scholarly journals Influence of Acidity and Oxidant Concentration on the Nanostructures and Electrochemical Performance of Polyaniline during Fast Microwave-Assisted Chemical Polymerization

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 310 ◽  
Author(s):  
Biwei Qiu ◽  
Jingyun Wang ◽  
Zhoujing Li ◽  
Xia Wang ◽  
Xiaoyan Li
Keyword(s):  
Electrical Conductivity ◽  
Electrochemical Performance ◽  
Oxidative Polymerization ◽  
Molecular Structures ◽  
Chain Growth ◽  
Acidic Solutions ◽  
Microwave Assisted ◽  
Oxidant Concentration ◽  
Weakly Acidic Solution ◽  
Hcl Concentration

Polyaniline (PANI), a typical conducting polymer, has attracted great interest as an electrode material. A series of PANIs were prepared through fast microwave-assisted chemical oxidative polymerization with varying HCl and APS concentrations here. It was found that the microwave synthesized PANIs had ~4 times higher for the yields and 7~10 times higher for the electrical conductivity in comparison to PANI samples prepared using conventional method. PANI nanosheets could easily be fabricated in weakly acidic solution due to their oligomeric structure, which contained flat phenazine rings. By contrast, linear PANI chains produced in highly acidic solutions formed nanofibers. The APS concentration did not significantly affect the molecular structures of PANIs under the conditions here. However, increasing the concentration of APS produced nanofibers with shorter branches, which may be due to secondary nucleation during chain growth resulting from increases in active initiation centers. The electrical conductivity and electrochemical performance of PANIs were both improved with increasing HCl and APS concentrations. Improvements due to increases in HCl concentration may be attributed to additions in conjugation length and enrichment of doping levels, while improvements due to increases in APS concentration could be attributed to the increased crystallinity of PANI, which facilitates ion transport.

Microwave Assisted Synthesis Polyaniline-Vanadium Oxide Nanocomposites and their Electrochemical Studies

2019 ◽  
Vol 4 (1-2) ◽  
pp. 14-17
Author(s):  
Sugam J. Shivhare ◽  
Praveen Kumar Loharkar ◽  
Supriya Vyas
Keyword(s):  
Electrical Conductivity ◽  
Vanadium Oxide ◽  
Oxidative Polymerization ◽  
Second Step ◽  
Microwave Assisted Synthesis ◽  
Electrochemical Studies ◽  
Microwave Assisted ◽  
Ftir Studies ◽  
Polymerization Method ◽  
Polyaniline Nanocomposite

In this article, we reported microwave assisted processing of vanadium oxide-polyaniline nanocomposite (PANI/V2O5). Firstly, polyaniline (PANI) is synthesized by oxidative polymerization method and vanadium pentoxide nanoparticles. In the second step, intercalation of PANI in V2O5 framework are carried out in the microwave at 80 ºC for 30 min in Teflon crucibles. The XRD exhibited a set of well-defined peak support the crystal nature of nanocomposites. FTIR studies of the composite supported the intercalation of PANI with V2O5. The peaks obtained by cyclic voltammetry shows marginal separation between anodic peaks at 3.6 and 3.7 V for polyaniline and shifted to the higher potential for PANI/V2O5 nanocomposite. Also, the electrical conductivity is found to be 10-6 S cm-1 for PANI and higher electrical conductivity, 10-4 S cm-1 for nanocomposites.

scholarly journals The Synthesis and Electrochemical Performance of Si Composite with Hollow Carbon Microtubes by the Carbonization of Milkweed from Nature as Anode Template for Lithium Ion Batteries

Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5124
Author(s):  
Eun Hyuk Chung ◽  
Jong Pil Kim ◽  
Hyun Gyu Kim ◽  
Jae-Min Chung ◽  
Sei-Jin Lee ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electrical Conductivity ◽  
Electrochemical Performance ◽  
Pore Size ◽  
Lithium Ion Batteries ◽  
Polyvinylidene Fluoride ◽  
Lithium Ion ◽  
Size Analysis ◽  
Pore Size Analysis ◽  
Hollow Carbon

It has been reported that improving electrical conductivity and maintaining stable structure during discharge/charge process are challenge for Si to be used as an anode for lithium ion batteries (LIB). To address this problem, milkweed (MW) was carbonized to prepare hollow carbon microtubes (HCMT) derived from biomass as an anode template for LIB. In order to improve electrical conductivity, various materials such as chitosan (CTS), agarose, and polyvinylidene fluoride (PVDF) are used as carbon source (C1, C2, and C3) by carbonization. Carbon coated HCMT@Si composits, HCMT@Si@C1, HCMT@Si@C1@C2, and HCMT@Si@C1@C3, have been successfully synthesized. Changes in structure and crystallinity of HCMT@Si composites were characterized by using X-ray diffraction (XRD). Specific surface area for samples was calculated by using BET (Brunauer–Emmett–Teller). Also, pore size and particle size were obtained by particle and pore size analysis system. The surface morphology was evaluated using high resolution scanning electron microscopy (HR-SEM), Field Emission transmission electron microscopy (TEM). The thermal properties of HCMT@Si composites were analyzed by thermogravimetric analysis (TGA). Our research was performed to study the synthesis and electrochemical performance of Si composite with HCMT by the carbonization of natural micro hollow milkweed to form an inner space. After carbonization at 900 °C for 2 h in N2 flow, inner diameter of HCMT obtained was about 10 μm. The electrochemical tests indicate that HCMT@Si@C1@C3 exhibits discharge capacity of 932.18 mAh/g at 0.5 A/g after 100 cycles.

Oxidative Polymerization of 3-Amino,2'-,(3')–Nitrodiphenylazomethin

2018 ◽  
Vol 935 ◽  
pp. 134-139 ◽  
Author(s):  
Timur A. Borukaev ◽  
A.Kh. Malamatov ◽  
M.K. Vindizheva ◽  
A.V. Orlov ◽  
S.G. Kiseleva
Keyword(s):  
Thermal Stability ◽  
Thermal Properties ◽  
Chemical Structure ◽  
Oxidative Polymerization ◽  
Polymerization Process ◽  
Chain Growth ◽  
Polymer Product ◽  
Two Stages

Oxidative polymerization of 3-amino,2'-,(3')-nitrodiphenylazomethine was carried out in various ways. A possible mechanism for the polymerization of 3-amino,2'-,(3')- nitrodiphenylazomethine, where chain growth occurs as type N-C, is shown. It has been found that the yield of the polymer product is affected by the polymerization process and time. The chemical structure of the polymers obtained is established. The study of the thermal properties of polymers showed a low thermal stability and the process of destruction proceeds in two stages.

scholarly journals Preparation and Thermoelectric Properties of Graphite/poly(3,4-ethyenedioxythiophene) Nanocomposites

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2849 ◽  
Author(s):  
Yong Du ◽  
Haixia Li ◽  
Xuechen Jia ◽  
Yunchen Dou ◽  
Jiayue Xu ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
Oxidative Polymerization ◽  
Polymerization Process ◽  
Measurement Temperature ◽  
Temperature Range ◽  
Different Content

Graphite/poly(3,4-ethyenedioxythiophene) (PEDOT) nanocomposites were prepared by an in-situ oxidative polymerization process. The electrical conductivity and Seebeck coefficient of the graphite/PEDOT nanocomposites with different content of graphite were measured in the temperature range from 300 K to 380 K. The results show that as the content of graphite increased from 0 to 37.2 wt %, the electrical conductivity of the nanocomposites increased sharply from 3.6 S/cm to 80.1 S/cm, while the Seebeck coefficient kept almost the same value (in the range between 12.0 μV/K to 15.1 μV/K) at 300 K, which lead to an increased power factor. The Seebeck coefficient of the nanocomposites increased from 300 K to 380 K, while the electrical conductivity did not substantially depend on the measurement temperature. As a result, a power factor of 3.2 μWm−1 K−2 at 380 K was obtained for the nanocomposites with 37.2 wt % graphite.

Bifunctional iron disulfide nanoellipsoids for high energy density supercapacitor and electrocatalytic oxygen evolution applications

2019 ◽  
Vol 6 (3) ◽  
pp. 659-670 ◽  
Author(s):  
Zhiqin Sun ◽  
Xue Yang ◽  
Huiming Lin ◽  
Feng Zhang ◽  
Qian Wang ◽  
...  
Keyword(s):  
Energy Density ◽  
Electrochemical Performance ◽  
Oxygen Evolution ◽  
High Energy ◽  
High Energy Density ◽  
Microwave Assisted ◽  
Iron Disulfide ◽  
Excellent Electrochemical Performance ◽  
Microwave Assisted Method

FeS2, prepared using a rapid microwave assisted method, exhibits excellent electrochemical performance for supercapacitor and OER applications.

DC electrical conductivity retention and antibacterial aspects of microwave-assisted ultrathin CuO@polyaniline composite

2020 ◽  
Vol 74 (11) ◽  
pp. 3887-3898 ◽  
Author(s):  
Mohammad Omaish Ansari ◽  
Mohammad Oves ◽  
Numan Salah ◽  
Mohammad Asad ◽  
Rajeev Kumar ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Microwave Assisted ◽  
Dc Electrical Conductivity ◽  
Conductivity Retention

Introduction of Fe2+ in Fe0.8Ti1.2O40.8− nanosheets via photo reduction and their enhanced electrochemical performance as a lithium ion battery anode

2019 ◽  
Vol 55 (2) ◽  
pp. 186-189 ◽  
Author(s):  
Xingang Kong ◽  
Xing Wang ◽  
Dingying Ma ◽  
Jianfeng Huang ◽  
Jiayin Li ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Electrochemical Performance ◽  
Lithium Ion Battery ◽  
Lithium Ion ◽  
Enhanced Electrochemical Performance ◽  
Battery Anode

Fe2+ doped Fe0.8Ti1.2O40.8− nanosheets were prepared via delaminating H0.8Fe0.8Ti1.2O4 precursor and further photo reduction. It shows improved electrochemical performance due to the enhanced electrical conductivity by the introduction of Fe2+.

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