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In order to improve the understanding of laser interactions of materials with homogeneous nano-structures, pulsed laser induced plasma from a low density, high-porosity multiwall carbon nanotube (CNT) sponge and a dense graphite block have been investigated by combinational spectroscopy approaches. We observe distinct differences in the laser-induced light emission of the CNT sponge and graphite block which we attribute to the occurrence of a phase explosion caused by the lower thermal conductivity and weaker mechanical strength of the CNT sponge. Furthermore, spectroscopy plasma analysis reveals that differences in the surface of the two systems play a key role in the generation of negative carbon ions. We observe a more effective production of negative ions for the CNT sponge as compared to the graphite block due to the greater number of surface defects of the CNT sponge. [ABSTRACT FROM AUTHOR]

The anisotropy in thermoelectric properties of three-dimensional carbon nanotubes (CNTs) and CNT/polyaniline (PANI) composites have been studied by utilizing an orderly aligned CNT arrays with a self-sustained construction. In the length direction of CNT, the electrical conductivity of the CNT array is ∼5 times larger as compared to the direction vertical to the alignment of CNTs, while the difference in thermal conductivity between these two directions is ∼25 times. As a result, strong anisotropic thermoelectric transportation has been also observed in the composites composed of PANI and CNT arrays. An enhanced thermopower in the composites, as compared to the pure PANI or CNTs, is only observed in the direction along the CNTs. This study helps the fundamental understanding on the un-conventional improved thermopower, which is more likely to be realized via adjusting the carrier transportation within the interface between CNTs and PANI rather than across it. [ABSTRACT FROM AUTHOR]

A lightweight 3D Ag/CNTs/SBS composite foam was successfully fabricated by a simple freeze-drying process followed by adsorbing and in-situ reducing of silver trifluoroacetate in ethanol solution, which exhibited robust mechanical–electrical performance and high EMI shielding performance due to the synergistic contribution of the CNTs with ultra-high aspect ratio inside the SBS matrix and Ag NPs partially embedded in the superficial surface of the SBS foam skeleton. [Display omitted] • Lightweight Ag/CNTs/SBS foam was fabricated by freeze-drying and in-situ reduction. • CNTs and partially embedded Ag NPs endow the foam with excellent properties. • The foam exhibits high EMI SE of 91 dB at 4 mm in the X band. • The foam possesses enhanced EMI SE value after the cyclic compressions. The porous conductive polymer composites have received great attention owing to their superiority of being utilized in electromagnetic interference (EMI) shielding applications. Herein, lightweight and highly compressible conductive composite foam composed of poly(styrene- block -butadiene- block -styrene) (SBS) polymer matrix, carbon nanotubes (CNTs) and silver nanoparticles (Ag NPs) is fabricated by freeze-drying technology, silver precursor absorption and in-situ reduction process. Three-dimensional CNTs conductive network and partially embedded Ag NPs synergistically endow the foam with excellent mechanical, electrical and EMI shielding performance. The flexible 8Ag/4CNTs/10SBS composite foam with a low density of 0.42 g/cm3 exhibits moderate compressive strength of 169.2 kPa at strain of 50%, remarkable conductivity of 753 S/m, and prominent EMI shielding effectiveness (SE) value of around 91 dB in the electromagnetic wave frequency range of 8.2–12.5 GHz. In addition, the 4Ag/4CNTs/10SBS composite foam exhibits robust mechanical–electrical property upon 1000 compression-release cycles at strain of 50%, and its SE value increased by about 33% compared with the initial state after the cyclic compression test. These results suggest that the Ag/CNTs/SBS foams possess promising potential to be used as lightweight, flexible, and high-performance EMI shielding materials in modern electronic devices. [ABSTRACT FROM AUTHOR]

A lightweight 3D Ag/CNTs/SBS composite foam was successfully fabricated by a simple freeze-drying process followed by adsorbing and in-situ reducing of silver trifluoroacetate in ethanol solution, which exhibited robust mechanical–electrical performance and high EMI shielding performance due to the synergistic contribution of the CNTs with ultra-high aspect ratio inside the SBS matrix and Ag NPs partially embedded in the superficial surface of the SBS foam skeleton. [Display omitted] • Lightweight Ag/CNTs/SBS foam was fabricated by freeze-drying and in-situ reduction. • CNTs and partially embedded Ag NPs endow the foam with excellent properties. • The foam exhibits high EMI SE of 91 dB at 4 mm in the X band. • The foam possesses enhanced EMI SE value after the cyclic compressions. The porous conductive polymer composites have received great attention owing to their superiority of being utilized in electromagnetic interference (EMI) shielding applications. Herein, lightweight and highly compressible conductive composite foam composed of poly(styrene- block -butadiene- block -styrene) (SBS) polymer matrix, carbon nanotubes (CNTs) and silver nanoparticles (Ag NPs) is fabricated by freeze-drying technology, silver precursor absorption and in-situ reduction process. Three-dimensional CNTs conductive network and partially embedded Ag NPs synergistically endow the foam with excellent mechanical, electrical and EMI shielding performance. The flexible 8Ag/4CNTs/10SBS composite foam with a low density of 0.42 g/cm3 exhibits moderate compressive strength of 169.2 kPa at strain of 50%, remarkable conductivity of 753 S/m, and prominent EMI shielding effectiveness (SE) value of around 91 dB in the electromagnetic wave frequency range of 8.2–12.5 GHz. In addition, the 4Ag/4CNTs/10SBS composite foam exhibits robust mechanical–electrical property upon 1000 compression-release cycles at strain of 50%, and its SE value increased by about 33% compared with the initial state after the cyclic compression test. These results suggest that the Ag/CNTs/SBS foams possess promising potential to be used as lightweight, flexible, and high-performance EMI shielding materials in modern electronic devices. [ABSTRACT FROM AUTHOR]