scholarly journals Development of Polymeric Membranes Based on Quaternized Polysulfones for AMFC Applications

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 283 ◽  
Author(s):  
Alessandra Carbone ◽  
Rolando Pedicini ◽  
Irene Gatto ◽  
Ada Saccà ◽  
Assunta Patti ◽  
...  
Keyword(s):  
Quaternary Ammonium ◽  
Mechanical Stability ◽  
Conductivity Measurement ◽  
Exchange Capacity ◽  
Spectroscopic Techniques ◽  
Step Method ◽  
Ion Exchange Capacity ◽  
Quaternary Ammonium Group ◽  
Group A ◽  
Blade Casting

A series of quaternary ammonium-functionalized polysulfones were successfully synthesized using a chloromethylation two-step method. In particular, triethylammonium and trimethylammonium polysulfone derivatives with different functionalization degrees from 60% to 150% were investigated. NMR spectroscopic techniques were used to determine the degree of functionalization of the polymers. The possibility to predict the functionalization degree by a reaction tool based on a linear regression was highlighted. Anionic membranes with a good homogeneity of thickness were prepared using a doctor-blade casting method of functionalized polymers. The chemical–physical data showed that ion exchange capacity, water content, and wettability increase with the increase of functionalization degree. A higher wettability was found for membranes prepared by the trimethylamine (TMA) quaternary ammonium group. A degree of functionalization of 100% was chosen for an electrochemical test as the best compromise between chemical–physical properties and mechanical stability. From anionic conductivity measurement a better stability was found for the triethylamine (TEA)-based membrane due to a lower swelling effect. A power density of about 300 mW/cm2 for the TEA-based sample at 60 °C in a H2/O2 fuel cell was found.

scholarly journals Crystal Structure of a Cationic Bile Salt Derivative ([3,5,7,12]-3-(2-naphthyloylamino)-7,12-dihydroxycholan-24-triethylammonium iodide)

Crystals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 135
Author(s):  
Francisco Meijide ◽  
María Pilar Vázquez-Tato ◽  
Julio Seijas ◽  
Santiago de Frutos ◽  
Juan V. Trillo Novo ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Quaternary Ammonium ◽  
Electrostatic Interactions ◽  
Amide Bond ◽  
Orthorhombic Space Group ◽  
Steroid Nucleus ◽  
Quaternary Ammonium Group ◽  
Group A ◽  
Hydroxy Groups

The crystal structure of the iodide salt of a quaternary ammonium derivative of cholic acid having a naphthalene group attached to the 3rd position of the steroid nucleus through an amide bond ([3,5,7,12]-3-(2-naphthyloylamino)-7,12-dihydroxycholan-24-triethylammonium iodide) has been resolved. The compound crystallizes in the P212121 orthorhombic space group (a/Å = 10.9458(3); b/Å = 12.1625(3); c/Å = 28.4706(7)). The lateral chain adopts a fully extended tttt conformation because the quaternary ammonium group cannot participate in the formation of hydrogen bonds. The iodide ion is involved in the formation of hydrogen bonds as well as the amide group and the two steroid hydroxy groups. Hirshfeld surface analysis confirms that these contacts, as well as the electrostatic interactions, stabilize the structure. The helixes around the 21 screw axis are right-handed ones.

scholarly journals CHARACTERIZATION OF SULFONATED POLYSULFONE/BENTONITE HYBRID MEMBRANES

2014 ◽  
Vol 13 (1) ◽  
pp. 7
Author(s):  
Bambang Piluharto ◽  
Imam Syafi’i ◽  
R. Indahsari ◽  
Tanti Haryati
Keyword(s):  
Ion Exchange ◽  
Water Uptake ◽  
Mechanical Stability ◽  
Group Analysis ◽  
Exchange Capacity ◽  
Polysulfone Membrane ◽  
Ion Exchange Capacity ◽  
Fuel Cell Application ◽  
Sulfonated Polysulfone ◽  
Functional Group Analysis

Sulfonated polysulfone membrane is one of the alternative membranes as replacing Nafion membrane for the fuel cell application. This membrane was prepared by introducing sulfonic group in the polysulfone structure backbone, so that provides the ionic membrane. However, more ionic groups in the SPSF membrane lead to loss mechanical stability. This study aims to prepare the hybrid membrane from SPSF and bentonite. In here, various of bentonite concentrations were used as variable to study water uptake and ion-exchange capacity properties. As the results, increasing bentonite concentrations lead to increase water uptake and ion-exchange capacity. By the functional group analysis, proved that adding bentonite in SPSF did not change structure of SPSF, means that interaction between SPSF and bentonite were physical interactions.

scholarly journals One-step method for obtaining bifunctional charcoal and study of its properties

2019 ◽  
Vol 55 (4) ◽  
pp. 472-482
Author(s):  
N. K. Luneva ◽  
T. I. Ezovitova ◽  
V. V. Shevchuk ◽  
A. A. Ratko
Keyword(s):  
Raw Materials ◽  
Exchange Capacity ◽  
Carbon Residue ◽  
Step Method ◽  
Ion Exchange Capacity ◽  
Plant Raw Materials ◽  
Different Types ◽  
High Sorption ◽  
One Step ◽  
Stage Process

Single-stage process of obtaining active carbon by thermal processing of plant raw materials (mixture of different types of wood sawdust) impregnated with the mixture of phosphoric acid, urea and nitric acid salts has been developed. Active influence of impregnates on the process of carbonization and formation of carbon residue has been demonstrated. It is established that carbon residue obtained in the interval of heating 20–700 °С possesses high sorption activity to the vapors of organic compounds and has ion-exchange capacity. It has been shown that the value of carbon residue depending on the impregnate used in the wood increases by 3,1 times at 600 °С and by 4,2 times – at 700 °С as compared to the yield of non-treated initial raw materials.

Equilibrium Sorptions in Heterogeneous Ion Exchange Membranes

1992 ◽  
Vol 57 (9) ◽  
pp. 1905-1914
Author(s):  
Miroslav Bleha ◽  
Věra Šumberová
Keyword(s):  
Experimental Data ◽  
Ion Exchange ◽  
Total Content ◽  
Distribution Coefficients ◽  
Exchange Capacity ◽  
Ion Exchange Membranes ◽  
Ion Exchange Capacity ◽  
Equilibrium Sorption ◽  
Inhomogeneity Factor

The equilibrium sorption of uni-univalent electrolytes (NaCl, KCl) in heterogeneous cation exchange membranes with various contents of the ion exchange component and in ion exchange membranes Ralex was investigated. Using experimental data which express the concentration dependence of equilibrium sorption, validity of the Donnan relation for the systems under investigation was tested and values of the Glueckauf inhomogeneity factor for Ralex membranes were determined. Determination of the equilibrium sorption allows the effect of the total content of internal water and of the ion-exchange capacity on the distribution coefficients of the electrolyte to be determined.

scholarly journals Application and practice of a step-by-step method combined with case-based learning in Chinese otoendoscopy education

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Fanqin Wei ◽  
Qiyang Sun ◽  
Zili Qin ◽  
Huiwen Zhuang ◽  
Guangli Jiang ◽  
...  
Keyword(s):  
Learning Experience ◽  
Step Method ◽  
Innovative Methods ◽  
Before And After ◽  
Case Based Learning ◽  
Group A ◽  
Clinical Thinking ◽  
Group B ◽  
Learning Interest ◽  
Case Based

Abstract Background Standardized training allows more physicians to master otoendoscopic surgery. However, the lecture-based learning (LBL) applied in otoendoscopy teaching may not be conducive to training students in clinical thinking and surgical ability. It is necessary to explore innovative methods for otoendoscopy teaching. This study aimed to determine the effect of a step-by-step (SBS) method combined with case-based learning (CBL) in otoendoscopy teaching. Methods Fifty-nine physicians who participated in otoendoscopy training were selected as the study subjects and randomly divided into two groups (A and B). Group A underwent training with the SBS & CBL method, while Group B underwent training with the LBL & CBL method. The effects of these two methods for otoendoscopy training were compared by evaluation of professional skills and questionnaires before and after the training. Results Proficiency in otoendoscopic anatomy and grades for both professional knowledge and otoendoscopic skills were significantly higher in Group A than in Group B(P < 0.05). In terms of learning interest, surgical ability, acting capacity during surgery, reducing surgical complications, and satisfaction with learning experience, all responses from Group A were better than those from Group B(P < 0.05). Conclusions The SBS & CBL method may help to improve ability in otoendoscopic surgery and clinical thinking and appears suitable for endoscopy teaching.

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