Synthesis of nano-sized polyindole via emulsion polymerization and doping

Polyindole (PIn) nanoparticles were synthesized through an emulsion polymerization technique in this study and then examined as an anhydrous semi‐conducting electro‐responsive material. Their surface morphology and chemical structure were observed with high‐resolution scanning electron microscopy and Fourier transform infrared spectroscopy, respectively. When dispersed in silicone oil, the electrorheological (ER) properties of the PIn particles were examined using a rotational rheometer with both steady shear and oscillatory tests under various applied electric field strengths with direct observation using an optical microscope. Flow curves of shear stress as a function of shear rate were well fitted using the Cho‐Choi‐Jhon model. Dielectric analysis was also performed to examine the permittivity and loss factor in relation to the ER effect. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46384.

Section: Resultsmentioning

confidence: 81%

Section: Resultsmentioning

confidence: 99%

Section: Characterizationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Emulsion‐polymerized polyindole nanoparticles and their electrorheology

Park

Kwon

Choi

2018

The modified polythiophene‐Cu NPs composites for Pb(II) ions removal from aqueous solution

Karegar

Khodaei

2021

The present work describes the use of chemically modified polythiophene with copper nanoparticles and polyvinylpyrolidine‐sulfonic acid (PTh‐PVP‐SA‐Cu) as an adsorbent for the removal of Pb(II) ions from aqueous solution. The synthesized composite, PTh‐PVP‐SACu, was characterized by different techniques including Fourier‐transform infrared spectrometer, scanning electron microscopy, energy dispersive X‐ray spectroscopy (EDX), transmission electron microscopy, X‐ray powder diffraction, thermogravimetric analysis (TGA), and differential scanning calorimetry. This nanocomposite has good conductivity and thermal stability due to the presence of copper nanoparticles. The acidic doping agent, polyvinylpyrolidine‐sulfonic acid, can act as the surfactant and improves the polymerization of thiophene in the aqueous medium. The conductivity of PTh was 0.54 S/cm, while the conductivities of PTh‐Cu with 10 and 20 wt% of PVP‐SA under the same reaction conditions were 2.3 and 2.7 S/cm, respectively. The influence of pH, adsorbent dosage, temperature, contact time, and concentration on the removal of Pb(II) ions was evaluated. The optimum conditions for the removal of Pb(II) ions were 25°C with the adsorbent dosage of 3 g.L−1 at pH = 7. The adsorption capacity was obtained to be 111 mg. g−1. The obtained equilibrium data for PTh‐PVP‐SA‐Cu was fitted well by Langmuir isotherm model indicating that the adsorption process was monolayer adsorption and distribution of adsorption sites on the surface of PTh‐PVP‐SA‐Cu was homogeneous. The maximum monolayer capacity obtained from the Langmuir isotherm was 121.9 mg. g−1 for Pb(II) ions at 45°C. The values of Gibbs free energy (ΔG), entropy change (ΔS) and enthalpy change (ΔH) indicated the feasibility, spontaneity and the endothermic nature of the adsorption process, respectively. The kinetic process followed the pseudo‐second‐order kinetic model. The recyclability studies revealed that PTh‐PVP‐SA‐Cu could be reused for three consecutive cycles.

Positional isomeric effect of nitro group substituted indoles on the electropolymerization and the capacitance performances of their polymers

Ma,

Zhu,

et al. 2023

The isomers of conducting polymers usually have different properties, however, there are still few studies on the isomeric effect of conducting polymers in supercapacitors field. In this work, four isomers (4‐nitroindole, 5‐nitroindole, 6‐nitroindole, and 7‐nitroindole) were selected as the research objects to study the positional isomeric effect of nitro group substituted indoles on the electropolymerization and the capacitance performances of their polymers. The results show that the prepared poly(5‐nitroindole) (5‐PNI) and poly(6‐nitroindole) (6‐PNI) are in nanowires structure, poly(7‐nitroindole) (7‐PNI) is in dense structure, while poly(4‐nitroindole) (4‐PNI) fails to be prepared. In addition, the as‐prepared 5‐PNI, 6‐PNI nanowires and dense 7‐PNI exhibit very different electrochemical properties and capacitance performances. Taking into account the specific capacitance (364 F g−1 at 5 mV s−1), rate capability (58.5%) and cyclic stability (94% capacitance retention after 1000 cycles test), it can be concluded that 5‐PNI is the most suitable electrode material in the field of supercapacitors.