A comparison study on polymeric nanocomposite foams with various carbon nanoparticles: adjusting radiation time and effect on electrical behavior and microcellular structure

Figures & data

Figure 1. TEM micrographs of the composites in two different scales: a) PS/CNT1, b) PS/G1, and c) PS/CB1.

Figure 2. (a). Schematic of microwave-assisted foaming procedure, and (b) PS/G1 foamed samples in various radiation times, (c) schematic of the gas foaming procedure.

Table 1. Solubility of CO₂ in produced nanocomposites.

Filler content (wt.%)	Solubility of CO2 (g/g polymer matrix)
	PS/CNT	PS/G	PS/CB
0.5	0.064 ± 0.003	0.068 ± 0.004	0.062 ± 0.005
1	0.076 ± 0.005	0.083 ± 0.006	0.068 ± 0.005
2.5	0.086 ± 0.002	0.091 ± 0.003	0.075 ± 0.004
5	0.095 ± 0.005	0.098 ± 0.007	0.084 ± 0.008

Figure 3. The density of microwave-assisted foam composites containing various types of fillers as a function of radiation time.

Figure 4. The density of microwave-assisted foams containing various types of fillers as a function of radiation power.

Figure 5. SEM micrographs and cell size distribution of microwave-assisted PS/CNT1 foams created at various radiation times.

Figure 6. SEM micrographs and cell size distribution of microwave-assisted PS/G1 foams created at various radiation times.

Figure 7. SEM micrographs and cell size distribution of microwave-assisted PS/CB1 foams created at various radiation times.

Table 2. Characteristics of the microwave-assisted foams.

Composite	Radiation time (s)	Density (g/cm3)	Average cell size (µm)	Cell density (g/cm^3)	Expansion ratio	Porosity (%)
	5	0.53 ± 0.03	7.16	5.40 × 10^9	1.97	49
	10	0.13 ± 0.01	20.08	1.62 × 10^9	7.59	87
PS/CNT1	20	0.11 ± 0.02	23.40	9.40 × 10^8	9.18	89
	30	0.08 ± 0.01	26.33	1.08 × 10^9	13.6	92
	45	0.07 ± 0.01	33.91	7.28 × 10^8	17.08	94
	60	0.06 ± 0.01	62.15	1.68 × 10^8	24.33	96
	60	0.73 ± 0.02	3.54	2.56 × 10^10	1.43	30
	90	0.45 ± 0.05	5.51	1.08 × 10^10	2.29	56
PS/G1	120	0.38 ± 0.05	9.91	3.97 × 10^9	2.73	63
	150	0.27 ± 0.08	12.21	2.43 × 10^9	3.86	74
	180	0.08 ± 0.01	18.18	3.12 × 10^9	12.1	92
	210	0.07 ± 0.01	24.64	1.93 × 10^9	13.65	93
	60	1.04 ± 0.03	–	–	–	0
	90	0.97 ± 0.03	8.53	1.31 × 10^8	1.08	7
PS/CB1	120	0.73 ± 0.04	12.55	3.07 × 10^8	1.42	30
	150	0.59 ± 0.06	13.78	5.60 × 10^8	1.76	43
	180	0.35 ± 0.05	16.92	6.64 × 10^8	2.96	66
	210	0.28 ± 0.02	23.26	7.57 × 10^8	3.74	73

Figure 8. (a) Electrical conductivity of the solid composites in different filler content. Electrical conductivity of (b) PS/CNT1, (b) PS/G1, and (c) PS/CB1 foams was produced in various radiation times as a function of cell size and final filler content.

Table 3. Summary of electrical conductivity of the foam composites.

Composite	Radiation time (s)	Filler content (wt. %)	Filler content (vol. %)	Average cell size (µm)	Electrical Conductivity (S/cm)	EMI SE (dB)	Specific EMI SE (dB cm^3/g)	dielectric constant at frequency of 100 Hz
	5	1	0.32	7.16	8.39 × 10^−9	2.1	3.9	25.2
	10	1	0.083	20.08	3.13 × 10^−8	2.6	19.2	18.1
PS/CNT1	20	1	0.068	23.40	1.45 × 10^−7	3.3	28.9	15.5
	30	1	0.05	26.33	8.33 × 10^−7	3.1	37.4	13.6
	45	1	0.046	33.91	3.29 × 10^−6	4.4	57.4	11.1
	60	1	0.036	62.15	6.40 × 10^−8	2.5	40	9.8
	60	1	0.34	3.54	3.05 × 10^−7	2.9	4	19.2
	90	1	0.21	5.51	8.31 × 10^−7	3.3	7.2	14.5
PS/G1	120	1	0.18	9.91	9.23 × 10^−8	2.2	5.8	14.1
	150	1	0.12	12.21	5.31 × 10^−8	2	7.4	12.3
	180	1	0.04	18.18	4.31 × 10^−8	1.9	23	10.8
	210	1	0.03	24.64	2.42 × 10^−8	1.8	24.2	10.6
	90	1	0.56	8.53	2.12 × 10^−9	0.9	1.1	11.4
	120	1	0.52	12.55	4.42 × 10^−9	0.9	1.4	10.3
PS/CB1	150	1	0.39	13.78	6.34 × 10^−9	1	1.8	8.7
	180	0.35	0.32	16.92	8.13 × 10^−9	1	2.9	8.5
	210	0.28	0.19	23.26	1.96 × 10^−8	1	3.6	6.8

Figure 9. EMI SE of the solid composites (a), PS/CNT1 (b), PS/CNT1 (c), and PS/CNT1 (d), foams as a function of cell size at a different frequency.