摘要
In this study, we present the development of a novel self-adsorbing palladium (Pd) nanoparticle catalyst designed for electroless copper deposition on purely organic substrates, specifically liquid crystal polymer (LCP) films. Traditional silane coupling agent-based modification is generally ineffective on organic materials due to their lack of distinct grafting mechanism. To overcome this limitation, we employed polyether diamines as both the capping agents for Pd nanoparticles and the surface modifiers for the LCP surface. The newly synthesized polyether diamine-capped Pd nanoparticles exhibit excellent dispersibility and retain stable catalytic activity for up to two months of storage. Comprehensive characterizations were performed, including nanoparticle size distribution, induction time analysis, the capping mechanism of polyether diamine, and the surface modification mechanism on LCP substrates. As a result, electroless copper films deposited on LCP substrates using these Pd activators achieved an outstanding peeling strength of 630 gf/cm, nearly three times higher than that obtained with conventional ionic Pd activators and well above the widely recognized practical benchmark of 500 gf/cm. This method provides a scalable, surfactant-free, and silane compound-free method for wet metallizing challenging organic substrates, making it highly promising for advanced flexible electronics and high-frequency circuit applications.