Conduction Mechanism Of Polymer Electrolyte Essay

1567 words - 7 pages

DC Conductivity Study
Figure 1 shows the typical impedance plot (imaginary part,Zi against real part, Zr of complex impedance, Z*) of CMC/CS doped with different NH4Br content at 303K. This impedance analysis is important in conductivity study and becomes a powerful tool in the investigation of ionically conduction behaviour in solid biopolymer electrolyte films. From the plot, it contains two-well defined regions, namely a high frequency region semicircle arc and low frequency region inclination spike. The semicircle represents the bulk effect of electrolyte which due to parallel combination of bulk resistance, R (proton migration) and bulk capacitance, C (immobile polymer chain). The inclination spike denotes the effect between two blocking electrodes which represent the formation of double layer capacitance of polymer electrolyte interface (proton migration at low frequency, f). The value of bulk resistance, Rb can be retrieved from the interception between low-frequency and high-frequency region on Zr-axis, which the value was then used to calculate ionic conductivity of the system.

Figure 1: The Cole-cole plots of the real impedance, Zr against imaginary impedance, -Zi biopolymer electrolyte system for (a) CMC/CS film, (b) CMC/CS-10 wt.% NH4Br, (c) CMC/CS-20 wt.% NH4Br and (d) CMC/CS-30 wt.% NH4Br at 303 K

Based on the plot, the value of Rb decrease with addition of NH4Br content up to 20 wt.%, and start to decrease beyond that concentration. Together with the decreasing in Rb value, the high semicircle arc seems to gradually fade away and completely disappears above 20 wt.% of NH4Br. Based on the previous study, the depressed semicircle and inclines spike (Figure 1a, 1b and 1 d) shows that the ion have different relaxation times and reveals non-Debye behaviour of the sample. From the calculation, 20 wt.% of NH4Br gives the highest conductivity value of 2.12 x 10-5 Scm-1. According to previous study, the increasing in conductivity value is due to the presence of ammonium salts (ionic dopant) in the system which believed to be a good proton donor in a polymer matrix and expected to enhance in conductivity value. Additionally, the low-frequency inclined spike beyond 20 wt.% of NH4Br prevails in the plot indicates that the system is monopolized by the only resistive component as illustrated in Figure 1c.

Further analysis has been done in this work with the aim to observe the effect of NH4Br addition with temperature on the electrical properties of biopolymer electrolyte film. Figure 2 shows the salts content dependence of conductivity value of CMC/CS-NH4Br at selected temperature. The conductivity together with amorphous nature of polymer blend (reduction in crystallinity with increasing amorphousity) increased gradually with increasing in salt content and reach the optimum value at 20 wt.% of NH4Br as proven in Cole-cole plot study (Figure 1).

Figure 2: Salts content dependence of CMC/CS-NH4Br...

Find Another Essay On Conduction Mechanism of Polymer Electrolyte

Chemistry: New Era for Organic Semiconducting Polymers

2723 words - 11 pages reaction. Hence, the addition of another Grignard reagent such as allyl, vinyl, phenyl, alkyl etc. will bind to the end of the polymer chain, and ultimately terminate the reaction resulting in both mono and di-capped functionalized polymers.46, 48 SCHEME mechanism of end capping of rr p3ht by in situ end functionalization Postpolymerization method is the other approach to end functionalizes polyalkyl thiophenes. McCullough’s group reported the

The New Batteries: Micro Fuel Cells...(essay written for Design & Technology)

869 words - 3 pages hydrogen fuel cell, except that the methanol fuel cell produces small amounts of carbon dioxide in addition to water. The current generation of polymer electrolyte membrane fuel cells being developed for transport applications to power cars and buses are extremely bulky devices, that require hydrogen and oxygen to be pumped into them under pressure. For a micro fuel cell, pumps and plumbing are out. A complex system of micro-channels will disburse the

Heat generation and loss in the human body, mechanisms of control and extreme heat and cold responses

1535 words - 6 pages The topic I have chosen to look at in this essay is to "discuss the principal ways in which heat is gained by and lost from the body, and explain the various mechanisms involved in regulation of body temperature. Briefly indicate how excessive cold and heat affect the body".The body gains and loses heat through the external environment by radiation, conduction, convection and evaporation of water. These are all physical mechanisms known to the

Experimental Study and Parameter Optimisation of Electro Chemical Discharge Machining on Silicon Wafers

1695 words - 7 pages spark will appear. A theoretical model was proposed by Basak and Ghosh [2] through which they explained the mechanism of spark generation during ECDM. They had reported the discharge phenomenon as a switching-off process in an electric circuit. Margareta et al.[3] conducted experimental study on steel with ECDM and reported that tool diameter, applied voltage, electrolyte concentration greatly influence the machined features. Bhattacharyya et al

Preparation of High Density Cellulose Membrane for Pressure Flux

2288 words - 9 pages each other during coagulation process induce more porous part on membrane. Therefore when membrane composed of mixed cellulose DP the porosity is decrease due to the low cellulose DP can reduce this mechanism, however this tend to induce a bigger mean pore size since the low homogeneity in casting solution. B. The Effect of Cellulose Concentration in casting solution To obtain membranes with good performance, the polymer concentration of the

photo catalytic degradation review

1828 words - 8 pages catalysis utilizes Photo-Fenton technology while Heterogeneous catalysis comprises TiO2 and Hydrogen Peroxide. This review paper gives an summary of the understanding of the mechanism of heterogeneous, homogeneous photocatalysis & various equipment’s used in the process of photocatalysis ie (through photochemical AOP). The paper also analyses the demerits of the aforementioned process and the alternatives used to overcome them

Hearing underwater

953 words - 4 pages . Statistical analyses determined that the differences in threshold SPL (due to the experimental conditions) were not significant at any frequency except 250 Hz. In addition, only the threshold SPL at 8000 Hz is significantly different from those at lower test frequencies. A way of explaining the data is that the middle-ear mechanism is not used in underwater hearing but, rather, is bypassed by the mechanism of bone conduction. If this is the case, and it

Impact of Silver Nanoparticle Embedment on the Frequency Dispersion and Dielectric Relaxation in Dodecylbenzenesulfonic Acid Doped Polyaniline

696 words - 3 pages mechanism of frequency dependent charge carrier transfer in metal nanoparticle incorporated semiconducting polymer composites, the specific features of this mechanism still have been the subject of theoretical and experimental investigations. Several relevant points concerning the charge transport are still unclear. There is no general concept of how the metal nano-fillers, dispersed within the moderately doped semiconducting polymer matrix

The Combustion of Polymers

1756 words - 8 pages properties of hydrocarbons have caused millions of dollars in property damage and claimed an untold number of human lives. It is this fact that has lead to scientists devoting time and resources to making polymers safer. In the following paragraphs the mechanism behind burning polymers will be discussed, as well as the techniques employed to either slow the rate of fire and/or extinguish it altogether. A section will also be devoted to a review

Fuel Cell Research

5842 words - 23 pages a reaction takes place is called the electrochemical fuel cell or fuel cell.Depending on the type of the electrolyte used, there are several types of fuel cells:Alkaline fuel cells (AFC) use concentrated (85 wt%) KOH as the electrolyte for high temperature operation (250°C) and less concentrated (35-50 wt%) for lower temperature operation (Polymer electrolyte membrane or proton exchange membrane fuel cells (PEMFC) use a thin polymer membrane


615 words - 3 pages most important mechanism in reaction kinetics of the battery. First, porous cathode must have good oxygen path for oxygen to pass through to electrolyte. At the same time, diffusion of the lithium ions from anodic side is important. Solubility also plays important role in the kinetics reaction of the battery. Oxygen becomes less mobile while dissolve into the electrolyte compared to oxygen in gas phase. This effects the reaction kinetics and

Similar Essays

Battery Storage Is Necessary To Provide Energy Storage For The Future

2587 words - 11 pages commercial batteries is that, their ionic conductivity is not good enough. In order to solve this problem, understanding of molecular structure is essential. It can help us have a clear idea of the working mechanism of polymer electrolytes, which is prerequisite for getting fast ion transport effect in polymers. 2.4 Polymer gel electrolyte Electrolytes made though sol-gel process is the main focus of this training. It’s important to know the

Natural Biopolymer Materials Carboxymethyl Cellulose Based Protonic Conducting Biopolymer Electrolyte And Application In Rechargeable Protonic Battery

642 words - 3 pages Over a year, the electrochemical power was obtained by using liquid electrolyte due to its high ionic conductivity. Yet, this liquid electrolyte gives a lot of problems such as leakage, reaction with electrode, and poor electrochemical stability, which makes it unsuitable for the use in electrochemical devices. When the first reported solid polymer electrolyte was made in 1973, the researcher realized that this polymer electrolyte can be used to

The Poylmer Electrolyte Membrane Fuel Cell

866 words - 4 pages A fuel cell is mainly used to provide electricity from chemical reactions. It harnesses the chemical energy of hydrogen and oxygen to generate electricity without combustion one of the basic types of fuel cells is the Polymer Electrolyte Membrane Fuel Cell (PEMFC). This section will give a general description of its parts, how do they function and the material they are consisted of. 3.2 Background Polymer electrolyte membrane fuel cells

Ti And Ti O2 Photocatalysis Essay

1097 words - 5 pages UV radiation. Figure 2. Photocatalysis of water[3] When the semiconductor TiO2 is in the electrolyte solution, thermodynamic equilibrium will occur at the interface. A space-charge layer will form at the thin surface region of the semiconductor. If the titanium dioxide receives higher energy than the gap between valence band and conduction band, the electron-hole pairs generate and separate in the space-charge layer. The space-charge layer will