This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (No. NRF-2017R1A2A2A05001329). The authors of the manuscript are grateful to the Sogang University, Seoul, Republic of Korea.

1. Experimental requirement
<ol>
	<li>Purchase ion-exchange ionomer polymer, E-550 sulfonated-PEEK polymer fiber to prepare CEM and FAA-3 to prepare AEM. Ensure that all ionomer polymers are stored in a clean, dry, and dust-free environment before use.</li>
	<li>Use high purity (&#62;99%) solvents, including N-Methyl-2- pyrrolidone with molecular weight 99.13 g mol-1 and N, N-Dimethylacetamide with molecular weight 87.12, for preparing homogeneous ionomer solution. Ensure all analytical grade chemicals and s...

<ol>
	<li>Dlugolecki, P., Gambier, A., Nijmeijer, K., Wessling, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Practical+potential+of+reverse+electrodialysis+as+process+for+sustainable+energy+generation.">Practical potential of reverse electrodialysis as process for sustainable energy generation.</a> Environmental Science &amp; Technology. 43, 6888-6894 (2009).</li><li>Kim, D., Kwon, K., Kim, D. H., Li, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Energy Generation Using Reverse Electrodialysis: Principles, Implementation, and Applications. , (2019).</li><li>Mei, Y., Tang, C. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recent+developments+and+future+perspectives+of+reverse+electrodialysis+technology:+A+review.">Recent developments and future perspectives of reverse electrodialysis technology: A review.</a> Desalination. 425, 156-174 (2018).</li><li>Yip, N. Y., Brogioli, D., Hamelers, H. V. M., Nijmeijer, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Salinity+gradients+for+sustainable+energy:+primer,+progress,+and+prospects.">Salinity gradients for sustainable energy: primer, progress, and prospects.</a> Environmental Science &amp; Technology. 50, 12072-12094 (2016).</li><li>Li, W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+hybrid+process+of+reverse+electrodialysis+and+reverse+osmosis+for+low+energy+seawater+desalination+and+brine+management.">A novel hybrid process of reverse electrodialysis and reverse osmosis for low energy seawater desalination and brine management.</a> Applied Energy. 104, 592-602 (2013).</li><li>Brauns, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Salinity+gradient+power+by+reverse+electrodialysis:+effect+of+model+parameters+on+electrical+power+output.">Salinity gradient power by reverse electrodialysis: effect of model parameters on electrical power output.</a> Desalination. 237, 378-391 (2009).</li><li>Cusick, R. D., Kim, Y., Logan, B. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Energy+capture+from+thermolytic+solutions+in+microbial+reverse-electrodialysis+cells.">Energy capture from thermolytic solutions in microbial reverse-electrodialysis cells.</a> Science. 335, 1474-1477 (2012).</li><li>Kim, D. H., Park, B. H., Kwon, K., Li, L., Kim, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modeling+of+power+generation+with+thermolytic+reverse+electrodialysis+for+low-grade+waste+heat+recovery.">Modeling of power generation with thermolytic reverse electrodialysis for low-grade waste heat recovery.</a> Applied Energy. 189, 201-210 (2017).</li><li>Hong, J. G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Potential+ion+exchange+membranes+and+system+performance+in+reverse+electrodialysis+for+power+generation:+A+review.">Potential ion exchange membranes and system performance in reverse electrodialysis for power generation: A review.</a> Journal of Membrane Science. 486, 71-88 (2015).</li><li>Choi, S. -. Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Controlling+fuel+crossover+in+open+electrochemical+cells+by+tuning+the+water+nanochannel+for+power+generation.">Controlling fuel crossover in open electrochemical cells by tuning the water nanochannel for power generation.</a> ACS Sustainable Chemistry &amp; Engineering. 8, 8613-8623 (2020).</li><li>Shah, S. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modified+single-wall+carbon+nanotube+for+reducing+fouling+in+perfluorinated+membrane-based+reverse+electrodialysis.">Modified single-wall carbon nanotube for reducing fouling in perfluorinated membrane-based reverse electrodialysis.</a> International Journal of Hydrogen Energy. 45, 30703-30719 (2020).</li><li>Kwon, K., Han, J., Park, B. H., Shin, Y., Kim, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Brine+recovery+using+reverse+electrodialysis+in+membrane-based+desalination+processes.">Brine recovery using reverse electrodialysis in membrane-based desalination processes.</a> Desalination. 362, 1-10 (2015).</li><li>Kwon, K., Park, B. H., Kim, D. H., Kim, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Parametric+study+of+reverse+electrodialysis+using+ammonium+bicarbonate+solution+for+low-grade+waste+heat+recovery.">Parametric study of reverse electrodialysis using ammonium bicarbonate solution for low-grade waste heat recovery.</a> Energy Conversion and Management. 103, 104-110 (2015).</li><li>Hatzell, M. C., Ivanov, I., Cusick, R. D., Zhu, X., Logan, B. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+hydrogen+production+and+electrical+power+generation+for+energy+capture+in+closed-loop+ammonium+bicarbonate+reverse+electrodialysis+systems.">Comparison of hydrogen production and electrical power generation for energy capture in closed-loop ammonium bicarbonate reverse electrodialysis systems.</a> Physical Chemistry Chemical Physics. 16, 1632-1638 (2014).</li><li>Zhu, X. P., He, W. H., Logan, B. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reducing+pumping+energy+by+using+different+flow+rates+of+high+and+low+concentration+solutions+in+reverse+electrodialysis+cells.">Reducing pumping energy by using different flow rates of high and low concentration solutions in reverse electrodialysis cells.</a> Journal of Membrane Science. 486, 215-221 (2015).</li><li>Vermaas, D. A., Saakes, M., Nijmeijer, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Doubled+power+density+from+salinity+gradients+at+reduced+intermembrane+distance.">Doubled power density from salinity gradients at reduced intermembrane distance.</a> Environmental Science &amp; Technology. 45, 7089-7095 (2011).</li><li>Veerman, J., Saakes, M., Metz, S. J., Harmsen, G. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reverse+electrodialysis:+Performance+of+a+stack+with+50+cells+on+the+mixing+of+sea+and+river+water.">Reverse electrodialysis: Performance of a stack with 50 cells on the mixing of sea and river water.</a> Journal of Membrane Science. 327, 136-144 (2009).</li><li>Veerman, J., Saakes, M., Metz, S. J., Harmsen, G. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrical+power+from+sea+and+river+water+by+reverse+electrodialysis:+a+first+step+from+the+laboratory+to+a+real+power+plant.">Electrical power from sea and river water by reverse electrodialysis: a first step from the laboratory to a real power plant.</a> Environmental Science &amp; Technology. 44, 9207-9212 (2010).</li><li>Batchelor, C. K., Batchelor, G. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> An Introduction to Fluid Dynamics. , (2000).</li><li>Schock, G., Miquel, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mass+transfer+and+pressure+loss+in+spiral+wound+modules.">Mass transfer and pressure loss in spiral wound modules.</a> Desalination. 64, 339-352 (1987).</li><li>Da Costa, A. R., Fane, A. G., Wiley, D. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spacer+characterization+and+pressure+drop+modelling+in+spacer-filled+channels+for+ultrafiltration.">Spacer characterization and pressure drop modelling in spacer-filled channels for ultrafiltration.</a> Journal of Membrane Science. 87, 79-98 (1994).</li><li>Vermaas, D. A., Veerman, J., Saakes, M., Nijmeijer, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Influence+of+multivalent+ions+on+renewable+energy+generation+in+reverse+electrodialysis.">Influence of multivalent ions on renewable energy generation in reverse electrodialysis.</a> Energy &amp; Environmental Science. 7, 1434-1445 (2014).</li><li>Vermaas, D. A., Saakes, M., Nijmeijer, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enhanced+mixing+in+the+diffusive+boundary+layer+for+energy+generation+in+reverse+electrodialysis.">Enhanced mixing in the diffusive boundary layer for energy generation in reverse electrodialysis.</a> Journal of Membrane Science. 453, 312-319 (2014).</li><li>Moreno, J., Grasman, S., van Engelen, R., Nijmeijer, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Upscaling+reverse+electrodialysis.">Upscaling reverse electrodialysis.</a> Environmental Science &amp; Technology. 52, 10856-10863 (2018).</li><li>Sarkar, S., SenGupta, A. K., Prakash, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+donnan+membrane+principle:+opportunities+for+sustainable+engineered+processes+and+materials.">The donnan membrane principle: opportunities for sustainable engineered processes and materials.</a> Environmental Science &amp; Technology. 44, 1161-1166 (2010).</li><li>Kim, H. -. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High+power+density+of+reverse+electrodialysis+with+pore-filling+ion+exchange+membranes+and+a+high-open-area+spacer.">High power density of reverse electrodialysis with pore-filling ion exchange membranes and a high-open-area spacer.</a> Journal of Materials Chemistry A. 3, 16302-16306 (2015).</li><li>D&#322;ugo&#322;&#281;cki, P., Nymeijer, K., Metz, S., Wessling, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Current+status+of+ion+exchange+membranes+for+power+generation+from+salinity+gradients.">Current status of ion exchange membranes for power generation from salinity gradients.</a> Journal of Membrane Science. 319, 214-222 (2008).</li><li>Geise, G. M., Curtis, A. J., Hatzell, M. C., Hickner, M. A., Logan, B. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Salt+concentration+differences+alter+membrane+resistance+in+reverse+electrodialysis+stacks.">Salt concentration differences alter membrane resistance in reverse electrodialysis stacks.</a> Environmental Science &amp; Technology Letters. 1, 36-39 (2014).</li></ol>

The RED&#39;s working principle is mainly dominated by the membrane&#39;s physicochemical properties, which is a crucial part of the RED system, as illustrated in Figure 3. Here, we describe the fundamental characteristics of the membrane for delivering a high-performance RED system. Membrane&#39;s specific ion permeability makes it pass one type of ions through their polymer nanochannel. As the name suggests, CEM can pass cation from one side to another and restricts anion, whereas AEM can ...

Energy harvesting from natural resources is an economical method that is environmentally friendly, thereby making our planet green and clean. Several processes have been proposed until now to extract energy, but reverse electrodialysis (RED) has an enormous potential to overcome the energy crisis issue1. Power production from Reverse electrodialysis is a technological breakthrough for the decarbonization of global energy. As the name suggests, RED is a reverse process, where the alternate cell compartment is filled with the high-concentrated salt solution and low-concentrated salt solution2. The chemical potential generated by the salt concentration difference across the ion-exchange membranes, collected from the electrodes at the compartment end.
Since the year 2000, many research articles have been published, providing insight into the RED theoretically and experimentally3,4. Systematic studies on the operation conditions and reliability studies under stress conditions improved the stack architecture and enhanced the overall cell performance. Several research groups have diverted their attention toward RED&#39;s hybrid application, such as RED with desalination process5, RED with solar power6, RED with reverse osmosis (RO) process5, RED with the microbial fuel cell7, and RED with the radiative cooling process8. As mentioned earlier, there is a lot of scope in implementing RED&#39;s hybrid application to solve the energy and clean water problem.
Several methods have been adopted to enhance the RED cell&#39;s performance and the membrane&#39;s ion-exchange capacity. Tailoring the cation-exchange membranes with different types of ions using sulfonic acid group (-SO3H), phosphonic acid group (-PO3H2), and carboxylic acid group (-COOH) is one of the effective ways to alter the physicochemical properties of the membrane. Anion-exchange membranes are tailored with ammonium groups (<img alt="Equation 1" src="/files/ftp_upload/62309/62209eq1.jpg" />)9. The high ionic conductivity of AEM and CEM without deteriorating the membrane&#39;s mechanical strength is the essential parameter for selecting an appropriate membrane for device application. The robust membrane under stress conditions provides mechanical stability to the membrane and enhances the device&#39;s durability. Here, a unique combination of high-performance free-standing sulfonated poly (ether ether ketone) (sPEEK) as cation-exchange membranes with FAA-3 as anion-exchange membranes are used in the RED application. Figure 1 shows the flow chart of the experimental procedure.
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/62309/62309fig01.jpg" /> 
Figure 1: Procedure chart. The flow chart presents the procedure adopted for the preparation of ion-exchange membrane followed by the process for measurement of reverse electrodialysis. <a href="https://www.jove.com/files/ftp_upload/62309/62309fig01large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>AEM based membrane</td>
			<td>Fumion</td>
			<td>P1810-194</td>
			<td>Ionomer</td>
		</tr>
		<tr>
			<td>CEM based membrane</td>
			<td>Fumion</td>
			<td>E550</td>
			<td>Ionomer</td>
		</tr>
		<tr>
			<td>Digital torque wrench</td>
			<td>Torqueworld</td>
			<td>WP2-030-09000251</td>
			<td>wrench</td>
		</tr>
		<tr>
			<td>Labview software</td>
			<td>Natiaonal Instrument</td>
			<td>-</td>
			<td>Software</td>
		</tr>
		<tr>
			<td>Laptop</td>
			<td>LG</td>
			<td>-</td>
			<td>PC</td>
		</tr>
		<tr>
			<td>Magnetic stirrer</td>
			<td>Lab Companion</td>
			<td>-</td>
			<td>MS-17BB</td>
		</tr>
		<tr>
			<td>N, N-Dimethylacetamide</td>
			<td>Sigma aldrich</td>
			<td>271012</td>
			<td>Chemical</td>
		</tr>
		<tr>
			<td>N-Methyl-2- pyrrolidone</td>
			<td>Daejung</td>
			<td>872-50-4</td>
			<td>Chemical</td>
		</tr>
		<tr>
			<td>Peristaltic pump</td>
			<td>EMS tech Inc</td>
			<td>-</td>
			<td>EMP 2000W</td>
		</tr>
		<tr>
			<td>Potassium hexacyanoferrate(II) trihydrate</td>
			<td>Sigma aldrich</td>
			<td>P3289</td>
			<td>Chemical</td>
		</tr>
		<tr>
			<td>Potassium hexacyanoferrate(III)</td>
			<td>Sigma aldrich</td>
			<td>244023</td>
			<td>Chemical</td>
		</tr>
		<tr>
			<td>Pressure Gauge</td>
			<td>Swagelok</td>
			<td>-</td>
			<td>Guage</td>
		</tr>
		<tr>
			<td>Reverse electrodialysis setup</td>
			<td>fabricated in lab</td>
			<td>-</td>
			<td>Device</td>
		</tr>
		<tr>
			<td>RO system pure water</td>
			<td>KOTITI</td>
			<td>-</td>
			<td>Water</td>
		</tr>
		<tr>
			<td>Rotary evaporator</td>
			<td>Hitachi</td>
			<td>YEFO-KTPM</td>
			<td>Induction motor</td>
		</tr>
		<tr>
			<td>Sodium Chloride</td>
			<td>Sigma aldrich</td>
			<td>S9888</td>
			<td>Chemical</td>
		</tr>
		<tr>
			<td>Sodium Hydroxide</td>
			<td>Merk</td>
			<td>1310-73-2</td>
			<td>Chemical</td>
		</tr>
		<tr>
			<td>Source meter</td>
			<td>Keithley</td>
			<td>-</td>
			<td>2410</td>
		</tr>
		<tr>
			<td>Spacer</td>
			<td>Nitex, SEFAR</td>
			<td>06-250/34</td>
			<td>Spacer</td>
		</tr>
		<tr>
			<td>Sulfuric acid</td>
			<td>Daejung</td>
			<td>7664-93-9</td>
			<td>Chemical</td>
		</tr>
		<tr>
			<td>Tube</td>
			<td>Masterflex tube</td>
			<td>96410-25</td>
			<td>Rubber tube</td>
		</tr>
	</tbody>
</table>

ion-exchange membranes for the fabrication of reverse electrodialysis device

Reverse electrodialysis (RED) is an effective way to generate power by mixing two different salt concentrations in water using cation-exchange membranes (CEM) and anion-exchange membranes (AEM). The RED stack is composed of an alternating arrangement of the cation-exchange membrane and anion-exchange membrane. The RED device acts as a potential candidate for fulfilling the universal demand for future energy crises. Here, in this article, we demonstrate a procedure to fabricate a reverse electrodialysis device using laboratory-scale CEM and AEM for power production. The active area of the ion-exchange membrane is 49 cm2. In this article, we provide a step-by-step procedure for synthesizing the membrane, followed by the stack&#39;s assembly and power measurement. The measurement conditions and net power output calculation have also been explained. Furthermore, we describe the fundamental parameters that are taken into consideration for obtaining a reliable outcome. We also provide a theoretical parameter that affects the overall cell performance relating to the membrane and the feed solution. In short, this experiment describes how to assemble and measure RED cells on the same platform. It also contains the working principle and calculation used for estimating the net power output of the RED stack using CEM and AEM membranes.

Net power output 
RED cell generally generates electrical energy from the salinity gradient of the salt solution, i.e., ions&#39; movement in the opposite direction through the membrane. To assemble the RED stack correctly, one needs to align all the layers, including electrodes, gaskets, membranes, and spacers in the stack carefully, as demonstrated in the schematic diagram in Figure 4 and Figure 5. If the stack is not perfectly aligned, t...

Watch this Scientific Journal Video about Ion-Exchange Membranes for the Fabrication of Reverse Electrodialysis Device at JoVE.com

Ion-Exchange Membranes for the Fabrication of Reverse Electrodialysis Device

We demonstrate the fabrication of a reverse electrodialysis device using a cation-exchange membrane (CEM) and anion-exchange membrane (AEM) for power generation.

Reverse electrodialysis (RED) is an effective way to generate power by mixing two different salt concentrations in water using cation-exchange membranes ...

This protocol is a noise-free, clean, and sustainable way of producing energy. It can easily solve the energy crisis problem by converting the water salinity gradient into electricity. The method provides a direct list for extending large area membrane with outstanding physiochemical properties for generating efficient power using RED.The output performance of the RED device can be scaled up and the membrane can be utilized in other electrochemical devices like phoresis and redox flow batteries. Homogeneous solution preparation, filtration, drying, control techniques, wash, membrane treatment, regulate the reproducible membrane performance. The stack alignment and pressure drop optimization are crucial for producing stable device performance.To prepare a cation exchange membrane, add 5%sulfinitated polyetheretherketone fibers to a 250 milliliter round bottom flask and dissolve the fibers in dimethylacetamide solvent. Then shake the flask for 10 minutes so that all of the ionomer polymers settle to the bottom of the flask. Place the mixture into a silicon oil bath with a magnetic stir bar and vigorously stir the solution at 500 revolutions per minute for 24 hours at 80 degrees Celsius to obtain a homogenous solution.On the next day, filter 30 milliliters of the solution through a 0.45 micrometer PTFE filter into a circular 18 centimeter diameter glass dish. Use an air blower to remove any bubbles before placing the dish in the oven for 24 hours at 90 degrees Celsius to generate an approximately 50 micrometer thick freestanding membrane. To extract the freestanding membrane, fill the dish with warm distilled water.After 10 minutes, the freestanding membrane will detach from the dish. To activate the membrane, immerse the membrane in one molar sulfuric acid solution for two hours at 80 degrees Celsius, followed by at least three 10 minute washes with one liter of distilled water at room temperature per wash. Dissolve 10%by weight FAA-3 ionomer solution in NMP solvent for two hours at room temperature and 500 revolutions per minute.At the end of the incubation, filter approximately 30 milliliters of solution through a 100 micron pore strainer into an 18 centimeter glass Petri dish. After removing any air bubbles, place the dish into a 100 degrees Celsius oven for 24 hours. Use hot distilled water to extract the dried membrane as demonstrated and activate the membrane in one liter of sodium hydroxide for two hours.Then wash the activated membrane three times with one liter of distilled water per wash as demonstrated. After activation, cut the cation and anion exchange membranes to 49 square centimeters. To fabricate a RED stack, position a three centimeter thick PMMA plate with the electrode facing up and place a rubber gasket and spacer onto the electrode.Place the cation exchange membrane and the anion exchange membrane on either side of the gasket. Place a silicon gasket and a spacer onto each membrane and place a second PMMA plate onto the second layer of spacers and gaskets. Then use a digital wrench drive with a 25 newton meter force to secure the setup with nuts, bolts, and washers.When the stack has been assembled, place one titanium mesh electrode coated with a one-to-one mixture of iridium and ruthenium at the end of each plate and use crocodile clips to connect the electrodes to the source meter. At least two hours before the analysis, add five liters of a 0.01 molar low sodium chloride solution and five liters of a 0.6 molar high sodium chloride solution to individual large containers connected to a peristaltic pump and stir the solutions continuously at room temperature. To perform the RED analysis add 0.05 molar rinse solution to a third container and use rubber tubes to connect all three containers through the peristaltic pump and pressure gauges to the RED assembly.Set the flow rate of the rinse solution to 50 milliliters per minute and the flow rate of the salt solutions to 100 milliliters per minute, and check the tubing to eliminate any crossflow or leakage. Perform a pressure gauge reading to be sure that the reading is stable. After the solutions have run through the stack at least for five minutes, use a source meter connected to both of the electrodes and to the RED stack to measure the reverse electrodialysis output performance by the galvanostat method.The reverse electrodialysis device acts as a potential candidate for fulfilling the universal demand for future energy crises. The difference in the salinity gradient of the salt concentration gives rise to the open circuit voltage, which depends on the internal resistance of the reverse electrodialysis stack. In this analysis, the maximum power density for the reverse electrodialysis stack was about 0.7 watts per square meter, and the calculated net power density was about 0.65 watts per square meter at a fixed flow rate.As observed, the power density of the cell increased initially to the maximum current density value before dropping in response to an increase in the internal resistance of the RED stack. It is important to regularly crosscheck the tubing connection, solution crossflow, and liquids for producing efficient and stable said performance. The preparation of a uniform large area membrane will destabilize the cell performance without fouling the membrane and solution leakage.Furthermore, it work efficiently under stress conditions.

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10.0K Views.  Energy Engineering Lab, Sogang University. This protocol is a noise-free, clean, and sustainable way of producing energy. It can easily solve the energy crisis problem by converting the water salinity gradient into electricity. The method provides a direct list for extending large area membrane with outstanding physiochemical properties for generating efficient power using RED.The output performance of the RED device can be scaled up and the membrane can be utilized in other electrochemical devices like phoresis and redox flow ...