic force microscopic (AFM) and scanning electron microscopic (SEM) micrographs of PLA-P3TMA fibers indicate that the presence of the conducting polymer inside the PLA matrix affects the surface morphology, resulting in a significant increment of the bulk conductivity with respect to PLA fibers. Electrospun hybrid fibers of PLA and P3TMA successfully load both hydrophilic and hydrophobic drugs, the release profiles depending on the release environment (i.e. the release rate increases with the hydrophobicity of the medium). Finally, our results prove that the antibacterial activity of the drugs is not affected by their interactions with the PLA-P3TMA matrix.

show abstract

“…The LCM Raman characteristic peaks (see Supporting Information for details) of the pristine P3MT single nanotube, obtained in this study, agreed well with those of the bulk P3MT materials reported earlier. [28][29][30][31] We also observed the Raman characteristic modes in the lower wavenumber range (450-1050 cm À1 ) for pristine P3MT nanotubes (see Supporting Information). The LCM Raman peaks of the P3MT single nanotube in the range of 1050-1600 cm À1 showed significant differences after E-beam irradiation with relatively high dosages (!2.4 Â 10 16 electrons cm -2 ).…”

Section: Introductionmentioning

confidence: 78%

Tuning and Enhancing Photoluminescence of Light‐Emitting Polymer Nanotubes through Electron‐Beam Irradiation

Hong¹,

Park²,

Park³

et al. 2009

Adv Funct Materials

View full text Add to dashboard Cite

A new method for the tuning and enhancing photoluminescence (PL) characteristics of light emitting poly (3‐methylthiopnehe) (P3MT) nanotubes through E‐beam irradiation under atmospheric environments is reported. An E‐beam generated from a linear electron accelerator (1 MeV, 1.6 × 1013–8.0 × 1016 electrons cm–2) is irradiated onto P3MT nanotubes including an Al2O3 template. From laser confocal microscope (LCM) PL experiments, significant enhancements in the PL intensity—up to about 90 times of an isolated single strand of the E‐beam irradiated P3MT nanotubes—are observed. The luminescent color of the P3MT nanotubes changes from green to red color depending on the variation of E‐beam dosage. These results might originate from the de‐doping effect and the conformational modification through E‐beam irradiations. Conformational changes of the E‐beam irradiated P3MT nanotubes are confirmed by LCM single Raman and ultraviolet‐visible (UV/Vis) absorption spectra. From UV/Vis absorption spectra, it is observed that the π–π* transition peak and the doping induced bipolaron peaks of the P3MT nanotubes dramatically vary with E‐beam irradiating conditions.

show abstract

Raman Spectroscopic and Electrochemical Studies on the Doping Level Changes of Polythiophene Films during Their Electrochemical Growth Processes

Cited by 114 publications

References 35 publications

Salt-induced thermochromism of a conjugated polyelectrolyte

Salt-induced thermochromism of a conjugated polyelectrolyte

Semiconducting, biodegradable and bioactive fibers for drug delivery

Tuning and Enhancing Photoluminescence of Light‐Emitting Polymer Nanotubes through Electron‐Beam Irradiation

Contact Info

Product

Resources

About