High-pressure resistance reversibility of polymer composites based on multiwalled carbon nanotubes

Abstract

A study on the electrical behavior of polymer composites based on multi-walled carbon nanotubes (MWCNT) under the application of hydrostatic pressure up to 9 GPa and at room temperature is reported. A higher resistance, with values of order of kΩ, is demonstrated for MWCNT with an aspect ratio R9GPa/Rint ≈7. Our observations also show that pressure induced a structural change of the MWCNT to an ellipsoid shape at P ∼ 1–1.5 GPa—a measurement that correlates rather well with theoretical predictions. By direct and reverse high-pressure measurements of resistance, as well as current-voltage characteristics, we have identified the reversibility of electrophysical properties. Our observations suggest that the polymer composite based on MWCNT is a promising material for pressure sensing devices.

Piezoresistive and Electrical Properties of a Catecholic Amino Acid–Polyacrylamide Single-Walled Carbon Nanotube Hydrogel Hybrid Network

“…Measurements under each of the uniaxial pressures were performed for 3000 s. These data show a negative piezoresistive effect, namely, that the electrical resistance on average decreases with an increase of applied pressure and it generally decreases with time under the same pressure, which may be attributed to the creep behavior of the polymer matrix. 21 For clarity, these are plotted in two groups in Figure 7: groups A and B, respectively. In group A, the electrical resistance generally decreases with time under the same pressure.…”

“…Figures and present electrical resistance dependencies on time and pressure of the l -DOPA-PAM hydrogel and the l -DOPA-PAM-SWCNT hydrogel hybrid network at an ambient temperature of 23 °C. Measurements under each of the uniaxial pressures were performed for 3000 s. These data show a negative piezoresistive effect, namely, that the electrical resistance on average decreases with an increase of applied pressure and it generally decreases with time under the same pressure, which may be attributed to the creep behavior of the polymer matrix …”

“…The sample holder prevented transverse movement of the sample under stress. 21 Different weights (0.01, 0.03, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, and 0.5 kg) with corresponding pressures of 0.31, 0.94, 1.56, 3.12, 4.68, 6.24, 7.80, 9.36, 10.9, 12.48, 14.05, and 15.61 kPa were applied to the top of the sample holder as a static load. Once the load is applied, the force generated by the weights was enough to ensure good electrical contact.…”

“…The sample was connected to a digital multimeter (RIGOL DM3061, Suzhou, China) using brass electrodes arranged at each side for two-probe measurements. The sample holder prevented transverse movement of the sample under stress . Different weights (0.01, 0.03, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, and 0.5 kg) with corresponding pressures of 0.31, 0.94, 1.56, 3.12, 4.68, 6.24, 7.80, 9.36, 10.9, 12.48, 14.05, and 15.61 kPa were applied to the top of the sample holder as a static load.…”