Various Concentrations Of Electrolytes Research Articles

Green fabrication and efficiency of activated biochar-layered double hydroxide (LDH) nanocomposites against toxic Pink-XFG dye

Removal of dyes has been a matter of great interest for researchers because of health and toxicity issues. In this research work, green biochar was produced using precipitation technique, and by the adsorption process, it was supported on layered double hydroxide (LDH). Biochar/LDH composites were synthesized from Neem, Amaltas, and Keekar stems, eggshells, and Eucalyptus (N, A, K, Egg, and Eu’s biochar/LDH-composite). These composites were employed to remove synthetic dyes from an aqueous solution. Recent studies have identified optimal conditions for LDH-composites under various parameters: pH 9 or 10 with a dosage of 0.05 g/50 mL yields higher adsorption capacities across different LDH composites, ranging from 40.74 to 48.30 mg/g at a reaction time of 90 min using a Pink-XFG dye concentration of 10 ppm, which is favorable. Temperatures of 303–308 K are suitable. Second-order kinetics, along with the Langmuir and Freundlich adsorption isotherms, along with exothermic reactions, presented good-fit results on adsorption kinetics and equilibrium data. The adsorption potential was significantly affected by various concentrations of electrolytes, surfactants, detergents, and heavy metal ions. 0.5 N hydrochloric acid was determined to be the most efficient agent for the process of desorption. These methods are very cost-effective, eco-friendly, and easy to manufacture.

A stretchable epidermal sweat sensing platform with an integrated printed battery and electrochromic display

Wearable electronic devices are of potential use in various health monitoring applications including non-invasive chemical sensing. However, such platforms are typically limited by the need to connect to external devices for power and data visualization. Here we report a stretchable epidermal sweat sensing platform that integrates a stretchable battery and a low-power digital electrochromic display. The patch can operate as a standalone device to directly display the concentration of various electrolytes or metabolites in sweat, such as glucose and lactate, without any wired or wireless connection to external devices. It consists of electrochemical sensors, a stretchable Ag2O–Zn battery, ten individually addressable electrochromic pixels and a small microcontroller unit. All the components and interconnections, except the microcontroller, are fabricated via the high-throughput screen printing of customized elastomeric or silver inks. The integrated system is robust to mechanical deformation and is unaffected by 1,500 stretching cycles at 20% strain. The electrochromic display exhibits stability for 10,000 on/off cycles, and the battery can power 14,000 sensing sessions over a week-long use.

Improvement of ferning patterns of lubricant eye drops mixed with various electrolytes and carboxymethylcellulose

PurposeTo investigate the effect of the addition of electrolytes, basic tear solution (BTS), and sodium carboxymethylcellulose (SCMS) on the tear ferning (TF) patterns of Blink Contact Soothing Eye Drops® and Refresh Plus Tears®. MethodSamples of Blink Contact Soothing Eye Drops® and Refresh Plus Tears® (10 μL) were mixed with different volumes (3–30 μL) of several electrolytes, namely sodium chloride, potassium chloride, calcium chloride, magnesium chloride hexahydrate, sodium hydrogen carbonate, and sodium dihydrogen phosphate, BTS, and SCMS. Samples (1 μL) of the mixtures were dried on a glass slide at room temperature and the TF patterns were inspected using a light microscope, graded using the Masmali five-point grading scale and compared to the corresponding TF grades of the artificial tears. ResultsThe TF grades of Blink Contact Soothing Eye Drops® and Refresh Plus Tears® improved from 1.2 and 1.5, respectively to 0.2 when calcium chloride was used as the electrolyte. Improvements in TF grades were also observed when other electrolytes (e.g., sodium dihydrogen phosphate), BTS, and SCMS were used. ConclusionThe tear ferning test can be used to evaluate the effect of the addition of electrolytes to an artificial tear in-vitro. The TF patterns of artificial tear solutions such as Blink Contact Soothing Eye Drops® and Refresh Plus Tears® can be improved with the addition of various concentrations of electrolytes, BTS, and SCMS, however further research is still needed to understand the clinical relevance of TF patterns with respect to the management of dry eye symptoms and their potential role in the development of new artificial tears.

Estimation of transition concentration of aqueous mixtures of single and binary electrolytes for bubble coalescence inhibition

A bubble column was investigated in which a swarm of air bubbles was dispersed in aqueous electrolyte (NaCl, MgSO4·7H2O, CaCl2·2H2O, and Na2SO4) solutions. In the present work, study of coalescence inhibition has been targeted by applying gas holdup enhancement and surface tension gradient approaches for aqueous solutions in single and binary mixtures (CaCl2·2H2O + NaCl and Na2SO4 + NaCl) of electrolytes. Transition concentrations of a series of coalescence inhibiting inorganic electrolytes were determined. A qualitative comparison of these electrolytes revealed that strong electrolytes (Na2SO4, and CaCl2·2H2O) yield gas holdup enhancement ≥ 60% whereas moderate electrolytes (NaCl and MgSO4·7H2O) give gas holdup enhancement values ≤ 46%. It has been also found that the values of transition concentration for different electrolytes are of the same order in most of the cases and in line with those reported in the literature. Inhibition of bubble coalescence was also analyzed in terms of the parameter $$ C\left( {{\text{d}}\sigma /{\text{d}}C} \right)^{2} $$ . The large value of the parameter $$ ({\text{d}}\sigma /{\text{d}}C)^{2} $$ indicates that the electrolyte will inhibit bubble coalescence, and a smaller value indicates moderate effect on bubble coalescence. Surface elasticity values at transition concentration of various electrolytes were also determined. It was found that the surface elasticity values at transition concentration were in the order CaCl2·2H2O > MgSO4·7H2O > Na2SO4 > NaCl. Surface elasticity for binary electrolytes was also estimated at their transition concentrations. The values were found in the order CaCl2·2H2O + NaCl > Na2SO4 + NaCl. Furthermore, analysis of variance was employed to estimate significance of the parameters.

The adsorption of alkyl-dimethyl-benzyl-ammonium chloride onto cotton nonwoven hydroentangled substrates at the solid–liquid interface is minimized by additive chemistries

Quaternary ammonium compounds, commonly referred to as quats, are cationic surfactants widely used as the active biocidal ingredient for disposable disinfecting wipes. The cationic nature of quats results in a strong ionic interaction and adsorption onto wipes materials that have an anionic surface charge, such as cellulosic materials, including cotton. The degree of adsorption of quats onto cotton nonwovens is affected by pretreatment of the substrate, more specifically whether it is a greige or a scoured and bleached fabric. This study examined the effect of varying the chemical and physical properties of solutions on the adsorption of the quat alkyl-dimethyl-benzyl-ammonium chloride (ADBAC) onto greige and scoured and bleached cotton nonwoven fabrics produced by hydroentanglement. At a constant surfactant concentration, the liquor ratio, pH, temperature, and concentrations of various electrolytes in the solution were varied and the amount of ADBAC depleted from solution was determined over time. The results suggested that a more alkaline solution increased the amount of ADBAC adsorbed onto both cotton nonwoven fabrics, while a more acidic solution reduced ADBAC adsorption. Likewise, increasing the temperature and concentration of salts in the solution reduced the adsorption of ADBAC onto the cotton fabrics. The presence of nonionic surfactants or low molecular weight quats also reduced ADBAC adsorption onto cotton fabrics in a concentration-dependent manner. The results of this study will provide guidance for optimized chemical formulations compatible with disposable disinfecting cotton-based wipes, cloths, and other cotton-containing implements intended for use in cleaning and disinfecting applications.

Heavy and toxic metal ion removal by a novel polymeric ion-exchanger: synthesis, characterization, kinetics and equilibrium studies

BACKGROUND A novel synthetic terpolymer resin involving anthranilic acid/o-toluidine/formaldehyde (AOTF) was synthesized for the recovery of harmful and heavy metal ions. The resin was characterized by physico-chemical, elemental, FTIR, NMR and SEM analysis. Batch separation was used under the following conditions: different concentrations of various electrolytes; variation of pH and time intervals to determine the ion-exchange properties of the resin for specific metal ions viz. Fe3+, Co2+, Ni2+, Cu2+, Zn2+ and Pb2+. Kinetic and equilibrium studies were also carried out with the terpolymer resin to evaluate the effectiveness of metal ion removal. RESULTS The ion-exchange capacity for the resin was found to be 5.02 milli mol g−1 indicating that the resin is a more effective ion-exchanger than some phenolic and polystyrene ion-exchangers. The amount of Cu2+, Ni2+ and Fe3+ taken up by the resin was 3.12, 2.25 and 2.34 milli mol g−1 at 0.5 mol L−1, respectively, hence the order of metal ion uptake at high concentrations is Cu2+ > Fe3+ > Ni2+. But at lower concentration of 0.01 mol L−1, the uptake of Zn2+ was 2.54, Co2+ was 1.77 and Pb2+ was 0.99 milli mol g−1, respectively, and the order of metal ion uptake is Zn2+ > Co2+ > Pb2+. CONCLUSION The results revealed that the synthesized ion-exchanger could act as a good ion-exchanging agent for the removal of toxic and hazardous wastes from industrial effluents. The results are compared with those for some commercial resins and earlier reported resins which indicate that the resin has an excellent capability to remove specific metal ions from waste solutions. © 2014 Society of Chemical Industry

Zeta potential study of natural‐ and acid‐activated sepiolites in electrolyte solutions

AbstractDetailed characterisation of natural sepiolite from the Eskisehir region of Turkey was performed using X‐ray diffraction, X‐ray fluorescence, field emission scanning electron microscopy, specific surface area (BET method), Fourier transform infrared spectra, derivative thermogravimetry (DTG) and differential thermal analysis. Electrokinetic properties of natural‐ and acid‐activated sepiolites were investigated as a function of the concentration of various electrolytes, such as NaCl, KCl, LiCl, CaCl2, MgCl2, NaNO3, Na2CO3, FeCl3 and Al(NO3)3. While mono and divalent cations and anions did not change the surface charge of natural‐ and acid‐activated sepiolite, trivalent cations changed the surface charge from negative to positive. Acid‐activated sepiolite samples shifted towards the positive region in nearly all electrolyte solutions when compared with the natural sepiolite. © 2011 Canadian Society for Chemical Engineering

Investigation of electric double layer and crystal shapes of electrochemically grown zinc oxide

AbstractZinc oxide (ZnO) films were electrochemically deposited on n‐Si(001) substrates and indium‐tin oxide substrates with various concentrations of electrolytes. The crystal shape and orientation of ZnO were depends both on the type of substrates and the concentration. Denser film was obtained using more concentrated electrolyte or using substrate with lower resistivity. For a unified treatment, we investigate the thickness of the electric double layer (EDL) on the growth surface by measuring the capacitance between two electrodes.The dependence between the thickness of EDL and the crystal shapes indicates that the mass transport beyond the EDL region would govern the electrochemical growth of ZnO. Selective growths on 1 μm/1 μm line and space patterns were demonstrated as a trial. Crystal shapes were similar to those grown on non‐patterned substrates. Control of the crystal orientation is necessary for the application of optoelectronic devices. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

The Nature of Surface Charges on α‐Cellulose Particles and the Implication for Stability of its Aqueous Dispersions to Electrolytes

Aqueous dispersions of α‐cellulose are inherently unstable, behaving as lyophobic colloids. The purpose of the present study is to investigate the nature of surface charges (positive or negative) on the dispersed particles and to study the influence of such charges on the stability of the aqueous dispersions to electrolytes. The influence of interparticulate cohesion in forming a rigid polymeric network in the dispersion was also considered. The electropotentials of the aqueous dispersions were measured, and their stability was determined for various concentrations of electrolytes (NaCl, BaCl2, and AlCl3). The maximum degree of separation (S%) and the time to attain it (tmax) were evaluated. The dispersions generally exhibited electronegative potentials, suggesting that the dispersed particles carried negative charges. Dispersions of concentration <5% w/v were inherently unstable with S% values ≥72% and tmax=4 hour. Dispersions of concentrations as high as 15% w/v were stable with no observable separation even after 24 hour, attributable to mutual repulsion of the disperse particles (due to the surface charges) and possibly to formation of a rigid polymeric network. The test electrolytes were generally ineffective in flocculating these dispersions; S% values were ≤25%, attributable to the formation of a rigid polymeric network.

Effects of follicle size and electrolytes and glucose in maturation medium on nuclear maturation and developmental competence of bovine oocytes.

The concentrations of electrolytes (Na, K, Cl, Mg and Ca) and glucose in small follicle (SF) follicular fluid (SFF) and large follicle (LF) follicular fluid (LFF) from slaughterhouse-derived ovaries were studied. Oocytes were matured in medium based on synthetic oviductal fluid. The effects of various concentrations of electrolytes (Na, K, Ca and Mg) and glucose in the maturation medium on the progression of nuclear maturation and subsequent development were also studied. K in SFF was significantly greater than that in LFF. The Mg concentration in follicular fluid (FF) is 2.0-2.3 mM, which is greater than the concentration present in medium generally used for culture. The glucose concentration in FF is about 3.5-3.9 mM and rapidly decreases during the preservation of ovaries. LF oocytes resumed nuclear maturation and progressed to the M2 stage significantly faster than those collected from SF oocytes. In addition, more LF oocytes developed to blastocysts than did SF oocytes. Changing the Na/K ratio in the maturation medium from 16 to 24 did not affect either the progression of nuclear maturation or the rate of development. A low concentration of Mg (0.5 mM) combined with a low Ca concentration (0.5 mM) inhibited the rate of development, but did not affect the progression of nuclear maturation. On the other hand, increasing the Mg concentration to 2.0 mM from 0.5 mM hastened the progression of nuclear maturation and improved the rate of blastulation, irrespective of the Ca concentration. The progression of nuclear maturation was faster and the rate of development was greater with 5.56 mM glucose than with 1.5 mM glucose. The difference in time needed to progress to M2 among the experiment was about 2-3 h. Therefore, prolonging the maturation periods from 21 to 24 h did not change the rate of development. Our results show that the concentrations of Mg and glucose in the maturation medium and the follicle size enveloping the oocyte affect the progression of nuclear maturation and subsequent development. The time requirement for oocytes to reach M2 is strongly related to the developmental competence of the oocytes.

Salt Effects on Single Aqueous Drops Falling through an Immiscible Organic Liquid

Drop settling (or rising) is crucial to the breaking of liquid-liquid dispersions. Most of the empirical correlations for terminal velocity of drops are formulated based on experimental data for systems of dispersed organic phase and continuous aqueous phase using pure and nearly pure liquids. Because the presence of the various third components in one or both of the phases mayaffect the settling of the drops, the terminal velocity and the onset of oscillation of aqueous drops containing various concentrations of electrolytes falling through n-dodecane were studied in this work. The applicability of existing empirical correlations to these reversed systems of continuous organic phase and dispersed aqueous phase was also examined. Dissolved electrolytes have the effect of causing the terminal velocities and their peak velocities at the onset of drop oscillation to become faster and the peak diameters to become smaller when their concentrations are high enough to cause sufficient changes of physical properties. Existing correlations for drop terminal velocity in pure systems are shown to be adequate in the presence of electrolytes. For high interfacial tension systems, the Hu-Kinter correlation predicts the terminal velocity of organic drops in water and aqueous drops in organics equally well, independent of the presence of electrolytes. The criteria of Hu-Kintner can be used to estimate the peak velocities and peak diameters at the onset of oscillation within a deviation of 3.7%.

Optimization of nickel tetracarbonyl generation and nickel in situ trapping within a transversely heated graphite furnace for atomic absorption spectrometry

The efficiency of nickel tetracarbonyl generation and of in situ trapping within a transversely heated graphite furnace was studied. The influence of experimental parameters of the flow injection generation system and in situ collection procedure for atomic absorption spectrometric determination of nickel, i.e. pH of reaction mixture, concentration of sodium tetrahydroborate solution, reaction temperature, concentration of various electrolytes, several ‘heavy metal’ ions and hydride forming elements, trapping temperature, position of introduction capillary and carrier gas flow rates on the overall efficiency were investigated. The acidity of the reaction mixture and the kinetics of carbonyl formation are the limiting parameters of the whole generation procedure. The temperature of the tube, gas flow rate and the position of the capillary are the most critical parameters in trapping nickel from nickel tetracarbonyl. Under optimum conditions, an overall efficiency of approximately 80% was found, evaluating atomic absorption spectrometric signals obtained by carbonyl generation/trapping procedure and by conventional liquid sampling procedure.

Phase behavior and detergency study of lauryl alcohol ethoxylates with high ethylene oxide content

AbstractNonionic surfactants such as fatty alcohol ethoxylates have been extensively used in many detergent applications, because of their high calcium ion tolerance, low critical micelle concentrations, and mildness. Although ethoxylates containing high ethylene oxide (EO) content (EO&gt;10 moles) score higher than their low‐FO counterparts on many of these desired properties, they have not been studied adequately in the context of detergency, primarily because their cloud points (CP) are higher than normal wash temperatures, typically &gt;100°C, and thus cannot be measured. However, once the CP are manipulated appropriately using salting‐out electrolytes, these surfactants can offer certain distinct advantages in terms of their molecular and phase structure. We have studied the phase structure and clouding behavior of tetradecyl ethylene‐oxide mono dodecyl alcohol (C12EO14), a broad‐range ethoxylate, as a function of the concentrations of various electrolytes. We found that, beyond a certain critical concentration, the CP decreases monotonically with increasing salt concentration. For sodium salts of various anions, the CP depression is inversely proportional to the lyotropic number of the anion. Similarly, for chloride salts of various cations, CP depression is inversely proporitional to the lyotropic number of the cation However, the effect of changing anion is stronger than that of changing cation. A micrograph of a water penetration scan at room temperature indicates the presence of isotropic L1; hexagonal, isotropic L2; and solid phases with increasing surfactant concentration. As is the case with low‐FO nonionics, a maximum in detergency of model oily soils was found to correlate well with the minimum in oil/water interfacial tension when plotted vs. temperature. Ross Miles foam height increases with increasing concentration of salt.

Adsorption and interface accumulation of aquasol and organosol carbon particles labeled with99mTc

Aerosol particles of99mTc-labeled carbon were prepared by sublimation and introduced in various liquid media. The adsorption of the aquasol and organosol particles were studied for various adsorbing substances and media, with the effect of surface treatment and voltage application. The particles often accumulated at the aqueous-organic interface, and also on the vessel surface in the presence of both aqueous and organic phases. The distribution of the particles was examined by a gamma-camera for different organic phases under various concentrations of electrolytes in the aqueous phase.

Phase equilibria of methane and carbon dioxide hydrates in the aqueous MgCl 2 solutions

The ternary water+MgCl 2+CH 4 phase equilibria were determined at the MgCl 2 concentration ranges of 3–15 wt.% and at temperature and pressure ranges of 272–286 K and 30–130 bars, respectively. The ternary water+MgCl 2+CO 2 phase equilibria are also determined at the MgCl 2 concentration ranges of 3–10 wt.% and at the temperature and pressure ranges of 272–282 K and 15–45 bars, respectively. The quadruple points of the water+MgCl 2+CO 2 system where the four phases, hydrate, water-rich liquid, CO 2-rich liquid, and vapor phases, coexist were also carefully measured and found to be located just below the vapor pressure curve of pure carbon dioxide. For the prediction of hydrate phase equilibria, the vapor and liquid phases were treated with the Redlich–Kwong–Soave equation of state with the Modified Huron–Vidal second order mixing rule and the hydrate phase with the van der Waals–Platteeuw model. The Pitzer-based model was adopted to estimate the activity of water in the aqueous electrolyte solution. This predictive approach was found to be well applicable to hydrate systems containing various concentrations of electrolytes.

Synthesis and characterization of some water soluble polymers

Homopolymers and copolymers of acrylamide (AA) and acrylic acid (AAc) were synthesized by the free radical solution polymerization technique. Feed ratios of the monomers were 85 : 15 (w/w), 65 : 35 (w/w), and 50 : 50 (w/w) of acrylamide and acrylic acid, respectively, for synthesis of copolymers. All reactions were carried out in aqueous media, except for the synthesis of polyacrylic acid, where the medium was n-butanol. Hydrogen peroxide, potassium persulfate, and benzoyl peroxide were used as initiators. The copolymers were purified by removing homopolymers. The homopolymers and copolymers were characterized by infrared (IR), 13C-nuclear magnetic resonance (NMR), 1H-NMR, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and viscosity measurements. The fusion temperature and the energy change for various phase transitions were obtained from DSC measurements. The activation energy values for various stages of decomposition were calculated from TGA. The activation parameters for the viscous flow (i.e., free energy, enthalpy, and entropy of activation) were evaluated from the viscosity measurements. Voluminosity and Simha shape factor were also calculated for different systems. Effects of various concentrations of electrolytes, NaNO3, and Al(NO3)3 on viscosity behavior were studied. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 45–56, 1997

Short term fasting and lactovegetarian diet does not affect human saliva.

Forty-two adults, visiting a Swedish health home, participated in the investigation, which included a 6-day period of fasting, followed by a 6-day period with a lactovegetarian diet. The results obtained indicated only a minor and mostly not significant influence on secretion rate, buffer effect, concentration of various electrolytes, and number of lactobacilli and S. mutans of whole saliva.

Reactions in chloroplasts, cytoplasm and mitochondria of leaf slices under osmotic stress

The effect of osmotic dehydration on metabolic reactions in three different subcellular compartments (chloroplast, cytoplasm and mitochondria) was studied in vacuum-infiltrated thin leaf slices from various plants, in the absence of stomatal control. The reactions tested were CO2 fixation in the light (chloroplast), CO2 fixation in the dark (cytoplasm), and O2 uptake in the dark (mitochondria). In most plants, the sensitivity of dark CO2 fixation to dehydration was similar to the sensitivity of photosynthesis. In leaf slices from a plant with Crassulacean acid metabolism (Kalanchoe pinnata), dark CO2 fixation (which reached similar rates as light fixation) was slightly more sensitive to osmotic stress than photosynthesis. Dark respiration (measured as O2 uptake) was significantly more resistant to hypertonic stress than both types of CO2 fixation. In crude leaf extracts from spinach, the response of soluble enzymes from the three different subcellular compartments to high concentrations of various electrolytes and neutral compounds was examined and compared with the in-vivo data.

Histochemical investigation of acid mucopolysaccharides in amyloid, colloid and hyaline

The carbohydrate component in amyloid was histochemically compared with that in colloid or hyaline. Alcian blue, azure A, and periodic acid Schiff were used to stain mucopolysaccharides. In a further attempt to identify various polyanions, staining was carried out with alcian blue containing various concentrations of electrolytes. Methylation, saponification, acid hydrolysis, and digestion with streptomyces or testicular hyaluronidase, or chondroitinase ABC were also employed. The results obtained suggest that the presence of heparitin sulfate in amyloid, of chondroitin sulfate A in hyaline, and of chondroitin sulfate C in colloid.

Histochemical demonstration of hyaluronic acid in human dermal mast cells.

Acid mucopolysaccharides in mast cell granules were histochemically studied in the lesion of urticaria pigmentosa and in the dermis of normal human skin. Alcian blue and azure A were used to stain mucopolysaccharides. Bromphenol blue was employed for detection of basic proteins. In a further attempt to identify various polyanions, staining was carried out with alcian blue containing various concentrations of electrolytes. Methylation, saponification, and digestion with streptomyces or testicular hyaluronidase, chondroitinase ABC, sialidase, or desoxyribonuclease were also employed. The results obtained are most likely to suggest the presence of hyaluronic acid in mast cell granules.