Optimization of waste quail eggshells as biocomposites for polyaniline in ammonia gas detection

A simple, cost-effective, and novel chemical sensor for ammonia (NH₃) gas detection was developed from polyaniline (PANI)/quail eggshell (QES) composites. QES is a natural waste enriched in calcium carbonate. In this work, pure PANI was synthesized from chemical oxidation method and PANI/QES composites were prepared from physical mixing of QES with the synthesized PANI at different mass ratio. A series of complementary techniques including Fourier transform infrared and ultraviolet-visible spectrometers, scanning electron microscope with energy dispersive detection coupled with mapping, thermogravimetric analysis, and X-ray diffractometer were used to characterize the physicochemical and textural properties of the biocomposites. From the results, PANI/QES composite with a mass ratio of 1 exhibited the lowest NH₃ detection limit of 5.24 ppm with a linear correlation coefficient (R²) of close to unity (0.9932) between the signal and NH₃ gas concentration. As a whole, the PANI/QES biocomposites synthesized from this work exhibited excellent selectivity toward NH₃ gas even in the presence of other gas impurities, such as acetone, ethanol, and hexane. For the sensor reusability, the PANI/QES biocomposites can be reused in the application of NH₃ gas detection for at least 4 cycles.     

Electrochemical synthesis and characterization of chloride doped polyaniline

Chloride doped polyaniline conducting polymer films have been prepared in a protic acid medium (HCl) by potentiodynamic method in an electrochemical cell and studied by cyclic voltammetry and FTIR techniques. The FTIR spectra confirmed Cl^- ion doping in the polymers. The polymerization rate was found to increase with increasing concentration of aniline monomer. But the films obtained at high monomer concentration were rough having a nonuniform flaky polyaniline distribution. Results showed that the polymerization rate did not increase beyond a critical HCl concentration. Cyclic voltammetry suggested that, the oxidation-reduction current increased with an increase in scan rate and that the undoped polyaniline films were not hygroscopic whereas chloride doped polyaniline films were found to be highly hygroscopic.     

碘掺杂聚苯胺催化合成丁醛乙二醇缩醛

制备了碘掺杂聚苯胺催化剂,采用正交实验探讨了合成丁醛乙二醇缩醛的影响因素。结果表明,在n (丁醛)：n(乙二醇)=1：1．5,催化剂的用量为反应物料总质量的0．60%,带水剂环己烷的用量为8 mL,反应时间为1．0 h条件下,丁醛乙二醇缩醛的收率可达71．6%。     

Synthesis and characterization of conducting copolymers from aniline and o‐anisidine in HCl solutions

Conducting poly(aniline‐co‐o‐anisidine) (PAS) films with different ratios of aniline units in the polymer chain were prepared by oxidative polymerization of different molar ratios of aniline and o‐anisidine in 1 M HCl using cyclic voltammetry. Due to the much higher reactivity of o‐anisidine, the structure and properties of PASs were found to be dominated by the o‐anisidine units. The polymerization of poly‐o‐anisidine and PASs followed zero‐order kinetics with respect to formation of the polymer (film thickness) and the autocatalytic polymerization of aniline was completely inhibited. In contrast to polyaniline, a decrease in the polymerization temperature was found to increase the amount of copolymer formed and its redox charge. The presence of aniline units in PASs led to a pronounced increase in the molecular weight and conductivity, and a decrease in the solubility in organic solvents. Repetitive charging/discharging cycles showed that PASs resist degradation more than polyaniline. Copyright © 2003 Society of Chemical Industry     

掺杂聚苯胺导电膜的制备及对核设施表面铀的去污

制备了掺杂导电聚苯胺可剥离膜，首次采用涂膜、电解联用去污方法，进行涂膜电解去除渗透到核设施金属材料内部形成氧化物的铀。在膜中，聚苯胺、盐酸、EDTA-2Na含量各为4％、0．5％～1%、1％；电解电压2．3V、电解时间25min～30min时，其去污率可达99％，优于其它的方法。     

Sensitometric characteristics of an all‐solid‐state photoelectrochromic pixel for an electrochromic light‐addressable display

Abstract— An all solid‐state photoelectrochromic element (PECE) was developed on the basis of electrochromic layers of WO₃ and polyaniline with a layer of polymer electrolyte placed on a base of polyamidosulfoacid, in which a thin‐film CdS_xSe_1?x photoresistor was used as an electronic key. The dependence of the sensitometric characteristics of the PECE on the applied voltage was studied.     

聚苯胺锂基润滑脂载流润滑下的摩擦学性能

制备了导电聚苯胺锂基润滑脂（简称PANI脂）和铜基银镀层材料（简称银层材料）。采用摩擦磨损试验机考察在无载流、载流及边界润滑条件下，铜基体材料（简称铜基材料）和银层材料的摩擦磨损性能。采用X射线衍射（XRD）、扫描电子显微镜（SEM）和电子能谱（EDS）对银层材料晶相及其表面磨斑形貌进行表征。结果表明，载流条件下，PANI脂润滑试验时的银层材料不仅具有良好的减摩抗磨性能，而且导电能力更强，其优异的减摩和抗磨性能归功于摩擦表面的保护膜和电流热效应引起的表面软化双重作用。     

聚苯胺电化学性能的改性研究

改善聚苯胺的电化学性能是聚苯胺研究中的一个重点，介绍了对聚苯胺的取代，共聚，复合和掺杂等几种改性方法，及其对聚苯胺电化学性能和其他性能的影响。     

Effect of organic dopants on electrodeposition and characteristics of polyaniline under the varying influence of H2SO4 and HClO4 electrolyte media

Electrodeposition of conducting polyaniline (Pani) was made under potentiostatic condition at pH 1.0 in different electrolyte media (H₂SO₄ and HClO₄) in the absence and presence of two organic dopants, disodium salts of naphthalene-1,5-disulphonic acid (NSA) and of catechol-3,5-disulphonic acid (CSA). The rate and yield of Pani deposition were dependent on the acid medium and the dopant employed. NSA in H₂SO₄ caused an increase in rate and yield but CSA decrease when compared to the rate and yield of H₂SO₄ alone. In HClO₄ medium, both the dopants showed a decrease. With regard to DC electrical conductivity, both the dopants exhibited an enhancement in H₂SO₄ medium but NSA a decline in HClO₄. Characterisation of the electrosynthesised polymer samples by various instrumental techniques (cyclic voltammetric: CV, FTIR, UV-Visible: UV-Vis, EPR, XRD, TGA and DTG methods) revealed that between the two acid media, H₂SO₄ was the better one. Further, it enlightened the role of two organic dopants in relation to the acid media. The advantageous role of NSA in H₂SO₄ had origin on its molecular characteristics such as non-polarity, larger π-electron cloud etc., while CSA could not perform such a role because of its easily oxidisable hydroxyl groups. In HClO₄, however, both the dopants could play only an unfavourable role owing to its greater polarity and oxidizing power than H₂SO₄.     

乙炔黑吸附聚合制导电聚苯胺

用乙炔黑吸附化学聚合新工艺制备导电聚苯胺，可保持电导率不变，但转化率和堆密度提高，并明显改善了聚苯胺的颗粒形态和制膜加工性，使由其制备的聚苯胺复合正极膜和固体聚苯胺锂蓄电池的电化学性能得以改进。