PPV and their oligomers have been shown to be useful as active sensing materials. PPV has been shown to detect eight organic solvents (chloroform, acetone, ethanol, ethyl acetate, toluene, hexane, acetic acid, methanol, diethyl ether); their sensitivity values were between 10�C40% [10]. In our work, we demonstrate further etc that PPV can detect NH4NO3 vapor, commonly found in fertilizers and explosive material industries [11]. In this paper, PPV/zeolite Y composites were prepared and electrical conductivity sensitivities of the composites under the NH4NO3 exposure were investigated, and data were compared with those of pristine PPV and zeoltite Y. Influence of Si/Al ratios of the zeolite Y on the electrical conductivity sensitivities was studied.

Based on IR spectroscopy studies, interactions between NH4NO3 molecules and PPV, zeolite Y, and the PPV/zeolite Y composites are proposed.2.?Experimental2.1. Materials��, ����-Dichloro-p-xylene, Inhibitors,Modulators,Libraries tetrahydrothiophene and methanol (Aldrich) were used to synthesize Inhibitors,Modulators,Libraries p-xylene-bis(tetrahydrothiophenium chloride) monomer. Sodium hydroxide (Merck) and hydrochloric acid (Merck) were used as the basic and the acidic reagents, respectively. Sulfuric acid (Merck) was used as the oxidant. Zeolites: CVB400 (Si/Al = Inhibitors,Modulators,Libraries 5.1, H+), CVB720 (Si/Al = 30, H+), CVB760 (Si/Al = 60, H+) and CVB780 (Si/Al = 80, H+) (all from Zeolyst) were used as the adsorbents. Ammonium hydroxide (Suksapan, Thailand) and nitric acid (Fluka) were used to make ammonium nitrate (NH4NO3) as the target chemical. Nitrogen (N2, TIG) was used as the surface cleaning gas and to vaporize ammonium nitrate.

All chemicals were used without further purification.2.2. Poly(p-phenylenevinylene) Synthesis and Doping ProcessSynthesis of the p-xylene-bis(tetrahydrothiophenium chloride) monomer was achieved by reacting ��,����-dichloro-p-xylene with tetrahydrothiophene [12]. The precursor sulfonium polyelectrolyte Inhibitors,Modulators,Libraries was prepared in an aqueous solution by the base induced polymerization of an appropriate bis-sulfonium monomer. The polymerization reaction was terminated by the addition of dilute aqueous hydrochloric acid to the reaction mixture which was then dialyzed against water in order to separate the high molecular weight fraction from the monomeric and oligomeric residues as well as the sodium and chloride ions.

Poly(p-phenylenevinylene) (PPV) was obtained by heating pol[(p-xylene-bis(tetrahydro-thiophenium chloride)] under vacuum at 180 ��C for 6 hours [12]. 18 M sulfuric acid was Anacetrapib used as a dopant solution at the mole ratios NSC639966 between PPV repeating unit per sulfuric acid equal to 1:300. The doping process occurred after adding the dopant solution to a polymeric powder, and it was monitored by observing the color changes of the powder from bright yellow to black [13].2.3.