Molecular Dynamics Simulations of Polymer Nanocomposites Welding: Interfacial Structure, Dynamics and Strength
RS Chen and ZY Zhang and MY Zhou and Y Han and FZ Li and J Liu and LQ Zhang, MACROMOLECULAR RAPID COMMUNICATIONS, 43, 2200221 (2022).
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, the 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 epsilon(NP-p) is focused. Remarkably, at low epsilon(NP-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 epsilon(NP-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- (R-g,R-xy) and z- (R-g,R-z) component. The welding interdiffusion depth increases the fastest at low epsilon(NP-p), attributed to the high mobility of polymer chains and NPs. Lastly, although the mechanical properties of PNCs at high epsilon(NP-p) is the strongest because of the presence of the NPs in the bulk region, the welding efficiency is the greatest at low epsilon(NP-p). Generally, this work provides a fundamental understanding of the interfacial welding of PNCs, in hopes of guiding to design and fabricate excellent self-healable PNCs.
Return to Publications page