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Surfactant-Aided Stabilization of Individual Carbon Nanotubes in Water around the Critical Micelle Concentration.
Wang, Peng; Misra, Rahul Prasanna; Zhang, Chiyu; Blankschtein, Daniel; Wang, YuHuang.
Afiliación
  • Wang P; Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States.
  • Misra RP; Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
  • Zhang C; Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States.
  • Blankschtein D; Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
  • Wang Y; Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States.
Langmuir ; 40(1): 159-169, 2024 Jan 09.
Article en En | MEDLINE | ID: mdl-38095654
Surfactants are widely used to disperse single-walled carbon nanotubes (SWCNTs) and other nanomaterials for liquid-phase processing and characterization. Traditional techniques, however, demand high surfactant concentrations, often in the range of 1-2 wt/v% of the solution. Here, we show that optimal dispersion efficiency can be attained at substantially lower surfactant concentrations of approximately 0.08 wt/v%, near the critical micelle concentration. This unexpected observation is achieved by introducing "bare" nanotubes into water containing the anionic surfactant sodium deoxycholate (DOC) through a superacid-surfactant exchange process that eliminates the need for ultrasonication. Among the diverse ionic surfactants and charged biopolymers explored, DOC exhibits the highest dispersion efficiency, outperforming sodium cholate, a structurally similar bile salt surfactant containing just one additional oxygen atom compared to DOC. Employing all-atomistic molecular dynamics simulations, we unravel that the greater stabilization by DOC arises from its higher binding affinity to nanotubes and a substantially larger free energy barrier that resists nanotube rebundling. Further, we find that this barrier is nonelectrostatic in nature and does not obey the classical Derjaguin-Landau-Verwey-Overbeek (DLVO) theory of colloidal stability, underscoring the important role of nonelectrostatic dispersion and hydration interactions at the nanoscale, even in the case of ionic surfactants like DOC. These molecular insights advance our understanding of surfactant chemistry at the bare nanotube limit and suggest low-energy, surfactant-efficient solution processing of SWCNTs and potentially other nanomaterials.

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Idioma: En Revista: Langmuir Asunto de la revista: QUIMICA Año: 2024 Tipo del documento: Article País de afiliación: Estados Unidos Pais de publicación: Estados Unidos

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Idioma: En Revista: Langmuir Asunto de la revista: QUIMICA Año: 2024 Tipo del documento: Article País de afiliación: Estados Unidos Pais de publicación: Estados Unidos