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As technology advances toward ongoing circuit miniaturization and device size reduction followed by improved power density, heat dissipation is becoming a key challenge for electronic equipment. Heat accumulation can be prevented if the heat from electrical equipment is efficiently exported, ensuring a device's lifespan and dependability and preventing otherwise possible mishaps or even explosions. Hence, thermal management applications, which include altering the role of aerogels from thermally insulative to thermally conductive, have recently been a hot topic for 3D-aerogel-based thermal interface materials. To completely comprehend three-dimensional (3D) networks, we categorized and comparatively analyzed aerogels based on carbon nanomaterials, namely fibers, nanotubes, graphene, and graphene oxide, which have capabilities that may be fused with boron nitride and impregnated for better thermal performance and mechanical stability by polymers, including epoxy, cellulose, and polydimethylsiloxane (PDMS). An alternative route is presented in the comparative analysis by carbonized cellulose. As a result, the development of structurally robust and stiff thermally conductive aerogels for electronic packaging has been predicted to increase polymer thermal management capabilities. The latest trends include the self-organization of an anisotropic structure on several hierarchical levels within a 3D framework. In this study, we highlight and analyze the recent advances in 3D-structured thermally conductive aerogels, their potential impact on the next generation of electronic components based on advanced nanocomposites, and their future prospects. [ABSTRACT FROM AUTHOR]

In this study, three-dimensional (3D) polyvinyl alcohol (PVA)/aligned boron nitride (BN) aerogel framework nanocomposites with high performance were fabricated by a facile strategy. The boron nitride powder was initially hydrolyzed and dispersed with a chemically crosslinked plasticizer, diethyl glycol (DEG), in the PVA polymer system. The boron nitride and DEG/PVA suspensions were then mixed well with different stoichiometric ratios to attain BN/PVA nanocomposites. Scanning electron microscopy revealed that BN platelets were well dispersed and successfully aligned/oriented in one direction in the PVA matrix by using a vacuum-assisted filtration technique. The formed BN/PVA aerogel cake composite showed excellent in-plane and out-of-plane thermal conductivities of 0.76 W/mK and 0.61 W/mK with a ratio of BN/PVA of (2:1) in comparison with 0.15 W/mK for the pure PVA matrix. These high thermal conductivities of BN aerogel could be attributed to the unidirectional orientation of boron nitride nanoplatelets with the post-two days vacuum drying of the specimens at elevated temperatures. This aerogel composite is unique of its kind and displayed such high thermal conductivity of the BN/PVA framework without impregnation by any external polymer. Moreover, the composites also presented good wettability results with water and displayed high electrical resistivity of ~1014 Ω cm. These nanocomposites thus, with such exceptional characteristics, have a wide range of potential uses in packaging and electronics for thermal management applications. [ABSTRACT FROM AUTHOR]

In most countries, rapid industrialization poses a threat to the environment upon discharging the wastewater streams containing heavy metals, especially hexavalent chromium (Cr(VI)), into the environment. In this work, sustainable and biodegradable bacterial cellulose (BC)/polyaniline (PANI) nanocomposite aerogels with different morphology were fabricated in the presence of sodium dodecylbenzene-sulfonate (SDBS) and sodium dodecyl sulfate (SDS). The fabricated BC/PANI in the existence of SDBS and SDS showed thistle like and a cluster of grapes, respectively. The Cr(VI) removal was performed at a neutral pH condition. The highest adsorption capacity of 189 mg/g was determined at pH 7 for BC/PANI/SDBS (BPDB) compared with 151 mg/g for BC/PANI/SDS (BPDS) after 24 h. After five cycles, re-adsorption efficiency was reached to 68% for BPDB and 59% for BPDS. Simulation results showed that the effect of surface diffusion was prevailing compared with the pore volume diffusion (nearly 90% after 1 h). BPDB showed a faster adsorption rate than BPDS. Predicted concentration decay curves had good agreement with experimental data. Image 1 • Bacterial cellulose/polyaniline with anionic surfactants was used as adsorbents. • The highest adsorption capacity of 189 mg/g was determined at pH 7. • Average re-adsorption efficiency of 64% was observed after five cycles. • Surface and pore volume diffusion simultaneously exist in the adsorption process. • Surface diffusion is dominant in the intraparticle mechanism by nearly 90% after 1 h. [ABSTRACT FROM AUTHOR]