Recent developments in the preparation of nano-gold composite coatings

Abstract

New possibilities in the design of gold-containing electrochemical coating systems for electronic applications are given by the incorporation of gold-nanoparticles in metal-matrix-systems. The major problem for the application of nanoparticles is the strong agglomeration of the particles in the electrolyte solutions, preventing the incorporation of nanoscaled dispersants.A complete new concept for the deposition of nano dispersion layers, overcoming this agglomeration challenge, is the application of core shell systems. Using these systems, it becomes possible for the first time to incorporate metal nanoparticles into electrodeposited metal layers to form metal nanoparticle metal matrix systems (MNP-MMS). The advantage of such layers is to form nanocomposite materials far away from the thermodynamic equilibrium. Especially for the combination of gold nanoparticles with a nickel matrix, a way is shown for the manufacturing of temperature-stable nanocomposite structures, because at least in the temperature range of electronic applications no loss of the dispersive character by diffusion processes is expected. By incorporating the precious metal material into the nickel matrix as the main electrodeposit, and reducing the top gold layer thickness, a possible way of reducing the gold consumption and an economic use of gold resources is shown.

Versatile electrochemical coatings and surface layers from aqueous methanesulfonic acid

“…By incorporating the precious metal material into the nickel matrix as the main electrodeposit, and reducing the top gold layer thickness, gold consumption may be reduced. Studies by German researchers [85] have used a sulphite containing, MSA based nickel bath containing conventional additives to deposit on 2 cm 2 area copper cylinder electrodes rotating at 250-1000 rev min −1 . The 1 mol dm −3 MSA nickel sulphamate bath contained saccharin for stress reduction, particularly to avoid crack formation in the deposits along with a boric acid buffer (pH 4), naphthalene sulfonic acid, sodium dodecyl sulphate (anionic surfactant) and triton X-100 surfactant, and phenolphthalein, representing a complex electrolyte to maintain.…”

“…The current density was changed between 0.2 and 8 A/dm 2 . The gold nanoparticles are very homogeneously distributed on the surface and inside the coatings, gold incorporation of 2-3 wt.% in the nickel layers was achieved by a low gold concentrations in the electrolyte of only 70 mg dm −3 [85].…”

Facile synthesis of concentrated gold nanoparticles with low size-distribution in water: temperature and pH controls

“…Remarkably, novel emerging applications bring a huge growth of the global demand of GNPs. For instance, (1) biomolecule- and/or biopolymer-conjugated GNPs are largely used as biomarkers and biodelivery vehicles in the medicine/pharmacy, and in cosmetic products, GNPs are employed as anti-aging components for skin protection [ 3 - 5 ]; (2) GNPs are used to treat wool or cotton fibers for a permanent coloration [ 6 ] of value textiles; (3) various polymer/gold nanocomposites display a high potential for novel coatings and paintings [ 7 - 11 ]; (4) GNPs are used to enhance the performance of non-volatile memory devices [ 12 ] and low temperature printing metal inks in electronics [ 13 ]; and (5) GNPs as catalysts are developed in novel usages [ 14 - 18 ]. Therefore, more attention should be paid on effective synthesis methods to match the enlarging demand of GNPs.…”

Dendronized core-multishell nanocarriers for solubilization of guest molecules

“…Furthermore, we were able to show that the penetration of the hydrophilic dye rhodamine B and the hydrophobic dye Nile red (NR) into skin could be enhanced compared to solid lipid nanoparticles and normal cream formulations [20,25]. Besides these biomedical applications CMS nanocarriers have been successfully used for the stabilization of metal nanoparticles, in catalytic reactions involving stabilized metal nanoparticles, and for the fabrication of nanogold-nickel coatings by electrodeposition [26][27][28][29][30].…”