Polyaniline polystyrene composite

Ruckenstein, E. and Yang, S. (1993) An emulsion pathway to electrically conductive polyaniline-polystyrene composites. Synth. Met., 53,283-292. 

Polypyrrole/poly(ethylene-co-vinyl acetate) conducting composites with improved mechanical properties were prepared by a similar method [167], In addition, polyaniline/polystyrene [168] and polyaniline/poly(alkyl methacrylate) [169] composites have been synthesised. A solution of persulphate in aqueous HC1 was added to an o/w HIPE of polymer and aniline in an organic solvent, dispersed in aqueous SDS solution, causing aniline polymerisation. Films were processed by hot- or cold-pressing. 

Figure 14.7 TEM ofPANI hollow spheres produced by chemical polymerization of aniline on polystyrene particles and removal with tetrahydrofuran, and decorated with gold nanoparticles. (Reprinted with permission from Langmuir, Polyaniline / Au composite hollow spheres Synthesis, characterisation, and application to the detection of dopamine by X. M. Feng, C.J. Mao, C. Yang et al., 22, 9, 4384-4389. Copyright (2006) American Chemical Society)...

P. Saini, V. Choudhary, Enhanced Electromagnetic Interference Shielding Effectiveness of Polyaniline Functionalized Carbon Nanotubes Filled Polystyrene Composites. J. Nanopart. Res. 2013,15. 

Similarly, Aussawasathien et al. [185] compared the performance of CSA-doped polyaniline-polystyrene electrospun nanofibers with a thin film of the same composition for the electrochemical detection of hydrogen peroxide. As expected, the thin-film sensor showed significantly weaker currents than those of the electrospun nanofibers, with both materials showing a linear response of the redox current as a function of hydrogen peroxide concentration. However, the electrospun nanofiber sensor showed a much higher sensitivity, as evidenced by the greater slope. It was also shown that the detection of... 

Some measurements of this property have been made in a range of electrically conducting polymers. These include epoxy resin/polyaniline-dodecylbenzene sulfonic acid blends [38], polystyrene-black polyphenylene oxide copolymers [38], semiconductor-based polypyrroles [33], titanocene polyesters [40], boron-containing polyvinyl alcohol [41], copper-filled epoxy resin [42], polyethylidene dioxy thiophene-polystyrene sulfonate, polyvinyl chloride, polyethylene oxide [43], polycarbonate/acrylonitrile-butadiene-styrene composites [44], polyethylene oxide complexes with sodium lanthanum tetra-fluoride [45], chlorine-substituted polyaniline [46], polyvinyl pyrolidine-polyvinyl alcohol coupled with potassium bromate tetrafluoromethane sulfonamide [47], doped polystyrene block polyethylene [38, 39], polypyrrole [48], polyaniline-polyamide composites [49], and polydimethyl siloxane-polypyrrole composites [50]. 

Figure 14.9 The application of porous PAN films and composites to the sensing of nitrite. Scale 7 gm (A) Porous film ofpoly(aniline) formed from the in situ electrochemical synthesis in the presence of WO nm polystyrene nanoparticle templates. (B) Enhanced electrocatalysis of concentrations of 50 gM nitrite in 0.7 M HCI at+ 50 mVvs. Ag/AgCI of the nanocomposite film (d) compared to classy carbon (a), pre-treatedglassy carbon (b) and bulk PANI [85]. (Reprinted with permission from Chemistry A European journal, Nanocomposite and nanoporous polyaniline conducting polymers exhibit enhanced catalysis of nitrite reduction by X. Luo, A.j. Killard and M.R. Smyth, 13, 2138-2143. Copyright (2007) Wiley-VCH)...

Kitani et al. have prepared polyaniline composites using poly(aniline-2-sulfonic acid) [142] and poly(2,5-disulfonic acid) [143] instead of conventional electroinactive sulfonated polymers like polystyrene sulfonic acid. These composites were prepared by electrochemical dopant exchange. Electrochemically prepared polyaniline films were dedoped by treating 1M NaOH solution. Furthermore, these dedoped films were... 

Figure 3.19 Vickers hardness of crosslinked PABA in comparison with other materials, a functionally graded polymer composite with 45 % SiC b heat treated crosslinked PABA c common hard plastics including PVC, PMMA, polycarbonate, polystyrene and acetal d heat treated polyaniline (polyaniline). (Reprinted with permission from Chemistry of Materials, 17, 3803. Copyright (2005) American Chemical Society.)...

As far as processing of ICPs is concerned, various methods have been developed to prepare electrically conductive composites [139], among which melt processing is quite popular for thermoplastics [140, 141]. Martins and De Paoli [142] prepared polystyrene and polyaniline blends in a double-screw extruder, giving a conductive thermoplastic with electrical conductivity of 10 to 10 S cm . In most cases, conducting polymers are incompatible with thermoplastic, so a fimctional dopant is needed to improve compatibility. For example, dodecylbenzenosulfonic acid... 

Aniline was added to a monodisperse cationic polystyrene latex and polymerisation initiated by the addition of ammonium persulphate solution, forming a core-shell latex, which was characterised by infrared spectroscopy, and scanning and transmission electron microscopy. The composites exhibited electrical conductivity comparable to that of pure polyaniline, with a percolation threshold of approximately 3 wt% polyaniline. 12 refs. 

The volume resistivity, permittivity, and dielectric loss factor of nanostructured interpenetrating polymer networks based on natural rubber/polystyrene have been found to increase as a function of blend composition, reaching a maximum of 10 -10 Hz dielectric loss factor [27]. Measurements of volume resistivity have also been reported on epoxy resin-polyaniline blends resulting in the establishment of a correlation between a shoulder on the 1583 cm band with the degree of volume resistivity [31]. 

Electrical properties have been reported on numerous carbon fiber-reinforced polymers, including carbon nanoflber-modified thermotropic liquid crystalline polymers [53], low-density polyethylene [54], ethylene vinyl acetate [55], wire coating varnishes [56], polydimethyl siloxane polypyrrole composites [50], polyacrylonitrile [59], polycarbonate [58], polyacrylonitrile-polycarbonate composites [58], modified chrome polymers [59], lithium trifluoromethane sulfonamide-doped polystyrene-block copolymer [60], boron-containing polyvinyl alcohols [71], lanthanum tetrafluoride complexed ethylene oxide [151, 72, 73], polycarbonate-acrylonitrile diene [44], polyethylene deoxythiophe-nel, blends of polystyrene sulfonate, polyvinyl chloride and polyethylene oxide [43], poly-pyrrole [61], polypyrrole-polypropylene-montmorillonite composites [62], polydimethyl siloxane-polypyrrole composites [63], polyaniline [46], epoxy resin-polyaniline dodecyl benzene sulfonic acid blends [64], and polyaniline-polyamide 6 composites [49]. 

For example, blends and semi-IPN of polypyrrole and EPDM rubber, prepared by calendering, absorb 85% of microwave radiation in the 10-13 GHz range [167]. Surface deposition of polypyrrole onto poly-(vinylchloride) produced composites with microwave absorption properties in the 0.1-20 GHz frequency range [168]. The same authors also studied the shielding characteristics of blends of polyaniline and poly(3-octylthiophene) with polystyrene and with the copolymer of ethylene and vinyl acetate. For defense purposes, however, a larger frequency range should be covered, but this only encourages continuation of the research. 

The polyaniline synthesized in this way was dissolved in concentrated sulfuric acid and sulfonated polystyrene beads were added. The mixture was stirred for 1 hour at room temperature. The mixture was then filtered and the composite beads were washed with water in several portions. The green colored... 

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