Molecular Alignment of a Meta-Aramid on Carbon Nanotubes by In Situ Interfacial Polymerization

Abstract

Molecularly organized nanocomposites of polymers and carbon nanotubes (CNTs) have great promise as high-performance materials; in particular, conformal deposition of polymers can control interfacial properties for mechanical load transfer, electrical or thermal transport, or electro/chemical transduction. However, controllability of polymer–CNT interaction remains a challenge with common processing methods that combine CNTs and polymers in melt or in solution, often leading to nonuniform polymer distribution and CNT aggregation. Here, we demonstrate CNTs within net-shape sheets can be controllably coated with a conformal coating of meta-aramid by simultaneous capillary infiltration and interfacial polymerization. We determine that π-interaction between the polymer and CNTs results in chain alignment parallel to the CNT outer wall. Subsequent nucleation and growth of the precipitated aramid forms a smooth continuous layered sheath around the CNTs. These findings motivate future investigation of mechanical properties of the resulting composites, and adaptation of the in situ polymerization method to other substrates.

Scalable, Versatile Synthesis of Ultrathin Polyetherimide Films and Coatings via Interfacial Polymerization

“…This is explained by the aromatic structure of both PAA and PEI that enables π‐interaction with the CNTs, and chain alignment parallel to the CNT outer wall. [ 55 ] Further evidence of π‐interaction through FT‐IR measurement can be found in the Supporting Information.…”

“…CNT-PEI Composite Fabrication: Details on the CNT sheets used for composite fabrication and in-situ interfacial polymerization (ISIP) process can be found elsewhere. [54,55] ISIP was conducted using BPADA as the organic monomer, with φ Bz = 0.5, [MPD] 0 = [BPADA] 0 = 0.07 mol L −1 , and t rxn = 5 min.…”

“…This was achieved through in-situ interfacial polymerization (ISIP) (Figure 7c,d). [54,55] ISIP results in nanocomposites with a tailored morphology through the interplay of fluid displacement, transport-reaction kinetics, and polymer precipitation. Unlike IP at the static liquid-liquid interface, ISIP relies on the sequential immersion of a porous substrate in the aqueous and organic phase.…”

Molecular Dynamics Simulation of In Situ Polymerization: Chain Conformation Transition

“…However, for the polymer in situ growth process on supported catalysts, the chain conformation undergoes continuous changes, and simulation studies on this dynamic process are relatively more complex. Density functional theory (DFT), based on quantum mechanical principles, can accurately describe the electronic structures and free energy changes, making it widely used in simulating chemical reaction processes. , Additionally, the development of the reactive force field (ReaxFF) within the molecular dynamics (MD) method allows for some of the polymer reaction simulation. − Although these methods exhibit high accuracy and can predict intermediate and deep-level reaction products, the system size is limited to thousands of atoms, with simulation time ranging from tens to hundreds of picoseconds, which is far from meeting the requirement of in situ polymerization simulation. In the case of polymer synthesis, where the molecular composition and reaction pathways are well-defined, researchers seek to understand the evolution of polymer conformation and aggregation structures during the growth process and the underlying dominant mechanisms, which is a mesoscale problem between the growth and motion of the nascent chain. , Therefore, when investigating conformational transitions during polymerization, it is common to sacrifice a certain degree of precision and simplify the polymerization process into bond formation under certain conditions.…”

ReaxFF reactive force field model enables accurate prediction of physiochemical and mechanical properties of crystalline and amorphous shape‐memory polyurethane

“…The reactive force field (ReaxFF) 27 molecular dynamics framework was used to simulate the two SMPU models. ReaxFF has been successfully used to study a wide variety of physical processes including heterogeneous catalysis, 28 2D materials such as ZIFs, 29 covalent organic frameworks 30,31 carbonization using polymer precursors, 32 interfacial polymerization, 33 polymer cross-linking and mechanical properties 34,35 and battery materials. 36 Since ReaxFF has been developed mainly to study chemical reactions, 27 it can be advantageous in terms of accuracy for non-reactive environments involving molecules with high chemical complexity and reactivity.…”