Preparation and Characterization of Water Self-dispersible Poly(3-hexylthiophene) Particles

Abstract

The present paper describes the preparation and characterization of stable aqueous dispersions of poly (3-hexylthiophene) (P3HT) by a precipitation method. P3HT was first synthesized by oxidative polymerization of 3HT with iron(III) chloride as an oxidant. Number-average molecular weight (M n ) of P3HT increased with an increase in 3HT concentration. Colloidal particles were prepared by adding a tetrahydrofuran (THF) solution of P3HT into a large amount of distilled water. TEM observations showed that the particle size increased with an increase in the concentration and M n of P3HT. The size of the particles was in the range of 50 to 600 nm. The spectral features of the aqueous dispersions were investigated by means of UV-vis spectroscopy. P3HT provided the -Ã absorption band at 436 nm in THF. On the other hand, the dispersions brought about a bathochromic shift of the bands and a larger red shift was observed as the polymer concentration became higher, indicating that P3HT would take a well-stacked structure in the particles. Temperature dependence of UV-vis absorption spectra for P3HT aqueous dispersions was also studied in the temperature range of 0 to 80 C, which revealed that P3HT in the dispersed state showed a thermochromism similar to that of P3HT in THF.KEY WORDS: Polythiophene / -Conjugated Polymer / Poly(3-hexylthiophene) / Colloidal Particle / Conducting Polymer / Precipitation Method / Thermochromism / Poly(3-hexylthiophene) (P3HT) is a subject of extensive study because of its solubility, fusibility, and environmental stability.1 P3HT also exhibits unique properties such as thermochromism and solvatochromism. [2][3][4][5][6] This functional polymer is viewed as potentially useful materials in fieldeffect transistors, optical and electronic sensors, light-emitting devices, nonlinear optical materials, etc. 7-9Our attention has focused on colloidal dispersions of P3HT particles. Colloidal particles are of great importance due to their interesting physical properties as well as their potential technological applications.10,11 Several attempts have been made so far to produce P3HT particles. Yamamoto et al. employed a reprecipitation method to prepare colloidal dispersions of P3HT. Methanol, which is a poor solvent for P3HT, was added to the CHCl 3 solution of P3HT, resulting in the formation of P3HT particles. 12,13 Takeuchi and Kobashi also investigated in detail the kinds of poor solvents and clarified the precipitation conditions for improved yields. 14 Furthermore, it has been reported that the use of a nonionic surfactant, Tween 80, provided stable aqueous dispersions of P3HT. 15To our knowledge, few reports on water self-dispersible P3HT particles have been published. 15 There is hence a lack of information about colloidal properties of P3HT water dispersions, such as particle size, particle morphology, optical property, etc. Development and characterization of such dispersions are of great significance from an environmental as well as industrial aspect. The purpose of the present study is to de...

Tuning optical properties of poly(3-hexylthiophene) nanoparticles through hydrothermal processing

“…A blue shift in the absorption peaks upon annealing P3HT NPs and films was reported in [16,21,22], which was associated with the decrease in the π-conjugation length in the polymer chain, and changes in the peak intensities with annealing were noted in [23,24]. In contrast, a redshift was observed in this study.…”

“…The P3HT NPs were fabricated by a reprecipitation method [16]. Regioregular P3HT powder (regioregularity: 90-93%, Mw = 50 k, Sigma-Aldrich Corp) was used without further purification.…”

“…In this study, P3HT NPs were fabricated in an aqueous suspension using a reprecipitation method [16]. To modify the optical properties, the P3HT NPs were hydrothermally treated in an aqueous suspension, i.e., pressurized in a chamber at various temperatures.…”

Solar Paint: From Synthesis to Printing

“…As an alternative to the miniemulsion approach, precipitation techniques offer a simple route to the production of semiconducting polymer nanoparticles via the injection of a solution of active material into a second solvent of poor solubility [27,28]. As such, the synthesis is quick, does not use surfactant, requires no heating (and therefore, no prefabrication annealing of the nanoparticles) in the nanoparticle synthesis phase and can readily be scaled up for the large-scale synthesis of material.…”

Optical Degradation of Colloidal Eu-Complex Embedded in Silica Glass Film Using Reprecipitation and Sol–Gel Methods

“…In generally, the aggregation of Eu(TTA) 3 phen in the poor solvent (water) efficiently occurs when the concentration is high. 38 Therefore, the optical degradation is seems to be occurred at the high concentration of Eu(TTA) 3 phen in DMSO. Anyhow, the PL degradation is successfully prevented by forming colloidal nanoparticles into the sol-gel derived silica glass network compared to Eu(TTA) 3 phen powder.…”