- Relaxation NMR as a tool to study the dispersion and formulation behavior of nano-structured carbon materials. D Fairhurst, T Cosgrove and SW Prescott. Magnetic Resonance in Chemistry, 54(6), 521–526, 2016.
Abstract:
Solvent relaxation NMR has been used to estimate the surface areas and
wettability of various types of nanostructured carbon materials in a range of
solvents including water, ethanol and tetrahydrofuran.
We illustrate the application of the technique through
several short case studies using
samples including nano carbon blacks, graphene oxide,
nanographites and porous graphenes.
The technique is shown to give a good measure of surface area, correlating well with conventional surface area estimates obtained by nitrogen adsorption, TEM or light scattering for the non-porous samples.
NMR relaxation has advantages in terms of speed of analysis
and being able to use concentrated, wet and opaque samples.
For
samples that are porous, two distinct surface areas can be estimated
assuming the two environments (`inner' and `outer')
have the same surface chemistry and that there is a slow exchange of solvent
molecules between them.
Further, we show that differences
in wettability and dispersability between samples dispersed in water,
ethanol and cyclopentanone can be observed, along
with changes to the surface chemistry of the interface.
Last edited: Friday September 10, 2010
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