Effect of dopant and oxidant on the electrochemical properties of polyaniline/graphite nanoplate composites

Optimizing the synthesis parameters of polyaniline/graphite nanoplate (PANI/GNP) composite is essential to the final electrochemical performance. Herein, the electrochemical properties of PANI/GNP composites, prepared by in situ chemical polymerization using varying amounts of different oxidants, with or without the addition of 4‐dodecylbenzenesulfonic acid (DBSA) as dopant, were investigated. Cyclic voltammetric results suggested that a stoichiometric amount of the oxidant iron chloride (FeCl₃) was beneficial to the electrochemical properties of the composites. The use of ammonium persulfate (APS) instead of FeCl₃ as oxidant largely increased the actual PANI content, conductivity and specific capacitance of the PANI/GNP composites. The dopant DBSA increased the conductivity of the PANI/GNP composites but did not show a positive effect on the electrochemical behavior. The cyclic voltammograms of the PANI/GNP composites indicated that the pseudocapacitance of PANI contributes more than the electrical double‐layer capacitance of GNP to the capacitance of the composites, while the presence of GNP plays an essential role in the rate capability of the composites. In this study, PANI/GNP (1:1) composite synthesized with an APS to aniline molar ratio of 1 showed a balanced combination of high specific capacitance (180.5 F g^?1 at 20 mV s^?1) and good rate capability (78% retention at 100 mV s^?1). © 2018 Society of Chemical Industry     

A novel soluble PANI/TPU composite doped with inorganic and organic compound acid

A series of novel soluble and thermoplastic polyurethane/polyaniline (TPU/PANI) composites doped with a compound acid, which was composed of an organic acid (p‐toluene sulfonic acid) and an inorganic acid (phosphoric acid), were successfully prepared by in situ polymerization. The effect of aniline (ANI) content, ratio of organic acid/inorganic acid, and different preparation methods on the conductivity of the TPU/PANI composites were investigated by using conductivity measurement. Lithium bisoxalato borate (LiBOB) was added to the prepared in situ TPU/PANI to coordinate with the ether oxygen groups originating from the soft molecular chains of TPU, and thus the conductivity of the composites was further enhanced. The molecular structure, thermal properties, and morphology of the TPU/PANI composites were studied by UV–visible spectroscopy, differential scanning calorimetry, and scanning electron microscopy, respectively. The results show that the in situ TPU/PANI composites doped with the compound acid can be easily dissolved in normal solvents such as dimethylformamide (DMF) and 1,4‐dioxane. The conductivity of the TPU/PANI composites increases with the increase of the ANI content, in the ANI content range of 0–20 wt %; however, the conductivity of the composites reduces with further increment of ANI content. The conductivity of the TPU/PANI composites prepared by in situ polymerization is about two orders of magnitude higher than that prepared by solution blending method. LiBOB can endow the in situ TPU/PANI composites with an ionic conductivity. The dependence of the conductivity on temperature is in good accordance with the Arrhenius equation in the temperature range of 20–80°C. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Effect of dopant mixture on the conductivity and thermal stability of polyaniline/nomex conductive fabric

Electrically conductive polyaniline (PANI)/[poly(m‐phenylene isophthalamide)] Nomex composite fabric was prepared by in situ polymerization of aniline doped by a mixture of hydrochloride (HCl) and various sulfonic acids such as benzenesulfonic acid (BSA), sulfosalicylic acid (SSA), and dodecylbenesulfonic acid (DBSA); their effect on conductivity and physical properties were then investigated. PANI/Nomex composite fabrics doped by a mixture of protonic acids exhibited higher conductivity than those doped by other single dopants such as camphorsulfonic acid (CSA), p‐toluenesulfonic acid (TSA), BSA, SSA, and HCl. The conductivity of PANI/Nomex fabrics especially doped by a mixture of HCl and DBSA was evenly maintained up to 100°C without depression of mechanical properties of Nomex. Their conductivity was also maintained under extension of the composite fabric. In addition, electrical conductivity of PANI/Nomex fabrics was highly increased by ultrasonic treatment, which facilitated better diffusion and adsorption of aniline by cavitation and vibration. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2245–2254, 2002     

Studies of AC conductivity and dielectric relaxation behavior of CdO‐doped nanometric polyaniline

The Cadmium oxide doped in nanocrystalline polyaniline (CdO/PANI) composite were prepared with various weight percentages by in situ polymerization method using aniline, ammonium per sulfate, and CdO as starting materials. The frequency dependent conductivity and dielectric behavior of PANI/CdO composites have been studied. The formation of nano PANI and PANI/CdO composites with regards to the structural and microstructural properties of the materials were investigated by XRD, FTIR, and SEM techniques. The variation of σ_ac with frequency obeys Jonscher power law except a small deviation in the low frequency region and is due to dipole polarization effect. The σ_ac increases with increase in CdO concentration. Studies of dielectric properties at lower frequencies show that the relaxation behavior is superimposed by dipole polarization effect. The appearance of peak for each concentration in the loss tangent suggests the presence of relaxing dipoles in the PANI/CdO composite. On addition of CdO, the peak shifts toward higher frequency side indicating the speed up of the relaxation time. Analysis of frequency dependent dielectric suggests that the electronic and polymer segmental motions are strongly coupled. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Aliphatic–aromatic polyester–polyaniline composites: preparation,characterization, antibacterial activity and conducting properties

Poly(butylene adipate‐co‐terephthalate) (PBAT) composites containing polyaniline (PANI) were prepared using a melt blending process. Acrylic‐acid‐grafted PBAT (PBAT‐g‐AA) and PANI were used to improve the compatibility and dispersibility of PANI within the PBAT matrix. The composites were characterised morphologically using scanning electron microscopy, chemically using Fourier transform IR spectrometry and ¹³C solid‐state nuclear magnetic resonance, and optically using UV‐visible spectroscopy. The electrical conductivity of the composites was also evaluated with a resistance tester and a cyclic voltameter. Escherichia coli (BCRC 10239) was chosen as the standard bacterium for determining the antibacterial properties of the composite materials. The anti‐static properties of the composites were also evaluated. The PBAT‐g‐AA/PANI composite showed markedly enhanced antibacterial and anti‐static properties due to the formation of amide bonds by the condensation of the carboxylic acid groups of PBAT‐g‐AA with the amino groups of PANI. The optimal level of PANI was 9 wt%, as excess PANI led to separation of the two organic phases, lowering their compatibility. Copyright © 2012 Society of Chemical Industry     

Doping effects of cerium ion on structure and electrochemical properties of polyaniline

Polyaniline (PANI)/Ce³⁺ and PANI/Ce⁴⁺ composites were successfully prepared by in situ polymerization in an aqueous solution of poly(2‐acrylamido‐2‐methylpropane sulfonic acid) and characterized by Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, X‐ray photoelectron spectroscopy, SEM, TEM and electrochemical methods. The results showed that the PANI/Ce ion composites had a high degree of sphericity, high electrical conductivity and good electrochemical performance. The conductivity of PANI/Ce(NO₃)₃ reaches a maximum of 46.76 S cm^?1 at 20 wt% of Ce(NO₃)₃. It is increased by 377% by comparison with that of pure PANI. In particular, the polarization results showed that the corrosion current density (0.47 µA cm^?2) and the inhibition efficiency (97%) of PANI/Ce(NO₃)₃ were better than the results for PANI and PANI/Ce(SO₄)₂ composite. This suggested that the PANI/Ce(NO₃)₃ composite has promising applications in conductive materials, anticorrosion coatings and other related fields. © 2017 Society of Chemical Industry     

Water‐dispersible nanocomposites of polyaniline and montmorillonite

The polymerization of aniline (ANI) in aqueous medium in the presence of (NH₄)₂S₂O₈ and montmorillonite (MMT) resulted in the formation of a nanocomposite (PANI–MMT). The inclusion of PANI in the composite was confirmed by FTIR studies. The extent of PANI loading in the composite increased with ANI concentration at a fixed oxidant/MMT amount and with the oxidant amount at a fixed ANI and MMT weight, but decreased with an MMT amount at a fixed ANI and oxidant level. TGA revealed a higher stability for the PANI–MMT composite relative to PANI and confirmed a PANI loading of ca. 51% in the composite. The conductivity increased in all the cases. XRD analysis revealed no expansion of the d₀₀₁ spacing at 9.8 Å, implying no intercalation of PANI within the MMT layers. Scanning electron micrography studies revealed interesting morphological features for the composites. Transmission electron micrography analysis revealed distinctive features and confirmed the formation of PANI–MMT composite particles of diameters in the 300‐ to 400‐nm range. These composites could be obtained as stable colloids in the presence of poly (N‐vinyl pyrrolidone) under selective conditions. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 2948–2956, 2000     

Photo‐induced protonation and conductivity of polyaniline/poly(ethylene glycol) and polyaniline/[poly(ethylene glycol)‐grafted polyaniline] composites

Composites of polyaniline in its emeraldine base form (PANI‐EB) and photo‐acid generators (PAG) show an increase in conductivity upon photo‐irradiation due to the protonation of PANI‐EB. Such materials may be utilized to fabricate conducting patterns by photo‐irradiation. However, the conductivity obtained by direct irradiation of PANI‐EB/PAG composites was normally quite low (<10^?3 S/cm) due to aggregation of highly loaded PAG. In this work, poly(ethylene glycol) (PEG), which is a proton transfer polymer, was added to PANI‐EB/PAG. Results showed that addition of low M_w (550) PEG significantly enhance the photo‐induced conductivity. Conductivities as high as 10^?1–10⁰ S/cm were observed after photo‐irradiation. This conductivity is comparable to that of PANI‐salt synthesized by oxidizing aniline in the presence of an acid. High M_w (8000) PEG is much less effective than PEG 550, which is attributed to its lower compatibility with PANI. PEG‐grafted PANI (N‐PEG‐PANI) was also studied as an additive. Composites of PANI‐EB and N‐PEG‐PANI showed conductivity as high as 10² S/cm after treatment with HCl vapor. The photo‐induced conductivity of the N‐PEG‐PANI/PANI‐EB/PAG composite reached 10^?2–10^?1 S/cm. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Surface graft polymerization of conducting polyaniline on waterborne poyurethane‐urea film and its phenol sensing

Waterborne polyurethane‐ureas (pristine WBPUs: WBPU‐19 and WBPU‐24, fixed soft segment content: 60 wt %) containing dimethylol propionic acid (DMPA)/ethylene diamine (EDA) contents (19/16.8 and 24/11.4 mol %) were prepared. The polyaniline (PANI)‐graft‐WBPU (PANI‐graft‐WBPU) films were prepared by oxidative graft polymerization of aniline on the surface layer of WBPU films. This study focused on the effects of reaction conditions (concentrations/treating times/temperatures of aniline and APS) and DMPA content on the %grafting, conductivity, and mechanical properties of PANI‐graft‐WBPU films. To obtain the maximum %grafting (PANI‐graft‐WBPU‐19: 6.2, and PANI‐graft‐WBPU‐24: 7.4) and conductivity (PANI‐graft‐WBPU‐19: 3.6 × 10^?2S/cm, and PANI‐graft‐WBPU‐24: 4.7 × 10^?2S/cm), the optimum concentrations/treating times/temperatures of aniline and APS, were found to be 0.35M/10 min/25°C and 0.2M/10 min/0°C, respectively. The tensile strength of film samples was found to be increased in the order of PANI‐graft‐WBPU‐19>pristine WBPU‐19>PANI‐graft‐WBPU‐24>pristine WBPU‐24. The PANI‐graft‐WBPU‐19 (%grafting: 6.2) films on exposure to 0–10,000 ppm phenol solutions showed a well‐defined response behavior, demonstrating high promise for application in aqueous phenol sensors. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Oxidative graft polymerization of aniline on the modified surface of polypropylene films

A novel method for preparing electrically conductive polypropylene‐graft‐polyacrylic acid/polyaniline (PP‐g‐PAA/PANI) composite films was developed. 1,4‐Phenylenediamine (PDA) was introduced on the surface of PP‐g‐PAA film, and then, chemical oxidative polymerization of aniline on PP‐g‐PAA/PDA film was carried out to prepare PP‐g‐PAA/PANI electrically conductive composite films. After each step of reaction, the PP film surface was characterized by attenuated total reflectance Fourier transform infrared spectroscopy. Static water contact angles of the PP, PP‐g‐PAA, and PP‐g‐PAA/PANI films were measured, and the results revealed that graft reactions took place as expected. The morphology of the PP‐g‐PAA film and the PP‐g‐PAA/PANI composite film were observed by atomic force microscopy. The conductivity and the thickness of the PP‐g‐PAA/PANI composite films with 1.5 wt % PANI were around 0.21 S/cm and 0.4 μm, respectively. The PANI on the PP‐g‐PAA/PANI film was reactivated and chain growing occurred to further improve the molecular weight of PANI. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2442–2450, 2007     

Frequency‐dependent conductivity and dielectric permittivity of polyaniline/CeO2 composites

The PANI/CeO₂ composites were synthesized using in situ deposition technique by placing fine graded CeO₂ in polymerization mixture of aniline. This is the single step polymerization process for the direct synthesis of emeraldine salt phase of polymer. Low frequency dielectric studies were carried out on pressed pellets of PANI/CeO₂ with various concentrations of cerium oxide (10, 20, 30, 40, and 50 wt % of CeO₂ in PANI). The results are interpreted in terms of polarons and bipolarons, which are responsible for the dielectric relaxation mechanism and frequency dependence of conductivity. It is found that a.c. measurements at room temperature may well serve as a parallel way to the time consuming d.c. conductivity versus temperature technique, to detect the thermal degradation of the transport properties in conducting polymers. It is observed that the charge motion via creation/annihilation of polarons and bipolarons increases as the weight percentage of the composite is increased. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1403–1405, 2006     

Polyaniline-Coated Short Nylon Fiber/Natural Rubber Conducting Composite

Natural rubber-Polyaniline (PANI)-Polyaniline coated short nylon-6 fiber (PANI-N6) composites were prepared by mechanical mixing and its cure characteristics, filler dispersion, mechanical properties, conductivity and thermal stability were evaluated. PANI was synthesized by chemical oxidative polymerization of aniline in presence of hydrochloric acid. PANI-N6 was prepared by in situ polymerization of aniline in the presence of short nylon-6 fiber. The composite showed higher tensile strength, tear strength and modulus values and lower elongation at break. The DC electrical conductivity and the thermal stability of the composites increased with PANI and PANI-N6 concentration. The highest conductivity obtained was 1.99 × 10^?6 S/cm.     

Facile preparation of conductive paint made with polyaniline/dodecylbenzenesulfonic acid dispersion and poly(methyl methacrylate)

We investigated an easy way to prepare industrially a conductive paint made with polyaniline (PANI)/dodecylbenzenesulfonic acid (DBSA) dispersion and poly(methyl methacrylate) (PMMA) in organic media. First, water‐dispersible PANI doped with DBSA was chemically synthesized with aniline sulfate using ammonium persulfate in water, and the resulting PANI/DBSA was readily extracted from the reaction medium with a mixture of toluene and methyl ethyl ketone (MEK) (toluene:MEK = 1:1 (v/v)), which is useful for industrial applications. The obtained PANI/DBSA organic dispersion was mixed with PMMA organic solution to give the corresponding PANI/DBSA conductive paint containing PMMA. A film prepared with the resulting PANI/DBSA conductive paint was found to possess relatively good conductivity and low surface resistivity for a conductive paint utilized for an electrostatic discharge even at low PANI/DBSA content in the PANI/DBSA–PMMA composite film (the conductivity and the surface resistivity were 9.48 × 10^?4 S cm^?1 and 3.14 × 10⁶ Ω cm^?2, respectively, when the feed ratio of PANI/DBSA:PMMA was 1:39 (w/w)). Furthermore, it was found that the conductivity of the film composed of PANI/DBSA–PMMA composite can be readily and widely controlled by the PANI/DBSA content of the composite or by the amount of DBSA used during the PANI/DBSA synthesis. The highest conductivity of PANI/DBSA–PMMA composite film (7.84 × 10^?1 S cm^?1) was obtained when the feed ratio of PANI/DBSA:PMMA was 1:4 (w/w). Copyright © 2007 Society of Chemical Industry     

Novel electrically conductive and ferromagnetic composites of poly(aniline‐co‐aminonaphthalenesulfonic acid) with iron oxide nanoparticles: Synthesis and characterization

Nanocomposites of iron oxide (Fe₃O₄) with a sulfonated polyaniline, poly(aniline‐co‐aminonaphthalenesulfonic acid) [SPAN(ANSA)], were synthesized through chemical oxidative copolymerization of aniline and 5‐amino‐2‐naphthalenesulfonic acid/1‐amino‐5‐naphthalenesulfonic acid in the presence of Fe₃O₄ nanoparticles. The nanocomposites [Fe₃O₄/SPAN(ANSA)‐NCs] were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X‐ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, elemental analysis, UV–visible spectroscopy, thermogravimetric analysis (TGA), superconductor quantum interference device (SQUID), and electrical conductivity measurements. The TEM images reveal that nanocrystalline Fe₃O₄ particles were homogeneously incorporated within the polymer matrix with the sizes in the range of 10–15 nm. XRD pattern reveals that pure Fe₃O₄ particles are having spinel structure, and nanocomposites are more crystalline in comparison to pristine polymers. Differential thermogravimetric (DTG) curves obtained through TGA informs that polymer chains in the composites have better thermal stability than that of the pristine copolymers. FTIR spectra provide information on the structure of the composites. The conductivity of the nanocomposites (～ 0.5 S cm^?1) is higher than that of pristine PANI (～ 10^?3 S cm^?1). The charge transport behavior of the composites is explained through temperature difference of conductivity. The temperature dependence of conductivity fits with the quasi‐1D variable range hopping (quasi‐1D VRH) model. SQUID analysis reveals that the composites show ferromagnetic behavior at room temperature. The maximum saturation magnetization of the composite is 9.7 emu g^?1. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Conducting composites of poly(N‐vinylcarbazole), polypyrrole,and polyaniline with 13X‐zeolite

N‐vinylcarbazole (NVC) was polymerized by 13X zeolite alone in melt (65°C) or in toluene (110°C) and a poly(N‐vinylcarbazole) (PNVC)‐13X composite was isolated. Composites of polypyrrole (PPY) and polyaniline(PANI) with 13X zeolite were prepared via polymerization of the respective monomers in the presence of dispersion of 13X zeolite in water (CuCl₂ oxidant) and in CHCl₃ (FeCl₃ oxidant) at an ambient temperature. The composites were characterized by Fourier transform infrared analyses. Scanning electron microscopic analyses of various composites indicated the formation of lumpy aggregates of irregular sizes distinct from the morphology of unmodified 13X zeolite. X‐ray diffraction analysis revealed some typical differences between the various composites, depending upon the nature of the polymer incorporated. Thermogravimetric analyses revealed the stability order as: 13X‐zeolite > polymer‐13X‐zeolite > polymer. PNVC‐13X composite was essentially a nonconductor, while PPY‐13X and PANI‐13X composites showed direct current conductivity in the order of 10^?4 S/cm in either system. However, the conductivity of PNVC‐ 13X composite could be improved to 10^?5 and 10^?6 S/cm by loading PPY and PANI, respectively. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 913–921, 2006     

Highly Conductive Cellulose Network/Polyaniline Composites Prepared by Wood Fractionation and In Situ Polymerization of Aniline

Highly conductive cellulose network/polyaniline (PANI) composites are successfully formed using chemical fractionation of solid wood followed by in situ polymerization of aniline monomers in the purified wood. The increased porosity of the wood caused by the fractionation process enables the uniform deposition of PANI particles in the microstructure of the material, resulting in a high electrical conductivity of up to 36.79 S cm^?1, and a high weight gain rate of up to 143%. The interaction between PANI and the cellulose microfibril network leads to a decreased crystallinity of the composites. The electrode prepared from the cellulose network/PANI composites exhibits promising gravimetric specific capacitances of up to 218.75 F g^?1 and areal specific capacitances of up to 0.41 F cm^?2, and it can be assembled into all‐solid‐state supercapacitors with favorable energy storage performance, which may be attributed to the larger surface area, higher PANI content of the electrode, and the positive effect of the cellular structure of the cellulose network on electron transport. The present process can preserve the naturally hierarchical structure of wood and impart a promising conductivity to the composites, and it provides a promising way to produce hierarchical biomass‐based electronic materials for high‐performance storage field.     

Novel conducting polyaniline blends with cyanoresin

Novel conducting polyaniline (PANI)/cyanoresin (Cyan) blends were prepared by the addition of Cyan/dimethylformamide solutions to aniline monomer/dopant solutions and the in situ chemical oxidative polymerization of aniline with ammonium persulfate as an oxidant in aqueous p‐toluene sulfonic acid solutions. The PANI/Cyan blends were prepared with various compositions (5:95, 10:90, 20:80, 30:70, 40:60, 50:50, 60:40, and 70:30), and blend films of PANI/Cyan were obtained with a casting method. The conductivity of the PANI/Cyan blend films was 10^?7 to 10^?2 S/cm, which was measured by a four‐probe technique. The tensile strength of the blend films was maintained with an increasing amount of PANI (up to 50 wt %), and this was attributed to intermolecular interactions such as hydrogen bonding between PANI and Cyan and a reinforcing effect through blending. This hypothesis was corroborated by Fourier transform infrared spectroscopy. Field emission scanning electron microscopy and thermogravimetric analysis were also used to investigate the morphology and thermal properties of the conducting PANI/Cyan blend films, respectively. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1035–1042, 2005     

High Thermal Conductivity Nanocomposites Based on Conductive Polyaniline Nanowire Arrays on Boron Nitride

With the development of soft electronics, conductive composites are garnering an increasing amount of attention. The electrical conductivity, thermal conductivity, and electrical stability of conductive composites are all very important. In particular, the thermal conductivity of conductive composites is critical to the stability of their conductive properties. However, little is reported on thermal management in conductive systems. Herein, sufficiently hydroxylated boron nitride nanosheets (BN‐OH)@polyaniline (PANI) composite nanosheets with a high thermal conductivity and outstanding conductance stability are reported. PANI nanowire arrays are aligned vertically on BN‐OH. This well‐ordered nanostructure provides the means to form a good conductive and thermally conductive path. Notably, the composite through‐plane thermal conductivity is 2.1 W m^?1 K^?1(≈1000% that of pure PANI) and that the resistivity of the composite is 1.38 Ω cm. Importantly, the resistivity of the composite remains unchanged after 1 h of work. The results show that this composite has prospective applications for use in soft electronics.     

Methacrylated calix[4]arene phosphonic acids as functionalized crosslinker for radical polymerization

We describe the synthesis of 5,11,17,23‐tetra‐tert‐butyl‐25,27‐dioxypropylphosphonic acid‐26,28‐dimethacryloyloxy‐calix [4]arene and 5,11,17,23‐tetra‐tert‐butyl‐25‐oxypropylphosphonic acid‐27‐hydroxy‐26,28‐dimethacryloyloxy‐calix[4]arene starting from para‐tert‐butyl‐calix[4]arene. The complete reaction was proved by matrix‐assisted laser desorption ionization time of flight mass spectrometry and nuclear magnetic resonance spectroscopy. The influence of these compounds on the kinetics of the radical polymerization of methyl methacrylate was shown by dilatometry. Furthermore, the adhesive properties of dental adhesives containing these calix[4]arene derivatives were investigated. Copyright © 2012 Society of Chemical Industry     

Electrochemical oxidation of <Emphasis Type="Italic">p</Emphasis>-sulfonated calix[8]arene

The water-soluble p-sulfonated sodium salt of calix[8]arene (III) was synthesized. The product was characterized by FT-IR, NMR and UV–Vis spectra.Then the electrochemical behaviors of p-sulfonated sodium salt of calix[8]arene in NaAc+HAc (pH = 4) buffer solution was studied. In aqueous solution, p-sulfonated calix[8]arene can be oxidized when the potential is more than 0.7 V vs SCE. It was confirmed that the reaction was a two-electron irreversible electrochemical reaction. The transfer coefficient, α, was measured as 0.7. At 25°, the diffusion coefficient of p-sulfonated calix[8]arene was determined as 8.6 × 10⁻⁷ cm² s⁻¹. The diffusion activation energy of p-sulfonated calix[8]arene was 18.9 kJ mol⁻¹ at pH = 4.