Effect of metal ion loaded in a resin towards fluoride retention

Indion FR 10 is a commercially available ion exchange resin with sulphonic acid functionality named as H⁺ form, has appreciable defluoridation capacity (DC). It has been chemically modified to La³⁺, Fe³⁺, Ce³⁺ and Zr⁴⁺ forms by incorporating respective metal ions into the resin in order to know their fluoride selectivity by measuring the DC of the respective resin. The maximum DC of these chemically modified ion exchange resins namely La³⁺, Fe³⁺, Ce³⁺ and Zr⁴⁺ forms were found to be 469.7, 467.5, 456.3 and 470.9 mg F⁻/kg respectively suggests their higher selectivity towards fluoride than H⁺ form which has the DC of only 275 mg F⁻/kg at 11 mg/L initial fluoride concentration. The higher DC of the modified resins was explained by electrostatic adsorption and complexation whereas H⁺ form retains fluoride by hydrogen bond. The functional groups present in the sorbents were identified by FTIR and the existence of fluoride onto the resins was confirmed by EDAX analysis. The experimental data was fitted with both Freundlich and Langmuir isotherms. Thermodynamic parameters such as ΔG°, ΔH° and ΔS° indicate that the nature of sorption is spontaneous and endothermic. The applicability of reaction-based and diffusion-based kinetic models was investigated. A field trial was carried out with fluoride water collected from a nearby fluoride-endemic village to test the suitability of these sorbents at field conditions.     

Study on the fluoride adsorption of various apatite materials in aqueous solution

The aim of this study was to evaluate the defluoridation efficiencies of various sorbents in aqueous solution. These sorbents include synthetic nano-hydroxyapatite (n-HAp), biogenic apatite (bone meal), treated biogenic apatite (bone meal prepared by H₂O₂ oxidation) and geogenic apatite (rock phosphate), which were characterized by XRD, FTIR, TEM and SEM. It has been observed that the defluoridation capacities follow the order: n-HAp > BH₂O₂ > B > rock phosphate. The controlling factors, sorbent dose, initial fluoride concentration, pH, contact time and temperature were investigated. The defluoridation capacities increased with the increase in the initial fluoride concentration and contact time, decreased with the increase in the sorbent dose. The optimum pH range for removal of fluoride on various apatite sorbents was considered to be 5.0-6.0. The fluoride adsorption can be explained by Langmuir, Freundlich isotherms, and the adsorption kinetic data follow the pseudo-second-order model. Thermodynamic parameters such as ΔH⁰, ΔS⁰ and ΔG⁰ indicated that the adsorption on various apatite sorbents was spontaneous and endothermic. These results showed that bone meal is a promising material for fluoride adsorption.     

Defluoridation kinetics of 200 °C calcined bauxite, gypsum, and magnesite and breakthrough characteristics of their composite filter

Reaction kinetics and breakthrough characteristics in water defluoridation were studied through experiments with 200 °C-calcined bauxite, gypsum and magnesite and their composite filter. The aim was to determine defluoridation potential of a composite filter of the three locally sourced natural materials in contribution towards fluorosis mitigation. The materials were crushed and sieved to particle sizes of 1.2-1.4 mm diameter, and then heat-treated at 200 °C for 2 h. Their defluoridation capacities and reaction kinetics were determined in batch. A composite was then prepared in the ratio of the loading capacities. Breakthrough characteristics were experimented on in fixed bed through bed depth service time (BDST) design model, empty bed residence time (EBRT) optimisation model and the two parameter-logistics (2-PL) model. Mean loading capacities of 5.6, 3.4 and 1.7 mg F⁻/g were obtained for bauxite, gypsum and magnesite, respectively. Loading capacities decreased, while sorption percentages increased, with increase in dose level. Second order kinetics observed had rate constants 4.07 × 10⁻², 1.87 × 10⁻², 1.59 × 10⁻² g mg⁻¹ min⁻¹ for bauxite, gypsum and magnesite, respectively. Composites, bauxite and gypsum decreased, while magnesite increased water pH. Time at 50% breakthrough (τ) obtained experimentally compared well with τ obtained through the two-parameter logistics model indicating good fitness of data to the model. Greater doses obtained higher breakthrough times that were, 120, 210, 255 and 360 min for 45, 75, 120 and 150 g, respectively. Critical bed depth (Z_o), 7.71 cm and an operating line, ? = 4 × 10⁻⁴δ − 0.0757δ + 4.86 (? = adsorbent exhaustion rate, δ = EBRT) were obtained. The water quality was within recommended quality limits for pH, apparent colour, hardness, and residual concentrations of SO₄²⁻, Cl⁻, Fe²⁺, and Al³⁺ in fixed bed. The research showed that a composite filter of the three materials, prepared in the ratio of their loading capacities and calcined at 200 °C, is a potential defluoridating filter in fixed bed configuration.     

A chelating resin containing S, N and O atoms: Synthesis and adsorption properties for Hg(II)

A novel chelating resin containing S, N and O atoms (PSME-EDA) was synthesized by using poly(2-hydroxyethylmercaptomethylstyrene) (PSME) and diethanolamine (EDA) as materials. Its structure was characterized by elemental analysis, Fourier transform-infrared spectra (FTIR), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The adsorption of the resin for Hg²⁺ was investigated. The saturated adsorption capacity of PSME-EDA for Hg²⁺ could reach to about 1.1 mmol/g at 25 °C when the initial Hg²⁺ concentration was 0.02 mol/l. Some factors affecting the adsorption such as temperature, reaction time and ion concentration were also studied. The results showed that adsorption was controlled by liquid film diffusion. The increasing of temperature was beneficial to adsorption. The Langmuir model was better than the Freundlich model to describe the isothermal process. The values of ΔG, ΔH, and ΔS calculated at 25 °C were −7.99 kJ mol⁻¹, 22.5 kJ mol⁻¹ and 34.4 J mol⁻¹ K⁻¹, respectively. The adsorption mechanism of PSME-EDA resin for Hg(II) was confirmed by X-ray photoelectron spectroscopy (XPS).     

Thermodynamics of chromium acetylacetonate sublimation

The equilibrium sublimation pressure Cr(acac)₃(s) = Cr(acac)₃(g) was measured in the range 320 ≤ T (K) ≤ 476 by two procedures. One of them is Knudsen's effusion procedure with mass spectrometric analysis of the composition of the gas phase, which proved to be good in measuring low pressure. The second is mass spectrometric procedure “calibrated volume method” (CVM), which helped us to expand the possibilities of the effusion method toward high pressure range. Experimental data are in good agreement with each other.For this process were obtained ln(P (Pa)) = 39.197 − 15 308.5/T, enthalpy Δ_subH° (T) = 127.28 ± 0.22 kJ mol⁻¹ and entropy Δ_subS° (T) = 230.1 ± 0.5 J mol⁻¹ K⁻¹.     

Removal of fluoride ions using cuttlefish bones

Because of the high toxicity of fluoride to mankind, there is an urgent need to treat fluoride-contaminated drinking water to make it safe for human consumption. This work investigated the possibility of eliminating, by sorption, the excess of fluoride in overloaded water according to World Health Organization WHO recommendations. We tested the cuttlefish bone as an adsorbent material (available in Tunisia) for the defluoridation of water. Initially, we determined the optimal conditions of use (contact time, pH effect, adsorbent dose, initial fluoride concentration) of the cuttlefish bone on synthetic solutions of sodium fluoride. The second step was to verify the effectiveness of the sorption process on the cuttlefish bone by testing it on natural waters loaded with fluoride. The results obtained showed that sorption on the cuttlefish bone could be an effective method for the removal of fluoride. The efficacy of cuttlefish bone to remove fluoride from water was found to be 80% at pH 7.2, 1 h contact time, 15 g L⁻¹ adsorbent dose and 5 mg L⁻¹ initial fluoride concentration. Despite the different anions (Cl⁻ and SO₄²⁻) generally present in natural waters, a fluoride concentration in agreement with the norm (<1.5 mg L⁻¹) could be reached whatever the water treated. The regeneration of the cuttlefish bone was performed with a NaOH solution (10 g of cuttlefish bone/1000 mL NaOH 3 M). After 1 h of agitation, 95% of fluorides were desorbed. Following regeneration, the adsorbent can be used for further removal of fluoride.     

An experimental and theoretical reinvestigation of the Michael addition of primary and secondary amines to dimethyl acetylenedicarboxylate

Theoretical calculations of the Michael addition of diethylamine, pyrrolidine, and benzylamine to DMAD at the DFT (B3LYP/6-31+G^∗) level indicate that the reaction follows a stepwise mechanism via a zwitterionic intermediate. The reactions have low activation barriers, 13–15 kcal mol⁻¹ and are exothermic, ΔH° = −29 to −44 kcal mol⁻¹. The detailed investigation of the reaction of benzylamine with DMAD reveals participation of the reactant-, transition structure-, and the product-complexes and that the 1,3-prototropic shift occurs through the benzylamine molecule. It also predicts formation of dimethyl 2-(N-benzylimino)butane-1,4-dicarboxylate as one of the products, which has been duly isolated and characterized experimentally.     

Thermodynamics of BaNd2Fe2O7(s) and BaNdFeO4(s) in the system BaNdFeO

Two compounds, BaNd₂Fe₂O₇(s) and BaNdFeO₄(s) in the quaternary system BaNdFeO were prepared by citrate-nitrate gel combustion route and characterized by X-ray diffraction analysis. Heat capacities of these two oxides were measured in two different temperature ranges: (i) 130-325 K and (ii) 310-845 K, using a heat flux type differential scanning calorimeter. Two different types of solid-state electrochemical cells with CaF₂(s) as the solid electrolyte were employed to measure the e.m.f. as a function of temperature. The standard molar Gibbs energies of formation of these quaternary oxides were calculated as a function of temperature from the e.m.f. data. The standard molar enthalpies of formation from elements at 298.15 K, ΔfHm° (298.15 K) and the standard entropies, Sm° (298.15 K) of these oxides were calculated by the second law method. The values of ΔfHm° (298.15 K) and Sm° (298.15 K) obtained for BaNd₂Fe₂O₇(s) are: −2756.9 kJ mol⁻¹ and 234.0 J K⁻¹ mol⁻¹ whereas those for BaNdFeO₄(s) are: −2061.5 kJ mol⁻¹ and 91.6 J K⁻¹ mol⁻¹, respectively.     

Thermodynamic properties of hydrated sodium l-threonate Na(C4H7O5)·H2O(s)

Low-temperature heat capacities of the compound Na(C₄H₇O₅)·H₂O(s) have been measured with an automated adiabatic calorimeter. A solid-solid phase transition and dehydration occur at 290-318 K and 367-373 K, respectively. The enthalpy and entropy of the solid-solid transition are Δ_transH_m = (5.75 ± 0.01) kJ mol⁻¹ and Δ_transS_m = (18.47 ± 0.02) J K⁻¹ mol⁻¹. The enthalpy and entropy of the dehydration are Δ_dH_m = (15.35 ± 0.03) kJ mol⁻¹ and Δ_dS_m = (41.35 ± 0.08) J K⁻¹ mol⁻¹. Experimental values of heat capacities for the solids (I and II) and the solid-liquid mixture (III) have been fitted to polynomial equations.     

Simultaneous voltammetric detection of ascorbic acid, dopamine and uric acid using a pyrolytic graphite electrode modified into dopamine solution

Pyrolytic graphite electrodes (PGE) were modified into dopamine solutions using phosphate buffer solutions, pH 10 and 6.5, as supporting electrolyte. The modification process involved a previous anodization of the working electrode at +1.5 V into 0.1 mol L⁻¹ NaOH followed by other anodization step, in the same experimental conditions, into dopamine (DA) solutions. pH of the supporting electrolyte performed an important role in the production of a superficial melanin polymeric film, which permitted the simultaneous detection of ascorbic acid (AA), (DA) and uric acid (UA), ΔE_AA-DA = 222 mV; ΔE_AA-UA = 360 mV and ΔE_DA-UA = 138 mV, avoiding the superficial poisoning effects. The calculated detection limits were: 1.4 × 10⁻⁶ mol L⁻¹ for uric acid, 1.3 × 10⁻⁵ mol L⁻¹ for ascorbic acid and 1.1 × 10⁻⁷ mol L⁻¹ for dopamine, with sensitivities of (7.7 ± 0.5), (0.061 ± 0.001) and (9.5 ± 0.05) A mol⁻¹ cm⁻², respectively, with no mutual interference. Uric acid was determined in urine, blood and serum human samples after dilution in phosphate buffer and no additional sample pre-treatment was necessary. The concentration of uric acid in urine was higher than the values found in blood and serum and the recovery tests (92-102%) indicated that no matrix effects were observed.     

Tetramidocavitand: strong anion receptor by well-organized four -(CO)N-H?X interactions

Resorcin[4]arene-based tetramidocavitands containing four secondary amide groups on their upper rim showed strong (R = methyl or ethyl) binding properties. The caviplex formation through hydrogen bonds of -(CO)N-H?X⁻ was supported by ¹H NMR and crystal structure analyses. In a mixture of C₂D₂Cl₄/DMSO/D₂O = 5:15:2 at 25 °C, the thermodynamic parameters for caviplex @1, ΔG (kcal mol⁻¹), ΔH (kcal mol⁻¹), and ΔS (cal K⁻¹ mol⁻¹), are −3.7, −8.6, and −16.7, respectively.     

Spectroscopic, thermal, magnetic and structural characterization of K3VF6 prepared at room temperature

A straight forward room-temperature synthesis of V(III) containing complex fluoride K₃VF₆, using KF and vanadium(III) acetylacetonate is reported. The pale green colored powder was characterized by chemical analysis, powder X-ray diffraction; diffuse reflectance spectroscopy, infrared spectroscopy, Raman spectroscopy, differential scanning calorimetry, scanning electron microscopy, photoluminescence spectroscopy, magnetic susceptibility measurements and photoluminescence spectroscopy. The powder X-ray diffraction pattern was fitted in P2₁/n space group (monoclinic) with a = 12.106 (1) Å, b = 17.685 (0) Å, c = 11.802 (0) Å, β = 92.23° (1). Differential scanning calorimetry showed phase transitions, occurring at 158 °C and 190 °C. In the FT-IR spectrum, characteristic band for the VF₆³⁻ group was observed at 508 cm⁻¹. The bands observed in the 335-361 cm⁻¹ region and at 504 cm⁻¹ in the room temperature Raman spectrum of K₃VF₆ corresponded to the F_2g and A_1g modes, respectively. The ratio of the frequencies (F_2g/A_1g) observed in the diffuse reflectance spectrum was fitted on the Tanabe-Sugano diagram to determine the Racah parameter B value of 712 cm⁻¹. Magnetic ordering was not observed down to the lowest measured temperature of 5 K.     

Thermodynamic studies on SrFe12O19(s), SrFe2O4(s), Sr2Fe2O5(s) and Sr3Fe2O6(s)

The citrate-nitrate gel combustion route was used to prepare SrFe₂O₄(s), Sr₂Fe₂O₅(s) and Sr₃Fe₂O₆(s) powders and the compounds were characterized by X-ray diffraction analysis. Different solid-state electrochemical cells were used for the measurement of emf as a function of temperature from 970 to 1151 K. The standard molar Gibbs energies of formation of these ternary oxides were calculated as a function of temperature from the emf data and are represented as (SrFe₂O₄, s, T)/kJ mol⁻¹ (±1.7)=−1494.8+0.3754 (T/K) (970?T/K?1151). (Sr₂Fe₂O₅, s, T)/kJ mol⁻¹ (±3.0)=−2119.3+0.4461 (T/K) (970?T/K?1149). (Sr₃Fe₂O₆, s, T)/kJ mol⁻¹ (±7.3)=−2719.8+0.4974 (T/K) (969?T/K?1150).Standard molar heat capacities of these ternary oxides were determined from 310 to 820 K using a heat flux type differential scanning calorimeter (DSC). Based on second law analysis and using the thermodynamic database FactSage software, thermodynamic functions such as Δ_fH°(298.15 K), S°(298.15 K) S°(T), C_p°(T), H°(T), {H°(T)-H°(298.15 K)}, G°(T), free energy function (fef), Δ_fH°(T) and Δ_fG°(T) for these ternary oxides were also calculated from 298 to 1000 K.     

Fluorometric determination of fluoride ion by reagent tablets containing 3-hydroxy-2'-sulfoflavone and zirconium(IV) ethylenediamine tetraacetate

A reagent tablet for determination of fluoride ion has been prepared using ethylenediamine-N,N,N′,N′-tetraacetate complex of zirconium (Zr-EDTA), 3-hydroxy-2′-flavone (FS) and an appropriate pH buffer. Dissolving of the tablet into water exhibits an intense blue fluorescence (λ_max = 460 nm) upon excitation at 377 nm and the fluorescence intensity decreases with the presence of fluoride ion. Hence, a simple fluorescent detection procedure for fluoride ion in aqueous media was successfully constructed with this tablet. The principle of this detection system is the ligand exchange reaction of FS bound to Zr-EDTA with fluoride ion. The present system provides an easy, rapid and selective determination method of fluoride ion ranging from 5 × 10⁻⁶ to 1 × 10⁻³ mol dm⁻³. The measurement of real samples with this tablet showed the similar results as those by the common method with the Alfusone reagent.     

Layer-by-layer self-assembly of polyelectrolyte complexes and their multilayer films for pervaporation dehydration of isopropanol

Two negatively charged polyelectrolyte complex colloidal nanoparticles (PEC⁻) and one positively charged nanoparticle (PEC⁺) were prepared and used as novel layer-by-layer (LbL) building blocks. These PEC nanoparticles include poly(2-methacryloyloxy ethyl trimethylammonium chloride)/sodium carboxymethyl cellulose (PDMC/CMCNa PEC⁻), poly(diallyldimethylammonium chloride)/CMCNa (PDDA/CMCNa PEC⁻) and PDDA/poly(sodium-p-styrenesulfonate) (PDDA/PSS PEC⁺). LbL multilayer films based on (PEC⁺/PEC⁻) were constructed on both quartz slides and modified polyamide (MPA) reverse osmosis support membranes. UV–vis spectroscopy, quartz crystal microbalance (QCM), field emission scanning microscopy (FESEM) and atomic force microscopy (AFM) were utilized to follow the thickness growth and morphology evolution of these multilayer films with increasing bi-layer numbers. LbL multilayer films deposited on MPA support membranes were subjected to pervaporation dehydration of 10 wt% water–isopropanol and effect of bi-layer numbers and feed temperature on pervaporation performance was studied. Generally, PEC⁺/PEC⁻ can be LbL self-assembled successfully on both substrates with a thickness growth rate ca. 200 nm/bi-layer. Moreover, PEC⁺/PEC⁻ multilayer films show high pervaporation performance with film thickness up to several micrometers. For example, performance of the multilayer films in dehydrating 10 wt% water–isopropanol at 50 °C is J = 1.18 kg/m² h, α = 1013 for (PEC⁺/PDMC-CMCNa PEC⁻)₂₄ and J = 1.36 kg/m² h, α = 938 for (PEC⁺/PDMC-CMCNa PEC⁻)₂₅, respectively.     

Solid phase extraction-spectrophotometric determination of fluoride in water samples using magnetic iron oxide nanoparticles

A new, sensitive, fast and simple method using magnetic iron oxide nanoparticles (MIONs), as an adsorbent has been developed for extraction, preconcentration and determination of traces of fluoride ions. The determination method is based on the discoloration of Fe(III)-SCN complex with extracted fluoride ions which was subsequently monitored spectrophotometrically at λ_max = 458 nm. Various parameters affecting the adsorption of fluoride by the MIONs have been investigated, such as pH of the solution, type, volume and concentration of desorbing reagent, amount of adsorbent and interference effects. A linear response for the determination of fluoride was achieved in the concentration range of 0.040-1.250 μg mL⁻¹. The limit of detection (LOD) and limit of quantification (LOQ) for fluoride based on 3 times and 10 times the standard deviation of the blank (3S_b, 10S_b) were 0.015 and 0.042 μg mL⁻¹ (n = 20) for fluoride ion, respectively. A preconcentration factor of 50 was achieved in this method. The proposed procedure has been applied for determination of fluoride concentration in various water samples. The results obtained from this method were successfully compared with those provided by standard SPADNS method.     

Low-temperature heat capacity and thermodynamic properties of endo-Tricyclo[5.2.1.0]decane

Endo-Tricyclo[5.2.1.0^2,6]decane (CAS 6004-38-2) is an important intermediate compound for synthesizing diamantane. The lack of data on the thermodynamic properties of the compound limits its development and application. In this study, endo-Tricyclo[5.2.1.0^2,6]decane was synthesized and the low temperature heat capacities were measured with a high-precision adiabatic calorimeter in the temperature range from (80 to 360) K. Two phase transitions were observed: the solid-solid phase transition in the temperature range from (198.79 to 210.27) K, with peak temperature 204.33 K; the solid-liquid phase transition in the temperature range from 333.76 K to 350.97 K, with peak temperature 345.28 K. The molar enthalpy increments, ΔH_m, and entropy increments, ΔS_m, of these phase transitions are ΔH_m=2.57 kJ · mol⁻¹ and ΔS_m=12.57 J · K⁻¹ · mol⁻¹ for the solid-solid phase transition at 204.33 K, and, Δ_fusH_m=3.07 kJ · mol⁻¹ and Δ_fusS_m=8.89 J · K⁻¹ · mol⁻¹ for the solid-liquid phase transition at 345.28 K. The thermal stability of the compound was investigated by thermogravimetric analysis. TG result shows that endo-Tricyclo[5.2.1.0^2,6]decane starts to sublime at 300 K and completely changes into vapor when the temperature reaches 423 K, reaching the maximal rate of weight loss at 408 K.     

X-ray diffraction study on the thermal expansion behavior of cellulose Iβ and its high-temperature phase

Oriented films of cellulose prepared from algal cellulose were hydrothermally treated to convert them into highly crystalline cellulose Iβ. The lateral thermal expansion behavior of the prepared cellulose Iβ films was investigated using X-ray diffraction at temperatures from 20 to 300 °C. Cellulose Iβ was transformed into the high-temperature phase when the temperature was above 230 °C, allowing the lateral thermal expansion coefficient of cellulose Iβ and its high-temperature phase to be measured. For cellulose Iβ, the thermal expansion coefficients (TECs) of the a- and b-axes were α_a = 9.8 × 10⁻⁵ °C⁻¹ and α_b = 1.2 × 10⁻⁵ °C⁻¹, respectively. This anisotropic thermal expansion behavior in the lateral direction is ascribed to the crystal structure and to the hydrogen-bonding system of cellulose Iβ. For the high-temperature phase, the anisotropy was more conspicuous, and the TECs of the a- and b-axes were α_a = 19.8 × 10⁻⁵ °C⁻¹ and α_b = −1.6 × 10⁻⁵ °C⁻¹, respectively. Synchrotron X-ray fiber diffraction diagrams of the high-temperature phase were also recorded at 250 °C. The cellulose high-temperature phase is composed of a two-chain monoclinic unit cell, a = 0.819 nm, b = 0.818 nm, c (fiber repeat) = 1.037 nm, and γ = 96.4°, with space group = P2₁. The volume of this cell is 4.6% larger than that of cellulose Iβ at 30 °C.     

Enhanced fluoride sorption using La(III) incorporated carboxylated chitosan beads

The carboxylated chitosan beads (CCB), which have a defluoridation capacity (DC) of 1385 mg F(-)/kg, have been further chemically modified by incorporating La(3+) ion (La-CCB) and its DC was found to be 4711 mg F(-)/kg whereas the raw chitosan beads (CB) possess only 52 mg F(-)/kg. The fluoride removal by La-CCB is governed by both adsorption and complexation mechanism. The functional groups present in beads were identified by FTIR analysis. The surface condition and existence of fluoride on the beads was confirmed by SEM with EDAX analysis. The experimental data have been analyzed using Freundlich and Langmuir isotherm models. Thermodynamic parameters such as DeltaG(o), DeltaH(o) and DeltaS(o) were calculated to predict the nature of sorption. The kinetic studies were investigated with reaction-based and diffusion-based models. A field trial was carried out with fluoride water collected from a nearby fluoride-endemic village.     

Viscometric study on the miscibility of polystyrene/brominated polystyrene blends

The miscibility of polystyrene/brominated polystyrene blends (PS/PBrS) was investigated by using dilute-solution viscometry (DSV) method. The intrinsic viscosity and the viscometric parameters of this system have been determined at 20 ± 0.1 °C for prepared several PS/PBrS compositions (85/15, 75/25, 50/50, 25/75, 10/90). The binary systems were prepared in chloroform at five different concentrations; 0.15, 0.30, 0.60, 0.90, 1.20 g 100 ml⁻¹. The miscibility criteria on the basis of the sign of Δ[η] _m, Δb and Δb′, which are based on the difference between experimental and ideal values of [η]_m, and b_m were calculated by applying the Garcia et al., Catsiff-Hewett and Krigbaum-Wall theoretical equations. The thermodynamic parameter, α, modified thermodynamic parameter, β, and interaction parameter, μ, were also estimated. The data obtained from the viscometry studies showed that the examined blends were immiscible in all the compositions range besides the composition (10/90). The results from the DSV method are correlated with the miscibility data obtained for the same blend by differential scanning calorimetry (DSC) find.