Effect of Crosslinking Time on Ion Exchange Capacity of Polystyrene Nanofiber Ion Exchangers

2012 ◽  
Vol 506 ◽  
pp. 437-440 ◽  
Author(s):  
T. Nitanan ◽  
Prasert Akkaramongkolporn ◽  
Theerasak Rojanarata ◽  
Tanasait Ngawhirunpat ◽  
Praneet Opanasopit
Keyword(s):  
Sulfuric Acid ◽  
Controlled Release ◽  
Ion Exchange ◽  
Cation Exchange ◽  
Functional Groups ◽  
Crosslinking Agent ◽  
Exchange Capacity ◽  
Ion Exchanger ◽  
Ion Exchangers ◽  
Ion Exchange Capacity

In this study, polystyrene nanofiber ion exchangers (PSNIE) were successfully prepared by a new method comprising of electrospinning and the subsequent crosslinking with formaldehyde and sulfonation in sulfuric acid to create the cation exchange functionality on the fibers surfaces. The PS solution at 15% w/v in dimethylacetamide (DMAc) produced the smallest PS nanofibers (399±38 nm) with good performance. The degree of crosslink and ion exchange capacity (IEC) of PSNIE depended upon the crosslinking time. The longer crosslinking time caused the greater crosslinked PS fibers. At the longest crosslinking time of 75 min, the remaining crosslinked PS fibers in dichloromethane were 94.12%; whereas, the starting fibers completely dissolved. This crosslinking agent (e.g. formaldehyde) might introduce methylene bridges in addition to sulfone bridges into the fibers. However, IEC decreased as crosslinking time increased, probably due to the difficulty of sulfonic functional groups to react with crosslinked PS fibers. The PSNIE crosslinked for 10 min showed the maximum IEC of 2.86 meq/g-dry-PSNIE, and the diameter of the PSNIE after sulfonation increased to 450-460 nm. Since cationic drug could be loaded onto this novel PSNIE, this nanofiber ion exchanger may be applied for controlled release delivery.

scholarly journals Preliminary Study on Enzymatic-Based Cleaning of Cation-Exchange Membranes Used in Electrodialysis System in Red Wine Production

Membranes ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 114 ◽  
Author(s):  
Bdiri ◽  
Bensghaier ◽  
Chaabane ◽  
Kozmai ◽  
Baklouti ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Contact Angle ◽  
Ion Exchange ◽  
Cation Exchange ◽  
Red Wine ◽  
Exchange Capacity ◽  
Operating Conditions ◽  
Cleaning Efficiency ◽  
Wine Production ◽  
Ion Exchange Capacity

The use of enzymatic agents as biological solutions for cleaning ion-exchange membranes fouled by organic compounds during electrodialysis (ED) treatments in the food industry could be an interesting alternative to chemical cleanings implemented at an industrial scale. This paper is focused on testing the cleaning efficiency of three enzyme classes (β-glucanase, protease, and polyphenol oxidase) chosen for their specific actions on polysaccharides, proteins, and phenolic compounds, respectively, fouled on a homogeneous cation-exchange membrane (referred CMX-Sb) used for tartaric stabilization of red wine by ED in industry. First, enzymatic cleaning tests were performed using each enzyme solution separately with two different concentrations (0.1 and 1.0 g/L) at different incubation temperatures (30, 35, 40, 45, and 50 °C). The evolution of membrane parameters (electrical conductivity, ion-exchange capacity, and contact angle) was determined to estimate the efficiency of the membrane′s principal action as well as its side activities. Based on these tests, we determined the optimal operating conditions for optimal recovery of the studied characteristics. Then, cleaning with three successive enzyme solutions or the use of two enzymes simultaneously in an enzyme mixture were tested taking into account the optimal conditions of their enzymatic activity (concentration, temperatures, and pH). This study led to significant results, indicating effective external and internal cleaning by the studied enzymes (a recovery of at least 25% of the electrical conductivity, 14% of the ion-exchange capacity, and 12% of the contact angle), and demonstrated the presence of possible enzyme combinations for the enhancement of the global cleaning efficiency or reducing cleaning durations. These results prove, for the first time, the applicability of enzymatic cleanings to membranes, the inertia of their action towards polymer matrix to the extent that the choice of enzymes is specific to the fouling substrates.

scholarly journals Studies of the Separation of Palladium(II) Microquantities from Macroquantities of Salts of other Elements on Selective Ion Exchangers

1996 ◽  
Vol 14 (1) ◽  
pp. 5-23 ◽  
Author(s):  
Zbigniew Hubicki ◽  
Halina Hubicka ◽  
Bozena Lodyga
Keyword(s):  
Hydrochloric Acid ◽  
Ion Exchange ◽  
Ammonium Chloride ◽  
High Resistance ◽  
Exchange Capacity ◽  
Frontal Analysis ◽  
Thiol Groups ◽  
Ion Exchangers ◽  
Ion Exchange Capacity ◽  
Mineral Acids

The applicability of selective ion exchangers for the removal of palladium(II) from solutions of copper(II), nickel(II), aluminium(III) salts, hydrochloric acid, a mixture of hydrochloric and nitric acids as well as a mixture of hydrochloric acid and ammonium chloride has been studied by frontal analysis. The best results were obtained in the purification of copper(II) and nickel(II) salts on Chelite S with functional thiol groups, Duolite ES-346 with functional amidoxime groups and Lewatit TP-214 with functional thiourea groups. A decrease of palladium(II) content below 5 × 10−5% was obtained in the process of purification of macroquantities of these salts. In addition, these ion exchangers possess a considerable ion-exchange capacity (e.g. 3.18 mequiv. Pd/g for Lewatit TP-214) and a high resistance to mineral acids.

Preparation of Cation Exchanger Using Electrospun Polystyrene Nanofiber

2006 ◽  
Vol 10 (2) ◽  
pp. 196-200 ◽  
Author(s):  
Hyung-Hwan An ◽  
◽  
Changyun Shin ◽  
Keyword(s):  
Ion Exchange ◽  
Glass Fiber ◽  
Water Uptake ◽  
Cation Exchanger ◽  
Fiber Surface ◽  
High Water ◽  
Exchange Capacity ◽  
Experimental Results ◽  
Ion Exchanger ◽  
Ion Exchange Capacity

We studied a new ion exchanger for high ion exchange capacity (IEC) and rapid ion exchange. Polystyrene nanofiber ion exchangers (PSNIEs) were prepared by electrospinning from solutions of dissolved polystyrene followed by sulfonation. Coating and sulfonation were used to modify the glass fiber surface with polystyrene to produce cation exchanger fiber (CEF). We present new experimental results on the performance of PSNIE and CEF related to parameters of IEC, water uptake, and surface morpoholgy. IEC and water uptake of PSNIE depend on sulfonation time. IEC reached 3.74 mmol/g at relatively high water uptake of 0.6 to 0.77g H2O/g-dry-PNIE. IEC and water uptake of CEF reached 3.61mmol/g-CEF and 0.25g H2O/g-dry-CEF.

Study of the Inorganic Ion Exchanger Li3Mn0.25Ti0.5O3

2012 ◽  
Vol 178-181 ◽  
pp. 471-474
Author(s):  
Jin He Jiang
Keyword(s):  
Ion Exchange ◽  
Spinel Structure ◽  
Exchange Capacity ◽  
Ion Exchanger ◽  
Inverse Spinel ◽  
Ion Exchange Capacity ◽  
Inorganic Ion Exchanger ◽  
Inverse Spinel Structure ◽  
Inorganic Ion ◽  
Crystallization Method

Inorganic ion exchanger (Li3Mn0.25Ti0.5O3) with an inverse spinel structure was synthesized by solid state reaction crystallization method. The results showed that the Li+ extraction/insertion be progressed mainly by an ion-exchange mechanism. The acid treated samples had an ion exchange capacity of 9.2mmol/g for Li+.

scholarly journals Modified Phillipsite as a Novel Ion-Exchanger for Potassium Extraction from Seawater

2019 ◽  
Vol 25 (4) ◽  
pp. 441-445
Author(s):  
Chunxia MENG ◽  
Jin HOU
Keyword(s):  
Hydrothermal Synthesis ◽  
Ion Exchange ◽  
Average Particle Size ◽  
Selectivity Coefficient ◽  
Exchange Capacity ◽  
Ion Exchanger ◽  
Average Particle ◽  
Mixed Solution ◽  
Ion Exchange Capacity ◽  
X Ray

Template-free preparation of phillipsite as a novel K+ ion-exchanger was studied systematically by hydrothermal synthesis. The alkalinity, dosage of water glass, dosage of H2O, aging time, reaction temperature and time of hydrothermal synthesis were discussed in detail. The optimized material obtained about phillipsite through the synthesis and testing methods was performed. The K+ ion-exchange capacity and selectivity coefficient were tested. The molar composition for preparing high performance phillipsite obtained was 2K2O:18SiO2:Al2O3:510H2O by optimizing synthetic conditions. The K+ ion-exchange capacity of phillipsite was 57.3 mg/g in seawater. The K+ selectivity coefficient was 88.6 in an equimolar K+ and Na+ mixed solution. Phillipsite can selectively capture K+ over other ions, and therefore can be used for potassium extraction selectively from seawater. Phillipsite was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The XRD pattern indicated that the synthetic zeolite was phillipsite. The phillipsite particles exhibited cross-like shape and the average particle size was about 2.5 μm. The synthetic phillipsite was mainly consisted of Si, Al, K and O elements.

Synthesis of Li+ Memorized Spinel Li3Mn0.75O3 by a Solid State Reaction Crystallization Method

2012 ◽  
Vol 178-181 ◽  
pp. 475-478
Author(s):  
Jin He Jiang
Keyword(s):  
Solid State ◽  
Ion Exchange ◽  
Solid State Reaction ◽  
Exchange Capacity ◽  
Ion Exchanger ◽  
Exchange Mechanism ◽  
Spinel Type ◽  
Ion Exchange Capacity ◽  
Crystallization Method

The ion-exchanger Li3Mn0.75O3 of spinel type was prepared by a solid state reaction crystallization method. The results showed that the Li+ extraction/insertion be progressed mainly by an ion-exchange mechanism. The acid treated samples had an ion exchange capacity of 8.3mmol/g for Li+.

scholarly journals A New Hybrid EDTA–Zirconium Phosphate Cation-Exchanger: Synthesis, Characterization and Adsorption Behaviour for Environmental Monitoring

2009 ◽  
Vol 27 (4) ◽  
pp. 423-434 ◽  
Author(s):  
S.A. Nabi ◽  
Mu. Naushad ◽  
Rani Bushra
Keyword(s):  
Ion Exchange ◽  
Zirconium Phosphate ◽  
Cation Exchanger ◽  
Exchange Capacity ◽  
Ion Exchanger ◽  
Ion Exchange Capacity ◽  
Inorganic Ion ◽  
Ft Ir ◽  
Distribution Studies ◽  
Binary Separations

EDTA–zirconium phosphate has been synthesized as a new amorphous hybrid cation-exchanger by the combination of the inorganic ion-exchanger zirconium phosphate and EDTA, thereby providing a new class of organic–inorganic hybrid ion-exchanger with better mechanical and granular properties, a good ion-exchange capacity (2.40 mequiv/g dry exchanger for Na+), good reproducibility, and a higher stability and selectivity towards heavy metal ions. It has been characterized using FT-IR, TGA/DTA, X-ray and SEM methods, in addition to ion-exchange studies such as the determination of its ion-exchange capacity, elution and distribution behaviour, to provide a better understanding of the ion-exchange behaviour of the material. On the basis of distribution studies, the material was found to be highly selective towards Th(IV) and its selectivity was examined by achieving some important binary separations such as Cd(II)–Th(IV), Ni(II)–Th(IV), Hg(II)–Th(IV), Zn(II)–Th(IV), Pb(II)–Th(IV) and Al(III)–Th(IV) by column means, indicating its utility in environmental pollution control in one way or other.

Sorption of Cadmium and Lead by Chelating Ion Exchangers Ostsorb DITHIZON and Ostsorb SALICYL

1994 ◽  
Vol 59 (6) ◽  
pp. 1319-1325 ◽  
Author(s):  
Ladislav Svoboda ◽  
Stanislav Jech
Keyword(s):  
Salicylic Acid ◽  
Ionic Strength ◽  
Aqueous Solutions ◽  
Functional Groups ◽  
Exchange Capacity ◽  
Ion Exchanger ◽  
Alkaline Media ◽  
Ion Exchangers ◽  
Metal Concentrations ◽  
Cadmium And Lead

The pH and I (ionic strength) dependences of exchange capacity of chelating ion exchangers Ostsorb based on spherical cellulose modified with functional groups of dithizone and salicylic acid have been studied in the sorption of Pb(II) and Cd(II) ions. The cellulosic selective sorbents Ostsorb DITHIZON and Ostsorb SALICYL can be used for sorption of Pb(II) and Cd(II) ions from aqueous solutions of I = 0 - 1 mol l-1 (Pb) and I = 0 - 5 mol l-1 (Cd); the dithizone ion exchanger retains both metals most effectively at pH 7 - 8, the salicyl ion exchanger at pH 5.5 - 6.5 (Pb) or pH 4 - 9 (Cd). Because of the formation of precipitates of hydrolytic products of the two metals in neutral and alkaline media, it is suitable to carry out the sorption in media of mild acidity if possible, particularly so at the metal concentrations above 1 mg l-1. Increasing ionic strength affects the exchange capacity for both metals in a negative way.

Synthesis, Characterization and Evaluation of Property Profile of Hybrid Ion- Exchanger

2013 ◽  
Vol 856 ◽  
pp. 64-68 ◽  
Author(s):  
Balbir Singh Kaith ◽  
Saruchi ◽  
Sandeep Kaur ◽  
Meenakshi Devi
Keyword(s):  
Ion Exchange ◽  
Chemical Properties ◽  
Reaction Medium ◽  
Monomer Concentration ◽  
Exchange Capacity ◽  
Ion Exchanger ◽  
Reaction Conditions ◽  
Ion Exchange Capacity ◽  
Physico Chemical ◽  
Different Temperatures

Gum tragancanthbased organic-inorganic hybrid ion exchanger has been synthesized using a mixture of sodium tungstate, orthophosphoric acid and potassium iodate. The different reaction conditions like reaction temperature, reaction time, pH of reaction medium, solvent volume, monomer concentration and initiator concentration were optimized in order to get the semi-IPN Gt-cl-poly (AA). Onto semi IPN, methylmethacrylate was incorporated using lipase-gluteraldehyde as the initiator-crosslinker system. The IPN finally was converted into ion-exchanger and was studied for its different physico-chemical properties. Ion exchange capacity was studied for Na+and effect of different temperatures on ion exchange capacity was evaluated. Characterization was done using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and EDS techniques.

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