Determination of the eutectic solubility lines of the ternary system NaHCO3–Na2CO3–H2O

A crystallizer was built and a procedure developed to accurately measure the eutectic solubility lines where ice and salt coexist in equilibrium with the solution, for potential application of Eutectic Freeze Crystallization. The eutectic solubility lines of the ternary system NaHCO₃–Na₂CO₃–H₂O were determined experimentally and calculated with the extended UNIQUAC model. The extended UNIQUAC model describes the experimental data quite well. Anhydrous NaHCO₃ and Na₂CO₃·10H₂O were the only two types of crystals present in equilibrium with ice crystals in the ternary system. At the quadruple point NaHCO₃ and Na₂CO₃·10H₂O are in equilibrium with a solution of about 4.34 wt% of Na₂CO₃ and 4.77 wt% of NaHCO₃ at −3.32 °C. The anhydrous NaHCO₃ crystals were needle shaped with lengths between 5 and 10 μm, that were agglomerated into particles of about 100–300 μm, while the Na₂CO₃·10H₂O crystals were hexagonally shaped with sizes between 100 and 500 μm.     

Mechanism of hardening of refractory concrete composites containing water glass with CO2 purging

Conclusions The mechanism by which refractory concrete composites based on water-glass with CO₂ purging are hardened has been refined. The x-ray studies of the binder have established the formation of the chemical compounds: Na₂CO₃ · H₂O, Na₂CO₃ · NaHCO₃ · 2H₂O, and NaHCO₃.The proposed hardening systems reconcile the contradictory data from other research workers.To prepare these particular refractory concrete articles it is recommended that high-modulus glasses be used since they provide more rapid setting of the strength after purging with CO₂ and lower the labor and material requirements.The finished articles should be heat-treated at 800°C which ensures that a glassy binder with high-water-resistance is formed.Translated from Ogneupory, No. 1, pp. 38–41, January, 1982.     

Mineralogical characteristics of Ettringites synthesized from solutions and suspensions

Due to the wide technical importance of Ettringite (3CaO·Al₂O₃·3CaSO₄·32H₂O) in hydrated cement based systems, four different synthesis methods were applied to get a better overview on how and under what favoring conditions Ettringite can be formed. In the first step different precipitation methods resulting in Ettringite were established. For all methods Al³⁺ was supplied by aqueous CO₂-free solution of Al₂(SO₄)₃·18H₂O. As a source of CaO-supply a clear solution and otherwise a Ca(OH)₂-suspension was utilized. Four synthesis routes with and without sucrose were employed.Variation of reaction parameter like temperature, time of reaction, pH-value of synthesis solution and influence of additional Gypsum were investigated. The qualitative phase analysis was performed by X-ray diffraction method (XRD). Morphological aspects of some synthesis products were studied by scanning electron microscopy (SEM). Finally lattice and structural parameter of the Ettringites were determined by refinement of XRD-pattern using the Rietveld-Method.     

Synthesis, characterization, and reactivity ratio studies on new sulfide copolymers containing ethylbenzene units

Soluble new sulfide copolymers were synthesized readily by the polycondensation of ethylene dibromide (EDB) (or methylene dibromide (MDB)) with styrene dibromide (SDB) and sodium sulfide (Na₂S) in the presence of phase transfer catalyst. The copolymers were characterized by using Fourier transform-infrared, ¹H NMR, ¹³C NMR, gel permeation chromatography, and thermogravimetric analysis (TGA) techniques. The copolymer composition obtained from the ¹H NMR spectra led to the determination of reactivity ratios. The analysis of reactivity ratios revealed that both EDB and MDB are more reactive than SDB towards Na₂S, and copolymers formed are random in nature. Furthermore, it also gave an insight on the microstructure of the copolymers that both poly (ethylene sulfide-co-styrene sulfide) (p(ES-co-SS)), and poly(methylene sulfide-co-styrene sulfide) (p(MS-co-SS)) copolymers have more of blocky structure with increase in the concentration of ethylene sulfide (ES) or methylene sulfide (MS) units in the respective copolymers. The TGA was used to find out the thermal stability of these polymers. The XRD data indicated an increase in the amorphous content of the copolymers with an increase in the concentration of styrene sulfide (SS) units and thereby resulting in most of these copolymers being soluble in common organic solvents. The solubility and molecular weight of the polymers formed were dependent on the concentration of SDB taken in the feed.     

The solubility of selenate-AFt (3CaO·Al2O3·3CaSeO4·37.5H2O) and selenate-AFm (3CaO·Al2O3·CaSeO4·xH2O)

The Se(VI)-analogues of ettringite and monosulfate, selenate-AFt (3CaO·Al₂O₃·3CaSeO₄·37.5H₂O), and selenate-AFm (3CaO·Al₂O₃·CaSeO₄·xH₂O) were synthesised and characterised by bulk chemical analysis and X-ray diffraction. Their solubility products were determined from a series of batch and resuspension experiments conducted at 25 °C. For selenate-AFt suspensions, the pH varied between 11.37 and 11.61, and a solubility product, log K_so=61.29±0.60 (I=0 M), was determined for the reaction 3CaO·Al₂O₃·3CaSeO₄·37.5H₂O+12 H⁺⇔6Ca²⁺+2Al³⁺+3SeO₄²⁻+43.5H₂O. Selenate-AFm synthesis resulted in the uptake of Na, which was leached during equilibration and resuspension. For the pH range of 11.75 to 11.90, a solubility product, log K_so=73.40±0.22 (I=0 M), was determined for the reaction 3CaO·Al₂O₃·CaSeO₄·xH₂O+12 H⁺⇔4Ca²⁺+2Al³⁺+SeO₄²⁻+(x+6)H₂O. Thermodynamic modelling suggested that both selenate-AFt and selenate-AFm are stable in the cementitious matrix; and that in a cement limited in sulfate, selenate concentration may be limited by selenate-AFm to below the millimolar range above pH 12.     

Crosslinking of addition copolymers from tricyclononenes bearing (CH3)3Si‐ and (C2H5O)3Si‐groups as a modification of membrane gas separation materials

Here, we report the synthesis and the study of gas‐transport properties of crosslinked highly permeable copolymers from Si‐containing norbornene derivatives. The initial high‐molecular‐weight copolymers were prepared via addition copolymerization of 3‐trimethylsilyltricyclo[4.2.1.0^2,5]non‐7‐ene (TCNSi1) with 3‐triethoxysilyltricyclo[4.2.1.0^2,5]non‐7‐ene (TCNSiOEt) in good or high yields using a Pd‐catalyst. The obtained copolymers included up to 10 mol% of TCNSiOEt units bearing reactive Si–O–C‐containing substituents. The crosslinking was readily realized by using simple sol–gel chemistry in the presence of Sn‐catalyst. The formed crosslinked copolymers were insoluble in common organic solvents. Permeability coefficients of various gases (He, H₂, O₂, N₂, CO₂, CH₄, C₂H₆, C₃H₈, n‐C₄H₁₀) in these copolymers before and after crosslinking were determined and the influence of the incorporated TCNSiOEt units as well as the crosslinking on gas transport properties were established. As a result, it was found that only a small reduction of gas‐permeability was observed when TNCSiOEt units were incorporated into the main chains, and the copolymers were crosslinked. At the same time, the selectivity for C₄H₁₀/CH₄ pair was increased. The suggested approach has allowed obtaining crosslinked polymers from Si‐containing monomers without a loss of the main membrane characteristics. POLYM. ENG. SCI., 59:2502–2507, 2019. © 2019 Society of Plastics Engineers     

Synthesis and characterization of Schiff base derivative with pyrrole ring and electrochromic applications of its oligomer

In this study, Schiff base monomer, 2-[(1H-pyrrol-2-yl-methylene)amino]phenol (2-PMAP) was obtained by condensation reaction of 2-aminophenol with pyrrole-2-carbaldehyde. This monomer was oxidized in an aqueous alkaline medium by NaOCl to obtain the corresponding oligomer (O-2-PMAP). The resulting compounds were characterized by ¹H- and ¹³C-NMR, FT-IR, UV–vis, TG-DTA and size exclusion chromatography (SEC) techniques. Metal complexes compounds of O-2-PMAP were prepared with various metal salts, such as Cu (AcO)₂·H₂O, Zn (AcO)₂·2H₂O, Cd (AcO)₂·2H₂O, Pb (AcO)₂·3H₂O and Co (AcO)₂·4H₂O. In addition to this, electrochemical copolymerization of O-2-PMAP with thiophene (Th), 3,4-ethylenedioxythiophene (EDOT) and pyrrole (Py) were performed onto indium/tin oxide (ITO)-coated glass plate. The spectral changes of the co-polymeric films were recorded in the range of the different potentials. The film stabilities of its EDOT and Py copolymers were determined. Consequently, it was realized that the copolymer films kept their stability for a long time.     

Large-scale synthesis of WO3 nanoplates by a microwave-hydrothermal method

Tungsten oxide (WO₃) nanoplates were synthesized by a 270 W microwave-hydrothermal reaction of Na₂WO₄·2H₂O and citric acid (C₆H₈O₇·H₂O) in deionized water. X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), and selected area electron diffraction (SAED) were used to reveal the synthesis of WO₃ complete rectangular nanoplates in the solution of 0.2 g citric acid for 180 min, with O-W-O FTIR stretching modes at 819 and 741 cm⁻¹, and two prominent O-W-O Raman stretching modes at 804 and 713 cm⁻¹. The 2.71 eV indirect energy gap, and 430-460 nm blue emission wavelength range of WO₃ complete rectangular nanoplates were determined using UV-visible and photoluminescence (PL) spectrometers. The formation mechanism was also proposed according to the experimental results.     

The mechanism for soluble phosphates to improve the water resistance of magnesium oxychloride cement

This paper discusses the reasons why the addition of some soluble phosphates to magnesium oxychloride cement (MOC) can greatly improve its water resistance. With the XRD analysis and the determination of the strength retention coefficients (a judging index for the water resistance), it has been shown that the addition of small quantity of the soluble phosphates, such as H₃PO₄, NaH₂PO₄·2H₂O, and NH₄H₂PO₄, to MOC pastes does not influence the phases formed in the MOC pastes, but can result in the great increases of the strength retention coefficients of hardened MOC pastes, i.e., the great improvement of the water resistance of MOC. It was considered that the key components being responsible for the improvement of the water resistance could be the anions H₂PO₄⁻, HPO₄²⁻, and PO₄³⁻ yielded by the ionization of these phosphates in the solution of MOC pastes. These anions can decrease the lowest concentration of Mg²⁺ ions in the solution required by the formation of 5Mg(OH)₂·MgCl₂·8H₂O (5-phase) or 3Mg(OH)₂·MgCl₂·8H₂O (3-phase) in the MOC pastes and increase the stability of these phases in water. Thus, when the hardened MOC pastes with small quantity of the soluble phosphates are immersed in water, the 5-phase or 3-phase in them will not be decomposed by water, which makes the strength of the hardened MOC pastes remain unchanged in water.     

Thermoanalytical and infrared spectroscopy investigations of some mineral pastes containing organic polymers

The interaction in the presence of water between organic polymers [two polyvinyl alcohol acetate (PVA1 and PVA2)-, one polyvinyl acetate (PVAc)-, and one acryloethyl-metacrylomethyl (R)-type copolymers] and inorganic materials (3CaO·Al₂O₃+CaSO₄·2H₂O, 12CaO·7Al₂O₃, and CaO·Al₂O₃) was investigated using complex thermal analyses and infrared (IR) spectroscopy. The DTA curves of the 1-to 28-day-hydrated organo-mineral composite samples showed some significant differences in comparison with those of the hydrated inorganic materials. The most important differences consist in the presence of some exothermic peaks that are not attributable to the pure organic polymers. More than that, none of the specific effects of the pure organic polymers are evidenced on the DTA curves of the hydrated organo-mineral composite materials. This, in connection with their IR spectra, which clearly evidence the disappearance of some investigated polymers specific IR bands, can be considered as an indirect evidence of the cross-linking of polymer chains via metal ions.     

Carbonate and sulphate green rusts—Mechanisms of oxidation and reduction

The oxidation and reduction of carbonate, GR(CO₃), and sulphate, GR(SO₄), green rusts (GR) have been studied through electrochemical techniques, electrochemical quartz crystal microbalance (EQCM), FTIR, XRD and SEM. The used samples were made of thin films electrodeposited on gold substrate. The results from the present work, from our previous studies and from literature were compiled in order to establish a general scheme for the formation and transformation pathways involving carbonate or sulphate green rusts. Depending on experimental conditions, two routes of redox transformations occur. The first one corresponds to reaction via solution and leads to the formation of ferric products such as goethite or lepidocrocite (oxidation) or to the release of Fe^II ions into the solution (reduction) with soluble Fe^II-Fe^III complexes acting as intermediate species. The second way is solid-state reaction that involve conversion of lattice Fe²⁺ into Fe³⁺ and deprotonation of OH groups in octahedra sheets (solid-state oxidation) or conversion of lattice Fe³⁺ into Fe²⁺ and protonation of OH groups (solid-state reduction). The solid-state oxidation implies the complete transformation of GR(CO₃) or GR(SO₄) to ferric oxyhydroxycarbonate exGRc-Fe(III) or ferric oxyhydroxysulphate exGRs-Fe(III), for which the following formulas can be proposed, Fe^III₆(OH)_(12−2y)(O)_(2+y)(H₂O)_(y)(CO₃) or Fe^III₆(OH)_(12−2z)(O)_(2+z)(H₂O)_(6+z)(SO₄) with 0 ≤ y or z ≤ 2. The solid-state reduction gives ferrous hydroxycarbonate exGRc-Fe(II) or ferrous hydroxysulphate exGRs-Fe(II), which may have the following chemical formulas, [Fe^II₆(OH)₁₀(H₂O)₂]·[CO₃, 2H₂O] or [Fe^II₆(OH)₁₀(H₂O)₂]·[SO₄, 8H₂O].     

“Metakaolin‐Slag‐Clinker Blends.” The Role of Na+ or K+ as Alkaline Activators of Theses Ternary Blends

This article reports on research into the use of solid alkalis (Na₂CO₃ and K₂CO₃) as activators to obtain hybrid cement (cement whose hydration generates a mix of C–A–S–H and (N,C)–A–S–H gels) from a blend of 20% clínker + 40% blast furnace slag + 40% metakaolin. More specifically, the study aimed to determine the effect of activator dosage (5 and 8 wt%) and type of alkaline cation (Na⁺ or K⁺) on the 2‐ and 28‐d mechanical strength of the end materials. The findings showed that the highest mechanical strength values were obtained with 5% Na₂CO₃. According to the XRD, NMR, and SEM/EDX analyses conducted on the reaction products, the alkalinity and solubilized chemical species generated by adding 5% Na₂CO₃ to the system yielded a mix of (N,C)–A–S–H and C–A–S–H cementitious gels as the main reaction products. The secondary reaction products included metastable (3CaO·Al₂O₃·CaCO₃·11H₂O‐type) carboaluminates that evolved into the calcite or vaterite forms of calcium carbonate. When K₂CO₃ was used (instead of Na₂CO₃), a (3CaO·Al₂O₃·0.5Ca(OH)₂·0.5CaCO₃·11H₂O‐type) hemicarboaluminate also formed. The study also revealed that Na⁺ favors coagulation/precipitation more effectively than K⁺, generating gels with a wider range of Qⁿ species.     

Synthesis of poly(hemispherand) via cyclopolymerization of diepoxide

Summary Cyclopolymerization of 2,6-bis[3-(4,5-epoxy-2-oxapentyl)-2-methoxy-5-methylphenyl]-4-methylanisole was carried out with cationic, anionic, and coordination catalysts. The polymers obtained with BF₃·OEt₂ or SnCl₄ in dichloromethane and with t-BuOK in DMSO were soluble in benzene, chloroform, and THF. The mole fractions of the cyclic units in these polymers were from 0.65 to 0.75. The resulting poly(hemispherand) bound alkali metal cations and the selectivity was in the order of Rb⁺>K⁺>Cs⁺>Na⁺>Li⁺.     

Electrokinetic Properties of Vermiculite and Expanded Vermiculite: Effects of pH,Clay Concentration and Mono- and Multivalent Electrolytes

Abstract

In this study, the zeta potential values of vermiculite and expanded vermiculite were measured to determine the effect of pH, clay concentration, and various mono- and multivalent electrolytes including NaCl, KCl, NH₄Cl, NaNO₃, NaClO₄, Na₂SO₄, Na₂CO₃, Na₃PO₄·12H₂O, MgCl₂·6H₂O, CaCl₂·2H₂O, BaCl₂, SrCl₂·6H₂O, CuCl₂·2H₂O, CoCl₂·6H₂O, NiCl₂, AlCl₃, and CrCl₃·6H₂O on the electrokinetic properties of vermiculite samples. It was found that generally the measured zeta potential values of expanded vermiculite for the studied systems were slightly more negative than that of vermiculite. The pH profiles of vermiculite and expanded vermiculite at acidic, natural, and basic pH values were obtained to determine the effect of time on the pH values of clay suspensions. The zeta potential measurements showed that the surface charge of clay particles was negative in water. The isoelectric point of vermiculite and expanded vermiculite were determined as pH 2.30 and 2.57, respectively. Divalent cations (Mg²⁺, Ca²⁺, Sr²⁺, and Ba²⁺), heavy metal ions (Cu²⁺, Ni²⁺, and Co²⁺) and trivalent cations (Al³⁺ and Cr³⁺) were potential determining ions for vermiculite and expanded vermiculite particles. Moreover, divalent and trivalent cations caused the change of surface charge from negative to positive. On the other hand, monovalent cations (Na⁺, K⁺ and NH₄ ⁺), monovalent anions (Cl^?, NO₃ ^?, and ClO₄ ^?) and multivalent anions (SO₄ ^2?, CO₃ ^2?, and PO₄ ^3?) acted as indifferent ions for these clay particles.     

A novel (3,4,8)-connected 3D topology framework based on [Gd2(bpdc)3(H2O)3] second building units

A new 3D coordination polymer {[Gd₂(bpdc)₃(H₂O)₃]·H₂O}_n(1) has been isolated from the reaction of 2,2′-bipyridine-4,4′-dicarboxylic acid (H₂bpdc) and Gd(III) salts under hydrothermal conditions. Single-crystal X-ray diffraction study shows that compound 1 is constructed from Gd₂-based second building units (SBUs) [Gd₂(bpdc)₃(H₂O)₃] and displays a 3D (3,4,8)-connected net with (4²·6)(3²·4²·5²)(3²·4⁵·5⁴·6¹¹·7⁶) topology. A thermogravimetric analysis of 1 shows a high thermal stability. The magnetic behavior of 1 reveals a weak antiferromagnetic interaction between Gd(III) ions.     

Synthesis,characterizations, and crystal structure of a novel 2D metal phosphonate: Na2[Cd2(H2O)3(O3PCH(OH)CO2)2] · 2H2O

A novel cadmium phosphonate compound Na₂[Cd₂(H₂O)₃(O₃PCH(OH)CO₂)₂] · 2H₂O (1) has been synthesized by hydrothermal reaction at 120 °C and characterized by single-crystal X-ray diffraction as well as with infrared spectroscopy, elemental analysis and thermogravimetric analysis. The structure of compound 1 comprises CdO₆ octahedra and CdO₇ pentagonal bipyramid connected by [O₃PCH(OH)CO₂]³⁻ to form a 2D layered structure with a one-dimensional channel system and the charge-compensating Na⁺ cations being located between two adjacent layers.     

Preparation and characterization of basic carbonates as novel anode materials for lithium-ion batteries

Three basic carnobates, (PbCO₃)₂·Pb(OH)₂, NiCO₃·2Ni(OH)₂·4H₂O, and CuCO₃·Cu(OH)₂, are prepared and used for the first time as anode materials for lithium-ion batteries. Electrochemical results show that (PbCO₃)₂·Pb(OH)₂, NiCO₃·2Ni(OH)₂·4H₂O and CuCO₃·Cu(OH)₂ can deliver high initial discharge capacities of 1175.8, 1742.6 and 1356.2 mAh g⁻¹, respectively. The lithium storage mechanisms of basic metal carbonates are observed by various electrochemical, ex-situ and in-situ methods during the initial charge–discharge cycle. It can be found that basic metal carbonates decompose into metal (M=Pb, Ni or Cu), Li₂CO₃, LiOH and H₂O upon the preliminary discharge. With further lithiation, the active metal can alloy with Li to form several Li_xM phases. During the reverse charge process, Li extraction from the de-alloying reaction, M/Li₂CO₃ and M/LiOH mixtures can be observed. However, the cycling efficiency is low. Electrochemically inactive particles generated from pulverization, structural collapse and electronic contact loss result in the large irreversible capacity and low initial cycling efficiency. By using carbon black as conductive additive and buffer layer, the electrochemical properties of composite can be greatly improved. Carbon black–(PbCO₃)₂·Pb(OH)₂ composite shows a reversible charge capacity of 244.7 mAh g⁻¹ after 20 cycles, which is much higher than the value (77.2 mAh g⁻¹) of the pristine sample.     

Atom transfer radical polymerizations of methyl methacrylate catalyzed by EBiB/SnCl2·2H2O(FeCl2·4H2O)/FeCl3·6H2O/MA5-DETA systems

The ATRP of methyl methacrylate (MMA) with the system of FeCl₂·4H₂O, N,N,N′,N″,N″-penta(methyl acylate)diethylenetriamine (MA₅-DETA) and ethyl 2-bromoisobutyrate (EBiB) showed high activity and is not well-controlled. The addition of a certain amount of FeCl₃·6H₂O as the additive into the above system results in the decrease of the polymerization rate and the improvement of the controllability. When SnCl₂·2H₂O was added instead of FeCl₂·4H₂O, a novel catalyst system SnCl₂·2H₂O/FeCl₃·6H₂O/EBiB/MA₅-DETA formed shows better controllability, higher catalytic activity and higher initiating efficiencies (more than 90%) in comparison with the system FeCl₂·2H₂O/FeCl₃·6H₂O/EBiB/MA₅-DETA. The polydispersities of the polymers kept range from M_w/M_n=1.18-1.26. The real active species in the new system is Fe (II) formed from the reaction of FeCl₃·6H₂O with the active radical species produced from the reaction of SnCl₂·2H₂O with EBiB.     

Phase Equilibria in Water-Salt Systems Consisting of Potassium,Sodium, and Ammonium Carbonates and Anti-Icing Properties of Carbonate Compositions

Phase equilibria in K₂CO₃–H₂O, Na₂CO₃–H₂O, K₂CO₃–Na₂CO₃–H₂O, K₂CO₃–(NH₄)₂CO₃–H₂O systems under temperatures ranging from 0 down to ?36°C are investigated. The carbonate compositions forming low-temperature eutectics are revealed. Their melting ability with respect to ice under temperatures ?5 and ?10°C is determined. It was found that potassium carbonate is characterized by sufficient anti-icing properties. Potassium carbonate composition activity is determined with respect to metals. Efficient corrosion inhibiters are selected. It was found that potassium carbonate is aggressive with respect to cement concrete. Special protection is necessary, if potassium carbonate is used on cement concrete coatings.     

Synthesis of stimuli-responsive ionic cyclopolymers in search of phosphorous-free antiscalants

Ammonium persulfate-initiated cyclopolymerization of maleic acid (HO₂CC=CCO₂H) (MA) with diallylamine (–NR₂, R = CH₂ = CH-CH₂) derivatives (DADs): R₂NH⁺CH₂CO₂⁻ ( I ), R₂NCH₂CO₂⁻Na⁺ ( II ), R₂NCH₂CO₂Et ( III ), R₂NH⁺(CH₂)₃CO₂⁻ ( IV ), R₂N(CH₂)₃CO₂Et ( V ), R₂NH⁺(CH₂)₃SO₃⁻ ( VI ) and R₂N(CH₂)₃SO₃⁻Na⁺ ( VII ) gave a series of new pH-responsive alternate copolymers: –[(DAD-alt-MA)]_n– VIII - XIV , respectively. Homopolymers XV and XVI of the corresponding monomers IV and V ·HCl were also synthesized. The evaluation of the synthesized polymers as potential antiscalants in reverse osmosis (RO) plants was examined. An effective scale inhibitor must arrest the formation of scale for a residence time (≈15 min) of feed water in the RO chamber. R₂NH⁺(CH₂)₃CO₂⁻ ( IV )-alt-MA copolymer XI at a concentration of 5 ppm imparted 99% scale inhibition for 360 min, while at 2.5 and 1 ppm concentrations, the CaSO₄ scale inhibitions were found to be 99% and ≈ 100% during 120 and 20 min, respectively, at 40°C. Homopolymers XV and XVI , at a 20-ppm concentration, demonstrated ≈ 95% efficiency in inhibiting mild steel corrosion in 1 M HCl. In some important oilfield applications, requirement of simultaneous scale and corrosion inhibition make these polymers potential candidates for desalination and oilfield applications.