Polyelectrolyte-Assisted Hybrid Nanostructures from Self-Assembly of Graphene Oxide Sheets and Carbon Nanotubes

Achieving precise control over the hierarchical assembly of rigid anisotropic, low-dimensional nanomaterials remains a critical challenge in materials science. We explored solution-based self-assembly of hybrid nanostructures composed of two-dimensional (2D) graphene oxide (GO) sheets and one-dimensional (1D) carbon nanotubes (CNTs), functionalized by the noncovalent adsorption of cationic PDDA and anionic PSS polyelectrolytes (PELs), yielding m-GO and m-CNTs, respectively. The spontaneously self-assembled m-GO/m-CNT hybrids exhibited tunable architecture with a two-level hierarchical microstructure: lamellar GO layers separated by CNTs as spacers and lateral alignment of CNTs within interlayer galleries. Experimental characterization confirmed the colloidal stability of the hybrids through dynamic light scattering (DLS) and ζ-potential measurements, while cross-sectional scanning electron microscopy (SEM) revealed the formation of layered hybrid nanostructures with m-CNTs intercalated between m-GO sheets. The morphology was found to be modulated by an interplay between charge stoichiometry and reconfiguration of adsorbed PELs, where hybrid nanostructures remain well-dispersed at off-stoichiometric ratios of m-GO and m-CNTs, while mesoscopic aggregation is triggered near charge-stoichiometric neutrality. Coarse-grained MD simulations revealed the self-assembly pathways of layered hybrid nanostructures driven by electrostatic complementarity between oppositely charged nanomaterials. The directional alignment of confined CNTs in the hybrid lamellae directly resulted from the dynamic reorganization of surface-bound flexible PELs. This work also establishes a scalable platform for constructing hierarchically ordered 1D–2D hybrid materials with potential opportunities in anisotropic functional films, energy storage devices, membranes, and soft electronic applications.