Figure 1: Adhesion enhancement of the carbon nanotube (CNT) adhesive at high and low temperatures.
From: Carbon nanotube dry adhesives with temperature-enhanced adhesion over a large temperature range
(a–d) Diagram showing the preparation procedure of the CNT dry adhesive. (e,f) Top-view scanning electron microscopic (SEM) image of the rationally designed fibrillar adhering surface generated by plasma etching the nonaligned, entangled top nanotube segments on the as-grown VA-DWNT array (e) to form the bundled top nodes (f) (scale bars, 2 μm). (g–j) Digital photo images illustrating the adhesion force measurements at different temperatures. (g) room temperature measurement (24 °C), inset in the up-right showing the two copper foils to be ‘glued’ together by the VA-CNT dry adhesive within the black squared area. (h,i) Enhanced adhesion with increasing temperature up to 1,033 °C (inset at the bottom-right in i showing the debonding at 1,085 °C and the CNT dry adhesive after the high temperature test). (j) Liquid N2 cooling (−190.7 °C) by using a thick piece of tissue papers pre-immersed in liquid N2. (k) Side-view SEM image showing the structure integrity after the test at 1,033 °C (scale bar, 1 μm). (l) Raman spectra of the CNT dry adhesive after tests at 24 and 1,033 °C for comparison, and (m) the corresponding XPS spectra. (n) Temperature dependence of the adhesion force for the CNT dry adhesive (red curve). The inset shows temperature dependence of the adhesion forces for commercial adhesive tapes, including the Duro Liquid Super Glue (green curve), 3 M Polyimide Film Tape 5413 (black curve), and 3 M 410M Double-Sided Masking Tape (blue curve) of the same size (4 mm × 4 mm). Each of the adhesion strength data points was averaged from five samples measured under the same thermal control conductions. The variation of the error bars is caused by the temperature fluctuation and the system error.
