LAUSR

Polymer welding has received numerous scientific attention, however, the welding of polymer nanocomposites (PNCs) has not been studied yet. In this work, via coarse-grained molecular dynamics simulation, we focus our attention on investigating the welding interfacial structure, dynamics and strength by constructing the upper and lower layers of PNCs, by varying the polymer-nanoparticle (NP) interaction strength εNP-p . Remarkably, at low εNP-p , the NPs gradually migrate into the top and bottom surface layer perpendicular to the z direction during the adhesion process, while they are distributed in the middle region at high εNP-p . Meanwhile, the dimension of polymer chains is found to exhibit a remarkable anisotropy evidenced by the root-mean-square radius of gyration in the xy- (Rg,xy ) and z- (Rg,z ) component. The welding interdiffusion depth increases the fastest at low εNP-p, attributed to the high mobility of polymer chains and NPs. Lastly, although the mechanical properties of PNCs at high εNP-p is the strongest because of the presence of the NPs in the bulk region, the welding efficiency is the greatest at low εNP-p . Generally, our work could provide a fundamental understanding of the interfacial welding of PNCs, in hopes of guiding to design and fabricate excellent self-healable PNCs. This article is protected by copyright. All rights reserved.