Formation and properties of nano- and micro-structured conducting polymer host–guest composites

Pud, A. A.; Noskov, Yu. V.; Ogurtsov, N.A.; Dimitriev, Oleg P.; Piryatinskiĭ, Yu. P.; Osipyonok, N.M.; Смертенко, П. С.; Kassiba, A.; Fatyeyeva, Kateryna; Шаповал, Г. С.

doi:10.1016/j.synthmet.2009.08.043

Cited by 9 publications

(20 citation statements)

References 48 publications

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“…The character of potential variation in acid medium strongly differs from that observed in alkaline medium [43,44,[56][57][58]. In acid medium the initial stage is accompanied by increase of the oxidation potential, which corresponds to accumulation of phenazine units.…”

Section: Polymerization Initiation Centermentioning

confidence: 79%

“…Reaction of oligomer with monomer leads to chain growth, and the degree of polymerization may attain several tens. As shown in [43,44], the oxidation of aniline with persulfate in alkaline medium is accompanied by monotonic reduction of the open circuit potential, which suggests reduction of the oxidation potential of the products.…”

mentioning

confidence: 89%

“…The presence of buffering agents capable of binding protons also affects pH in the oxidation process. A reaction started at pH 10 may be complete at pH 1 [32][33][34][40][41][42][43]. Variation of pH is accompanied by change of redox potentials of the reactants and hence of reaction mechanism and nature and morphology of oxidation products.…”

mentioning

confidence: 99%

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Oxidation of aniline with strong and weak oxidants

Sapurina

Stejskal

2012

Russ J Gen Chem

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Oxidative polymerization of aniline by the action of a strong oxidant, ammonium peroxodisulfate, and a weak oxidant, silver nitrate, was studied in media with different acidities. Depending on the reaction conditions, the organic fraction of the products contained either nonconducting aniline oligomers or conducting high-molecular polyaniline. The effect of the oxidation potential on the oxidation process and formation of supramolecular structures by oxidation products was discussed on the basis of analysis of the kinetics and products of aniline oxidation by spectroscopic, conductometric, thermogravimetric, chromatographic (gel permeation), and electron microscopic methods. A relation was revealed between the morphology of composite materials and their electric conductivity.Oxidation of aniline gives rise to numerous useful products such as drugs, dyes, explosives, and polymeric materials. Polyaniline (PANI) obtained by oxidative polymerization of aniline is among the most widely known representatives of conducting polymers. Polyaniline has found practical applications due to its redox and acid-base properties, high thermal stability, and electric conductivity. It is used in energy-saving devices and sensors, for electromagnetic shielding, and for the preparation of antistatic and conducting coatings; it also acts as corrosion inhibitor. Polyaniline possesses a high potential for use in medicine and heterogeneous catalysis [1].Polyaniline is synthesized by oxidation of aniline in aqueous or aqueous-organic medium. Polymerization of aniline is a chain process, i.e., monomer units are successively appended to a polymer chain bearing an active terminal group. Wei [2] considered aniline polymerization to be a specific reactivated chain process. Chain propagation involves repeated activation-deactivation acts which imply oxidation-reduction. Inactive polymer chain is activated by the action of oxidant, but the subsequent reaction with monomer leads to reversible reduction and deactivation. During the reduction process, polymer chain extends due to addition of monomeric unit, and two protons are released thereby.Oxidation of aniline in acid medium gives regular polymer chains containing more than 95% of parasubstituted units connected in a head-to-tail mode [3]. Regular structure determines polyconjugation and a unique set of properties intrinsic to polyaniline, in particular high electronic and proton conductivity, redox power, and paramagnetism [1]. Unlike other kinds of chain polymerization, e.g., radical polymerization where oxidant participates only in chain initiation, oxidative polymerization requires a large amount of oxidant [4] which is consumed for each act of addition of monomer unit. Therefore, molar concentration of oxidant should be comparable with the monomer concentration. Here, oxidant operates throughout the entire process until addition of the last monomer portion to polymer chain.Polymerization of aniline can be performed by electrochemical or chemical methods with the use of various oxidants. In ...

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Section: Polymerization Initiation Centermentioning

confidence: 79%

mentioning

confidence: 89%

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Oxidation of aniline with strong and weak oxidants

Sapurina

Stejskal

2012

Russ J Gen Chem

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“…In order to find a way to realize such control, we monitored changes of the open circuit potential (OCP) and pH of the reaction media in the course of oxidative polymerization of aniline and heterocyclic monomers in absence and presence of other components. This approach enabled tracking changes in oxidation states of the conducting polymers forming the shells at the surface of the matrix (template) components [10][11][12]. Specifically, OCP and pH profiles for aniline polymerization can reveal characteristic time points corresponding to the most important stages of this process.…”

Section: Physical-chemical Aspects Of the Nanocomposites Formationmentioning

confidence: 99%

“…In general, polymerization proceeds through two main steps: 1) adsorption of the monomer on the surface of nanoparticles dispersed in the reaction medium, and 2) its activation under the action of a suitable oxidant [7][8][9][10]. This process is completed with formation of hybrid particles with the ICP shell and core composed by another component.…”

Section: Introductionmentioning

confidence: 99%

On the importance of interface interactions in core-shell nanocomposites of intrinsically conducting polymers

Pud¹

2019

Semicond. phys. quantum electr. optoelectron

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In this mini-review, we address the importance of specific interactions in coreshell structures composed with intrinsically conducting polymers (ICPs) as a shell and various nanoparticles used as a core. These interactions that can appear during the polymerization process of corresponding monomers or in the course of subsequent treatments of already formed core-shell nanocomposites play a crucial role in determining their structure and unique physical properties. They also lead to significant differences in molecular weight, structure, oxidation state, electronic properties, thermal stability and other properties of synthesized ICP shells in comparison to their pure state when polymerization proceeds without a template. This work was reported on the joint Ukrainian-Japan workshop in the V. Lashkaryov Institute of Semiconductor Physics, NAS of Ukraine on 23rd December 2018.

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