High-performance conductive adhesives based on water-soluble resins for printed circuits, flexible conductive films, and electromagnetic interference shielding devices

Herein, we report high-performance electrically conductive adhesives (ECAs) as promising materials for flexible conductive films, printed circuits, and electromagnetic interference shielding devices. Through combining a small amount of water-dispersible polyaniline (PANI) nanorods and silver flakes into water-based polyurethane (WPU), the obtained ECAs showed high electrical conductivity with a low Ag content (4.8 x 10(4) S/cm, 60 wt% of silver, and 6% PANIs) and excellent stability; this stability withstood aging without change at 85 degrees C/65% RH for at least 20 days. Prototyped applications of the ECAs for flexible conductive films, printed circuits, and electromagnetic interference shielding devices were demonstrated. When these ECAs were used as flexible conductive films, these films exhibited excellent electrical performance under high mechanical deformation. The resistance of films remained unchanging after being bent with a 6-mm radius for over 8000 cycles, applied with 1000 kPa pressure, or stretched 20% for over 1000 cycles. The printed circuits had excellent flexibility and good adhesion on flexible substrates, enabling the circuits' stable operation at a high deformation. Moreover, novel conductive foams with high conductivity of 283.4 S/m and reasonable electromagnetic interference shielding effectiveness (EMI SE) of above 34 dB were obtained by integrating the ECAs with PU sponges to broaden the applications of ECAs. Therefore, this study provided an original, uncomplicated, low-price route to fabricate high-performance ECAs based on water-soluble resins for various flexible electronic devices.