Functionalized multi‐wall carbon nanotubes/silicone rubber composite as capacitive humidity sensor

Abstract

Functionalized multi-wall carbon nanotubes (MWCNTs) treated by mixed acids have been used to develop a capacitive humidity sensor based on MWCNTs/silicone rubber (SR) composite film. The MWCNTs/SR composites were prepared through conventional solution processed method. The micrographs of MWCNTs/SR composites were observed by transmission electron microscopy (TEM) and scanning electron microscope. The FT-IR spectra demonstrated the successfully grafting of AOH groups on the treated MWCNTs. The sensing properties of the composite at different relative humidity (RH) and frequency were characterized and linear sensing responses of the MWCNTs/SR composites to RH were observed. The treated MWCNTs/SR composite film (Tr-film) had higher sensitivity than that of the untreated MWCNTs/SR composite film (Un-film). Experimental data indicate that the Tr-film exhibits an excellent long-term stability, small hysteresis, and fine reproducibility. The response and recovery time of the Tr-film were 30 and 27 s, respectively. Thereby, such Tr-film had potential applications as humidity sensors. V C 2014 Wiley Periodicals, Inc. J. Appl.Polym. Sci. 2014, 131, 40342.

Suspended Carbon Nanotubes for Humidity Sensing

“…However, the aim of this work is to demonstrate the advantages of suspended nanotube networks, in terms of response time, hysteresis and sensitivity. Many functionalization schemes have been reported in the literature [ 19 , 31 , 32 ] and could be used to improve response time, while benefiting from the suspended structure. The recovery time can also be further improved by incorporating a micro-heater into the device to promote heating and therefore faster desorption.…”

Electrostatic self-assembly enabled flexible paper-based humidity sensor with high sensitivity and superior durability

“…Specifically, conductive polymer composite-based humidity sensors with incorporated electrically conductive fillers in insulating polymer matrixes are attracting much attention owing to their excellent flexibility, low cost, and ease of processing [21] , [22] , [23] , [24] , [25] , [26] , [27] . A range of polymers, such as poly (ethylene terephthalate) [28] , [29] , poly (ethylene-co-vinyl acetate) [30] , polyimide [31] , [32] , [33] , poly (ethyleneimine) [34] , poly (vinylidene fluoride) [35] , and silicone rubber [36] , have been demonstrated as platforms for the preparation of flexible humidity sensors. However, these petroleum-based polymers are nonbiodegradable that inevitably pose negative impacts on the environment.…”

Strain Sensing by Electrical Capacitive Variation: From Stretchable Materials to Electronic Interfaces

“…Conventional flexible capacitive sensors consist of a parallel‐plate capacitor, which comprises two conformable electrodes with a dielectric layer in‐between, [ 62–64 ] as presented in Figure . Stretchable dielectric materials are commonly used as flexible supports for soft strain sensors, such as rubbers (e.g., natural rubber and thermoplastic elastomers (TPEs)) [ 65–71 ] and silicone‐based elastomers (e.g., Ecoflex, Dragon Skin, and polydimethylsiloxane (PDMS)). [ 72–80 ] A huge difference in Young modulus between the thin metallic film (gold, aluminum, and platinum) and flexible elastomer or rubber causes cracks and buckling under stretching.…”