scholarly journals Humidity Sensing Properties of Surface Modified Polyaniline Metal Oxide Composites

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
S. C. Nagaraju ◽  
Aashis S. Roy ◽  
J. B. Prasanna Kumar ◽  
Koppalkar R. Anilkumar ◽  
G. Ramagopal

Polyaniline- (PANI) praseodymium Oxide (Pr2O3) composites have been synthesized by in situ polymerization method with different weight percentages. The synthesized composites have been characterized by Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy. The temperature dependent conductivity shows that the conductivity is due to the hopping of polarons and bipolarons. These composites show negative thermal coefficient (α) behavior as a function of temperature, which is characteristic behavior of semiconducting materials. Sensor studies have been carried out by two-probe method and found that the sensitivity increases with increase in % RH. It is noticed that stability increase is due to the presence of Pr2O3in polyaniline up to 30 wt%. A fast recovery and response time along with high sensitivity make these composites suitable for humidity sensors.

Sensor Review ◽  
2015 ◽  
Vol 35 (4) ◽  
pp. 366-373 ◽  
Author(s):  
Omar Alhartomy

Purpose – The aim of this study is to investigate the humidity-sensing of polyaniline–zinc oxide (PANI–ZnO) nanocomposites. Humidity sensor has wide applications in drug industries, food industries and domestic purpose to regulate the humidity level. Design/methodology/approach – PANI–ZnO composites were prepared by in situ polymerization method, and further humidity response was tested by using a two-probe sensor setup. Findings – PANI-ZnO composites surface were modified by using camphor sulphonic acid. DC conductivity is due to the hopping of polorans. Thermal coefficient value varies from 1.7 to 2.3. The 30 weight per cent composite shows high sensitivity among other composites. Research limitations/implications – These composites can be used only at room temperature or moderate temperature, i.e. below 280°C. Practical implications – The composites are prepared in tetrapod shape that has a large surface area and more stability. Therefore, these materials would be the replacement for conventional materials. Social implications – These sensors have many applications in food and drug preservation, domestic purposes, etc. Originality/value – This work is original, and not being considered for publication elsewhere. In this work, the charge transport properties were evaluated based on the resistivity change when samples were exposed to humidity.


2017 ◽  
Vol 52 (1) ◽  
pp. 17-25 ◽  
Author(s):  
Ahmad Mohaddespour ◽  
Seyed J Ahmadi ◽  
Hossein Abolghassemi ◽  
Seyed M Mahjoub ◽  
Saeid Atashrouz

The effect of electron beam irradiation on pristine poly(vinyl ester) and cured poly(vinyl ester)/clay nanocomposite with different clay contents is studied at irradiation doses ranging from 100 to 1000 kGy at room temperature. Poly(vinyl ester)/clay nanocomposites were prepared with different amounts of organically modified montmorillonite (1, 3, and 5 wt.%) by in situ polymerization method. Morphology properties of synthesized nanocomposites were studied by X-ray diffraction and transition electron microscopy. The irradiation dose up to 500 kGy yields an increase in Young’s modulus and tensile strength of nanocomposites while further irradiation deteriorates the mechanical strength of samples. Irradiation has no considerable influence on the surface hardness of synthesized nanocomposites. Thermogravimetric analysis results reveal the thermal stability of poly(vinyl ester), and its nanocomposites is improved with irradiation up to 500 kGy. However, similar to mechanical perdition at 1000 kGy irradiation, thermal resistance of nanocomposites decreases. The enhancement in mechanical and thermal properties of synthesized nanocomposites is attributed to the cross-linking effect as bonds can be formed directly between the neighbouring chains.


2014 ◽  
Vol 904 ◽  
pp. 7-9
Author(s):  
Xiao Hua Gu ◽  
Xi Wei Zhang ◽  
Bao Yun Xu ◽  
Peng Zeng

In this paper, the diphenyl methane diisocyanate (MDI) was used to modify montmorillonoid (MMT) and got the organic montmorillonite (OMMT), which was used with the monomers of PET by in situ polymerization method to prepare PET/MMT nanocomposition. The OMMT was analyzed by the X ray diffraction (XRD) to test the change of the spacing layer. Dispersion of MMT in the PET/MMT nanocomposites were studied with XRD and SEM and by means of thermogravimetric analyzer (TGA) on the thermal stability of PET/MMT nanocomposites. The results showed that, MDI modified MMT successfully, and the compatibility of MMT and PET was increased .


2020 ◽  
Vol 855 ◽  
pp. 308-314
Author(s):  
Nadiya Miftachul Chusna ◽  
Sunaryono ◽  
Yunan Amza Muhammad ◽  
Rosabiela Irfa Andin ◽  
Ahmad Taufiq

The Fe2.75Mn0.25O4 nanoparticles were successfully synthesized by using the coprecipitation method, while the Fe2.75Mn0.25O4@PANI materials were successfully fabricated by using the in situ polymerization method. This research aimed to investigate the magnetic properties and nanostructure of the Fe2.75Mn0.25O4 nanoparticles and Fe2.75Mn0.25O4@PANI materials. Some characterizations of the samples were successfully carried out by using X-Ray Diffraction (XRD) instruments, Fourier Transform Infrared (FTIR), and Vibrating Sample Magnetometer (VSM) each of which was conducted to characterize the crystal structure, functional groups, morphology, and the magnetic properties of the materials. The XRD analysis results showed that the Fe2.75Mn0.25O4@PANI materials had a crystal size of 8.09 nm. Meanwhile, the FTIR spectrum represented vibrations due to the atomic bonds that made up the Fe2.75Mn0.25O4@PANI materials. Furthermore, the hysteresis curve from the VSM characterization results showed that the Fe2.75Mn0.25O4@PANI material saturation magnetization value was around 2.85 emus/g. From those characterization results, the Fe2.75Mn0.25O4@PANI materials are very potential to be applied as magnetic ink


2011 ◽  
Vol 343-344 ◽  
pp. 11-15
Author(s):  
Fan Hu ◽  
Zu Xun Xu ◽  
Bing Hai Dong ◽  
Li Wan ◽  
Xiu Hua Zhang ◽  
...  

The Polyaniline-poly(vinyl alcohol)-intercalated graphite oxide (GO) composites were synthesized through in-situ polymerization methods. The characterizations were illuminated by using X-ray diffraction (XRD), scanning electron microscopy (SEM), cyclic voltammetry(CV) and thermal analysis(TGA), respectively. TGA shows that composites have stable thermal properties. CV curves show charge-transport processes within the film are diffusion-controlled. The new composites reveal the potential application in the future.


2013 ◽  
Vol 724-725 ◽  
pp. 844-847
Author(s):  
Ying Jiang ◽  
Fu Xin Zhong ◽  
Zhong Yuan Cheng ◽  
Peng Fei Yu ◽  
Yun Xia Jin ◽  
...  

The LiFePO4/C cathode material was synthesized by two–step addition of dual carbon sources method based on the in situ polymerization method combining with two–step sintering process. In this study, the structure and morphology have been studied systematically by X–ray diffraction (XRD) and scanning electron microscope (SEM).The electrochemical performances have been shown by the charge/discharge capacity, rate property, cycle performance. It was evidenced that the two–step addition of dual carbon sources had remarkable advantages, including the more complete coating carbon, and the improvement in the electrochemical performance of LiFePO4/C.


Author(s):  
Hemalatha Parangusan ◽  
Jolly Bhadra ◽  
Zubair Ahmad ◽  
Shoaib Mallick ◽  
Farid Touati ◽  
...  

In this letter, we report the structural, morphological and CO2 gas sensing properties of the polyaniline (PANI) coated Cu-ZnS microspheres. PANI coated Cu-ZnS microspheres were prepared by hydrothermal and in-situ polymerization method. X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and transmission electron microscope (TEM) were used to investigate the structural and morphological properties. The fabricated sensor based on PANI coated Cu-ZnS microspheres exhibits good CO2 sensing performance with rapid response (31 s) and recovery (23 s) times.


Author(s):  
SS Rana ◽  
MK Gupta

The present study aims to fabricate the epoxy-based bionanocomposites reinforced with hemp nanocellulose and the evaluation of their mechanical, thermal and dynamic mechanical properties. Nanocellulose from hemp fibres was isolated via the chemo-mechanical method and its bionanocomposites were prepared using the in situ polymerization method. Although many researchers have reported studies on the preparation and characterization of bionanocomposites however, studies on the mechanical, thermal, and dynamic mechanical properties of epoxy-based bionanocomposites reinforced with hemp nanocellulose are still unreported. The mechanical properties (i.e. tensile, flexural, hardness, and impact) and dynamic mechanical properties (i.e. glass transition temperature, damping behaviour, storage, and loss modulus) of the developed bionanocomposites were investigated. Further, the crystalline behaviour and thermal stability were also studied using the X-ray diffraction and thermogravimetric analysis techniques, respectively. The results revealed that an addition of nanocellulose considerably improved the mechanical, thermal, and viscoelastic properties of the bionanocomposites. As much as 52.17%, 48.17%, 89.08%, and 15.67% improvements in the tensile strength, flexural strength, impact strength, and hardness, respectively, for the 2 wt.% nanocellulose composites were found over the epoxy matrix.


2014 ◽  
Vol 1015 ◽  
pp. 381-384
Author(s):  
Li Liu ◽  
Li Hai Cai ◽  
Dan Liu ◽  
Jun Xu ◽  
Bao Hua Guo

The poly (butylene succinate) (PBS) and 3 wt% attapulgite (ATP) reinforced PBS/ATP nanocomposites with 1,6-hexanediol were fabricated using an in situ polymerization method. The crystallization behaviors indicated that ATP had effectively acted as nucleating agent, resulting in the enhancement on the crystallization temperature. The SEM results showed a superior interfacial linkage between ATP and PBS. Also, ATP could disperse as a single fiber and embed in the polymer matrix, which resulted in the improved mechanical properties.


2019 ◽  
Vol 361 ◽  
pp. 897-907 ◽  
Author(s):  
Jingchun Lv ◽  
Peiwen Zhou ◽  
Linping Zhang ◽  
Yi Zhong ◽  
Xiaofeng Sui ◽  
...  

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