title: Development of ammonia sensors by using conductive polymer/hydroxyapatite composite materials.
abstract: In order to improve the gas sensing properties, hydroxyapatite (HAp)-based composites were prepared by mixing with different contents of conductive polymers: polypyrrole (PPy) and polyaniline (PAni). The compositions, microstructures and phase constitutions of polymer/HAp composites were characterized, and the sensing properties were studied using a chemical gas sensing (CGS-8) system. The results showed that, compared to pure HAp, the sensitivities of the composites to ammonia were improved significantly. 5%PPy/HAp and 20%PAni/HAp composites exhibited the best sensitivities to ammonia, and the sensitivities at 500ppm were 86.72% and 86.18%, respectively. Besides, the sensitivity of 5%PPy/HAp at 1000ppm was up to 90.7%. Compared to pure PPy and PAni, the response and the recovery time of 5%PPy/HAp and 20%PAni/HAp at 200ppm were shortened several times, and they were 24s/245s and 15s/54s, respectively. In addition, the composites showed a very high selectivity to ammonia. The mechanism for the enhancement of the sensitivity to ammonia was also discussed. The polymer/HAp composites are very promising in applications of ammonia sensors.
authors.affiliation: State Key Laboratory of Powder Metallurgy, Central South University, 932 Lushan South Road, Changsha 410083, PR China. Electronic address: huixialee1990@163.com.
authors.forename: Li
authors.initials: L
authors.lastname: Huixia
authors.affiliation: State Key Laboratory of Powder Metallurgy, Central South University, 932 Lushan South Road, Changsha 410083, PR China. Electronic address: yonliu@csu.edu.cn.
authors.forename: Liu
authors.initials: L
authors.lastname: Yong
authors.affiliation: State Key Laboratory of Powder Metallurgy, Central South University, 932 Lushan South Road, Changsha 410083, PR China. Electronic address: luolanlan1991@163.com.
authors.forename: Luo
authors.initials: L
authors.lastname: Lanlan
authors.affiliation: State Key Laboratory of Powder Metallurgy, Central South University, 932 Lushan South Road, Changsha 410083, PR China. Electronic address: tanyanni@csu.edu.cn.
authors.forename: Tan
authors.initials: T
authors.lastname: Yanni
authors.affiliation: State Key Laboratory of Powder Metallurgy, Central South University, 932 Lushan South Road, Changsha 410083, PR China. Electronic address: zhts0211@hotmail.com.
authors.forename: Zhang
authors.initials: Z
authors.lastname: Qing
authors.affiliation: State Key Laboratory of Powder Metallurgy, Central South University, 932 Lushan South Road, Changsha 410083, PR China. Electronic address: kunlee@csu.edu.cn.
authors.forename: Li
authors.initials: L
authors.lastname: Kun
mesh_terms: D000641:Ammonia / Q000032:analysis*; D000814:Aniline Compounds / Q000737:chemistry*; D017886:Durapatite / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D011758:Pyrroles / Q000737:chemistry*
chemical_list: D000814:Aniline Compounds; D011108:Polymers; D011758:Pyrroles; C416807:polyaniline; C067635:polypyrrole; D000641:Ammonia; D017886:Durapatite
keywords: Ammonia; Gas sensing property; Hydroxyapatite; Polyaniline; Polypyrrole