Facile Synthesis and Intrinsic Conductivity of Novel Pyrrole Copolymer Nanoparticles with Inherent Self-Stability

Abstract

Intrinsically self-stabilized nanoparticles of a copolymer from 4-sulfonic diphenylamine (SD) and pyrrole (PY) were facilely synthesized in HCl solution at 10 degrees C by a chemically oxidative polymerization. The critical reaction parameters such as SD/PY ratio, polymerization time, and oxidant species were studied to significantly optimize the polymerization yield, size, conductivity, and solubility of the final copolymer particles. The molecular structure, size, size distribution, and morphology of the particles were analyzed by IR spectroscopy, laser particle-size analysis (LPA), atomic force microscopy, and transmission electron microscopy (TEM). It was found that the polymerization yield of the SD/PY (50/50) copolymers increased dramatically in the initial 2 h of polymerization and then slowly enlarged in the subsequent 22 h. However, the copolymerization yield for the polymerization time of 24 h exhibited a nonlinear dependence on the SD/PY molar ratio, i.e., a maximum at 10/90 and a minimum at 80/20. The number-average diameter, Dn, of the copolymer particles strongly depended on the SD/PY ratio, decreasing rapidly from 6402 to 291 nm as the SD/PY molar ratio changed from 30/70 to 50/50, whereas the polydispersity index, PDI = Dw/Dn (where Dw is the weight-average diameter), surprisingly maintained very small values, decreasing slightly from 1.21 to 1.08. The SD/PY (80/20) copolymer particles prepared with (NH4)2S2O8 as the oxidant had the smallest size of ca. 10 nm by TEM and the lowest Dw/Dn value of 1.03 by LPA, whereas the copolymer particles prepared with FeCl3 as the oxidant exhibited the second smallest size of ca. 20 nm by TEM and the highest conductivity. The conductivity of the SD/PY (50/50) copolymers rose first and then decreased with increasing polymerization time from 10 min to 24 h, exhibiting a maximum (0.217 S/cm) at 12 h. It is of interest that the copolymer particles with SD/PY molar ratios in the range between 50/50 and 80/20 surprisingly exhibited the smallest size, the narrowest size distribution, and the highest conductivity at the same time. In particular, the copolymer nanoparticles exhibited high purity, clean surfaces, good self-stability, high conductivity, and strong chemoresistance that were very important to nanomaterial processibility and application. The obtained copolymers were partially soluble in concentrated H2SO4, demonstrating a new direction for synthesizing a soluble pyrrole copolymer.

Bulk synthesis, optimization, and characterization of highly dispersible polypyrrole nanoparticles toward protein separation using nanocomposite membranes

“…4e). While PPy nanoparticles demonstrated that stretching bands at 1472 and 1550 cm À1 due to the pyrrole ring [27], a shoulder band at 1690 cm À1 assigned to part of the oxidized pyrrole ring [28], two bands at 1032 and 1301 cm À1 attributed to CÀN stretching bands [29], and stretching bands at 923 and 1202 cm À1 generated by doped PPy [30]. Note that a small shoulder band at 740 cm À1 appeared in spectra of PPy nanoparticles, indicating that a small amount of 2,4-diaminodiphenylamine has copolymerized with pyrrole, as shown in Scheme 1.…”

N‐Doped Polypyrrole‐Based Porous Carbons for CO2 Capture

“…The IR spectrum of polypyrrole exhibits well-defi ned peaks that are characteristic of this polymer (see Table S1). [39][40][41][42] In contrast, the carbonized and activated samples exhibit broader and overlapping bands due to the strong absorption of carbon. All the spectra exhibit a peak that is characteristic of C = C stretching vibrations in aromatic rings at ≈ 1590 cm − 1 for the carbonized sample and 1590-1620 cm − 1 for the activated samples.…”

Development and Characterization of Stimulus-Sensitive Nano/Microparticles for Medical Applications

“…Polypyrrole (PPy) is a commonly used conducting polymer due to its good stability, ease of synthesis, and greater conductivity compared to other conductive polymers [32]. It is used for a wide range of biological applications due to its ability to support growth of electrically responsive cells such as neuronal cells [33], bone cells, and smooth muscle cells [34].…”

“…It is used for a wide range of biological applications due to its ability to support growth of electrically responsive cells such as neuronal cells [33], bone cells, and smooth muscle cells [34]. Li et al [32] had synthesized stable, conductive NPs using a copolymer of PPy and 4-sulfonic diphenylamine (SD). The NPs having 50/50 monomer ratio showed the smallest size (20 nm) and highest conductivity (0.217 S cm À1 ) when using FeCl 3 as an oxidant during synthesis.…”