Studying the Stability of Aqueous Suspensions of Multiwalled Carbon Nanotubes Used for the Modification of Composite Materials

In this paper, the stability of aqueous suspensions of multiwalled carbon nanotubes (MWCNTs) has been studied with physical and chemical methods. The optimum dispersion time of MWCNT suspension in a rotary homogenizer has been found. The dispersion time being increased, the quality of the suspension decreases. The data of the physical and chemical studies has also been confirmed experimentally on gypsum samples. The samples modified with MWCNT suspension of 2-hour dispersion show an increase in flexural strength and compressive strength by 40% and 48%, respectively, in comparison with the control sample, whereas the samples modified with MWCNT suspension of 10-hour dispersion show a decrease in flexural strength and compressive strength. The microstructure of the gypsum samples was studied with a scanning electron microscope.