Antioxidation Properties and Surface Interactions of Polyvinylpyrrolidone-Capped Zerovalent Copper Nanoparticles Synthesized in Supercritical Water

Abstract

Zerovalent copper nanoparticles (CuNPs) (diameter, 26.5 ± 9 nm) capped with polyvinylpyrrolidone (PVP) were synthesized in supercritical water at 400 °C and 30 MPa with a continuous flow reactor. The PVP-capped CuNPs were dispersed in distilled water, methanol, ethanol, 1-propanol, 2-propanol, butanol, and their mixed solvents to study their long-term stability. Temporal variation of UV-vis spectra and surface plasmon resonance were measured and showed that ethanol, the propanols, and butanol solvents provided varying degrees of oxidative protection for Cu(0). Fourier transform infrared spectroscopy showed that PVP adsorbed onto the surface of the CuNPs with a pyrrolidone ring of PVP even if the CuNPs were oxidized. Intrinsic viscosities of PVP were higher for solvents that provided antioxidation protection than those that give oxidized CuNPs. In solvents that provided Cu(0) with good oxidative protection (ethanol, the propanols, and butanol), PVP polymer chains formed large radii of gyration and coil-like conformations in the solvents so that they were arranged uniformly and orderly on the surface of the CuNPs and could provide protection of the Cu(0) surface against dissolved oxygen. In solvents that provided poor oxidative protection for Cu(0) (water, alcohol-water mixed solvents with 30% water), PVP polymer chains had globular-like conformations due to their relatively high hydrogen-bonding interactions and sparse adsorption onto the CuNP surface. Antioxidative properties of PVP-capped CuNPs in a solvent can be ascribed to the conformation of PVP polymer chains on the Cu(0) particle surface that originates from the interaction between polymer chains and its interaction with the solvent.

Investigation of the Characteristics and Antibacterial Activity of Polymer-Modified Copper Oxide Nanoparticles

“…As shown in Figure 2 , three clear signals can be observed in the spectrum of the pure CuO nanoparticles. These correspond to stretching vibrations of Cu–O in the ( 02) direction at 610 and 495 cm −1 , and stretching vibrations of Cu–O in the (202) direction at 416 cm −1 ( Figure 2 a) [ 33 , 34 ]. As observed in the spectrum of the PEG-modified CuO nanoparticles ( Figure 2 b), characteristic signals for PEG were observed at 1061, 1411, and 2940 cm −1 , which correspond to C–O vibrations, C–H bending, and CH 2 stretching, respectively [ 35 , 36 ].…”

Polyvinylpolypyrrolidone‐Stabilized Copper Nanoparticles as an Efficient and Recyclable Heterogeneous Catalyst for the Click of 1,2,3‐Triazoles in Water

“…All data discussed above confirm that the PVPP acts as a polymeric capping agent, size‐controller polymeric capping agent and it prevents against copper aggregation through the polar groups, which strongly interact with the CuNPs on the surface generating highly stable dispersions of CuNPs‐PVPP …”

The direct-writing of low cost paper based flexible electrodes and touch pad devices using silver nano-ink and ZnO nanoparticles

“…If the coating material does not form stable clusters then stabilizers are added in very small amounts to form a homogenous stable phase. [25][26][27] The methods for fabrication of conductive NPs on a solid surface are done through printing, lithography, stamping, chemical vapor deposition, sputtering, spin coating and direct-writing. The method of direct-writing is easy, user friendly and cost effective.…”