Enhanced electromagnetic interference shielding and mechanical properties of foamed epoxy nanocomposites containing carbon nanofiber treated with silicone surfactant

Abstract

Thermosetting epoxy (EP)-based composites containing various carbon nanofiber (CNF) contents (0-5 wt %) were fabricated using high speed mechanical stirring and surfactant assisting method. Then EP/CNF composites were foamed through a supercritical CO 2 (scCO 2 ) foaming method. The cellular morphology of the foamed EP/CNF nanocomposites has been analyzed by scanning electron microscopy (SEM), and the results demonstrated that the CNFs could be served as heterogeneous nucleating agent to increase nucleation sites in nanocomposites, leading to higher cell density and larger cell size. The influences of foaming on conductivity and electromagnetic interference (EMI) shielding effectiveness (SE) were investigated. Due to the introduction of microcellular structure, the conductivity was improved from 9.53 × 10 −8 S/cm to 6.75 × 10 −6 S/cm and the EMI SE was enhanced from 12.7 to 16.5 dB at the CNF content of 5 wt %.

A Short Review on the Effect of Surfactants on the Mechanico-Thermal Properties of Polymer Nanocomposites

“…Polymer nanocomposites are polymers incorporated with nanometer scale fillers, regardless of the origin of the materials, whether it is inorganic or organic. Synthetic polymers (examples are displayed in Table 1) are frequently utilized for the creation of polymer nanocomposites, including HDPE [1], PP [2], PS [3,4], DGEBA [5][6][7], PEVA [8,9], PBO [10], SR [11], PAN [12], PUA [13], etc. Synthetic biodegradable polymers (examples are also displayed in Table 1), such as PLA [14][15][16][17][18], PBAT [19], PBS [20], PVA [21], PCL [22], etc., are also utilized for nanocomposite preparation.…”

“…Synthetic biodegradable polymers (examples are also displayed in Table 1), such as PLA [14][15][16][17][18], PBAT [19], PBS [20], PVA [21], PCL [22], etc., are also utilized for nanocomposite preparation. On the other hand, nanofillers (examples are displayed in Table 2), such as MMT [2,9,12,20], Ag NPs [17,18], ZnO NPs [15], TiO 2 NRs [3], CNTs [10,23,24], CNFs [5,25,26], G NPs [11,13,23], GO NSs [6,27], LDHs [22], and HNTs [4], are used in the fabrication of polymer nanocomposites, as they possess a high aspect ratio, large surface area, high stiffness, and low density [17,20]. The application of bio-based nanofillers, for example, CNCs [15,18,28,29], CNPs [30], NCFs [8,19], and CNWs [7,16], also contribute to the production of nanocomposites because they are renewable and sustainable materials.…”

“…The application of bio-based nanofillers, for example, CNCs [15,18,28,29], CNPs [30], NCFs [8,19], and CNWs [7,16], also contribute to the production of nanocomposites because they are renewable and sustainable materials. Surfactants (examples are also displayed in Table 2), for instance, HTAB [13,20,31], DDAB [12,32], SDS [4,21], Ultraric PE 105 [19], Niax L-595 [8], HMAC [9], Triton X-100 [6,10,11,24], Beycostat A B09 [15,17,18,28], LAE [29], PEGMONO [14,16], Pluronic [7,14], OA [3], AK8805 [5], SA [2], PA [22], Span 60 [30], and BHHB [1], are commonly employed for modifying nanofillers in the preparation of polymer nanocomposites.…”

“…CNFs are also regarded as an inorganic nanofiller due to their preparation procedure and structure, which are the same as in CNTs, but CNFs have a larger diameter than CNTs [25]. CNFs could be modified by a silicone surfactant, like AK8805, to improve the dispersion of CNFs in an epoxy matrix, such as DGEBA [5]. CNF/DGEBA nanocomposites were prepared through solution blending and compression molding processes at an elevated temperature [5].…”

“…CNFs could be modified by a silicone surfactant, like AK8805, to improve the dispersion of CNFs in an epoxy matrix, such as DGEBA [5]. CNF/DGEBA nanocomposites were prepared through solution blending and compression molding processes at an elevated temperature [5]. On the other hand, G NPs could also be modified by Triton X-100 via sonication in the solvent [11].…”