Owing to the growth of demand for highly integrated electronic devices, high heat dissipation of thermal management materials is essential. Epoxy composites have been prepared with vertically aligned (VA) three-dimensional (3D)-structured SiC sheet scaffolds. The required VA-SiC sheet scaffolds were prepared by a novel approach starting with a graphene oxide (GO) scaffold. The VA-GO scaffolds were reduced to VA-graphene scaffolds in an argon environment, and the latter were subsequently transformed into VA-SiC sheet scaffolds by a template-assisted chemical vapor deposition method. Epoxy resin was filled in the empty spaces of the 3D scaffold of SiC sheets to prepare the composite mass. The material so prepared shows anisotropic thermal property with ultrahigh through-plane conductivity of 14.32 W•m −1 •K −1 at a SiC sheet content of 3.71 vol %. A thermal percolation is observed at 1.78 vol % SiC filler. The SiC sheet scaffold of covalently interconnected SiC nanoparticles plays a vital role in the formation of the thermal conductive network to significantly enhance the thermal conductivity of epoxy composites. The application of the VA-SiC/epoxy composite as an efficient thermal dissipating material has also been presented. The VA-SiC/epoxy composites have a strong potential for preparing heat-dissipating components in integrated microelectronics.

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A series of nanocomposites based on polystyrene (PS) and organophilic layered silicates (OLS) were prepared by solution blending method using organophilically modified silicate with ammonium salt of poly(styrene‐ran‐(4‐vinylbenzyl chloride)). Two different types of base layered silicate were used for the preparation of the nanocomposites: sodium montmorillonite (Na‐MMT) and synthetic smectite (SWN). The morphology and thermal stability of the PS/OLS nanocomposites were characterized by TEM and TGA. The rheological properties of the nanocomposites were investigated using a stress‐controlled rotational rheometer under small amplitude oscillation and steady transient shear in their melt state. In addition, the effects of the contents and aspect ratio of OLS on the melt rheological properties were investigated.

SynopsisIn order to study the synthesis and properties of polysulfonamides containing thiophene links, 2,2-bis(5-chlorosulfonyl-2-thienyl)propane [BCTP], 2,2-bis(5-chlorosulfonyl-2-thienyl)butane [BCTB], 1,1-bis(5-chlorasulfonyl-2-thienyl)cyclohexane [BCTC], and 2,4-dichlorosulfonyl thiophene [DCST] were prepared and interfacial polycondensations with various aliphatic diamines were carried out. The resulting polymers had inherent viscosities in the range of 0.13-0.41 dL/g and showed high extent of moisture absorptions. Most of the polysulfonamides were soluble in electron-donating solvents such as pyridine, DMF, DMSO, NMP, etc. These polysulfonamides exhibited relatively good thermal stabilities. The TGA data revealed 5% weight losses at 275-405°C and residual weights at 500°C were 13-40% under nitrogen. It was also found that dithienyldisulfonyl chlorides produced more thermally stable polymers than E S T , which were comparable to common polysulfonamides from aromatic disulfonyl chlorides.

Bi2Te3 nanotubes were synthesized by first synthesizing Te nanorods and then alloying it with Bi(O) reduced from Bi3+ using solution-phase reaction. The alloying of Bi(0) and Te nanorods was enabled by the atomic diffusion on the interface between two metals. The morphology of Bi2Te3 crystals was greatly influenced depending on kind and concentration ratio of capping agents during solution-phase reaction. When only a trioctylphosphine oxide (TOPO) was used as a capping agent, the cylinder like Bi2Te3 nanotubes with diameters of 130-160 nm or larger were formed while the rod like Bi2Te3 nanobelts with diameters of 25-40 nm were formed when only poly vinyl pyrrolidone (PVP) was used. When the mixture of trioctylphosphine oxide and poly vinyl pyrrolidone was used, Bi2Te3 nanotubes with diameters of 30-80 nm were formed.