Electrical composites with polystyrene

Hu et al. showed a decrease in electrical resistivity of PVA by four orders of magnitude with a percolation threshold of 6 wt% [68], while biodegradable polylactide-graphene nanocomposites were prepared with a percolation threshold as low as 3 5wt% [46]. For polystyrene-graphene composites, percolation occurred at only 0.1 °/o of graphene filler, a value three times lower than those for other 2D-filler [69]. Figure 6.7(b) shows the variation of conductivity of the polystyrene-graphene composite with filler content. A sharp increase in conductivity occurs at 0.1 % (the percolation threshold) followed by a saturation. The inset shows the four probe set up for in-plane and trans-... 

In a recent pubHcation, Alivisatos and co-workers reported the making of hybrid nanorods-polymer solar cells and their properties [122]. These solar cells were made by spin casting of a solution of both poly(3-hexylthiophene) (hole acceptor) and CdSe nanorods (electron acceptor) onto indium tin oxide glass substrates coated with poly(ethylene dioxythiophene) doped with polystyrene sulfonic acid and aluminum as a top contact. Nanorods have been used in composites so as to improve the carrier mobiHty. Indeed, the latter can be high for some inorganic semiconductors, but it is typically extremely low for conjugated polymers [123]. The use of the nanorods suppHes an interface for the charge transfer as well as a direct path for electrical transport. Also, because of their anisotropy, self-assembly of these nanorods is observed by electron microscopy. It shows... 

Zhang B, Dong X, Song W, Wu D, Fu R, Zhao B, Zhang M (2008) Electrical response and adsorption performance of novel composites from polystyrene filled with carbon aerogel in organic vapors. Sensor Actuator B 132(1) 60-66. 

The chemical route is considered highly promising due to the positive effect of chemically reduced GO nanosheets on multifunctional properties of nanocomposites prepared using various polymer matrices. Composites of polystyrene, poly(methyl methacrylate), epoxy, and vinyl chloride/vinyl acetate copolymer with chemically reduced GO were reported to have electrical percolation thresholds as low as 0.1—0.52% vol. In addition, epoxy—GO composite (Liang et al., 2008) exhibited EMl-shielding effectiveness of 21 dB in the X-band at 15% wet filler loading against the minimum required 20 dB for commercial applications. 

Fig. 4.5 Optical photograph of the composite colloidal crystal array film self assembled on a Teflon film. The submicron particles were composed of 326 nm diameter polystyrene beads coated with a 20 nm thick Si02 shell. Reprinted from Ref. 15 with permission. 2008 Institute of Electrical and Electronics Engineers...

Composite conductive fibers based on poly(3,4-ethylene-diox)d hiophene]-polystyrene sulfonic acid (PEDOT-PSS) solution blended with polyacrylonitrile (PAN] were obtained via wet spinning. The influence of draw ratio on the morphology, structure, thermal degradation, electrical conductivity, and mechanical properties of the resulting fibers was investigated. The results revealed that the PEDOT-PSS/PAN composite conductive fibers crystallization, electrical conductivity and mechanical properties were improved with the increase of draw ratio. The thermal stability of the fibers was almost independent of draw ratio, and only decreased slightty with draw ratio. Besides, when the draw ratio was 6, the conductivity of the PEDOT-PSS/PAN fibers was 5.0 S cm, ten times the conductivity when the draw ratio was 2 (Fig 5.10]. ... 

Wei X, Yates MZ (2010) Nafion/polystyrene-b-poly(ethylene-ran-butylene)-b-polystyrene composite membranes with electric field-aligned domains for improved direct methanol fuel cell performance. J Power Sources 195 736-743... 

---