Dispersion-Free Layer-by-Layer Assembly Enabled by Continuous As-Synthesized CNT Nanofilms

Layer-by-layer (LbL) assembly is a powerful route to multifunctional thin films, but every reported version depends on pre-dispersed CNT suspensions. Such wet processing cuts the tubes into short, damaged fragments and destroys the pristine framework. Here we report a fundamentally different LbL process that is uniquely enabled by our ability to continuously synthesize sub-100 nm CNT films by floating catalyst chemical vapor deposition (FCCVD). Because the CNT network is formed in-situ as a long, intact aerogel, no dispersion step is ever required.

Each cycle directly transfers an as-grown CNT layer, loads a guest material, and redeposits a fresh CNT layer, building multilayer films with a programmable architecture. The pristine, long-tube scaffold is preserved throughout, so the films retain the intrinsic crystallinity and properties of the source nanotubes. The process is dimension and size agnostic, accepting 0D nanoparticles, 1D nanowires, and 2D nanosheets from 100 nm to 1 micrometer, which enables heterostructures and gradient stacking on a single platform. Being fully dry and continuous, it is directly compatible with roll-to-roll manufacturing.

We demonstrate MXene/CNT, AgNW/CNT, and multilayer films with clean interfaces, reaching GPa-level tensile strength at sub-micrometer thickness with tunable EMI shielding and strong ambient stability. This work establishes as-grown film LbL as a scalable route to pristine, universally hybridizable CNT films.