# Preparation Methods and Properties of CNT/CF/G Carbon-Based Nano-Conductive Silicone Rubber
## 2 Experimental Materials and Methods
### Performance Testing and Structural Characterization Methods  
(1) Electrical performance test  
The two ends of the conductive silicone rubber sample were wrapped with copper sheets to ensure the accuracy of the resistance value. The rise was clamped to prevent shaking, and the resistance was measured with a resistance meter. When the sample resistance was lower than 10\({}^{6}\)\(\Omega\), the Geely 6514 electrometer was used to measure the sample resistance, and when the sample resistance was higher than 10\({}^{6}\)\(\Omega\), a high resistance meter was used to measure the sample resistance. Thereafter, the volume resistance was calculated using the following formula:  
\[\rho_{V}=R_{\sigma}\frac{s}{h} \tag{1}\]  
The unit of \(\rho_{V}\) is \(\Omega\) m (ohm m), \(h\) is the thickness of the sample (the distance between the two poles), and \(S\) is the area of the electrode. The measurements were repeated three times and the average value was taken. The volume resistance under different concentrations of the fillers was analyzed and the percolation value range of the carbon-based conductive fillers was simultaneously determined.  
(2) Tensile sensitivity test  
Both ends of the prepared 30 mm \(\times\) 10 mm \(\times\) 1 mm sample were wrapped with copper sheets, and the sample was placed into the fixture of the textile dynamic resistance testing instrument. The maximum effective resistance of the tensile value at the rate of v = 100 mm/min was adopted. Reciprocating stretching was realized. The drawing rate formula is as follows:  
\[\varepsilon=\frac{\Delta\mathrm{L}}{\mathrm{L}}=\frac{\mathrm{v}\mathrm{t}}{ \mathrm{L}} \tag{2}\]  
where \(\varepsilon\) is the drawing rate, v is the drawing rate, and t is the recording time of the universal drawing machine.  
(3) Thermogravimetric analysis and testing  
The thermal stability of the conductive silicone rubber was analyzed by weighing about 5 mg of the sample and using the German resistance thermogravimetric analyzer TG209F1. The test conditions were as follows: 50 mL/min nitrogen protection, 20 mL/min purge gas, and heating from room temperature to 800 \({}^{\circ}\)C at a heating rate of 10 \({}^{\circ}\)C/min.  
(4) Glass transition temperature and melting point test  
The effects of conductive fillers on the Tg and melting point of the composites were investigated using an MDSC 2920 DSC analyzer. The test conditions were as follows: first, the sample was heated from room temperature to 220 \({}^{\circ}\)C, cooled to \(-\)70 \({}^{\circ}\)C, and then heated again 220 \({}^{\circ}\)C at the rate of 10 \({}^{\circ}\)C/min. All the above processes were conducted under the protection of 20 mL/min nitrogen.  
(5) Raman spectrum test  
The prepared materials were characterized by Raman spectroscopy using the Renishaw inVia confocal Raman microscope in Lei Nishao, UK. The test conditions were as follows: resolution of 1 cm\({}^{-1}\), scanning range of 80-4000 cm\({}^{-1}\), and laser wavelength of 532 nm.  
(6) X-ray diffraction test X-ray diffraction (XRD) analysis of the conductive silicone rubber was conducted using a Panaco Empyrean sharp-edged X-ray diffractometer. The test conditions were as follows: voltage of 40 kV, current of 40 mA, scanning angle of 5-85\({}^{\circ}\), scanning rate of 10\({}^{\circ}\)/min, and scanning step size of 0.02.