Reversible aggregation of carbon nanohorns triggered by electrostatic interactions

The assembly of nanomaterials into larger, functional frameworks is a growing area of nanotechnology. This study focuses on the reversible aggregation of carbon nanohorns (CNHs) functionalized with quaternary ammonium salts (Q-CNHs) using negatively charged azobenzenes as ionic glue. CNHs, character...

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Detalles Bibliográficos
Autores: García Núñez, María Paz, Vázquez Fernández-Pacheco, Ester, Herrero Chamorro, María Antonia, Iglesias Asperilla, Daniel
Tipo de recurso: artículo
Fecha de publicación:2025
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:RUIdeRA. Repositorio Institucional de la UCLM
OAI Identifier:oai:ruidera.uclm.es:10578/47695
Acceso en línea:https://doi.org/10.1016/j.carbon.2025.120513
https://hdl.handle.net/10578/47695
Access Level:acceso abierto
Palabra clave:Carbon nanohorns
Nanomaterial functionalization
Nanomaterial self-assembly
Reversible nanoparticle frameworks
Descripción
Sumario:The assembly of nanomaterials into larger, functional frameworks is a growing area of nanotechnology. This study focuses on the reversible aggregation of carbon nanohorns (CNHs) functionalized with quaternary ammonium salts (Q-CNHs) using negatively charged azobenzenes as ionic glue. CNHs, characterized by high surface area were modified through a three-step process to enhance their aqueous dispersibility. A series of azobenzenes with varying numbers of carboxylate groups were synthesized to investigate their effect on Q-CNHs aggregation. The synthesis involved reductive coupling and the Mills reaction. Aggregation experiments demonstrated that the efficiency of Q-CNHs precipitation correlated with the azobenzene charge. Notably, the [2,2] azobenzene, with four carboxylate groups, was the most effective, forming frameworks around 1 μm in size. The reversibility of the assemblies was confirmed through multiple sonication and stirring cycles, with no significant fatigue observed. This dynamic behavior was monitored using scanning electron microscopy and dynamic light scattering, highlighting the potential for creating recyclable nanomaterial frameworks. This study underscores the importance of molecular charge in nanoparticle assembly and paves the way for designing responsive and reconfigurable nanostructures.