2025 AIChE Annual Meeting

Nanoscale Structure of Homopolymer in Highly Loaded Nanoparticle Packing

Compatibilization of polymer blends can produce tunable materials with a wide range of mechanical, thermal, and transport properties, making them attractive for numerous applications, such as advanced coatings, membranes, ion channels, and high-performance nanocomposites. However, achieving a miscible blend remains a significant challenge, as many polymer pairs are inherently immiscible. Traditional compatibilization methods, such as copolymer addition or chemical modification, often fail to provide the desired control over blend properties. Nanoparticles have emerged as promising compatibilizers due to their ability to alter interfacial interactions, yet the influence of confinement by densely packed nanoparticles on blend miscibility and phase behavior is not fully understood.

This poster presents a comprehensive computational study using theoretically informed Langevin dynamics to explore a diblock copolymer system confined by nanoparticles. Specifically, we investigate thermodynamic interactions within the interstitial spaces of densely packed nanoparticle-copolymer systems, where one polymer preferentially wets the nanoparticle surface. These simulations provide detailed insight into how the morphology and phase separation of polymer blends are affected by varying degrees of asymmetric wetting and confinement in nanoparticle packings.

The structure of the confined system is characterized by the wavevector corresponding to the maximum of the structure factor function during quenching. The results of the simulation reveal that the length scale of the phase-separated structures is significantly influenced by the degree of wetting asymmetry. Systems with asymmetric polymer-nanoparticle interactions exhibit smaller phase-separated domains compared to systems with symmetric interactions. This reduction in domain size suggests that confinement-induced miscibility can be enhanced by tailoring nanoparticle surface chemistry to promote selective wetting of one polymer component.

The implications of these findings are significant for advancing the design of nanocomposite materials. By precisely controlling interaction asymmetry and confinement effects, it is possible to create materials with finely tuned mechanical properties, enhanced stability, and improved transport behavior, offering new pathways for the development of advanced functional materials for cutting-edge industrial and technological applications.