Characterization and Electrical Properties of PVA Films with Self-Assembled Chitosan-AuNPs/SWCNT-COOH Nanostructures

Abstract

Nanostructured films with electrical conductivity in the semiconductor region were prepared in a polymeric matrix of poly(vinyl alcohol) (PVA) with nanostructures of chitosan-gold nanoparticles (AuNPs)/single-wall carbon nanotubes carboxylic acid functionalized (SWCNT-COOH) (chitosan-AuNPs/SWCNT-COOH) self-assembled. Dispersion light scattering (DLS) was used to determine the average particle sizes of chitosan-AuNPs, z-average particle size (Dz) and number average particle size (Dn), and the formation of crystalline domains of AuNPs was demonstrated by X-ray diffraction (XRD) patterns and observed by means of transmission electron microscopy (TEM). The electrostatic interaction was verified by Fourier transform infrared spectroscopy (FTIR). The electrical conductivity of PVA/chitosan-AuNPs/SWCNT-COOH was determined by the four-point technique and photocurrent. The calculated Dn values of the chitosan-AuNPs decreased as the concentration of gold (III) chloride trihydrate (HAuCl4·3H2O) increased: the concentrations of 0.4 and 1.3 mM were 209 and 90 nm, respectively. Average crystal size (L) and number average size (D) of the AuNPs were calculated in the range of 13 to 24 nm. Electrical conductivity of PVA/chitosan-AuNPs/SWCNT-COOH films was 3.7 × 10−5 σ/cm determined by the four-point technique and 6.5 × 10−4 σ/cm by photocurrent for the SWCNT-COOH concentration of 0.5 wt.% and HAuCl4·3H2O concentration of 0.4 mM. In this investigation, the protonation of the amine group of chitosan is fundamental to prepare PVA films with nanostructures of self-assembled chitosan-AuNPs/SWCNT-COOH.

Highly Sensitive Electrochemical Detection of ERα Based on AuNPs-SWCNT Composites and Hemin@HKUST-1

“…The synthesized AuNPs were added to the dispersion of SWCNT-COOH. Then, 1 ml H 2 SO 4 (0.1 N) was added to the reaction solution and the mixture reacted at 60 °C for 1 h. 24 The supernatant was removed by centrifugation and the solid was dried to obtain the product. PEI is a high cationic density organic polymer with a variety of amino functional groups, which results in a positive surface charge on the prepared AuNPs.…”

“…23 The composite nanomaterial AuNPs-SWCNT obtained by AuNPs and SWCNT in a non-covalent way own the advantages of strong electrocatalytic ability, large specific surface area, easy attachment of biomolecules and favorable electronic properties. 24 According to literature reports, AuNPs-SWCNT has been applied in electrochemical biosensors. For example, Yu et al constructed a nanogap electrochemical biosensor using AuNPs-SWCNT composites to achieve sensitive detection of DNA with a LOD of 1 pM.…”

Poly(vinyl alcohol)/Plant Extracts Films: Preparation, Surface Characterization and Antibacterial Studies against Gram Positive and Gram Negative Bacteria

“…Poly(vinyl alcohol) (PVA) is one of the best known environmentally friendly polymers and is obtained in a hydrolysis reaction of poly(vinyl acetate) [ 6 ]. The polymer is characterized by a lot of significant features such as water solubility, non-toxicity, chemical resistance, biocompatibility and biodegradability [ 7 , 8 , 9 ]. One of its important features is the hydrophilicity.…”

In Situ Synthesis of a Double-Layer Chitosan Coating on Cotton Fabric to Improve the Color Fastness of Sodium Copper Chlorophyllin

“…Chitosan contains primary amines which can be positively charged after protonation [30]. It can be used to adsorb anionic ions in the wastewater via electrostatic interactions.…”