reveals the presence of non-Debye nature of the sample due to the potential well for each site through which ion transport take place. The low frequency spike denotes the effect between two blocking electrodes which represent the formation of double layer capacitance of polymer electrolyte interface produced by the accumulation of ions. Furthermore, the inclination of the spike at an angle less than 90˚ to the real axis is due to the inhomogeneity at the electrode electrolyte interface . Point of intersection of semicircle on the horizontal axis gives the value of bulk resistance. The obtained value of R b
The other method of boundary relaxation is relatively new in electrostatics. It involves setting up an artificial boundary enclosing the region of interest. The potential at this boundary is given by considering the effect of charges in the whole inner region, that is on electrodes, and polarization charge on dielectric interface, SOR is applied to the whole region to obtain improved values of V on all the inner nodes which in turn are used to evaluate the boundary values of V by charge simulation. This method has only been used for simple electrode and dielectric
PProDOT-EtO-BZA films coated at different scan rates on SPCE showed dominance of the capacitive line, close to 90 o , which is extended down to low frequencies (Figure 4). The length differences of the steep slope which are associated with the capacitance of electrodes at low frequency region [34,35] may be due to the film thickness, correlated with the polymerization charge as shown in the inset of Figure 4. Although there is no semicircle in the high frequency region, slight deviations indicate fast charge transport from the polymer bulk as well as fast charge transfer to metal between polymer and solution interface.
Abstract—Investigations on contact connector materials for different applications such as in the automotive industry have focused toward the increasing interest of using conducting poly- mers, as compared to conventional metallic contacts. The aim is to achieve overall improvements in performance as well as cost effectiveness. Currently, extrinsic conducting polymers (ECPs) are employed as conductive coats or adhesives at contact interfaces. However, frictional abrasion within the metal doped polymer (ECP) causes fretting corrosion, which leads to instability in the contact resistance. To overcome this, intrinsically conducting polymers (ICPs) are explored. Hemispherical contact coatings were fabricated using poly(3,4-ethylenedioxythiopene) (PEDOT) or polyaniline/polyvinylchloride (PANI/PVC) commodity blends. Contact resistances were taken using four-wire resistance mea- surement techniques. The conductivities of in-house fabricated ICP contacts were found to be in the range of 10 2 S cm 1 . The response relating the change of contact resistance under varying compression force appeared to be repeatable with minimum deviation of 2%. The surface profiles of the ICP contacts were also recorded by an optical confocal system. The initial investigation results presented in this paper were used to evaluate and validate the hypothesis of employing ICP contacts to eliminate or minimize wearing and fretting effects.
This can be taken in a beaker like container with suitable quantity two electrodes are used which are cathode and anode. Graphite used as a cathode electrode, at one end and steel plate at other end as an anode. This deposition requires very low voltage. A constant voltage power supply is generally preferred for the application of voltage to the cell so that constant voltage can be applied for the preparation of films of polymers. This voltage can be applied by two different methods. But in this project potentiostatic method is used.
The sample disk for the fuel cell measurement was comprised of the cathode, the anode and the reference electrode onto BCZY622 disk (diameter = 13 mmº, thick- ness = 0.5 mm). LSCF6428 cathode was prepared by spin- coating using the bead-milled slurry on one surface and baked at 1150°C for 1 h in air. As a comparison, another cathode made of LSCF6428 which was not bead-milled was prepared from the paste containing the as-calcined LSCF6428 powder using screen printing. The micro structure of the prepared cathode was observed by ﬁeld emission scanning electron microscope (FE-SEM, JSM-7001F, JEOL). Porous Ni prepared from screen printed NiO paste on the counter side of the electrolyte disk was used as anode. The NiO was baked at 950°C and was annealed in wet hydrogen atmosphere at 600°C to form porous metallic Ni in situ after the sample was assembled to the experimental apparatus. The diameter of the anode and cathode was 8 mmº. Platinum paste was applied on the rim of the disk, to form the reference electrode.
In recent years, polymers such as polyvinyl alcohol (PVA) poly (vi-nylidene fluoride) (PVdF), Poly ethylene glycol (PEG), poly(vinyl chloride) (PVC), poly(acrylonitrile) (PAN), poly(vinyl pyrrolidone) (PVP) and poly(vinyl sulfone) (PVS) have been prominently used in development of GPEs [8-11]. In gel polymer electrolytes (GPEs), which have both solid and liquid like properties,. These electrolytes have been found to possess ionic conductivity, electrochemical stability and transport properties similar to their liquid counter parts along with better dynamical properties suitable for electrochemical applications. Among the listed polymeric hosts, Poly (vinyl alcohol) has been intensely investigated .Poly(vinyl alcohol) (PVA) appears to be very attractivematerial for preparing proton conductingpolymer gel electrolyte because this polymer can function as an excellent methanolbarrier. PVA also has both very good mechanical propertiesand chemical stability, which are adequate for preparing proton conductingpolymer gel electrolyte.
Current electrode attachment methods within standard myoelectric sockets are fixed within a position determined by the Prosthetist. As a result, the clarity and strength of the signal acquisition is still very much determined by the ability of the Prosthetist to locate an effective electrode position and indeed for this position to be accurately transferred to the socket during the manufacturing process. Ideally, given the facts described in previous chapters about variations in signal strength and the production and dissipation of the myoelectric signal, the new electrode housing design should provide for some adjustment with respect to its position and contact over the residual limb even after completion of the manufacturing process. Indeed, this principle is keenly observed in almost other aspects of prosthetic treatment and provision. For example, the Prosthetist is not expected to initially provide the finalised set up, alignment and position of componentry in lower limb prostheses. Lower limb prostheses include numerous modular components offering multiple adjustment features to allow numerous post-fitting adjustments for the Prosthetist to assist the prosthesis user. For optimum performance, the electrode housing to be employed for this study would therefore need to be adjustable and indeed movable in terms of its positioning over the residual limb. This would be achieved by making the housing unit an external attachment to the socket – rather than being laminated into the socket itself.
EIS Experiments: Impedance spectroscopy technique was used to study the electrode/electrolyte interface behavior of the electrode and corrosion processes taking place on the surface of mild steel in presence and absence of Citrus sinensis peels. For understanding the phenomenon, electronic structure of electrified interface formed at the surface of working electrode and surface processes, EIS experiments were carried out at equilibrium potential in frequency range i.e. 10,000 to 0.1 Hz at 298.0 K. Figure 3 shows EIS plots for MS coupons dipped in 5.0 M HCl medium at 298.0 K with and without green corrosion inhibitor at the OCP. It is also observed from Nyquest plots that the diameter of the semicircle augment with the augment in concentration of Citrus sinensis peels in the corroding medium, which indicates an increase in resistance to corrosion.
are thoroughly studied using combined focused ion beam and transmission electron microscopy (FIB-TEM). In the case of LSM/YSZ and LSM/GDC electrodes, a significant reduction in the electrode ohmic resistance was found after cathodic polarization at 900 o C and 500mAcm -2 , indicating the formation of an intimate interface. However, LSM particle starts to disintegrate at the electrode/electrolyte interface with increasing polarization time in the case of LSM/YSZ electrode. On the other hand, the LSM/GDC interface is very stable with negligible disintegration of LSM phase at the interface. Mn segregation from the LSM perovskite structure was identified under the influence of polarization, regardless of the electrolyte materials. The results demonstrate that nature of the electrolyte plays a critical role in the interface stability of LSM based electrodes under SOFC operation conditions.
A number of dimers will be formed when additional APS is added to the aniline solution. The interaction between the dimers will result in the formation of a long-chain polymer at the end of the polymerisation process. Previous studies have shown that the polymerisation of polyaniline is more likely to occur at the N- and para site of the aniline that the coupling of dimers (i.e., head to tail coupling) as shown in Fig. 3, because ortho coupling is unlikely due to steric effects. 34-37
Once in the vapour phase, sample molecules must somehow interact with the conductingpolymer matrix to generate a response. The mechanisms of this process are poorly understood. Initial interactions between the analyte and the polymer are likely to involve hydrogen bonding and other inter molecular attractions. It would therefore seem logical to assume that the polarity of a test compound will have an effect upon sensor response. Unfortunately, there does not seem to be any simple method for determining what contribution the volatility or any other property of a molecule will have towards response since it is difficult to envisage how a single property may be studied whilst keeping other parameters constant. For example, the test series may be arranged into order of polarity but the fact each compound possesses a different volatihty/functionality and so on makes analysis of the effect of polarity on response rather problematic. There is obviously a need to somehow develop a profiling strategy so that a study of the effects of single parameters can be made. Such a programme of response mapping would obviously need to incorporate a far more comprehensive series o f test compounds and sensors. Cluster analysis and other statistical techniques would prove to be invaluable tools when analysing such a large set of response data.
Electrically conducting polymers describe as a new class of synthetic metals. In this study conducting polymers prepared by insitu blending technique. Aniline was blended by polymethylmetacryalte and metal alloy poly(ba acrylate). We were examined all prepared polymer films physical properties like appearance, polymerization yield, absorption quality. The conductivity levels of the blended polymers were examined by the four point probe technique. Molar magnetic susceptibility of polymer was found to be –28.8 BM so we can says the blended polymer was diamagnetic and shows bipolaron conduction mechanism. New blended polymer was highly conductive in nature . UV visible, FTIR and NMR spectra were taken in order to analyze the structural properties of the resulting copolymer. The molecular wt. of polymer was determined by GPC technique. Surface micrographs were taken by SEM.
j × log(ppm As) plots extrapolation of the detection and quantification limit signals at each time showed that all the points are above the resulting measurements. It follows, therefore, that a blank correction would be a mistake, because, in the absence of analyte anions, an interaction between the electro-deposit and sulfate anions from the supporting electrolyte present in the blank exists and this interaction would be different in the presence of arsenate ions during the doping process. 21 On the other hand, in solutions containing the analyte a competitive effect of these anions with charges of the doped polymer would occur. In summary, the obtained response is clearly due to arsenate interaction with the doped polymer, making blank correction impossible.
The characterization of conducting polymers was carried out by using UV- Visible spectroscopy and FT- IR techniques. Figure 1 represents the FT- IR of polyaniline. Figure 2 represents the FT- IR of polythiopehene. Figure 3 represents the UV- Visible spectra of polyaniline. Figure 4 represents the UV- Visible spectra of polythiophene. FTIR spectra of conducting polyaniline and polythiophene shows characteristics absorption peak in finger print region of the spectrum. UV-visible absorption spectra of conductingpolymer i.e. polyaniline and polythiophene shows characteristics absorption peak in visible region of the spectrum. Cyclic voltamogram shows clear oxidative and reductive peak due to hydrazine present in the analyte. Detection of hydrazine hydrate and other environment pollutants are possible with the help of conductingpolymer based electrochemical biosensor.
In this study, we investigated the effect of blending CMC and PVA at different ratios (100/0, 90/10, 80/20, and 50/50) and compared them with the pure polymers. Here we report the optimum conductivity and occurrence of intermolecular attraction between the CMC and PVA, which increase the conductivity and thermal stability of the BPE system. To the best of our knowledge, this study is the first to reveal the simplest approach to enhance the interaction between the CMC and PVA, which affect the polymer chain fle xibility and stability. To date, no systematic study has been conducted to determine the molecular conductive behavior enhancement for the blended polymer electrolyte-based CMC/PVA.
The adhesive strength of polystyrene was found to be 0.2kN (Table 6). This value is much smaller than the values obtained for the other polymers. Thus, the mechanical interlocking contribution to the adhesive strength of any polymer may not be too high on a polished cast iron surface. For the most and least acetyl-substituted polymers, i.e. PVA and PVAc, the adhesive strength obtained from lap shear tests was proportional to the acetyl content, i.e. adhesive strength decreased with increasing acetyl content. These observations indicate two things. First, that the adhesive strength is due to more than mechanical interlocking based on the difference in strength between polystyrene and the other polymers. These results also support the hypothesis that acid-base interactions play a role in the interaction of the polymer and cast iron surface.
Before each experiment, the electrode mount force measurement was calibrated using a Soehnle Siena kitchen scale with an accuracy of 1 gr (Leifheit AG, Nassau, Germany). The electrodes were moistened with four drops of tap water to simulate the presence of sweat. It was observed that the moistness remained stable throughout the duration of the experi- ment. The stability of the conductive layer between the skin and the electrode was also observed to have stable impedance levels throughout the experiments. Therefore, reap- plication of moisture was unnecessary. An important factor here might be that the skin under an electrode starts to perspire a few minutes after electrode application . The electrode was mounted on the experiment location with the experiment-specific starting mounting force and the pre-programmed motion presented in Figure 2 was applied. At the same time, the skin–electrode impedance, the motion artifact, and the ECG with the motion artifact were measured. When the motion pattern finished, the applied mounting force was increased to the next level and the process repeated without lifting the electrode. When the final force level for that experiment was reached, the electrode was lifted from the skin completely and remounted at the same location. The experiment was then started again with the lowest force. For Electrodes A, B, and C, three such procedures were car- ried out for each electrode for each location. For the medical electrode, repeating the pro- cedure once was thought to be adequate as we were more interested in textile electrode behavior. Furthermore, the behavior of medical electrodes has been extensively studied, and in our previous research medical electrodes were found to be relatively stable against motion artifact. Because of complaints from the volunteers about the discomfort caused by the rigid support of Electrode D, only one repeat of the procedure was done for this electrode.
Voltametric behaviour of metronidazole was studied in Britton Robinson buffer system at composite polymer membrane working electrode. Cyclic voltammetric method has been developed for the determination of drug in pharmaceutical formulation. A well-defined cathodic peak was observed for the metronidazole in the entire pH range. The current increases steadily with diffusion scan rate and concentration. The results indicate that the process is irreversible and diffusion controlled. This composite film showed good current response.
The sensor responses of gases property have been investigated by several groups in literature Amer et al., 2010; Radhakrishnan and Paul, 2007; Arena et al., 1994; Li et al., Paul et al., 2009). In this work, conducting polymers of PPy was deposited by using electrochemical deposition technique (ECD) and employed as a adsorbing material for gases by using QCM technique for r applications. Langmuir model has been used to compare adsorption and desorption kinetics of bare PPy against gas with respect to inert N 2 gas. H 2 O, CO 2