Precipitation and surface polymerizations of aniline at different aniline:oxidizer molar ratios

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Lucia Helena Mascaro ◽  
Débora Gonçalves
Keyword(s):  
Oxidative Polymerization ◽  
Reaction Times ◽  
Ammonium Persulfate ◽  
Open Circuit ◽  
Polymerization Process ◽  
Pani Film ◽  
Electrode Surfaces ◽  
Molar Ratios ◽  
Pt Electrodes ◽  
Vis Spectroscopy

AbstractThe oxidative polymerization of aniline was monitored by means of open-circuit potential (OCP) measurements of Pt electrodes immersed in an aqueous acidic medium containing different aniline:oxidizer (ammonium persulfate) molar ratios. Thin polyaniline (PANI) films were formed on the Pt electrode surfaces during the OCP measurements, and they were studied by SEM and cyclic voltammetry in a monomer-free solution at different reaction times. A precipitate also obtained during the polymerization process was analyzed by UV-VIS spectroscopy in 1-methyl-2-pyrrolidinone. It is observed that aniline or short oligomeric species are necessary to initiate the growth of a PANI film, which takes place at the first few minutes of the reaction.

scholarly journals Obtaining conductive composites of PANI and thermoplastic polymers

2019 ◽  
pp. 11-15
Author(s):  
Diana Nelly Contreras-Zarazúa ◽  
David Contreras-Lopéz ◽  
Rosalba Fuentes-Ramirez ◽  
Rosario Galindo-González
Keyword(s):  
Cyclic Voltammetry ◽  
Impedance Spectroscopy ◽  
Vinyl Acetate ◽  
Oxidative Polymerization ◽  
Ammonium Persulfate ◽  
Polymerization Process ◽  
Chemical Oxidative Polymerization ◽  
Thermoplastic Polymers ◽  
Conductive Composites ◽  
Polar Monomer

Currently, the polymers industry has gained increasing importance due to the versatility of its properties. In this work were synthesized copolymers of styrene with vinyl acetate at different concentrations through a process polymerization of suspension, which are the starting points for obtaining of composites with polyaniline synthesized PANI chemical oxidative polymerization process, used for doping HCl at a concentration of 1.5 M and ammonium persulfate 0.5 M in a mass radio of 1:1. The conductivity was evaluated by means of cyclic voltammetry and impedance spectroscopy, in order to determine the effect of the concentration of the polar monomer in the composite founded that increase concentration of polar comonomer the conductivity also too.

scholarly journals Synthesis of nanostructured conducting polyaniline in the presence of 5-sulfosalicylic acid

2008 ◽  
Vol 62 (3) ◽  
pp. 107-113 ◽  
Author(s):  
Aleksandra Janosevic ◽  
Gordana Ciric-Marjanovic
Keyword(s):  
Molecular Structure ◽  
Oxidative Polymerization ◽  
Average Diameter ◽  
Polymerization Process ◽  
Molar Ratio ◽  
Sulfosalicylic Acid ◽  
Molar Ratios ◽  
Reaction Solution ◽  
Initial Ph ◽  
Constant Molar Ratio

Oxidative polymerizations of aniline with ammonium peroxydisulfate in aqueous solution of 5-sulfosalicylic acid (SSA), were performed at the constant molar ratio [oxidant]/[monomer] = 1.25, by using various initial molar ratios of SSA to aniline. It was shown that the ratio [SSA]/[aniline] has a crucial influence on the molecular structure, morphology, and conductivity of synthesized polyaniline5-sulfosalicylate (PANI-SSA), as well as on the yield and temperature profile i.e. the mechanism of polymerization process. The yield of PANI-SSA was 80 - 86% for [SSA]/[aniline] ratios in the range 0.25-1.0. Granular PANI-SSA was obtained by the oxidative polymerization of in situ formed anilinium 5-sulfosalicylate ([SSA]/[aniline] = 1.0). The initial induction period was followed by the rapid exothermic polymerization of aniline during the oxidation of anilinium 5-sulfosalicylate with peroxydisulfate. Nanostructured PANI-SSA was synthesized by the oxidation of the mixture of dianilinium 5-sulfosalicylate and aniline ([SSA]/[aniline] = 0.25), which proceeds in two exothermic phases well separated with an athermal period. The presence of nanocylinders (nanorods, possibly nanotubes), with the average diameter of 95-250 nm and the length of 0.5-1.0 ?m has been revealed by scanning electron microscopy. It was concluded that PANI nanocylinders are formed when reaction solution has the initial pH > 3.5. Electroconductivity of synthesized polyanilines was in the range 0.01-0.17 S cm-1, and it increases with increasing molar ratio of SSA to aniline. Molecular structure of synthesized polyanilines was investigated by FTIR spectroscopy. Besides the characteristic bands of standard PANI in emeraldine form (benzenoid, quinonoid, and semiquinonoid units), the band attributable to substituted phenazine structural units was observed at -1415 cm-1 in the FTIR spectrum of nanostructured PANI-SSA sample.

Green synthesis of mixed metallic nanoparticles using room temperature self-assembly

2017 ◽  
Vol 13 (2) ◽  
pp. 4671-4677 ◽  
Author(s):  
A. M. Abdelghany ◽  
A.H. Oraby ◽  
Awatif A Hindi ◽  
Doaa M El-Nagar ◽  
Fathia S Alhakami
Keyword(s):  
Self Assembly ◽  
Metallic Nanoparticles ◽  
Room Temperature ◽  
Bimetallic Nanoparticles ◽  
Reduction Process ◽  
Nano Particles ◽  
Nano Structure ◽  
Small Shift ◽  
Molar Ratios ◽  
Vis Spectroscopy

Bimetallic nanoparticles of silver (Ag) and gold (Au) were synthesized at room temperature using Curcumin. Reduction process of silver and gold ions with different molar ratios leads to production of different nanostructures including alloys and core-shells. Produced nanoparticles were characterized simultaneously with FTIR, UV/vis. spectroscopy, transmission electron microscopy (TEM), and Energy-dispersive X-ray (EDAX). UV/vis. optical absorption spectra of as synthesized nanoparticles reveals presence of surface palsmon resonance (SPR) of both silver at (425 nm) and gold at (540 nm) with small shift and broadness of gold band after mixing with resucing and capping agent in natural extract which suggest presence of bimetallic nano structure (Au/Ag). FTIR and EDAX data approve the presence of bimetallic nano structure combined with curcumin extract. TEM micrographs shows that silver and gold can be synthesized separately in the form of nano particles using curcumin extract. Synthesis of gold nano particles in presence of silver effectively enhance and control formation of bi-metallic structure.

Synthesis and Characterization of Polyaniline Film

2011 ◽  
Vol 239-242 ◽  
pp. 1382-1385
Author(s):  
Na Xu ◽  
Xiao Dong Shen ◽  
Sheng Cui
Keyword(s):  
Ammonium Persulfate ◽  
Pani Film ◽  
Cyclic Voltammograms ◽  
Ultrasonic Dispersion ◽  
Switching Speed ◽  
Color Changes ◽  
Fast Switching ◽  
Ft Ir ◽  
The Relationship

The electrochromic PANI film was prepared by emulsion polymerization with dodecyl benzene sulphonic acid (DBSA) as dopant and ammonium persulfate (APS) as initiator. Ultrasonic dispersion was adopted in the polymerization. The electrochemical properties, the surface morphology and structure of the prepared PANI film was characterized by means of Fourier Transform infrared spectroscopy (FT-IR), cyclic voltammograms (CV) and field emission scanning electron microscope (FE-SEM), respectively. The relationship between the morphology and properties of PANI film was detailedly discussed. The PANI film exhibited an excellent electrochromism with reversible color changes form yellow to purple. The PANI film also had quite good reaction kinetics with fast switching speed, and the response time for oxidation and reduction were 65 ms and 66 ms, respectively.

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.

Structure-Property Relationship of Dodecylbenzenesulfonic Acid Doped Polyaniline

2013 ◽  
Vol 721 ◽  
pp. 199-205 ◽  
Author(s):  
Ying Liu ◽  
Qi Wen ◽  
Jia Li Guan ◽  
Shi Jie Zhao ◽  
Qi Xing Hu ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Ammonium Persulfate ◽  
Degree Of Crystallinity ◽  
Structure Property ◽  
X Ray Diffraction ◽  
Electrospinning Technique ◽  
Dodecylbenzenesulfonic Acid ◽  
Molar Ratios ◽  
Liquid Crystal Property ◽  
Relationship Of

Dodecylbenzenesulfonic acid (DBSA) doped polypanilines (PANIs) were chemically synthesized in different molar ratios of aniline (An) to ammonium persulfate (APS) and An to DBSA. The microstructures of these PANIs were investigated by means of scanning electron microscope (SEM), X-ray diffraction (XRD), and Fourier Transform Infrared (FTIR). UV-Vis spectrometer, semiconductor parameter analyzer, ubbelohde viscometer and electrospinning technique were used to characterize the optical, electrical properties, viscosity and solubility of these PANIs. The results show that the molar rations of An to APS and An to DBSA had strong effect on the microstructure, molecular weight, degree of crystallinity, optical property, solubility and conductivity of obtained DBSA doped PANI. With the increase of the molar ratios of An to APS and An to DBSA, the conductivities and molecular weight of DBSA doped PANIs decreased, while the degree of crystallinity and solubility of DBSA doped PANIs increased. The DBSA doped PANI could dissolve in dichloromethane or HFIP and could be fabricated short fibers by electrospinning. Moreover, the solution of DBSA doped PANIs in concentrated sulphuric acid showed liquid crystal property.

Preparation of Highly Conductive Polyaniline in Carbamide Aqueous Solution Using SnCl4 as Initiator

2012 ◽  
Vol 476-478 ◽  
pp. 2205-2208 ◽  
Author(s):  
Guan Nan Lin ◽  
Qun Yu ◽  
Wei Wang ◽  
Gui Bao Wang
Keyword(s):  
Aqueous Solution ◽  
Ammonium Persulfate ◽  
Conductivity Measurements ◽  
X Ray ◽  
New Class ◽  
Vis Spectroscopy ◽  
Polymerization System ◽  
Novel Method ◽  
Conductive Polyaniline ◽  
Hydrolysis Of

In this paper, we demonstrated a novel method for the preparation of highly conductive polyaniline (PANI) compounded with Sn(OH)4. We obtained the PANI directly in the oxidation polymerization system via simultaneous reaction of aniline (using ammonium persulfate, APS as oxidant) and SnCl4 in carbamide aqueous solution. The resulting PANI was compounded with Sn(OH)4 had been characterized by FTIR, UV-Vis spectroscopy, X-ray diffractometry, thermal analysis, scanning electron microscope and conductivity measurements, and the results showed that PANI was in well doped state due to the hydrolysis of APS and the complex between PANI and Sn(OH)4. We are sure this alkali-guided polymerization to obtain conductive PANI will lead to the preparation of a new class of PANI composites.

scholarly journals Síntesis regioespecífica y estudio electroquímico de dos derivados carboxílicos C60 solubles en agua

2021 ◽  
Author(s):  
Juan D. Villada ◽  
Álvaro Duarte-Ruiz ◽  
Manuel N. Chaur
Keyword(s):  
Cyclic Voltammetry ◽  
Liquid Chromatography ◽  
Electronic Properties ◽  
Reaction Times ◽  
C60 Fullerene ◽  
Reduction Processes ◽  
Vis Spectroscopy ◽  
Highperformance Liquid Chromatography ◽  
Electron Transfers ◽  
Reversible Reduction

We report a new methodology for the synthesis of two highly symmetric equatorial malonate hexaadducts of C60 fullerene. The synthetic methodology is based on a series of protection and deprotection steps that allow the preparation of a fullerene [60] functionalized with six symmetrical positioned malonate addends without using complicated and expensive separation techniques (highperformance liquid chromatography, HPLC) or long reaction times. This methodology allowed us to prepare the carboxylic adducts 6 (equatorial octacarboxylic tetraadduct of C60) and 8 (equatorial dodecacarboxylic hexakisadduct of C60). As far as we  now, compound 6 has not yet been reported. We also studied the electronic properties of the main compounds by UV-Vis spectroscopy and cyclic voltammetry (CV). The reported fullerene adducts exhibited several reversible reduction processes whose electron transfers are controlled by diffusion. 

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