Preparation of polyaniline/phosphorylated poly(vinyl alcohol) nanoparticles and their aqueous redispersion stability

Abstract

A novel approach for the preparation of the colloidal conducting polyaniline (PANI) nanoparticles was developed. The polyaniline/partially phosphorylated poly(vinyl alcohol)(PANI/P-PVA) nanoparticles were prepared by the chemical oxidative dispersion polymerization of aniline monomer in 1.0 M HCl aqueous media with the partially phosphorylated poly(vinyl alcohol) (P-PVA) as the stabilizer and codopant. The PANI/ P-PVA nanoparticles were characterized by transmission electron microscopy (TEM), Fourier transform infrared (FTIR), thermal gravimetric analysis (TGA), electrical conductivity measurement, and redispersion stability testing. All the results were compared with the properties of the conventional polyaniline in the emeraldine salt form (PANI ES). It was found that the P-PVA/aniline feeding ratio obviously affected the morphology, redispersion stability and electrical conductivity of the PANI/P-PVA nanoparticles. When the P-PVA/aniline feeding ratio ranged from 50 to 60 wt %, the PANI/P-PVA nanoparticles showed spherical shape with good uniformity, significant redispersion stability in aqueous media, and good electrical conductivity up to 7 S/cm.

High electrically conductive polyaniline/partially phosphorylated poly(vinyl alcohol) composite films via aqueous dispersions

“…No precipitation was observed in these dispersions even after eight months, and the particle size distributions were almost unchanged for one year because of the stabilizing of the P-PVA. 34 The FTIR spectra of the P-PVA, the PAn emeraldine salt form (PAn-ES), and the PAn/P-PVA samples are shown in Figure 2. In the spectrum of P-PVA, the characteristic bands of the O-H stretching around 3250 cm -1 , the -CH 2 stretching (symmetric and asymmetric) at 2903 and 2810 cm -1 , the C-H bending at 1407 cm -1 are observed, and the absorbance peak at 1026 cm -1 is attributed to the stretching frequency of the -P-O-C-groups, and the strong absorbance peak at 1690 cm -1 is assigned to the stretching vibration of the -P=O-groups.…”

Conducting Polyaniline Nanoparticles and Their Dispersion for Waterborne Corrosion Protection Coatings

“…Coatings with high resistance values (>1 Â 10 7 Ω cm 2 ) and low capacitance values (<1 Â 10 À9 F cm À2 ) have been found to offer corrosion protection of steel. 28 Impedance plots (Bode plots, impedance versus frequency) of the bare steel, pure epoxy film-coated steel, 2.5 wt % PANI ES, 1.0 wt % PANI/P-PVA, 2.5 wt % PANI/P-PVA, and 4.0 wt % PANI/P-PVA-coated steels after 50 days of immersion in 3.0 wt % NaCl are shown in Figure 6. Obviously, 2.5 wt % PANI/P-PVA possessed the highest R c value (3.5 Â 10 7 Ω cm 2 ) at a low frequency of 0.025 Hz, followed by 4.0 wt % PANI/P-PVA (1.74 Â 10 7 Ω cm 2 ), 1.0 wt % PANI/P-PVA (7.85 Â 10 6 Ω cm 2 ), and 2.5 wt % PANI ES (3.58 Â 10 6 Ω cm 2 ).…”

“…In this work, we directed our efforts on the investigation of possibility for creation of waterborne anticorrosion coatings on mild steel with aqueous epoxy resin as matrix based on recently developed polyaniline/partially phosphorylated poly(vinyl alcohol) (PANI/P-PVA) nanoparticles. 28 Partially phosphorylated poly(vinyl alcohol) (P-PVA) acted as the codopant and polymeric stabilizer in this system.…”

“…PANI/P-PVA nanoparticles were synthesized through a procedure presented in our previous work. 28 Two grams of aniline was well-mixed with 300 mL of 0.2 M HCl aqueous solution containing 1.0 g of P-PVA. The system was cooled at 0 °C followed by the addition of 50 mL of 0.2 M HCl aqueous solution of APS; the mole ratio of aniline to APS was 2:1.…”

Inherently fluorescent polyaniline nanoparticles in a dynamic landscape

“…3c, with rice-grain nanoparticles of $100 nm for the long-axis and $10-30 nm for the short-axis. In consideration of the molecular characteristics of the chosen polymer (weight-average degree of polymerization, DPw < 650; degree of acetylation DA = 25-15%), the low pH and the high ionic strength of the aqueous solution (0.1 M HCl), chitosan chains in solution are quite isolated at the given concentration, still presenting some degree of chain flexibility for the free chlorine ions screening of electrostatic repulsions of protonated amino-groups responsible for chain expansion [40]. Aniline oligomers should favorably absorb to the hydrophobic sites of chitosan owing to the presence of the hydrophobic GlcNAc units, that are chemically stable in the chosen reaction conditions [41], and grow uniformly (Scheme 1c).…”