We have created PMMACNT matrices by embedding opened-tip vertically aligned multiwalled
carbon nanotubes (VA-MWCNTs) with poly(methyl methacrylate) (PMMA). These PMMACNT matrices are
excellent electron field emitters with an emission threshold field of 1.675 V/m, more than 2-fold lower that
that of the as-grown sample. In addition, the emission site density from these matrices is high, merely filling up
the entire sample surface. Emission stability test at 1.35 mA/cm2 was performed continuously for 40 h with no
significant degradation. On the basis of our theoretical simulation and hypothetical modeling, we attribute these
performances to the reduced screening effect and fewer Joule heatings due to the shorter effective transport
distance of the electrons in MWCNTs.