Effect of swelling pretreatment on the deposition structure on electroless copper of polyacrylonitrile nanocomposites for electromagnetic interference shielding

Abstract

In this investigation, the electroless copper method with various cupric sulfate concentrations (0.24, 0.36, 0.48, 0.60M) without sensitizing and activating is used to deposit electroless copper compounds (CuS) on the swelling pretreatment polyacrylonitrile(SPAN) surface for electromagnetic interference (EMI) shielding materials. The acetic acid can swell polyacrylonitrile (PAN) effectively which donot destroy the hexagonal structure of polyacrylonitrile, only looses the molecule chain of polyacrylonitrile then the hexagonal CuS crystal deposits on the SPAN easily, and increases the EMI shielding effectiveness (SE) of CuS-SPAN composites. However, the nearly amorphous of CuS deposits on the surface of without swelling pretreatment PAN(CuS-PAN). The EMI SE of CuS-SPAN composites are better than those of CuS-PAN, 10-15 dB larger from CuS-PAN. In the study, the best EMI SE of CuS-SPAN and CuS-PAN composites are about 30-35 dB and 18-20 dB respectively, as the cupric ion concentration is 0.48M. From the high resolution transmission electron micrographs(HR-TEM) analysis, there are two structures, face-centered cubic(FCC) Cu 2-x S crystal in the inner layer of CuS-SPAN composite and hexagonal CuS crystal on the outer layer of CuS-SPAN composite, in the SPAN as the cupric ion concentration is 0.48M. The particle size distribution of Cu 2-x S in the inner layer of CuS-SPAN is from 6 to 30 nm. However, the major particle size distribution of Cu 2-x S in the inner layer of CuS-SPAN is from 15 to 20 nm.

Preparation of durable antibacterial and electrically conductive polyacrylonitrile fibers by copper sulfide coating

“…A compact and uniform copper sulfide layer was successfully covered on the surface of PAN fibers as shown in Figure (b), which may be due to the a strong affinity for Cu 2+ ions provided by nitrile groups from PAN fibers and EDTA 2– . As reported before, it is believed that a continuous conducting layer could only be formed if there was a strong adhesive effect between the fiber matrix and the conductive phase . After ultrasonic washing in water for 30 min, the surface feature of copper sulfide‐coated PAN fibers [Figure (c)] remained intact, verifying the strong adhesion between the copper sulfide layer and PAN fibers.…”

CuxS/PAN 3D Nanofiber Mats as Ultra‐Lightweight and Flexible Electromagnetic Interference Shielding Materials

“…The Cu x S containing materials prepared in this study exhibit higher EMI SE per unit surface density compared to other copper sulfide containing materials in the range of 500–3000 MHz ( Table 2 ). Some researchers reported electroless copper sulfide deposition on PAN thin‐film substrates to produce CuS/(S)PAN composites . Owing to this electroplating method, the distribution of copper sulfide is very uniform and therefore stable EMI shielding is found.…”

“…To improve the wear and water stability of the shielding material, crosslinking polyacrylonitrile nanofiber/metal nanoparticle hybrid membranes, antibacterial cotton fabrics, and super hydrophobic foams have been successfully developed. In addition, research revealed copper sulfide (Cu x S) possesses excellent conductivity and plays an important role in preparation of electromagnetic shielding materials . Thin PET fabrics coated with the Cu x S nanoparticles exhibited excellent conductivity and electromagnetic shielding properties .…”

Electroless Plating Nickel Film on Surface of Epoxy Resin and Evaluation of its Electromagnetic Shielding Effectiveness

“…It must be processed for the metallization and conductive treatment in order to have the function of electromagnetic shielding effectiveness. The electroless plating as an effective method for non-metallic surface metallizing satisfies the performances including good plating layer uniformity, corrosion resistance, abrasion resistance, electrical and magnetic properties [4][5][6]. The coating parameters directly affect the coating performance.…”