Only a small volume fraction of Nanostrands are required to create conductivity in a wide variety of matrix materials. Many polymers have been rendered conductive, including thermosets, thermoplastics, paints, elastomers and adhesives.
By mixing the nanostrands into the matrix, volume resistivity as low as .01 ohm-cm has been achieved, at less than 20% loading. However, if the matrix is added to the compressed nanostrand preform, then a volume resistivity of .0002 ohm-cm can be achieved at about 20% loading. This is a remarkable amount of conductivity for a material that is still over 80% matrix.
The graph below illustrates the relationship of these two mixing methods as a function of volume fraction nanostrands. The top line is typical for mixing nanostrands into a matrix, while the lower line is typical of infusing a resin into a nanostrand preform.
When mixing nanostrands into a resin, the conductivity is also affected by the diameter, length, aspect ratio and orientation of the nanostrands.
Mixing MethodsIt doesn't take much energy to disperse nanostrands into most resins. In fact, too much mixing will tend to break up the strands, thus the gentlest mixing methods are recommended. Of course, when infusing resin into a nanostrand preform, lower viscosity materials work better.