Oxidative Polymerization of Polyaniline (PANI) Colloids with Different Oxidizing Agents

<div><div><div><p>Eumelanins are a family of natural and synthetic pigments obtained by oxidative polymerization of their natural precursors: 5,6 dihydroxyindole and its 2-carboxy derivative (DHICA). The simultaneous presence of ionic and electronic charge carriers makes these pigments promising materials for applications in bioelectronics. In this computational study we build a structural model of DHICA melanin considering the interplay between its many degrees of freedom, then we examine the electronic structure of representative oligomers. We find that a non-vanishing dipole along the polymer chain sets this system apart from conventional polymer semiconductors, determining its electronic structure, reactivity toward oxidation and localization of the charge carriers. Our work sheds light on previously unnoticed features of DHICA melanin that not only fit well with its radical scavenging and photoprotective properties, but open new perspectives towards understanding and tuning charge transport in this class of materials.<br></p></div></div></div>

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Fabrication of Conductive Textile via Chemical Oxidative Polymerization of Aniline on Polyester Cloth

10.26434/chemrxiv.6154757.v1 ◽

2018 ◽

Author(s):

alireza razaghi

Keyword(s):

Acidic Solution ◽

Oxidative Polymerization ◽

Morphological Structure ◽

Infrared Spectrometry ◽

Aniline Monomer ◽

Polyester Textile ◽

Conductive Polyaniline ◽

Conductive Textile ◽

Polymerization Conditions ◽

Aniline Polymerization

In this research aniline polymerization conditions were optimized in presence of pre-treated polyester textile to achieve as high electrical conductivity as 100 S/Cm. Alkaline activation of the polyester textile was followed by immersion in to aqueous acidic solution of aniline monomer. Then the oxidant solution was used to initiate the polymerization. Finally, the prepared product was washed and dried prior to ant test. Functional groups were studied by Fourie-transformed infrared spectrometry (FTIR) from the surface of the polyaniline coated textile. Also, morphological structure of synthesized conductive polyaniline was studied by scanning electron microscopy (SEM). The synthesized cloth was used in a closed circuit in order to light up alight emitting diode to emphasis the conductivity of the textile and fibres that synthesised by this method.

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Fabrication of Conductive Textile via Chemical Oxidative Polymerization of Aniline on Polyester Cloth

10.26434/chemrxiv.6154757 ◽

2018 ◽

Author(s):

alireza razaghi

Keyword(s):

Acidic Solution ◽

Oxidative Polymerization ◽

Morphological Structure ◽

Infrared Spectrometry ◽

Aniline Monomer ◽

Polyester Textile ◽

Conductive Polyaniline ◽

Conductive Textile ◽

Polymerization Conditions ◽

Aniline Polymerization

In this research aniline polymerization conditions were optimized in presence of pre-treated polyester textile to achieve as high electrical conductivity as 100 S/Cm. Alkaline activation of the polyester textile was followed by immersion in to aqueous acidic solution of aniline monomer. Then the oxidant solution was used to initiate the polymerization. Finally, the prepared product was washed and dried prior to ant test. Functional groups were studied by Fourie-transformed infrared spectrometry (FTIR) from the surface of the polyaniline coated textile. Also, morphological structure of synthesized conductive polyaniline was studied by scanning electron microscopy (SEM). The synthesized cloth was used in a closed circuit in order to light up alight emitting diode to emphasis the conductivity of the textile and fibres that synthesised by this method.

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Sterically Crowded Heterocycles. III. A General Approach to Imidazo[1,2-a]pyridines by Ferricyanide Oxidation of Quaternary Pyridinium Salts

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19960126 ◽

1996 ◽

Vol 61 (1) ◽

pp. 126-138 ◽

Cited By ~ 6

Author(s):

Richard Kubík ◽

Stanislav Böhm ◽

Iveta Ruppertová ◽

Josef Kuthan

Keyword(s):

Potassium Hydroxide ◽

Potassium Ferricyanide ◽

Pyridinium Salts ◽

Oxidizing Agents ◽

Quaternary Pyridinium Salts ◽

Substituted 1

Substituted 1-(pyridin-2-yl)-2,4,6-triphenylpyridinium perchlorates 1b-1e were converted with potassium ferricyanide and potassium hydroxide to sterically crowded 2-phenyl-3-[(Z)-1,3-diphenyl-3-oxopropenyl]imidazo[1,2-a]pyridines 2b-2e accompanied by minor isomeric 2-benzoyl-3,5-diphenyl-1-(pyridin-2-yl)pyrroles 3c-3e. 4-Phenyl-2,6-di(4-substituted phenyl)-1-(pyridin-2-yl)pyridinium salts 4a, 4b gave exclusively corresponding imidazo[1,2-a]pyridines 5a, 5b while the ferricyanide oxidation of 1-(5-iodo- and 5-cyanopyridin-2-yl)-2,4,6-triphenylpyridinium perchlorates 6a, 6b led to mixtures of major imidazo[1,2-a]pyridines 7a-7c and minor pyrroles 8a-8c. Some mechanistic aspects of the oxidation procedure are discussed in connection with a resistance of 2,6-diphenyl-1,3,5-trimethylpyridinium perchlorate (9c) towards the oxidizing agents.

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Preparation and Gas Sensing Properties of PANI/SnO2 Hybrid Material

Polymers ◽

10.3390/polym13091360 ◽

2021 ◽

Vol 13 (9) ◽

pp. 1360

Author(s):

Qiaohua Feng ◽

Huanhuan Zhang ◽

Yunbo Shi ◽

Xiaoyu Yu ◽

Guangdong Lan

Keyword(s):

Hybrid Material ◽

Room Temperature ◽

Tin Dioxide ◽

Gas Adsorption ◽

Gas Sensing ◽

Oxidative Polymerization ◽

Environmental Pollutants ◽

Decomposition Temperature ◽

Benzene Vapor ◽

Thermo Gravimetric Analyzer

A sensor operating at room temperature has low power consumption and is beneficial for the detection of environmental pollutants such as ammonia and benzene vapor. In this study, polyaniline (PANI) is made from aniline under acidic conditions by chemical oxidative polymerization and doped with tin dioxide (SnO2) at a specific percentage. The PANI/SnO2 hybrid material obtained is then ground at room temperature. The results of scanning electron microscopy show that the prepared powder comprises nanoscale particles and has good dispersibility, which is conducive to gas adsorption. The thermal decomposition temperature of the powder and its stability are measured using a differential thermo gravimetric analyzer. At 20 °C, the ammonia gas and benzene vapor gas sensing of the PANI/SnO2 hybrid material was tested at concentrations of between 1 and 7 ppm of ammonia and between 0.4 and 90 ppm of benzene vapor. The tests show that the response sensitivities to ammonia and benzene vapor are essentially linear. The sensing mechanisms of the PANI/SnO2 hybrid material to ammonia and benzene vapors were analyzed. The results demonstrate that doped SnO2 significantly affects the sensitivity, response time, and recovery time of the PANI material.

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NIR responsive tumor vaccine in situ for photothermal ablation and chemotherapy to trigger robust antitumor immune responses

Journal of Nanobiotechnology ◽

10.1186/s12951-021-00880-x ◽

2021 ◽

Vol 19 (1) ◽

Author(s):

Lirong Zhang ◽

Jingjing Zhang ◽

Lixia Xu ◽

Zijian Zhuang ◽

Jingjin Liu ◽

...

Keyword(s):

Immune Responses ◽

Tumor Vaccine ◽

Oxidative Polymerization ◽

Delivery Mode ◽

Tumor Treatment ◽

One Pot ◽

Photothermal Ablation ◽

Prolonged Retention ◽

The One

Abstract Background Therapeutic tumor vaccine (TTV) that induces tumor-specific immunity has enormous potentials in tumor treatment, but high heterogeneity and poor immunogenicity of tumor seriously impair its clinical efficacy. Herein, a novel NIR responsive tumor vaccine in situ (HA-PDA@IQ/DOX HG) was prepared by integrating hyaluronic acid functionalized polydopamine nanoparticles (HA-PDA NPs) with immune adjuvants (Imiquimod, IQ) and doxorubicin (DOX) into thermal-sensitive hydrogel. Results HA-PDA@IQ NPs with high photothermal conversion efficiency (41.2%) and T1-relaxation efficiency were using HA as stabilizer by the one-pot oxidative polymerization. Then, HA-PDA@IQ loaded DOX via π-π stacking and mixed with thermal-sensitive hydrogel to form the HA-PDA@IQ/DOX HG. The hydrogel-confined delivery mode endowed HA-PDA@IQ/DOX NPs with multiple photothermal ablation performance once injection upon NIR irradiation due to the prolonged retention in tumor site. More importantly, this mode enabled HA-PDA@IQ/DOX NPs to promote the DC maturation, memory T cells in lymphatic node as well as cytotoxic T lymphocytes in spleen. Conclusion Taken together, the HA-PDA@IQ/DOX HG could be served as a theranostic tumor vaccine for complete photothermal ablation to trigger robust antitumor immune responses.

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Role of the Anilinium Ion on the Selective Polymerization of Anilinium 2-Acrylamide-2-methyl-1-propanesulfonate

Polymers ◽

10.3390/polym13142349 ◽

2021 ◽

Vol 13 (14) ◽

pp. 2349

Author(s):

Alain Salvador Conejo-Dávila ◽

Marco Armando Moya-Quevedo ◽

David Chávez-Flores ◽

Alejandro Vega-Rios ◽

Erasto Armando Zaragoza-Contreras

Keyword(s):

Cyclic Voltammetry ◽

Optical Properties ◽

Thermal Properties ◽

Free Radical ◽

1H Nmr ◽

Molecular Interactions ◽

13C Nmr ◽

Oxidative Polymerization ◽

Cyclic Voltammetry Analysis

The development of anilinium 2-acrylamide-2-methyl-1-propanesulfonate (Ani-AMPS) monomer, confirmed by 1H NMR, 13C NMR, and FTIR, is systematically studied. Ani-AMPS contains two polymerizable functional groups, so it was submitted to selective polymerization either by free-radical or oxidative polymerization. Therefore, poly(anilinium 2-acrylamide-2-methyl-1-propanesulfonic) [Poly(Ani-AMPS)] and polyaniline doped with 2-acrylamide-2-methyl-1-propanesulfonic acid [PAni-AMPS] can be obtained. First, the acrylamide polymer, poly(Ani-AMPS), favored the π-stacking of the anilinium group produced by the inter- and intra-molecular interactions and was studied utilizing 1H NMR, 13C NMR, FTIR, and UV-Vis-NIR. Furthermore, poly(Ani-AMPS) fluorescence shows quenching in the presence of Fe2+ and Fe3+ in the emission spectrum at 347 nm. In contrast, the typical behavior of polyaniline is observed in the cyclic voltammetry analysis for PAni-AMPS. The optical properties also show a significant change at pH 4.4. The PAni-AMPS structure was corroborated through FTIR, while the thermal properties and morphology were analyzed utilizing TGA, DSC (except PAni-AMPS), and FESEM.

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