Poly[1,3(2-ethoxy-4-hydroxy-5-propylphenylene)propylene] copolymer as an ion exchanger

1994 ◽  
Vol 6 (3) ◽  
pp. 201-208 ◽  
Author(s):  
Jayesh R Patel ◽  
Dipan H Sutaria ◽  
Magan N Patel
Keyword(s):  
Metal Ion ◽  
Metal Uptake ◽  
Polyphosphoric Acid ◽  
Average Molecular Weight ◽  
Acid Catalyst ◽  
Wide Ph Range ◽  
Metal Ion Uptake ◽  
Viscosity Study ◽  
Ph Range

The present paper reports the synthesis and characterization of a copolymer, The copolymer sample was synthesized by Friedel-Crafts polycondensation of 2-hydroxy-4 ethoxypropiophenone with 1,3-propane diol in the presence of polyphosphoric acid catalyst. The copolymer was characterized by elemental analysis, IR spectroscopy and viscosity study, and its number-average molecular weight (M) was determined by non-aqueous titration and found to be 2855 g mol- 1. Chelation ion-exchange properties have also been studied, employing a batch-equilibration method. It was employed to study selectivity of metal ion uptake over a wide pH range and in media of various ionic strengths. The overall rate of metal uptake follows the order UOl + > Fe3 + > Cu2 + > Ni2 +.

Synthesis of resin I: salicylic acid, hexamethylene diamine and formaldehyde and its ion-exchange properties

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Dhanraj.T. Masram ◽  
Kiran.P. Kariya ◽  
Narayan.S. Bhave
Keyword(s):  
Salicylic Acid ◽  
Ion Exchange ◽  
Metal Ion ◽  
Average Molecular Weight ◽  
Acid Catalyst ◽  
Conductometric Titration ◽  
Spectral Studies ◽  
Wide Ph Range ◽  
Ph Range ◽  
Exchange Properties

AbstractThe terpolymer resin salicylic acid-hexamethylenediamine-formaldehyde (SHMF) was synthesized by the condensation of salicylic acid and hexamethylenediamine with formaldehyde in the presence of a hydrochloric acid catalyst. The number average molecular weight of the resin was determined by non-aqueous conductometric titration. Terpolymer resin was characterized by elemental analysis, infrared (IR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy and UV- Visible spectral studies. Chelation ion exchange properties have also been studied for Fe3+, Cu2+, Ni2+, Co2+, Zn2+, Cd2+ and Pb2+ions employing a batch equilibrium method. It was employed to study the selectivity of metal ion uptake involving the measurements of distribution of a given metal ion between the polymer sample and a solution containing the metal ion. The study was carried out over wide pH range and in the media of various ionic strengths. The terpolymer showed a higher selectivity for Fe3+, Cu2+ and Ni 2+ions than for Co2+, Zn2+, Cd2+, and Pb2+ ions.

scholarly journals Chelation Ion Exchange Properties of 2, 4-Dihydroxyacetophenone-Biuret-Formaldehyde Terpolymer Resin

2009 ◽  
Vol 6 (3) ◽  
pp. 835-843 ◽  
Author(s):  
Sanjiokumar S. Rahangdale ◽  
Anil B. Zade ◽  
Wasudeo B. Gurnule
Keyword(s):  
Hydrochloric Acid ◽  
Ion Exchange ◽  
Metal Ion ◽  
Spectral Studies ◽  
Molar Ratios ◽  
Wide Ph Range ◽  
Metal Ion Uptake ◽  
Uv Visible ◽  
Ph Range ◽  
Exchange Properties

The terpolymer resin 2, 4-HABF has been synthesized by the condensation of 2, 4-dihydroxyacetophenone (2, 4-HA) and biuret (B) with formaldehyde (F) in 1:1:2 molar ratios in presence of 2 M hydrochloric acid as catalyst. UV-Visible, IR and proton NMR spectral studies have been carried out to elucidate the structure of the resin. A terpolymer (2, 4-HABF) proved to be a selective chelating ion exchange polymer for certain metals. Chelating ion-exchange properties of this polymer were studied for Fe3+, Cu2+, Ni2+, Co2+, Zn2+, Cd2+and Pb2+ions. A batch equilibrium method was employed in the study of the selectivity of metal ion uptake involving the measurement of the distribution of a given metal ion between the polymer sample and a solution containing the metal ion. The study was carried out over a wide pH range and in media of various ionic strengths. The polymer showed highest selectivity for Fe3+, Cu2+ions than for Ni2+, Co2+, Zn2+, Cd2+, and Pb2+ions. Study of distribution ratio as a formation of pH indicates that the amount of metal ion taken by resin is increases with the increasing pH of the medium.

scholarly journals Characterization of a New Intracellular Alginate Lyase with Metal Ions-Tolerant and pH-Stable Properties

Marine Drugs ◽  
2020 ◽  
Vol 18 (8) ◽  
pp. 416
Author(s):  
Yan Ma ◽  
Jie Li ◽  
Xin-Yue Zhang ◽  
Hao-Dong Ni ◽  
Feng-Biao Wang ◽  
...  
Keyword(s):  
Metal Ion ◽  
Brown Seaweed ◽  
Alginate Lyase ◽  
Industrial Applications ◽  
Alginate Oligosaccharides ◽  
Potential Applications ◽  
Pharmaceutical Industries ◽  
Ph Range ◽  
Alginate Lyases

Alginate lyases play an important role in alginate oligosaccharides (AOS) preparation and brown seaweed processing. Many extracellular alginate lyases have been characterized to develop efficient degradation tools needed for industrial applications. However, few studies focusing on intracellular alginate lyases have been conducted. In this work, a novel intracellular alkaline alginate lyase Alyw202 from Vibrio sp. W2 was cloned, expressed and characterized. Secretory expression was performed in a food-grade host, Yarrowia lipolytica. Recombinant Alyw202 with a molecular weight of approximately 38.3 kDa exhibited the highest activity at 45 °C and more than 60% of the activity in a broad pH range of 3.0 to 10.0. Furthermore, Alyw202 showed remarkable metal ion-tolerance, NaCl independence and the capacity of degrading alginate into oligosaccharides of DP2-DP4. Due to the unique pH-stable and high salt-tolerant properties, Alyw202 has potential applications in the food and pharmaceutical industries.

scholarly journals Ion Exchange Properties of a Terpolymer Resin Derived from 2, 4-Dihydroxybenzaldehyde, Oxamide and Formaldehyde

2009 ◽  
Vol 6 (3) ◽  
pp. 639-650 ◽  
Author(s):  
M. V. Tarase ◽  
W. B. Gurnule ◽  
A. B. Zade
Keyword(s):  
Hydrochloric Acid ◽  
Ion Exchange ◽  
Metal Ions ◽  
Metal Ion ◽  
Polymer Sample ◽  
Equilibrium Method ◽  
Wide Ph Range ◽  
Ph Range ◽  
Exchange Properties

Terpolymer resins (2,4-DHBOF) were synthesized by the condensation of 2,4-dihydroxybenzaldehyde and oxamide with formaldehyde in the presence of hydrochloric acid as catalyst, proved to be selective chelation ion exchange terpolymer resins for certain metals. Chelation ion exchange properties of these polymers were studied for Fe+3, Cu+2, Hg+2, Cd+2, Co+2, Zn+2, Ni+2and Pb+2ions. A batch equilibrium method was employed in the study of the selectivity of the distribution of a given metal ions between the polymer sample and a solution containing the metal ion. The study was carried out over a wide pH range and in a media of various ionic strengths. The polymer showed a higher selectivity for Fe+3, Cd+2and Co+2ions than for Cu+2, Hg+2, Zn+2, Ni+2and Pb+2ions.

2´-carboxy-3-keto-D-arabinitol 1,5-bisphosphate, the six-carbon intermediate of the ribulose bisphosphate carboxylase reaction

1986 ◽  
Vol 313 (1162) ◽  
pp. 397-407 ◽  
Keyword(s):  
Metal Ion ◽  
Ribulose Bisphosphate Carboxylase ◽  
Ribulose Bisphosphate ◽  
Bisphosphate Carboxylase ◽  
Wide Ph Range ◽  
Alkaline Conditions ◽  
Divalent Metal Ion ◽  
Ph Range ◽  
Short Time ◽  
Hydrolysis Of

The six-carbon intermediate of the ribulose 1,5-bisphosphate (RuBP) carboxylase reaction, 2'-carboxy-3-keto-D-arabinitol 1,5-bisphosphate (CKABP), was prepared enzymatically by quenching the reaction with acid after a short time ( ca 12 ms). Over a wide pH range (4-11), GKABP undergoes a slow ( t 1/2 = 1 h), pH-independent decarboxylation. No detectable decomposition of CKABP occurs over a six-week period at — 80 °C. The decarboxylation of CKABP is acid-catalysed and is also catalysed by deactivated enzyme lacking the activator carbamate-divalent metal ion complex. Decarboxylation is accompanied by β-elimination of the C-1 phosphate from the 2,3-enediolate. Under alkaline conditions (pH >11) CKABP undergoes hydrolysis. Non-enzymatic hydrolysis of the intermediate is also accompanied by β-elimination of the C-1 phosphate (presumably from the aci-acid of the upper glycerate 3-phosphate) and the formation of pyruvate. Fully activated enzyme catalyses the complete hydrolysis of CKABP to glycerate 3-phosphate, although enzymic hydrolysis of CKABP is limited by an event not on the direct path of carboxylation. Carbon-13 NMR analysis of [2',3- 13 C]CKABP indicates that it exists in solution predominantly (> 85%) as the C-3 ketone. In contrast, borohydride trapping of CKABP formed from [3- 18 O]RuBP indicates that the intermediate exists on the enzyme predominantly (> 94%) as the hydrated C-3 gem-diol. In solution, the hydration of the C-3 ketone of CKABP proceeds slowly ( k = 2.5 x 10 -3 s -1 ). The enzymatic hydration of CKABP must proceed at least as fast as k cat ( ca. 5 s -1 ) or at least 2000 times faster than the hydration of CKABP in solution.

scholarly journals Biochemical Characterization of a New β-Agarase from Cellulophaga Algicola

2019 ◽  
Vol 20 (9) ◽  
pp. 2143 ◽  
Author(s):  
Han ◽  
Zhang ◽  
Yang
Keyword(s):  
Structural Model ◽  
Biochemical Characterization ◽  
Maximum Activity ◽  
Optimal Temperature ◽  
Salt Tolerant ◽  
Wide Ph Range ◽  
Specific Activities ◽  
Ph Range ◽  
Layer Chromatography

Cellulophaga algicola DSM 14237, isolated from the Eastern Antarctic coastal zone, was found to be able to hydrolyze several types of polysaccharide materials. In this study, a predicted β-agarase (CaAga1) from C. algicola was heterologously expressed in Escherichia coli. The purified recombinant CaAga1 showed specific activities of 29.39, 20.20, 14.12, and 8.99 U/mg toward agarose, pure agar, and crude agars from Gracilaria lemaneiformis and Porphyra haitanensis, respectively. CaAga1 exhibited an optimal temperature and pH of 40 oC and 7, respectively. CaAga1 was stable over a wide pH range from 4 to 11. The recombinant enzyme showed an unusual thermostability, that is, it was stable at temperature below or equal to 40oC and around 70 oC, but was thermolabile at about 50 oC. With the agarose as the substrate, the Km and Vmax values for CaAga1 were 1.19 mg/mL and 36.21 U/mg, respectively. The reducing reagent (dithiothreitol) enhanced the activity of CaAga1 by more than one fold. In addition, CaAga1 was salt-tolerant given that it retained approximately 70% of the maximum activity in the presence of 2 M NaCl. The thin layer chromatography results indicated that CaAga1 is an endo-type β-agarase and efficiently hydrolyzed agarose into neoagarotetraose (NA4) and neoagarohexaose (NA6). A structural model of CaAga1 in complex with neoagarooctaose (NA8) was built by homology modeling and explained the hydrolysis pattern of CaAga1.

Adsorption of hexavalent chromium on dunite

2011 ◽  
Vol 63 (4) ◽  
pp. 818-824 ◽  
Author(s):  
Antri Demetriou ◽  
Ioannis Pashalidis
Keyword(s):  
Experimental Data ◽  
Ionic Strength ◽  
Metal Ion ◽  
Outer Sphere ◽  
Atmospheric Conditions ◽  
Adsorption Model ◽  
Wide Ph Range ◽  
Ph Range ◽  
Relative Adsorption ◽  
Outer Sphere Complexes

The paper presents and discusses the effect of various physicochemical parameters (e.g. pH, ionic strength, Cr(VI) initial concentration, amount of the adsorbent, temperature and contact time between metal ion and adsorbent) on the adsorption efficiency of Cr(VI) on dunite in aqueous solutions under atmospheric conditions. Evaluation of the experimental data shows that dunite presents increased affinity for Cr(VI) over a wide pH range and Cr(VI) concentration, and the experimental data are well fitted by the Kd adsorption model. The relative adsorption is pH dependent and decreases slightly (about 10%) with increasing pH, because of changes in the surface charge of the solid. The effect of the ionic strength is significant (particularly at low pH), indicating the predominance of outer-sphere complexes. Moreover, adsorption experiments at various temperatures, two different pH values (pH 3 and pH 8) and three different ionic strengths (0.0, 0.1 and 1.0 M NaClO4), indicate an endothermic but spontaneous entropy-driven processes.

scholarly journals Enhanced Fenton-like oxidation of hydroxypropyl guar gum catalyzed by EDTA-metal complexes in a wide pH range

2019 ◽  
Vol 79 (9) ◽  
pp. 1667-1674 ◽  
Author(s):  
Ying Tang ◽  
Huan Liu ◽  
Ling Zhou ◽  
Haomiao Ren ◽  
Hong Li ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Metal Complexes ◽  
Guar Gum ◽  
Average Molecular Weight ◽  
Oxygen Demand ◽  
Catalytic Performance ◽  
Hydroxypropyl Guar ◽  
Wide Ph Range ◽  
Ph Range ◽  
Hydroxypropyl Guar Gum

Abstract A series of EDTA-metal complexes was prepared for the Fenton oxidation catalysts and Fe(II)L exhibits high catalytic performance for degradation of hydroxypropyl guar gum in a wide pH range 7.0–13.0. The viscosity of hydroxypropyl guar gum can be reduced with the 10.0% H2O2 and 5.0% Fe(II)L. The viscosity average molecular weight of hydroxypropyl guar gum was decreased from almost 2 million to 3,199. Most important of all, the chemical oxygen demand (COD) value can be decreased to 104 mg/L from 8,080 mg/L with enough H2O2, and Fe(II)L also shows great catalytic ability in the degradation of various polymers by H2O2. The proposed mechanism of the activation of H2O2 by the complex was studied.

scholarly journals A Minimally Invasive Microsensor Specially Designed for Simultaneous Dissolved Oxygen and pH Biofilm Profiling

Sensors ◽  
2019 ◽  
Vol 19 (21) ◽  
pp. 4747 ◽  
Author(s):  
Xavier Guimerà ◽  
Ana Moya ◽  
Antonio David Dorado ◽  
Xavi Illa ◽  
Rosa Villa ◽  
...  
Keyword(s):  
Minimally Invasive ◽  
Dissolved Oxygen ◽  
Ph Monitoring ◽  
Ph Sensing ◽  
Wide Ph Range ◽  
Ph Range ◽  
Biofilm Structure ◽  
Parallel Arrays ◽  
Ph Electrodes

A novel sensing device for simultaneous dissolved oxygen (DO) and pH monitoring specially designed for biofilm profiling is presented in this work. This device enabled the recording of instantaneous DO and pH dynamic profiles within biofilms, improving the tools available for the study and the characterization of biological systems. The microsensor consisted of two parallel arrays of microelectrodes. Microelectrodes used for DO sensing were bare gold electrodes, while microelectrodes used for pH sensing were platinum-based electrodes modified using electrodeposited iridium oxide. The device was fabricated with a polyimide (Kapton®) film of 127 µm as a substrate for minimizing the damage caused on the biofilm structure during its insertion. The electrodes were covered with a Nafion® layer to increase sensor stability and repeatability and to avoid electrode surface fouling. DO microelectrodes showed a linear response in the range 0–8 mg L−1, a detection limit of 0.05 mg L−1, and a sensitivity of 2.06 nA L mg−1. pH electrodes showed a linear super-Nernstian response (74.2 ± 0.7 mV/pH unit) in a wide pH range (pH 4−9). The multi-analyte sensor array was validated in a flat plate bioreactor where simultaneous and instantaneous pH and DO profiles within a sulfide oxidizing biofilm were recorded. The electrodes spatial resolution, the monitoring sensitivity, and the minimally invasive features exhibited by the proposed microsensor improved biofilm monitoring performance, enabling the quantification of mass transfer resistances and the assessment of biological activity.

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