Effects Of Salt Type Research Articles

Effect of salt type on the particle size of LaMn1-xFexO3 (0.1≤x≤0.5) synthesized in molten chlorides

LaMn1-xFexO3 perovskites were successfully synthesized via molten salt synthesis in NaCl-KCl and LiCl-KCl, for the first time. The effect of salt type on the size of the obtained perovskite particles was investigated using two procedures. The first, corresponding to the common “mixing” synthesis procedure, included heating the La-, Mn- and Fe-nitrates and chlorides mixture above the melting point of the chloride mixture. While the synthesis temperature (600–850 °C) and perovskite composition (0.1 ≤ x ≤ 0.5) had no significant effect on the LaMn1-xFexO3 particle size, the effect of molten salt type was dramatic. The average size of LaMn1-xFexO3 particles synthesized in LiCl-KCl was 0.7–0.8 μm, while more than twice smaller particles were obtained in NaCl-KCl. Since different salts have both different melting points as well as different chemical and physical properties, it is impossible to distinguish between the individual contributions of these characteristics to the observed size difference. In order to address this problem, a second “feeding” procedure was employed, which skips the melting event by feeding the metal nitrates into already molten salt. Particles obtained using “feeding” procedure in LiCl-KCl (∼0.5 μm) were still larger than those obtained in NaCl-KCl (∼0.3 μm). The remnant effect, attributed solely to the salt properties, is explained by the nucleation and crystal growth model, with respect to higher perovskite solubility in LiCl-KCl. The suggested “feeding” procedure renders the separate analysis of synthesis conditions (e.g. the sole effect of salt type) for the first time, and can assist in the unraveling of molten salt synthesis mechanistic aspects.

Partitioning of cefazolin in aqueous two-phase systems containing poly (ethylene glycol) and sodium salts (citrate, tartrate, and sulphate)

Aqueous two-phase systems (ATPSs) have been recognized as potential alternative techniques for extraction or purification of biomolecules. In this work, partitioning behavior of cefazolin has been investigated in polymer-salt ATPSs. Thus, systems containing polyethylene glycol (PEG) with two different molecular weights (6000 and 8000) and three forms of sodium salts, including sodium citrate, sodium tartrate, and sodium sulfate were examined. Firstly, the binodal curves were determined at 300 K and then correlated with Merchuk equation. Results indicate that the system PEG8000/sulfate owns a wider two-phase area. Then, the tie-lines were plotted for the systems under study, and their validity was evaluated using the Othmer-Tobias and Bancroft equations. Finally, the partition coefficient of cefazolin was investigated in 6 different two-phase systems and 28 tie-lines overall. Effect of salt type, polymer molecular weight and its concentration on partition coefficient were discussed. On the basis of the results it can be declared that as the polymer concentration increases, the partition coefficient increases but the increase of polymer molecular weight leads to partition coefficient reduction. Sodium citrate was better than the other salts used for studying the cefazolin partitioning, that is in good accordance with the excluded volume theory. The maximum amount of partition coefficient equals to 13.4 with a 90.5 recovery percentage in the top phase which belongs to the system combined of PEG6000 (16% w/w) and sodium citrate (14% w/w).

SEED GERMINATION AND RADICLE ESTABLISHMENT RELATED TO TYPE AND LEVEL OF SALT IN COMMON BEAN (PHASEOLUS VULGARIS L. VAR. DJEDIDA)

Saline soils contain multiple types of salt, each of them may exert a different effect on seed germination and seedling growth. The aim of this study is to assess the effects of five types of salt on the seed germination and radicle establishment of common bean (Phaseolus vulgaris L. var. Djedida). The experiment was set out as a factorial experiment based on completely randomized design with four replications of ten seeds for the seed germination and twelve replicates for the seedling growth. We used five kinds of salts (NaCl, Na2SO4, CaCl2, CaCO3 and KCl) with concentrations of 0, 100, 200 and 300 mM. Seeds were incubated in Petri dishes at 25°C, in the dark, for 10 days. The results of analysis of variance indicated that the effects of salt types and concentrations, and their interaction effect were significant in all measured traits (P< 0.01). However, no significance effect was found on secondary roots number and seedlings dry biomass with CaCO3 treatment solution. According to the results, the inhibitory effects of the five salt types differed significantly. Indeed, germination of common bean seeds by various salts were in the order of NaCl > KCl > CaCO3 > Na2SO4 > CaCl2. However, the taproot length, the number of secondary roots and the seedlings dry weight by various salts were in the order of CaCO3 > KCl > NaCl > CaCl2 > Na2SO4. The effect of salt concentration was also obvious. The reduction in dry biomass of cotyledons is proportional to germination rates and to the development of seedlings in dry biomass and in size. Seeds of P. vulgaris var. Djedida were able to germinate under all concentrations of the various types of salt. The lowest final germination percentage (FGP) was obtained under 300 mM of all salts recording the following values: CaCO3 - 60%, NaCl - 60%, KCl - 52.5%, Na2SO4 - 50% and CaCl2 - 27.5%. During germination stage, the radicle emergence would be controlled by the environment osmolarity, while the later growth of the seedling would be limited by the reserve mobilization.

Effect of Salt Type and Alkyl Chain Length on the Binodal Curve of an Aqueous Two-Phase System Composed of Imidazolium Ionic Liquids

The binodal data for an aqueous two-phase system (ATPS) containing 1-alkyl-3-methylimidazolium tetrafluoroborate ([Cnmim]BF4, n = 2, 3, 4) or 1-alkyl-3-methylimidazolium chloride ([Cnmim]Cl], n = 2, 4, 6, 8, 10, 12) and inorganic salts (K2HPO4, NaH2PO4, (NH4)2SO4, and NaCl) or organic salts (sodium citrate, sodium tartrate, and sodium acetate) were widely determined at T = 298.15 K. The various binodal curves could be fitted and summarized as two kinds of empirical nonlinear equations with the lowest standard deviation (SD). The effects of the salt type and cation alkyl chain length of the ionic liquid (IL) on ATPS binodal curves were further discussed. It was displayed that the salting-out ability of different salts was a major factor in these ATPS formations. For [Cnmim]BF4-based ATPS, the salting-out ability of various salts decreased in the following order: (NH4)2SO4 > Na3C6H5O7 > Na2C4H4O6 > NaH2PO4 > NaC2H3O2 > NaCl. For the [Cnmim]Cl aqueous solution, only K2HPO4 or (NH4)2SO4 could cause the phase ...

Preparation of High-Quality Porous Calcium Hexa-Aluminate Ceramics using Salt as Both Reaction Medium and Pore-Former

Porous calcium hexa-aluminate (CA6) ceramics were synthesized by a molten salt-mediated technique using CaCO3 and α-Al2O3 powders as the main raw materials. The effects of salt type and content, along with firing temperature on phase formation, microstructural evolution, pore generation and size distribution, and mechanical strength of fired samples were investigated and compared. Among the three tested salts (KCl, NaCl, and CaCl2), KCl showed the best whereas CaCl2 showed the worst accelerating effect on CA6 formation. In the case of the former, phase-pure CA6 was formed after 3 h at 1500 °C, whereas in the case of the latter, CA2 was formed instead as a main phase. The salt not only acted as a reaction medium, accelerating CA6 formation, but also acted as a pore former, creating high levels of porosity in the fired samples. The apparent porosity of the fired samples clearly increased with an increase in KCl content. But the majority of pores were still micron sized and the pore size distribution was relatively narrow. This, along with the possible toughening effect from the well-developed plate-like CA6, conferred relatively high mechanical strength on the final highly porous CA6 ceramics.

Germination and growth response of flax (Linum usitatissimum) to salinity stress by different salt types and concentrations

ABSTRACTThis investigation was conducted to explore the effects of salt types with different concentrations on germination and growth parameters of flax seeds. The experiment was set out as a factorial experiment based on a completely randomized design with three replications. We used six kinds of salts (NaCl, CaCl2, CaCO3, Na2SO4, Na2CO3 and KCl) with concentrations of 0, 50, 100 and 200 mM. According to the results, the inhibitory effects of the five salt types differed substantially, especially in the case of CaCO3, Na2CO3 and Na2SO4. Inhibitory effects of these salts were very strong compared to those of NaCl and CaCl2. Germination of flax seeds by various salts was in the order of NaCl > CaCl2 > KCl > Na2CO3 > Na2SO4 > CaCO3. The effect of salt concentration was obvious, too. Seeds of flax were able to germinate even in 200 mM NaCl, but they only germinated in distilled water or at very low CaCO3, Na2CO3 and Na2SO4 concentrations (50 mM).

Effect of salt type and concentration on the growth and lipid content of Chlorella vulgaris in synthetic saline wastewater for biofuel production

Microalgae can offer several benefits for wastewater treatment with their ability to produce large amounts of lipids for biofuel production and the high economic value of harvested biomass for biogas and fertilizer. This study found that salt concentration (∼45gL−1) had more of an effect than salt type on metabolisms of Chlorella vulgaris for wastewater treatment and biofuel production. Salinity stress decreased the algal growth rate in wastewater by 0.003day−1permScm−1 and slightly reduced nutrient removal rates. However, salinity stress was shown to increase total lipid content from 11.5% to 16.1% while also increasing the saturated portions of fatty acids in C. vulgaris. In addition, salinity increased the algal settling rate from 0.06 to 0.11mday−1 which could potentially reduce the cost of harvesting for algal biofuel production. Overall, C. vulgaris makes a suitable candidate for high salinity wastewater cultivation and biofuel production.

What makes aromatic polyamide membranes superior: New insights into ion transport and membrane structure

Polyamide composites are instrumental to modern desalination technology; however, reasons for the superior performance of polyamide membranes have been unclear. Models usually view membranes as an array of charged nanopores, however, observed discrepancies and inconsistencies call for more insights. Here ion conductance in polyamide membranes was analyzed using electrochemical impedance spectroscopy, focusing on the effects of salt type, concentration, and pH, which are compared with the conductance obtained for a dense linear polyamide Nomex® of similar superficial thickness. The results rule out the common view of polyamide membranes as homogeneous layers or nanopore arrays and indicate that they essentially behave as thin films of Nomex. The salt exclusion in both materials is so strong that uptake of protons (rather than sodium) dominates membrane conductivity, yielding a similar concentration-dependence. However, the conductivity of polyamide membranes is much higher and equivalent to sub-10nm Nomex films. These findings are explained by the sponge-like structure of polyamide, containing voids separated by thin polymer films, which can be adequately modeled as a 3D random resistor network. This unique structure, combining very dense (hence highly selective) and extremely thin (hence reasonably permeable) films supported within a ~100nm porous layer is what enables exceptional performance of polyamide membranes.

Low‐temperature preparation of titanium diboride fine powder via magnesiothermic reduction in molten salt

AbstractPhase pure titanium diboride (TiB2) powder of 100‐200 nm was synthesized from TiO2 and B2O3 using a molten‐salt‐assisted magnesiothermic reduction technique. The effects of salt type, Mg amount, reaction temperature, and TiO2 raw materials on the synthesis process were examined and the relevant reaction mechanisms discussed. Among the three chloride salts (NaCl, KCl, and MgCl2), MgCl2 showed the best accelerating‐effect. To synthesize phase pure TiB2, 20 mol% excessive Mg had to be used to compensate for the evaporation loss of Mg. Particle shape and size of raw material TiO2 showed little effect on the formation of TiB2 and its shape and size, suggesting that relatively cheaper and coarser TiO2 raw materials could be used for low‐temperature synthesis of TiB2 fine particles. The “dissolution‐precipitation” mechanism governed the overall molten salt synthesis process.

The Effects of Salt Type and Salt Concentration on the Performance of Magnetically Activated Nanofiltration Membranes

The effects of salt ion type and salt concentration on flux and rejection improvement of magnetically activated micromixer nanofiltration membranes were investigated. Polymers with varying chain length and chain density were grafted on the NF270 membranes using the well-controlled atom transfer radical polymerization reaction. Superparamagnetic nanoparticles that respond to an oscillating magnetic field were conjugated at the polymer chain ends. The effects of micromixing on breaking the concentration polarization boundary layer were investigated by determining the percentage improvement in flux and rejection in the presence of an external oscillating field. Systematic trends on the salt ion size and feed concentration as well as grafting degrees were observed. The magnetically activated micromixers are more effective in breaking down severer concentration polarization when the charge and concentration of the salt ions are higher. In addition, higher density and longer polymer chains induce stronger micro...

Growth of well-developed LaOCl microplates by chloride salt-assisted method

Lanthanum oxychloride (LaOCl) microplates were synthesized via the chloride salt-assisted method using lanthanum oxide, potassium chloride and lithium chloride as the raw materials. The effects of salt type and reaction temperature on the synthesis of LaOCl were investigated in detail. The lowest synthesis temperature in the present study was 300 °C, which was much lower than that required by other methods. The thickness and width of the as-prepared LaOCl microplates were about 200–500 nm and several microns, respectively. With potassium chloride and lithium chloride as the reaction medium, the latter acted not only as the molten salt but also as the reactant in the LaOCl synthesis. The chloride salt not only significantly lowers the synthesis temperature, but also provides the good conditions for the LaOCl growth of plate-like structures.

Phase Behavior of Inorganic Salts Sodium Succinate and Ammonium Citrate in N-Ethylpyridinium Tetrafluoroborate Solution at Different Temperatures

Phase diagrams of the aqueous two-phase system N-ethylpyridinium tetrafluoroborate + sodium succinate/ammonium citrate + water were experimentally determined at 308.15 K, 318.15 K, and 328.15 K, respectively. The binodal data and tie-line data were associated with numerous empirical formulas and good agreements have been obtained. The effect of salt type and temperature on binodal curves and tie-lines were emphatically discussed via observing the phase diagrams and analyzing the correlation data. It was found that there were significant differences between the two salts when they were constructing two phases with N-ethylpyridinium tetrafluoroborate. The effective excluded volume values used to evaluate the salt-out effect of two inorganic salts were derived from correlating the experimental binodal data of investigated systems.

Fabrication of polyvinylidene fluoride tree-like nanofiber via one-step electrospinning

A novel polyvinylidene fluoride (PVDF) tree-like nanofiber was controllably fabricated via one-step electrospinning by adding certain amount of salt into PVDF solution. A possible mechanism for the formation of the tree-like nanofibers was proposed by analyzing high speed camera photos of the spin jet and the result showed that the formation of tree-like nanofibers was due to the splitting of jets. The effects of salt type, salt content and processing parameter on the content of tree-like branches were investigated. The electrospun nanofibers were characterized by field emission scanning electron microscopy (FE-SEM), energy disperse spectroscopy (EDS), X-ray diffraction (XRD), pore size meter and mechanical properties measurement. It was found that the PVDF/TBAC tree-like nanofibers with improved crystallinity and mechanical strength. The decreased average pore size caused by the tree-like structure and the resistance to organic solvent, can make it as a potential candidate for membrane separation.

Low temperature molten salt preparation of molybdenum nanoparticles

Pure molybdenum (Mo) nanoparticles (NPs) were synthesized by a novel molten salt technique using Na2MoO4 and Al as starting materials and NaCl, KCl and NaF to form a reaction medium. The effects of salt type, reaction temperature and salt to reactant ratio on the synthesis of Mo NPs were investigated in detail. Phase pure Mo NPs with a crystalline size of about 46nm were synthesized at as low as 650°C which was much lower than that required by other conventional reduction methods. Among the salts tested, the NaClKClNaF ternary salt showed the best accelerating effect on the low temperature Mo NPs formation, and the optimal weight ratio of salt to reactant was 1.0:1.0. The “dissolution-precipitation mechanism” played a dominant role in the molten salt synthesis of Mo NPs.

Integrated method of thermosensitive triblock copolymer–salt aqueous two phase extraction and dialysis membrane separation for purification of lycium barbarum polysaccharide

A polymer–salt aqueous two-phase system (ATPS) consisting of thermosensitive copolymer ethylene-oxide-b-propylene-oxide-b-ethylene-oxide (EOPOEO) and NaH2PO4 was employed in deproteinization for lycium barbarum polysaccharide (LBP). The effects of salt type and concentration, EOPOEO concentration, amount of crude LBP solution and temperature were studied. In the primary extraction process, LBP was preferentially partitioned to the bottom (salt-rich) phase with high recovery ratio of 96.3%, while 94.4% of impurity protein was removed to the top (EOPOEO-rich) phase. Moreover, the majority of pigments could be discarded to top phase. After phase-separation, the LBP in the bottom phase was further purified by dialysis membrane to remove salt and other small molecular impurities. The purity of LBP was enhanced to 64%. Additionally, the FT-IR spectrum was used to identify LBP. EOPOEO was recovered by a temperature-induced separation, and reused in a new ATPS. An ideal extraction and recycle result were achieved.

Destabilization and removal of immobilized enzymes adsorbed onto polyethersulfone ultrafiltration membranes by salt solutions

In this work the effectiveness of two saline solutions (NaCl and Na2SO4) to clean a permanently hydrophilic polyethersulfone (PESH) ultrafiltration (UF) membrane with a molecular weight cut-off (MWCO) of 30kDa previously fouled with enzymatic solutions was investigated. The influence of protein concentration in the enzymatic solution during the fouling step and the effect of salt type during the cleaning procedure were studied.The protein aggregation was analyzed in solution and onto the membrane surface by using several techniques including Dynamic Light Scattering (DLS), Atomic Force Microscopy (AFM) and Infrared Spectroscopy with Attenuated Total Reflectance (ATR-FTIR). In addition, mechanisms that dominate membrane fouling were studied by fitting some mathematical models (Hermia׳s models adapted to crossflow filtration, a combined model based on the complete blocking and cake formation equations and a resistance-in-series model) to the experimental data.Fouling results showed that the complete blocking/adsorption on membrane surface was the predominant fouling mechanism. Regarding the cleaning results, higher cleaning efficiency and low residual protein concentration was obtained with NaCl solutions for all the feed solutions tested due to the favorable interaction between Cl− and proteins.

Aqueous two-phase systems of polyoxyethylene lauryl ether and potassium gluconate/potassium oxalate/potassium citrate at different temperature-experimental results and modeling of (liquid + liquid) equilibrium data

The binodal data for the systems containing the POELE10 and KC6H11O7/K2C2O4/K3C6H5O7 were determined at the T=(288.15, 298.15, 308.15)K. The three experiential equations were used to fit the binodal data and they achieved the satisfactory fitting effect. The effect of salt type on the phase-seperation ability of salt was studied. It was found that the phase-seperation ability of the salt with the higher valence anion is stronger than that with lower valence anion, namely, the order of the phase-seperation ability for the investigated salts is potassium citrate>potassium oxalate>potassium gluconate, which is also validated by the effective excluded volume (EEV). The (liquid+liquid) equilibrium data for the studied systems were determined and correlated by using the Pitzer–Debye–Hückel equation and Chen-NRTL model along with the Flory–Huggins equation, and good agreement was obtained with using these thermodynamic models.

Partitioning Studies of Glutaminase in Polyethylene Glycol and Salt‐Based Aqueous Two‐Phase Systems

AbstractThe partitioning behavior of glutaminase produced from Zygosaccharomyces rouxii in polyethylene glycol (PEG)‐salt aqueous two‐phase systems (ATPSs) was investigated. ATPSs comprising of different PEG‐salts were considered. Binodal data and tie lines generated for the selected systems were analyzed and correlated with Othmer‐Tobias and Bancroft equations. Effects of salt type, PEG molecular weight, concentrations of phase components, and tie line length on enzyme partitioning were evaluated.

Sensory Enhancement of Freshwater Prawns Through Post-Harvest Salt Acclimation

Freshwater prawns, Macrobrachium rosenbergii, were harvested and transferred to holding tanks containing aerated well water. One group of prawns was held in the well water without any addition of salt (control). For post-harvest salt acclimation, experimental treatments consisted of different salt sources (solar, halite, marine) that were initially added to achieve a salinity of 10 ppt. Then, 5-ppt increases occurred every two hours until the salinity was 30 ppt, with 10-h exposure at this salinity prior to harvesting. A randomized complete block design with three replications was used to evaluate the effect of salt type on the sensory acceptability (n = 60 consumers per replication) of prawns. All treatments had mean acceptability scores between like slightly and moderately; inclusion of solar, marine, and halite salts all enhanced (p < 0.05) flavor, texture, and overall acceptability. In addition, the clusters with the greatest numbers of consumers (n > 100) liked all treatments but preferred (p < 0.05) prawns from the solar or halite salt treatments over those from the control treatment. The addition of solar or halite salt enhanced the sensory acceptability of prawns, but further testing is needed to optimize acclimation conditions as comparatively high mortality occurred in two acclimation treatments.

Effect of pH, salt and chemical rinses on bacterial attachment to extracellular matrix proteins

Microbial contamination of carcass surfaces occurs during slaughter and post-slaughter processing steps, therefore interventions are needed to enhance meat safety and quality. Although many studies have been done at the macro-level, little is known about specific processes that influence bacterial attachment to carcass surfaces, particularly the role of extracellular matrix (ECM) proteins. In the present study, the effect of pH and salt (NaCl, KCl and CaCl2) on attachment of Escherichia coli and Salmonella isolates to dominant ECM proteins: collagen I, fibronectin, collagen IV and laminin were assessed. Also, the effects of three chemical rinses commonly used in abattoirs (2% acetic acid, 2% lactic acid and 10% trisodium phosphate (TSP)) were tested. Within a pH range of 5–9, there was no significant effect on attachment to ECM proteins, whereas the effect of salt type and concentration varied depending on combination of strain and ECM protein. A concentration-dependant effect was observed with NaCl and KCl (0.1–0.85%) on attachment of E. coli M23Sr, but only to collagen I. One-tenth percent CaCl2 produced the highest level of attachment to ECM proteins for E. coli M23Sr and EC614. In contrast, higher concentrations of CaCl2 increased attachment of E. coli EC473 to collagen IV. Rinses containing TSP produced >95% reduction in attachment to all ECM proteins. These observations will assist in the design of targeted interventions to prevent or disrupt contamination of meat surfaces, thus improving meat safety and quality.