This study delves into the potential application of whisker carbon nanotube (w-CNT) in terms of electrical heating performance, with a particular emphasis on its significance in high-efficiency electrothermal conversion applications. Meanwhile, a comparative study was conducted on traditional carbon nanotubes (T1 and T3) with different aspect ratios. A uniform and dense carbon nanotube paper (BP) was prepared using a vacuum filtration method, including single-layer (T1, T3 and w-CNT BP), double-layer gradient composite (T1/T3-g, w-CNT/T3-g), and mixed composite (T1/T3-m and w-CNT/T3-m). The thickness of each type of BP is approximately 100 μm. The results demonstrated that electrical conductivity and electrical heating performance of single-layer BPs follow the order of T1 > T3 > w-CNT. While, mixed composite BPs are superior to double-layer gradient composite BPs in electrical conductivity and thermal performance. Notably, w-CNT/T3-m BP exhibits excellent electrothermal performance. Under an applied voltage of 5 V, the surface temperature of w-CNT/T3-m BP reaches 190 ℃. When the voltage is increased to 6 V, the surface temperature rises by 150℃ within 10 s, reaching a steady-state temperature of 318 ℃. This excellent electrothermal performance can be attributed to the introduction of w-CNT, which has a perfect and defect free structure according to Raman analysis. In-depth analysis using X-ray diffraction (XRD) indicated a more complete and higher degree of crystallinity in the w-CNT structure. In summary, this study not only provides experimental and theoretical basis for the application of high-performance electrothermal materials based on carbon nanotubes, but also foreshadows their broad application prospects in the field of macroscopic materials.

Experimental design with pellet heating time of 1.00, 1.33, 1.67, 2.00, 2.33, 2.67, 3.00, 3.33, 3.67, and 4.00 min was studied to investigate the effects of pellet heating time on the physical properties (expansion ratio, density and breaking strength) of vacuum-puffed Yukwa. The size and shape of vacuum-puffed Yukwa varied with respect to the pellet heating time.As pellet heating time increased, a values and b values tended to increase. The maximum expansion (4.626) with the lowest bulk density (0.112) was obtained at 3.33 min heating time, whereas the minimum expansion (2.954) with the highest bulk density (0.208) was found at 1 min. The breaking strength of vacuumpuffed Yukwa decreased significantly as the pellet heating time increased. Overall, the heating time had significant impacts on the physical properties of vacuum-puffed Yukwa.