Ammonium Peroxydisulfate

2010 ◽  
Vol 64 (1) ◽  
Author(s):  
Elena Konyushenko ◽  
Miroslava Trchová ◽  
Jaroslav Stejskal ◽  
Irina Sapurina

AbstractConditions of polyaniline (PANI) nanotubes preparation were analyzed. Aniline was oxidized with ammonium peroxydisulfate in 0.4 M acetic acid. There are two subsequent oxidation steps and the products were collected after each of them. At pH > 3, neutral aniline molecules are oxidized to non-conducting aniline oligomers. These produce templates for the subsequent growth of PANI nanotubes, which takes place preferably at pH 2–3. At pH < 2, granular morphology of the conducting PANI is obtained. High final acidity of the medium should be avoided in the preparation of nanotubes, e.g., by reducing the amount of sulfuric acid which is a by-product. Reduction of the peroxydisulfate-to-aniline mole ratio was tested for this purpose in the present study. Lowering of the reaction temperature from 20°C to −4°C had a positive effect on the formation of nanotubes.


1980 ◽  
Vol 2 (3) ◽  
pp. 331-337
Author(s):  
Hiroshi NODA ◽  
Masao MlNEMOTO ◽  
Makoto NISHIKAWA ◽  
Masatomo HAMANA

2005 ◽  
Vol 77 (5) ◽  
pp. 815-826 ◽  
Author(s):  
Jaroslav Stejskal ◽  
Irina Sapurina

Several workers from various institutions in six countries have prepared thin films and colloidal polyaniline dispersions. The films were produced in situ on glass supports during the oxidation of anilinium chloride with ammonium peroxydisulfate in water. The average thickness of the films, assessed by optical absorption, was 125 ± 9 nm, and the conductivity of films was 2.6 ± 0.7 S cm–1. Films prepared in 1 mol l–1 HCl had a similar thickness, 109 ± 10 nm, but a higher conductivity, 18.8 ± 7.1 S cm–1. Colloidal polyaniline particles stabilized with a water-soluble polymer, poly(N-vinylpyrrolidone) [poly(1-vinylpyrrolidin-2-one)], have been prepared by dispersion polymerization. The average particle size, 241 ± 50 nm, and polydispersity, 0.26 ± 0.12, have been determined by dynamic light scattering. The preparation of these two supramolecular polyaniline forms was found to be well reproducible.


2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Jiufang Duan ◽  
Jianxin Jiang ◽  
Jianzhang Li ◽  
Liujun Liu ◽  
Yiqiang Li ◽  
...  

Molecules that associate to form cross-links by hydrophobic association are designed and synthesised. Hydrogels, based on cellulose nanowhiskers (CNWs), acrylamide (AM), and stearyl methacrylate (C18), were synthesised by micellar copolymerisation, using ammonium peroxydisulfate as an initiator. CNWs composite hydrogels were characterised by Fourier transform infrared spectroscopy (FTIR) and their morphologies were investigated by scanning electron microscope (SEM). The system shows the original extensibility up to about 2500%: the tensile strength and compressive strength have maximum values of 1.338 MPa and 2.835 MPa, respectively. Besides excellent mechanical properties, CNWs composite hydrogels also have the ability to self-heal and remould: this is mainly attributed to the dissociation and reassociation of the associated micelles. In contrast to conventional cellulose hydrogels, these systems, when broken or cut, can be simply repaired by bringing together fractured surfaces to self-heal at room temperature.


2014 ◽  
Vol 68 (3) ◽  
Author(s):  
Aleksandra Rakić ◽  
Marija Vukomanović ◽  
Gordana Ćirić-Marjanović

AbstractNanostructured polyaniline (PANI) was synthesised by the oxidation of aniline in a water/ isopropanol (propan-2-ol, IPA) (50 vol. %) mixture, without added acid, using ammonium peroxydisulfate (APS) as an oxidant. Influence of the IPA co-solvent and the reaction time on the molecular structure, morphology and properties of synthesised PANI samples was studied by FTIR, Raman, and UV-VIS spectroscopies, scanning and transmission electron microscopies (SEM and TEM), and conductivity measurements. The course of the reaction was followed by monitoring changes in the temperature and acidity of the reaction medium. The results were compared with those obtained for PANI prepared in water without IPA under the same reaction conditions. The importance of the solvation effects, dielectric constant of the solvent, and the enthalpy of mixing of IPA with water on the course of the polymerisation reaction and on the properties of polymeric products in the water/IPA medium in comparison with those in water was pointed out.


2009 ◽  
Vol 87-88 ◽  
pp. 311-316 ◽  
Author(s):  
Hui Huang ◽  
Zhong Cheng Guo

Doped polyaniline (PANI) was synthesized by chemical oxidative polymerization of aniline in aqueous acidic medium with mixed sulfuric acid and 5-sulfosalcyclic acid as complex dopant , and ammonium peroxydisulfate as an oxidant, and heat treated at 150°C, 200°C, 250°Cand 300°C for 2 hours in vacuum. Different intrinsic and extrinsic structural changes due to heat treatment were determined from FTIR and XRD measurements. When PANI is subjected to heat treatment, different changes are taking place in the system like doping, dedoping (extrinsic), oxidation and changes in crystal structure (intrinsic). Mechanisms for doping, dedoping and oxidation, are proposed.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Mohd. Khalid ◽  
Milton A. Tumelero ◽  
Iuri. S. Brandt ◽  
Vinicius C. Zoldan ◽  
Jose J. S. Acuña ◽  
...  

Self-assembled polyaniline (PANI) nanotubes were prepared in the presence of three different sulfonic acids as dopant, namely, p-toluenesulfonic acid, camphorsulfonic acid, and tetrakis(4-sulfonatophenyl)porphyrin, by oxidative polymerization using ammonium peroxydisulfate as the oxidant. The morphology of the PANI nanotubes was determined by SEM and TEM and the electrical conductivity was measured as a function of temperature. The PANI nanotubes were also characterized by FTIR, XRD, UV-Vis, and cyclic voltammetry. We have found that the dopants had a noteworthy effect on the electrical conductivity whithout significant changes in the morphology of the PANI nanotubes.


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