Electrodeposition of Nickel/Montmorillonite Layered Silicate Nanocomposite Thin Films

Abstract

In this study, the electrochemical deposition of nickel/montmorillonite nanocomposite films was investigated on stainless steel and copper substrates. Deposition variables that were investigated included electrochemical cell orientation, degree of agitation during deposition, and montmorillonite concentration in the electroplating solution. The resulting films were characterized with scanning electron microscopy, X-ray diffraction, and X-ray fluorescence techniques. By a novel electrochemical cell construction, an orderly deposition of nickel/montmorillonite nanocomposite films was ultimately achieved. Scanning electron microscopy images characterized these films with an ordered surface topography of horizontal montmorillonite platelets held in a nickel media. Profile scanning electron microscopy images further showed a heavily striated stack of aligned montmorillonite layered silicate platelets throughout the profile of the nickel/montmorillonite nanocomposite film. Also, X-ray fluorescence verified the presence of montmorillonite clay within the films, and nanoindentation results showed that the nanocomposite films had higher modulus values than nickel films. The green (unsintered) deposited films showed a 60% increase in hardness over that of pure nickel films. Thus, a successful electrochemical deposition of ordered nickel/montmorillonite nanocomposites has been achieved, and the montmorillonite content of these nanocomposites has been shown to strengthen the films when incorporated in a layered fashion.