Preparation and characterization of electroless nickel-coated cellulose fibres
The aim of this project was to fabricate electroless nickel-coated cellulose fibres. Ultimately, these nickel-coated cellulose fibres will be used to develop a cost-effective polymer composite for electromagnetic interference (EMI) shielding and/or electrostatic discharge (ESD) applications. An attempt has been made to impart electrical conductivity onto cellulose fibres via an electroless nickel plating process. The aim was to achieve a homogeneous, continuous layer of Ni on the cellulose fibres, and the plating conditions were optimized to achieve this. The relationship between the coating morphology and the performance of the coated fibre was also of interest. Testing was carried out using cellulose filter paper and then loose cellulose fibres. Scanning electron microscopic (SEM) images of nickel-coated filter paper showed that nickel particles are bonded to the cellulose fibres. The coating appeared more compacted and continuous as plating time increased, corresponding to lower surface resistivity. This observation suggested a correlation between morphology and electrical conductivity of the coating. For nickel-coated cellulose fibres, after optimization of plating conditions, a uniform deposition of nickel particles around the cellulose surfaces was confirmed by SEM images. EDS and XRD results confirmed similar coating could be produced on filter paper and cellulose fibres. SEM images of cross-sectioned nickel-coated cellulose fibres illustrated nickel particles had penetrated into the inner walls of the cellulose fibres. This impregnation of the fibres should act to increase the bonding between nickel coating and cellulose fibres. These nickel-impregnated cellulose fibres could now be incorporated into a polymer matrix to create an electrically conducting composite with the right processing parameters.
Properties and applications of electroless nickel
The information contained in this publication has been compiled from the literature and through communication with recognized experts within the metal finishing industry. It is presented as a guide to the use of electroless nickel for engineers, metallurgists, designers and others involved in materials selection. The important properties of electroless nickel deposits are described and examples given of how these properties have been used successfully to solve materials problems in various industries. Through presentation of this information, it is anticipated that new opportunities for the use of electroless nickel coatings will become apparent to those not already familiar with their broad range of properties, thereby promoting growth within the industry.
Formation of copper-containing fiber composite materials for microwave radiation screens
A new method is proposed for the synthesis of radio-wave-absorbing metal-containing composite materials based on polyacrylonitrile fibers. The interaction of electromagnetic radiation with samples of machine-knitted fabric made of copper-containing fibers has been studied in an 8–12 GHz frequency range. The chemical composition of the synthesized materials has been determined. The possible applications of new materials and related structures for the screening of stray electromagnetic radiation of data-processing devices and electronic components and suppressing negative effects of high-frequency electromagnetic fields are considered.