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Nanoparticle-nanotube electrostatic interactions in solution: the effect of pH and ionic strength
Graham A Rance1, Andrei N Khlobystov
1School of Chemistry, University of Nottingham & Nottingham Nanotechnology and Nanoscience Centre, University Park, Nottingham, NG7 2RD, UK.
Physical Chemistry Chemical Physics : PCCP
|July 7, 2010
Summary
Electrostatic interactions between gold nanoparticles (AuNP) and carbon nanotubes (MWNT) are governed by Coulomb forces, allowing precise control over AuNP-MWNT composite material structures.
Area of Science:
- Materials Science
- Nanotechnology
- Physical Chemistry
Background:
- Like-charged gold nanoparticles (AuNP) and multi-walled carbon nanotubes (MWNT) interact in aqueous suspensions.
- Understanding these electrostatic interactions is crucial for developing novel composite materials.
Purpose of the Study:
- To investigate the effect of pH and ionic strength on electrostatic interactions between AuNP and MWNT.
- To determine the primary driving force for AuNP adsorption onto MWNT.
- To demonstrate control over AuNP-MWNT composite material composition and structure.
Main Methods:
- UV-vis spectroscopy
- Zeta-potential analysis
- Transmission electron microscopy (TEM)
Main Results:
- External stimuli (pH, ionic strength) significantly alter the surface charge of AuNP and MWNT.
- The magnitude of electrostatic forces is inversely proportional to the number of AuNP adsorbed onto MWNT.
- Coulomb interactions are the primary mechanism governing AuNP adsorption onto MWNT.
Conclusions:
- Electrostatic interactions, specifically Coulomb forces, dictate the adsorption of AuNP onto MWNT.
- Precise control over the composition and structure of AuNP-MWNT composites can be achieved by manipulating the electrostatic environment.
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