Author
Hailin Zhao Hu
Other affiliations: University of California, Irvine
Bio: Hailin Zhao Hu is an academic researcher from National Autonomous University of Mexico. The author has contributed to research in topics: Thin film & Cadmium sulfide. The author has an hindex of 18, co-authored 56 publications receiving 1279 citations. Previous affiliations of Hailin Zhao Hu include University of California, Irvine.
Papers published on a yearly basis
Papers
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TL;DR: In this paper, the adsorption and desorption curves were carefully analyzed using Langmuir kinetic theory for PANI single and PANI-PMMA composite coatings.
Abstract: Polyaniline (PANI) shows electrical as well as optical property changes when it is in contact with oxidant/reductor gas. In this work, the optical transmittance changes in PANI coatings originated by their exposure to the ammonia gas were detected by a nulling optical transmittance bridge. The adsorption and desorption curves were carefully analysed using Langmuir kinetic theory for the adsorption of ammonia gas on PANI single and PANI–PMMA composite coatings. Because of the inhomogeneous nature of the PANI film surface adsorption isotherms were the best described by Freundlich model. From the numerical fitting equations it is suggested that there may be two energetically different adsorption sites on the PANI surface for NH 3 molecules, which corroborates with the no-uniform positive charge distribution on the nitrogen atoms of the PANI backbone chains. The activation energy of adsorption and the heat of adsorption were estimated to be about 0.3–0.5 eV at a NH 3 gas concentration of 10–1000 ppm.
162 citations
TL;DR: In this article, the morphology of electrosynthesized poly(3-methylthiophene) (P3MT) thin films was analyzed by atomic force microscopy and different film morphologies were found for different electrodeposition technique and solution temperature.
111 citations
TL;DR: In this paper, the optical-transmittance changes detected in PANI coatings as a function of the sensing ammonia gas concentrations are studied by using a nulling optical transmittance bridge with a 632nm laser (He-Ne) source, which allows a sensitive monitoring of optical property changes.
Abstract: Polyaniline (PANI) is a π-conjugated polymer that shows electric and optical property changes, when it is in contact with oxidant/reductor chemicals. In particular, the interaction between the conductive form of PANI, the emeraldine salt (ES), and the NH 3 gas results in a decrease of the polaron densities inside the band gap of the organic material. In this work, the optical-transmittance changes detected in PANI coatings as a function of the sensing ammonia gas concentrations are studied by using a nulling optical-transmittance bridge with a 632 nm laser (He–Ne) source, which allows a sensitive monitoring of optical property changes. It is observed that the conductive PANI–polymethyl methacrylate (PMMA) composite coatings are sensitive for very low concentrations of HN 3 (from ∼10 to 4000 ppm, depending on the PANI films’ electrical conductivity), and their optical response is reversible as the reduction gas is removed by N 2 .
102 citations
TL;DR: In this article, the chemical reactions between polyacrylic acid (PAA) and various divalent metal oxides (MO; M = Ca, Mg, Cu, Zn) were studied by Fourier transform infrared spectroscopy (FTIR).
77 citations
TL;DR: In this article, pyrrole monomer was dispersed in polyvinyl alcohol (PVA) solvents, which were previously mixed with an iron chloride solution, and the resulting mixtures were coated on substrates.
72 citations
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1,521 citations
TL;DR: In this article, a review of gas sensors fabricated by using conducting polymers such as polyaniline (PAni), polypyrrole (PPy) and poly (3,4-ethylenedioxythiophene) (PEDOT) as the active layers has been reviewed.
Abstract: The gas sensors fabricated by using conducting polymers such as polyaniline (PAni), polypyrrole (PPy) and poly (3,4-ethylenedioxythiophene) (PEDOT) as the active layers have been reviewed. This review discusses the sensing mechanism and configurations of the sensors. The factors that affect the performances of the gas sensors are also addressed. The disadvantages of the sensors and a brief prospect in this research field are discussed at the end of the review.
1,333 citations
TL;DR: The role of polymers as gas sensors, pH sensors, ion-selective sensors, humidity sensors, biosensor devices, etc., are reviewed and discussed in this article, and current trends in sensor research and also challenges in future sensor research are discussed.
1,126 citations
TL;DR: The review covers main applications of conducting polymers in chemical sensors and biosensors, such as pH sensitivity, sensitivity to inorganic ions and organic molecules as well as sensitivity to gases, and induced receptor properties.
819 citations
TL;DR: In this article, the authors present a detailed review of the state-of-the-art for electrochromics and its applications in smart windows and provide ample references to current literature of particular relevance.
801 citations