scholarly journals Anionic Exchange Membrane for Photo-Electrolysis Application

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2991
Author(s):  
Carmelo Lo Vecchio ◽  
Alessandra Carbone ◽  
Stefano Trocino ◽  
Irene Gatto ◽  
Assunta Patti ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Light Transmission ◽  
Cupric Oxide ◽  
Low Cost ◽  
Polymer Electrolyte Membrane ◽  
Exchange Process ◽  
Exchange Capacity ◽  
Electrolyte Membrane ◽  
Ion Exchange Process ◽  
Exchange Membrane

Tandem photo-electro-chemical cells composed of an assembly of a solid electrolyte membrane and two low-cost photoelectrodes have been developed to generate green solar fuel from water-splitting. In this regard, an anion-exchange polymer–electrolyte membrane, able to separate H2 evolved at the photocathode from O2 at the photoanode, was investigated in terms of ionic conductivity, corrosion mitigation, and light transmission for a tandem photo-electro-chemical configuration. The designed anionic membranes, based on polysulfone polymer, contained positive fixed functionalities on the side chains of the polymeric network, particularly quaternary ammonium species counterbalanced by hydroxide anions. The membrane was first investigated in alkaline solution, KOH or NaOH at different concentrations, to optimize the ion-exchange process. Exchange in 1M KOH solution provided high conversion of the groups, a high ion-exchange capacity (IEC) value of 1.59 meq/g and a hydroxide conductivity of 25 mS/cm at 60 °C for anionic membrane. Another important characteristic, verified for hydroxide membrane, was its transparency above 600 nm, thus making it a good candidate for tandem cell applications in which the illuminated photoanode absorbs the highest-energy photons (< 600 nm), and photocathode absorbs the lowest-energy photons. Furthermore, hydrogen crossover tests showed a permeation of H2 through the membrane of less than 0.1%. Finally, low-cost tandem photo-electro-chemical cells, formed by titanium-doped hematite and ionomer at the photoanode and cupric oxide and ionomer at the photocathode, separated by a solid membrane in OH form, were assembled to optimize the influence of ionomer-loading dispersion. Maximum enthalpy (1.7%), throughput (2.9%), and Gibbs energy efficiencies (1.3%) were reached by using n-propanol/ethanol (1:1 wt.) as solvent for ionomer dispersion and with a 25 µL cm−2 ionomer loading for both the photoanode and the photocathode.

scholarly journals Amberlite IRC-718 ion chelating resin extraction of hazardous metal Cr (VI) from aqueous solutions: equilibrium and theoretical modeling

2021 ◽  
Author(s):  
Abdelhamid Addala ◽  
Moussa Boudiaf ◽  
Maria Elektorowicz ◽  
Embarek Bentouhami ◽  
Yacine Bengeurba
Keyword(s):  
Ion Exchange ◽  
Aqueous Solutions ◽  
Exchange Process ◽  
Ion Exchange Resin ◽  
Exchange Capacity ◽  
Chelating Resin ◽  
Exchange Potential ◽  
Chromium Vi ◽  
Ion Exchange Process ◽  
Hazardous Metal

Abstract Under varied conditions, the IRC 718 ion-exchange resin is used to extract chromium (VI) ions from aqueous solutions. On chromium (VI) removal effectiveness, the effects of adsorption dosage, contact time, beginning metal concentration, and pH were examined. The batch ion exchange process reached equilibrium after around 90 minutes of interaction. With an initial chromium (VI) concentration of 0.5 mg/dm3, the pH-dependent ion-exchange mechanism revealed maximal removal in the pH 2.0–10 range . The adsorption mechanism occurs between Cr(VI) determined as the electron acceptor, and IRC 718 determined as the electron donor. The equilibrium ion-exchange potential and ion transfer quantities for Amberlite IRC 718 were calculated using the Langmuir adsorption isotherm model. The overall ion exchange capacity of the resin was determined to be 187.72 mg of chromium (VI)/g of resin at an ideal pH of 6.0.

scholarly journals The Li+, Na+ and K+ ion exchange reaction process on the surface of mixed oxide SiO2/TiO2/Sb2O5 surface prepared by the sol-gel processing method

2005 ◽  
Vol 30 (1) ◽  
pp. 51-58 ◽  
Author(s):  
C. U. Ferreira ◽  
J. E. Gonçalves ◽  
Y. V. Kholin ◽  
Y. Gushikem
Keyword(s):  
Ion Exchange ◽  
Mixed Oxide ◽  
Exchange Process ◽  
Sol Gel ◽  
Exchange Capacity ◽  
Processing Method ◽  
Exchange Property ◽  
Ion Exchange Process ◽  
Ion Exchange Reaction ◽  
Gel Processing

The porous mixed oxide SiO2/TiO2/Sb2O5 obtained by the sol-gel processing method presented a good ion exchange property and a high exchange capacity towards the Li+, Na+ and K+ ions. In the H+/M+ ion exchange process, the H+ / Na+ could be described as presenting an ideal character. The ion exchange equilibria of Li+ and K+ were quantitatively described with the help of the model of fixed tetradentate centers. The results of simulation evidence that for the H+ / Li+ exchange the usual situation takes place: the affinity of the material to the Li+ ions is decreased with increasing the degree of ion exchange. On the contrary, for K+ the effects of positive cooperativity, that facilitate the H+ / K+ exchange, were revealed.

Preliminary Study of ABS/Chitosan Blend Polymer for DMFC Membranes

2019 ◽  
Vol 961 ◽  
pp. 23-29
Author(s):  
Nur Hidayati ◽  
Muhammad Mujiburohman ◽  
Hamid Abdillah ◽  
Herry Purnama ◽  
Arnaldi Dwilaksita ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Direct Methanol Fuel Cells ◽  
Low Cost ◽  
Polymer Electrolyte Membrane ◽  
Exchange Capacity ◽  
Methanol Permeability ◽  
Ion Exchange Capacity ◽  
Electrolyte Membrane ◽  
Direct Methanol ◽  
Blend Polymer

The low cost of ABS polymer and natural polymer chitosan offer attractive chemical and physical properties for direct methanol fuel cells (DMFC). In this contribution, investigation of blend membrane made of ABS and chitosan, and their characterization for water uptake, swelling degree and ion exchange capacity (IEC) and methanol crossover are reported. This membrane was also assessed for its intermolecular interactions and thermal stability using FTIR and TGA compared to the pristine membrane. The water absorption and IEC values were affected by membrane network structure. The polymer blend had better thermal stability and a reduction of methanol permeability, this indicated the viability of utilization these materials as polymer electrolyte membrane in DMFC

scholarly journals High-performance, Durable and Low-Cost Proton Exchange Membrane Electrolyser with Stainless Steel Components

2021 ◽  
Author(s):  
Svenja Stiber ◽  
Noriko Sata ◽  
Tobias Morawietz ◽  
Syed Asif Ansar ◽  
Thomas Jahnke ◽  
...  
Keyword(s):  
High Performance ◽  
Proton Exchange Membrane ◽  
State Of The Art ◽  
Low Cost ◽  
Polymer Electrolyte Membrane ◽  
Water Electrolysis ◽  
Proton Exchange ◽  
Electrolyte Membrane ◽  
Current State ◽  
Exchange Membrane

Polymer electrolyte membrane water electrolysis (PEMWE) is the most promising technology for sustainable hydrogen production. However, it has been too expensive to compete with current state-of-the-art technologies due to the...

scholarly journals Sorption of pertechnetate anion by cation modified bentonites

2019 ◽  
Vol 322 (3) ◽  
pp. 1771-1776
Author(s):  
D. Buzetzky ◽  
E. M. Kovács ◽  
M. N. Nagy ◽  
J. Kónya
Keyword(s):  
Ion Exchange ◽  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Metal Ion ◽  
Exchange Process ◽  
Exchange Capacity ◽  
Ion Exchange Process

Abstract Pertechnetate anion sorption was investigated on modified bentonites. Mn-, Cr-, Sn-bentonites were prepared by ion exchange process to sorb radioactive pertechnetate ions. In the case of Mn-, Cr-bentonite the sorb amount of metal ion was 70–90% of the cation exchange capacity of the bentonite which is expected. Interestingly in the case of Sn-bentonite this amount was 1.42 times higher than the cation exchange capacity. On Mn-bentonite the sorption was 35% at pH 5. The removal of pertechnetate ions was 100% on Cr-, Sn-bentonites and the significant sorption was achieved below 650 mV/SHE.

scholarly journals Removal of quaternary ammonium compounds in ion exchange process

2019 ◽  
Vol 116 ◽  
pp. 00034
Author(s):  
Aleksandra Klimonda ◽  
Izabela Kowalska
Keyword(s):  
Ion Exchange ◽  
Cationic Surfactant ◽  
Exchange Process ◽  
Exchange Capacity ◽  
Resin Matrix ◽  
Ph Change ◽  
Ion Exchange Process ◽  
Batch Tests ◽  
Exchange Resins ◽  
Surfactant Removal

The study attempted to evaluate the effectiveness of ion exchange process in cationic surfactant (benzalkonium chloride, BAC) removal from model solutions. Four commercial cation-exchange resins were chosen for the batch tests in four doses (2.5–20 mL L-1). The experiments included evaluation of the following parameters on ion exchange efficiency: resin characteristics and dose, presence of inorganic salt and pH of treated solution. The ion exchange process was found to be very effective in cationic surfactant removal – two of tested resins allowed to remove up to 80% of contaminant after contact time of 40 minutes, the last two – after 60 minutes of mixing in all range of doses. The presence of electrolyte neither pH change has no essential effect on surfactant removal efficiency. The analysis of the ion exchange isotherms showed that the strongly-acidic macroporous resin C150 H was characterized by the highest BAC ion exchange capacity (153.8 mg mL-1), while the weakly-acidic gel resin C104 showed the best affinity of the exchanged ions to the resin matrix.

scholarly journals Mathematical modeling of the ion exchange processes of sodium clinoptilolite with heavy metal ions from residual waters

2005 ◽  
Vol 11 (4) ◽  
pp. 209-212 ◽  
Author(s):  
Claudia Cobzaru ◽  
Spiridon Oprea
Keyword(s):  
Mathematical Modeling ◽  
Ion Exchange ◽  
Exchange Process ◽  
Correlation Coefficients ◽  
Solution Concentration ◽  
Exchange Capacity ◽  
Response Surfaces ◽  
Ion Exchange Process ◽  
Model Equations ◽  
Necessary And Sufficient

The ion-exchange capacity of volcanic tuff in the Na+ form (70% clinoptilolite content), used for removing heavy metals in residual waters, was investigated under different conditions (temperature, time and exchange solution concentration). These parameters are necessary and sufficient for the mathematical modeling of the ion-exchange process. The corresponding mathematical models show common characteristics due to the good arrangement of the experimental points on the response surfaces and correlation coefficients close to unity. Differences appear with respect to the shape of the response surface and model equations. .

Removal of Toxic Dyestuffs from Aqueous Solution by Amphoteric Bioadsorbent

2020 ◽  
Vol 16 ◽  
Author(s):  
Reda M. El-Shishtawy ◽  
Abdullah M. Asiri ◽  
Nahed S. E. Ahmed
Keyword(s):  
Aqueous Solution ◽  
Ion Exchange ◽  
Dye Removal ◽  
Exchange Process ◽  
Cationic Dyes ◽  
Carboxyl Groups ◽  
Maximum Adsorption Capacity ◽  
Equilibrium Isotherm ◽  
Ion Exchange Process ◽  
Dyes And Pigments

Background: Color effluents generated from the production industry of dyes and pigments and their use in different applications such as textile, paper, leather tanning, and food industries, are high in color and contaminants that damage the aquatic life. It is estimated that about 105 of various commercial dyes and pigments amounted to 7×105 tons are produced annually worldwide. Ultimately, about 10–15% is wasted into the effluents of the textile industry. Chitin is abundant in nature, and it is a linear biopolymer containing acetamido and hydroxyl groups amenable to render it atmospheric by introducing amino and carboxyl groups, hence able to remove different classes of toxic organic dyes from colored effluents. Methods: Chitin was chemically modified to render it amphoteric via the introduction of carboxyl and amino groups. The amphoteric chitin has been fully characterized by FTIR, TGA-DTG, elemental analysis, SEM, and point of zero charge. Adsorption optimization for both anionic and cationic dyes was made by batch adsorption method, and the conditions obtained were used for studying the kinetics and thermodynamics of adsorption. Results: The results of dye removal proved that the adsorbent was proven effective in removing both anionic and cationic dyes (Acid Red 1 and methylene blue (MB)), at their respective optimum pHs (2 for acid and 8 for cationic dye). The equilibrium isotherm at room temperature fitted the Freundlich model for MB, and the maximum adsorption capacity was 98.2 mg/g using 50 mg/l of MB, whereas the equilibrium isotherm fitted the Freundlich and Langmuir model for AR1 and the maximum adsorption capacity was 128.2 mg/g. Kinetic results indicate that the adsorption is a two-step diffusion process for both dyes as indicated by the values of the initial adsorption factor (Ri) and follows the pseudo-second-order kinetics. Also, thermodynamic calculations suggest that the adsorption of AR1 on the amphoteric chitin is an endothermic process from 294 to 303 K. The result indicated that the mechanism of adsorption is chemisorption via an ion-exchange process. Also, recycling of the adsorbent was easy, and its reuse for dye removal was effective. Conclusion: New amphoteric chitin has been successfully synthesized and characterized. This resin material, which contains amino and carboxyl groups, is novel as such chemical modification of chitin hasn’t been reported. The amphoteric chitin has proven effective in decolorizing aqueous solution from anionic and cationic dyes. The adsorption behavior of amphoteric chitin is believed to follow chemical adsorption with an ion-exchange process. The recycling process for few cycles indicated that the loaded adsorbent could be regenerated by simple treatment and retested for removing anionic and cationic dyes without any loss in the adsorbability. Therefore, the study introduces a new and easy approach for the development of amphoteric adsorbent for application in the removal of different dyes from aqueous solutions.

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