Fabrication of Electrically Conductive Nickel–Silver Bimetallic Particles via Polydopamine Coating

Abstract

Inspired by adhesive proteins excreted by marine mussels, dopamine can act as a versatile surface modification agent for various organic and inorganic materials. By using adhesive polydopamine (PDA) as an intermediate layer, a simple and novel method for fabricating nickel-PDA-silver (Ni-PDA-Ag) bimetallic composite particles was developed. Ni-PDA-Ag bimetallic particles were fabricated by dispersing Ni particles in an aqueous dopamine solution followed by electroless Ag plating on the prepared Ni-PDA particles. A PDA layer with nano-meter thickness was deposited spontaneously on the surface of the Ni particles by oxidative self-polymerization of dopamine under alkaline conditions. Electroless Ag plating on the prepared Ni-PDA particles was carried out in the presence of a glucose solution as a reducing agent. Ni-PDA particles and Ni-PDA-Ag composite particles with a PDA intermediate layer were characterized by X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared (FT-IR) spectroscopy, field-emission scanning electron microscopy (FE-SEM), field-emission transmission electron microscopy (FE-TEM), and X-ray diffraction (XRD). In addition, the electrical conductivity of as-prepared composite particles was evaluated by a 4-point probe. The PDA layer deposited on the surface of Ni was confirmed by XPS spectra, FT-IR spectroscopy, and FE-TEM. FE-SEM images demonstrated that Ag nanoparticles were successfully plated on the PDA layer-coated Ni particles after the electroless Ag plating process. XRD patterns also confirmed the presence of Ag in a metallic state. In addition, the sheet resistance of as-prepared composite particles showed a tendency to decrease with increasing AgNO3 concentration.

Geometry and mesh size control the EMI shielding in 3D printed conducting shape memory PU structures

“…[29][30][31][32] Although both PU and polydopamine have a lot of overlapping peaks in FTIR spectra, the broad absorption band between 3600 and 3000 cm À1 corresponding to aromatic O-H and N-H stretching vibrations, present in PU@Dopa is absent in neat PU. 33 The FTIR characterization of PU@Dopa@Ag was performed using weakly resolved peaks which can be attributed to the silver coating on the samples. Fig.…”

One-Pot UV-Triggered o-Nitrobenzyl Dopamine Polymerization and Coating for Surface Antibacterial Application

“…1,2 Although the precise structure of polydopamine is still debatable, there is no shortage of applications of PDA as a versatile coating material. For example, PDA coatings have been explored as adhesive surfaces for surface immobilization of proteins, 3 functionalization of nanoparticles 4 and conductive electrodes, 5 as well as for preparation of antibacterial surfaces. 6,7 This material is unique due to its ability to coat almost any type of surfaces, 8 from metals to polymers, and these coatings are resistant and durable.…”

“…1 H NMR (400 MHz, CDCl 3 ) δ 6.79 (d, J = 8.0 Hz, 1H), 6.70 (br. s, 1H), 6.58 (d, J = 8.0 Hz, 1H), 3.34 (t, J = 6.9 Hz, 2H), 2.65 (t, J = 6.9 Hz, 2H), 1.44 (s, 9H (5). 2 (4.00 g, 15.8 mmol) was dissolved in 200 mL of acetone, and the solution then was purged with nitrogen for 30 min.…”

“…Polydopamine (PDA) is a naturally occurring biopolymer that arises from the oxidative polymerization of dopamine (DA), a naturally occurring catecholamine. , Although the precise structure of polydopamine is still debatable, there is no shortage of applications of PDA as a versatile coating material. For example, PDA coatings have been explored as adhesive surfaces for surface immobilization of proteins, functionalization of nanoparticles and conductive electrodes, as well as for preparation of antibacterial surfaces. , This material is unique due to its ability to coat almost any type of surfaces, from metals to polymers, and these coatings are resistant and durable. In addition, PDA can be readily functionalized, thus enabling the preparation of functional coating materials via either grafting methods or postmodification functionalization. , For these reasons, it is not surprising that there continues to be significant interest in the use of this material since its first reported application as a coating material in 2007 …”