Salts CaCl2 Research Articles

Efficient atmospheric water harvesting enabled by hierarchically structured cellulose foam

The sorption-based atmospheric water harvesting technique is an appealing solution for addressing the challenge of freshwater shortages. In this study, a composite foam was fabricated by confining hygroscopic salt (CaCl2) into a Cr-based metal–organic framework (MIL-101), which was then integrated into a bacterial cellulose (BC) skeleton. The hierarchical structure, which contains micron- and nanoscale pores, enhances water storage, transport, and vapor evaporation throughout the whole water capture and release process. The pore confinement effect of MIL-101 and the interconnected BC network effectively restricted the leakage of the liquefied salt solution. Interestingly, the color of the CaCl2@MIL-101@BC foam changed from light green to dark green as the amount of absorbed water increased. This moisture-induced color darkening improves the light absorption ability during the water release stage under sunlight. At 30 % relative humidity, the foam can absorb up to 0.78 g g−1 of water per cycle (8 h) and desorb quickly under solar radiation. This makes foam a promising method for water production in arid areas.

Kinetic modeling and mechanistic evaluation of oxidative-extractive desulfurization of actual diesel fuel using ionic liquids: Engineering aspects with parametric study

In the present research, oxidative-extractive desulfurization (OEDS) of actual diesel fuel is executed by utilizing coordinated ionic liquid (IL), and a novel kinetic model is put forward to explain the OEDS process. A series of ILs synthesized by the coordination of three solvents [N,N dimethyl-formamide (DMF), N-methyl-pyrrolidone and dimethyl sulfoxide] with three salts (CaCl2, ZnCl2, and MgCl2) were tested for OEDS of diesel fuel. The best-performing IL i.e., DMF.ZnCl2 was utilized to investigate the impact of oxidant-to-sulfur (O/S) molar ratio, diesel-to-IL volume ratio, temperature, and time. Thermal analysis; thermogravimetric analysis-differential thermogravimetric analysis (TGA-DTG), and differential scanning calorimetry (DSC) were conducted to understand their thermal stability. 1HNMR was used to examine the interactions between their components. To understand the mechanism of removal, Fourier transform infrared (FTIR) spectra and UV–visible spectra of IL were studied. The kinetic model used in the present investigation presumed the extraction of non-oxidized as well as oxidized sulfur compounds. Compared to earlier reported models, the present novel kinetic model provided an improved representation of the kinetic data. At the optimized conditions (O/S ratio = 6:1, diesel to IL volume ratio = 3:1, and temperature = 50 °C), a maximum of 86 % sulfur removal was estimated from actual diesel fuel.

Intensification of high-gravity brewer’s wort fermentation process with the use of microelements

In high-gravity brewing, conditions arise that adversely affect the yeast. These are high osmotic pressure, high fermentation temperature, high ethanol content. As a result of these unfavorable factors, the intensity of yeast reproduction and the rate of fermentation decrease, the duration of the process increases, the degree of fermentation decreases, which leads to a change in the taste and aroma profile of the drink. Cofactors of important enzymes and stress modulators are microelement ions, the optimal content of which can be provided by adding appropriate salts to the wort. In this work, the influence of calcium and zinc on the fermentation of high-gravity beer wort with the participation of Saccharomyces cerevisiae yeast strain Saflager W-34/70 was investigated. The optimal dosage of CaCl2 and ZnSO4 salts was determined, which is 5.0 and 0.1 mg/dm3, respectively. It was established that adding CaCl2 to the wort leads to an increase in the rate of fermentation by 21.9 %, the apparent and actual degree of fermentation by 17.8 and 17.0 %, respectively. At the same time, the ethanol content in young beer increases by 19.1 %, the content of visible and actual extract decreases by 28.8 and 17.5 %, respectively, and the biomass of yeast accumulated during fermentation increases by 14.0 %. When using ZnSO4, the changes in the values of all these indicators are significantly smaller and lie in the range of 3.2‒5.8 %. Other physical-chemical parameters of the studied samples of young beer, namely acidity, pH value, content of vicinal diketones, do not undergo significant changes. To enhance the growth and metabolism of yeast under adverse conditions that occur during high-gravity brewing, it is recommended to add CaCl2 to beer wort in the amount of 5.0 mg/dm3. This will make it possible to reduce the duration of fermentation of wort with a dry matter content of 18 % at a temperature of 15 ℃ by 1.5 days (21 %)

Effects of fluid composition and salinity on subcritical crack growth in granite

Using the double-torsion technique, the fracture mechanical response of granite specimens was investigated under the influence of fluid with different electrolyte types and salinities. The fracture toughness (KIC) and critical mechanical energy release rate (G0) of the granite in electrolyte solution are weakened compared to those in distilled water. The KIC in all electrolyte solutions is 2.08–2.28 MPa·m1/2, which is 8.4 % − 16.5 % lower than that in distilled water, and it is insensitive to ion type and salinity. In contrast, the subcritical crack growth index (n) shows different salinity dependence in three salt (AlCl3, CaCl2, and NaCl) solutions. The slight increase in n with rising salinity of the AlCl3 solution is attributed to crack tip blunting caused by over-dissolution of minerals. The n and G0 decrease and then increase with rising salinity of CaCl2 solution, which may be related to the salinity-dependent dissolution rate of quartz and the weakening of repulsive force between crack surfaces. The n and G0 shows a negative correlation with salinity and decrease by 26.4 % and 15.4 %, respectively as the NaCl salinity increases from 0.1 M to 1.0 M. Limitations in the dissolution reactions of the main minerals (albite, biotite and diopside) is accountable for enhancement of n in silica solutions. Experimental results emphasize the critical and subcritical fracture behavior of the granite in response to chemically reactive fluids with implications for both hydraulic fracture stimulations in geothermal fields and caprock integrity for CO2 sequestration. In these applications, the fracture properties of the reservoir rock can be enhanced or weakened by changing the electrolyte type and salinity of the fluid, depending on the actual requirements.

Metabolite Compounds of Euglena sp. on Mass Cultivation System under MgCl2 and CaCl2 Salt Stress

Euglena sp. is rich in primary and secondary metabolite compounds. This cosmopolitan organism can survive extreme conditions such as salt stress because it can increase cell growth rate and metabolism. This mass cultivation research uses an open pond system that is very vulnerable to contamination, so variations in salinity of MgCl2 and CaCl2 are used as treatments because they minimize contamination. The research examines the correlation of salt types to cell growth rate, biomass, monosaccharide profile, paramylon, pigment, and lipid of Euglena sp. Research methods include preparation, medium making, mass cultivation, and measurement of test parameters. Data were analyzed through One-Way ANOVA followed by DMRT, with a 5% confidence level. Based on the research result, the highest value of biomass and paramylon content and productivity at CaCl2 treatment with consecutive values 0.013 ± 0.001, 0.002 ± 0.000, 9.556 ± 0.070, and 0.149 ± 0.019. Monosaccharides analysis produced in the form of sucrose, glucose, fructose, and arabinose amounted to < 10 ppm. CaCl2 treatment produced the highest sucrose of 6251 ppm. The highest chlorophyll-a and carotenoid pigments are located at CaCl2 treatment, respectively (1.698 ± 0.051)b and (0.500 ± 0.032)b. At the same time, the salt treatment has a significant effect on lipid content. To summarize, almost all metabolite compounds were highest in CaCl2 treatment. This research is expected to contribute to developing the Euglena sp. mass cultivation system as a source of bioenergy and biomaterials.

Effects of Salts on Helical Protoplast-Callose-Fiber Formation and Cell Division in Leaf Protoplast Culture of Arabidopsis thaliana: Ultrastructure of PCF Using Transmission Electron Microscopy

Effects of four salts addition (10-200 mM), NaCl, KCl, MgCl2, and CaCl2 were examined on the growth of protoplasts and formation of helical 1.5 mm long, protoplast-callose-fibers (PCF) in Arabidopsis thaliana liquid leaf protoplast cultures. The basal medium was Murashige and Skoog’s medium containing 1 μM 2,4-dichlorophenoxyacetic acid and 0.1 μM benzyladenine, 3% sucrose, and 0.4 M mannitol. The protoplast division was highly stimulated by the addition of 50 mM Ca2+ ion but was totally inhibited by 50 mM Mg2+ ion. Inhibition by K+ and Na+ ions was in-between. By contrast, PCF formation, whose numbers were counted under a fluorescence inverted microscope after Aniline Blue staining for β-1,3-glucan (callose), was stimulated by both K+ and Ca2+ ions but inhibited by Mg2+ ion. After selecting Arabidopsis PCF using a micromanipulator, the sub-fibril ultrastructure was examined by transmission electron microscopy (TEM). The PCFs of Betula platyphylla and Larix leptolepis, cultured with 200 mM Ca2+ and 50 mM Mg2+ ions, respectively, after long-term storage and rehydration, were examined by TEM. The effects of different factors were discussed on PCF formation and sub-structures in different herbaceous and tree plant species.

Enhanced electroactive β‐phase and dielectric properties in P(VDF‐HFP) composite flexible films through doping with three calcium chloride salts: CaCl2, CaCl2·2H2O, and CaCl2·6H2O

AbstractFlexible dielectric films with a high dielectric constant, utilizing P(VDF‐HFP)/salt composites, were manufactured through the solution casting method. In this work, we studied the impacts of three calcium chloride salts—CaCl2, CaCl2·2H2O, and CaCl2·6H2O—on the surface morphology, crystalline phase transformation, mechanical properties, and dielectric responses of the P(VDF‐HFP) copolymer. The detailed structure and properties of all samples were assessed via scanning electron microscope (SEM), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), tensile testing, and LCR meter analysis. The experimental results demonstrated that the addition of calcium salts to the P(VDF‐HFP) composites induced a visibly microporous morphology, with the porosity and surface roughness of the composites gradually increasing with salt content. In comparison to the pure P(VDF‐HFP) film, the composite films exhibited decreased stiffness and heightened flexibility. Furthermore, a higher β‐phase fraction and notable enhancements in the dielectric constant resulting from the inclusion of calcium salts were observed. Consequently, the P(VDF‐HFP) composite filled with 3 wt% of CaCl2·6H2O demonstrated the highest capability for promoting the β‐phase fraction and dielectric constant, achieving values of 98.33% and 21.49% (at 10 Hz), respectively.

Investigating the mechanism of interfacial tension reduction through the combination of low-salinity water and bacteria

In the enhanced oil recovery (EOR) process, interfacial tension (IFT) has become a crucial factor because of its impact on the recovery of residual oil. The use of surfactants and biosurfactants can reduce IFT and enhance oil recovery by decreasing it. Asphaltene in crude oil has the structural ability to act as a surface-active material. In microbial-enhanced oil recovery (MEOR), biosurfactant production, even in small amounts, is a significant mechanism that reduces IFT. This study aimed to investigate fluid/fluid interaction by combining low biosurfactant values and low-salinity water using NaCl, MgCl2, and CaCl2 salts at concentrations of 0, 1000, and 5000 ppm, along with Geobacillus stearothermophilus. By evaluating the IFT, this study investigated different percentages of 0, 1, and 5 wt.% of varying asphaltene with aqueous bulk containing low-salinity water and its combination with bacteria. The results indicated G. Stearothermophilus led to the formation of biosurfactants, resulting in a reduction in IFT for both acidic and basic asphaltene. Moreover, the interaction between asphaltene and G. Stearothermophilus with higher asphaltene percentages showed a decrease in IFT under both acidic and basic conditions. Additionally, the study found that the interaction between acidic asphaltene and G. stearothermophilus, in the presence of CaCl2, NaCl, and MgCl2 salts, resulted in a higher formation of biosurfactants and intrinsic surfactants at the interface of the two phases, in contrast to the interaction involving basic asphaltene. These findings emphasize the dependence of the interactions between asphaltene and G. Stearothermophilus, salt, and bacteria on the specific type and concentration of asphaltene.

Effect of hydrothermal treatment on the rheological properties of xanthan gum

In this study, the effect of hydrothermal treatment with different temperatures (120–180 °C) on the rheological properties of xanthan gum was evaluated. When the temperature of hydrothermal treatment was relatively low (120 °C), the rheological properties of the hydrothermally treated xanthan gum was similar to the untreated xanthan gum (pseudoplastic and solid-like/gel-like behavior). However, as the temperature of hydrothermal treatment was higher, the rheological properties of the hydrothermally treated xanthan gum changed greatly (e.g., a wider range of Newtonian plateaus in flow curves, existence of a critical frequency between the storage modulus (G') and the loss modulus (G") in the dynamic viscoelasticity measurement, variation of complex viscosity). Although the hydrothermal treatment showed little influence on the functional groups of xanthan gum, it altered the micromorphology of xanthan gum from uneven and rough lump-like to thinner and smoother flake-like. In addition, higher concentration (2 %) of hydrothermally treated xanthan gum made its viscosity close to that of the untreated xanthan gum (1 %). Besides, hydrothermal treatment also affected the effect of temperature and salt (CaCl2) adding on the rheological properties of xanthan gum. Overall, this study can provide some useful information on the rheological properties of xanthan gum after hydrothermal treatment.

Influence of salt contamination on the rheological and filtration properties of bentonite-based mud

Bentonite-based mud has been widely used in petroleum, geotechnical and civil engineering to lubricate the drill bit, maintain wellbore stability, and lift the drilled cuttings up to the surface during drilling operations. Understanding salt contaminants influences the quality of bentonite-based mud is necessary to create a suitable formula for drilling mud to achieve a successful drilling process in deep formations and coastal regions. In this paper, several experiments were carried out on bentonite-based muds with different types of salt (NaCl and CaCl2) and various concentrations of salts (NaCl - 0.5, 1, 1.5, 2 wt%; CaCl2 - 0.1, 0.2, 0.3, 0.4 wt%). The properties of mud were examined by laboratory equipment, including an 8-speed viscometer, and American Petroleum Institute (API) Filter Press. The findings indicate that salt contamination impairs the characteristics of drilling fluid. The rheological parameters of mud, such as viscosity, yield point, and gel strength, drop dramatically as the concentration of salt increases. Furthermore, the filtration test indicated that the bentonite-based mud encountered severe water loss into the formation with increased salt concentration.

Interactions between chloride-based salts (CaCl2 and MgCl2), ionic liquids, pH, and titanium oxide nanoparticles under low and high salinity conditions, and synthetic resinous crude oil: dorud oilfield

AbstractUnfortunately, oil reservoirs are complex considering the fluids (e.g., crude oil composition) and rock properties making it hard to propose a simple enhanced oil recovery (EOR) method for higher oil production. Besides, most of the investigations had focused on crude oil which is a complex mixture of thousands of components making it hard to extract any reliable conclusions with respect to the crude oil type. So, the current study is focused on the application of ionic liquids from different families of pyridinium and imidazolium, titanium oxide nanoparticles, and salts (MgCl2 and CaCl2) in the presence of resinous synthetic oil for the first time. The obtained results using the central composite design (CCD) approach revealed the positive effect of resin fraction on the IFT reduction by 27% considering the initial value (34.9%). Using the CCD approach revealed that using pH = 7, MgCl2 concentration = 21,000 ppm, CaCl2 concentration = 21,000 ppm, resin fraction of 9wt%t and 500 ppm of [C12mim][Cl] concentration reduces the IFT to minimum value of 0.62 mN/m while the minimum IFT value for optimum conditions of solution includes [C12py][Cl] led to minimum IFT value of 2.2 mN/m. But, the contact angle measurements revealed better synergy between [C12py][Cl] and TiO2-NPs (0–200 ppm) for better wettability alteration toward water-wet condition (27.3°) than [C12mim][Cl] (33.2°). Moreover, the IFT measurements revealed that the presence of TiO2-NPs is effective in reducing the IFT of the optimum formulations to 0.55 and 0.84 mN/m for [C12mim][Cl], and [C12py][Cl], respectively. According to the results, it seems that the obtained optimum formulations for [C12mim][Cl], and [C12py][Cl] are applicable for EOR purposes as new hybrid solutions.

A noval salt effect coupled vacuum distillation process for high efficient ultra-azeotropic reuse of spent HCl

The escalating challenge of recycling and treating spent hydrochloric acid (HCl) in various industries, driven by stringent environmental regulations, necessitates urgent solutions for the reuse of spent HCl in industrial processes. However, the concentration and reuse of spent HCl have been impeded by azeotropism. In this study, an innovative salt effect coupled vacuum distillation process was introduced to enable the rapid and convenient recovery of HCl. Salts and vacuum environment both can be found to break the azeotropism effectively, augment the disparity in the dissociation abilities of HCl and H2O in clusters, and enhance the evaporation rate. Specifically, MgCl2 and CaCl2 salt systems were selected, achieving recovered HCl concentrations of 9.66 and 9.85 mol/L, with corresponding recovery rates of 86.45 % and 80.65 %, respectively. For the reuse of spent HCl from chlorinated distillation for extracting germanium (Ge), the presence of As(V) poses a risk to Ge recovery and potential contamination of the Ge product. Excellent resistance to As(Ⅴ) mobilization (<2%) was obtained in the CaCl2 system. To comprehensively understand the salt’s role in breaking azeotropism, molecular simulations were employed. The Mg2+/Ca2+ ions were observed to bind with H2O molecules in the solution, weakening the force between H2O and HCl, decreasing the dissociation energy of HCl molecules by 35 times (from 102.82 to 2.94 kJ/mol), and increasing the dissociation energy of H2O molecules from 52.5 to 61.5 kJ/mol. The proposed process integrates high HCl recovery with an ultra-azeotropic concentrating effect, offering a novel approach for reusing spent HCl in industrial applications.

The aggregation characteristics of Aspergillus spores under various conditions and the impact on LPUV inactivation: Comparisons with chlorine-based disinfection

Aggregation is the primary step prior to fungal biofilm development. Understanding the attributes of aggregation is of great significance to better control the emergence of waterborne fungi. In this study, the aggregation of Aspergills spores (A. flavus and A. fumigatus) under various salt, culture medium, and humic acid (HA) conditions was investigated for the first time, and the inactivation via low-pressure ultraviolet (LPUV) upon aggregated Aspergillus spores was also presented. The aggregation efficiency and size of aggregates increased over time and at low salt (NaCl and CaCl2) concentration (10 mM) while decreasing with the continuous increase of salt concentration (100 and 200 mM). Increasing the concentration of culture medium and HA promoted the aggregation of fungal spores. Spores became hydrated, swelled, and secreted more viscous substances during the growth period, which accelerated the aggregation process. Results also suggested that fungal spores aggregated more easily in actual water, posing a high risk of biohazard in real-life scenarios. Inactivation efficiency by LPUV decreased with higher aggregation degrees due to the protection from the damaged spores on the outer layer and the shielding of pigments in the cell wall. Compared to chlorine-based disinfection, the aggregation resulted in the extension of shoulder length yet neglectable change of inactivation rate constant under LPUV treatment. Further investigation of cell membrane integrity and intracellular reactive oxygen species was conducted to elucidate the difference in mechanisms between various techniques. This study provides insight into the understanding and controlling of the aggregation of fungal spores.

Effect of Na, Mg, Ca chloride salts on mineral element, proline and total protein contents in rice (Oryza sativa L.) grown in vitro

In this study, the effects of different types and concentrations of salts on local Siverek rice plant (Oryza sativa L.) grown in vitro were investigated in terms of mineral elements (K, Ca, P, Mg, Na, Fe, Cu, Zn, Mn, Mo, Co), proline, and total protein content. Sterilized seeds were planted in hormone-free and salt-free MS medium. After one week, the seedlings were subjected to different concentrations of NaCl, CaCl2, and MgCl2 salts (0, 30 mM, 90 mM) in order to evaluate the effect of salinity on plant growth and development. In response to salt stress, a decrease in nutrient elements was observed for all three types of salt compared to the control group, which can be attributed to disruptions in ion balance. Changes in element levels generally showed varying levels of increase or decrease depending on both the type and concentration of the salt and these changes were statistically significant. The increase in proline level was found to be directly proportional to the changes in the amounts of Ca, Mg, K, and Na elements. Both total protein and proline content showed the lowest values for all salt concentrations with CaCl2, while the highest values were obtained with NaCl. In conclusion, the changes in the level of mineral elements, total protein, and proline content levels, which decrease or increase in different ratios, depending on the type and concentration rising of the salt, are associated with the varying tolerance of the plant to different types of salts.

Experimental Investigation of a Modified Enzyme-Induced Carbonate Precipitation Solution for Sand Production Control Applications

Summary Sand production is one of the major problems that can occur in an oil or gas well. Enzyme-induced carbonate precipitation (EICP) methods have recently emerged as possible environment-friendly solutions for enhancing loose sand consolidation and preventing it from being produced with the fluids to the surface. This work explores increasing the consolidated sand strength and its treatment procedure using a modified EICP. The study also examines the characterization of precipitation generated by microorganisms using a computed tomography (CT) scan. To consolidate the sand specimen, nine different solutions were prepared. The solutions were a mixture of urea, urease, CaCl2, MgCl2, and xanthan gum in varying quantities. X-ray diffraction (XRD) analysis was conducted to determine the type of calcium carbonate (or CaCO3) polymorph. The morphology of calcium carbonate precipitation in the sand sample was visualized through scanning electron microscopy (SEM) imaging. The strength of consolidated samples was determined by the scratch test. The baseline EICP solution was exposed to different curing temperatures, namely, 25°C, 70°C, and 90°C. Out of these temperatures, the sample cured at 70°C showed the maximum strength, while the ones cured at 25°C demonstrated the weakest strength. This outcome emphasizes how crucial temperature control is in determining the strength development of the samples. The results highlight the importance of evaluating how varying curing temperatures affect specimen performance as well as emphasizing the need for accurate temperature control during experimental setups. Interestingly, samples made with a combination of CaCl2 and MgCl2 salts exhibited more strength when compared with EICP solutions formulated with only one type of salt. The consolidated sample that was prepared with xanthan gum with a concentration of 3 g/L showed high strength at 70°C. Notably, this technique offers a cost-effective solution compared with other methods developed to address sand production-related failures in production equipment. Furthermore, CT scans prove to be a valuable tool for investigating the characterization of microbially induced precipitation, including calcite, dolomite, and other minerals. This research underscores the professional approach in evaluating the efficacy of xanthan gum and CT scans in the context of EICP applications.

Clean-In-Place (CIP) wastewater management using nanofiltration (NF)-forward osmosis (FO)-direct contact membrane distillation (DCMD): Effects of draw salt

A substantial amount of water is being used during Clean-in-Place (CIP) operation, and is transformed into wastewater that can cause eutrophication to the nearby ecosystem. The present study proposed the Nanofiltration (NF) – Forward Osmosis (FO) – Direct Contact Membrane Distillation (DCMD) to recover the cleaning agents and reclaim freshwater from the model CIP wastewater. NF steps were suggested as prefiltration steps to remove organic compounds from the CIP wastewater. NF steps reduced the lactose and protein contents by 100 % and 95.6 %, respectively. The permeates from NF steps were further managed by the integrated FO-DCMD system. Several draw salts such as NaCl, KCl, MgCl2, and CaCl2 were compared to investigate the influence on FO and DCMD performance. It was found that monovalent salts (NaCl and KCl) outperformed the divalent salts (MgCl2 and CaCl2) in terms of water flux for both FO and DCMD. This can be attributed to the lower viscosity and higher mass transfer coefficient. In addition, the replenishment costs of each salt were evaluated since salts loss occurred during FO and DCMD operation. The cost evaluation revealed that NaCl is most the cheapest salts per reclaimed water. All of this observation indicates that NaCl is preferred in terms of water flux and replenishment cost. The NF permeate kept concentrated using the integrated FO-DCMD or single FO with 2 M of NaCl. Compared to a single FO that showed a consistent decline in draw solution concentration, FO-DCMD could maintain the concentration of the draw solution. Despite the constant concentration, flux decline of FO was observed due to fouling formation caused by the high-temperature operation. However, the FO-DCMD could accomplish the recovery of pure water. Finally, the cleaning agents recovered by the NF-FO-DCMD showed the cleaning efficacy comparable to the fresh NaOH. These results suggest the potential of the proposed system to manage the CIP wastewater.

Effect of Salt Stress on Morphological Characteristics and Secondary Metabolites of Some Forage Pea Cultivars

Forage pea (Pisum sativum L.) is an annual legume forage crop grown in various regions of Türkiye. It is high in protein, carbohydrate, and digestible matter and contains minerals such as phosphorus, calcium, and vitamins A and D. Salinity stress is an important problem in the cultivation of forage peas. Salinity reduces the osmotic potential of soil solutes, making it difficult for the roots to absorb the water. This study aimed to determine some parameters of two registered forage pea cultivars at different concentrations of two salt types. The effects of these salts on the morphological characteristics and biochemical components of two different registered cultivars of pea, cv. Ateş and cv. Töre were investigated in the present study. The trials were conducted in pots and Na2SO4 and CaCl2 were applied at concentrations of 0, 50, 100 and 150 mM. As a result of the trials, the morphological characteristics like fresh and dry weights and lengths of roots and shoots were investigated along with the biochemical properties like total antioxidant activity and total phenolic content. The study was performed in 2 replicates to determine the effect of different salt types and concentrations. The critical salt concentration values for the change in shoot and root fresh weight among morphological traits were determined as 100 and 150 mM for secondary metabolites. While the cv. Töre forage pea showed the highest salt resistance in shoot and root fresh weights in the presence of Na2SO4 the cv. Ateş forage pea showed the lowest salt resistance in the presence of CaCl2. In terms of shoot and root dry weights, the cv. Töre forage pea showed the least resistance at 50 mM Na2SO4 concentration. As for plant length, the cv. Ateş forage pea cultivar showed the least resistance in shoot length at 150 mM CaCl2 concentration, while it showed the highest resistance in root length at this value. The highest total antioxidant activity for the cv. Ateş forage pea and the highest total phenolic content for the cv. Töre forage pea were determined at 150 mM CaCl2 concentration. The lowest total phenolic content value was estimated in the cv. Töre forage pea cultivar at 150 mM Na2SO4 salt concentration.

Preparation of Alginic Acid/Poly(2‐Oxazoline) Hybrid Gels and Their Use in Cell Preservation

AbstractA hybrid gel is developed aiming to extend the storage period for cell preservation compared with an alginate gel. The introduction of poly(2‐oxazoline)s into alginic acid promises to improve functional materials by changing their functional groups (e.g., poly(2‐isopropyl‐2‐oxazoline) has the lower critical solution temperature behavior). This study demonstrates chemical modification of a carboxylate of sodium alginate by 1,3‐diaminopropane‐terminated poly(2‐oxazoline)s using 3‐ethylcarbodiimide hydrochloride (EDC) and N‐hydroxy succinimide (NHS) as the condensation reagents for the aminations. The incorporated ratio of poly(2‐oxazoline)s side chains into the carboxylates estimated by 1H NMR is ca. 5–12% and the remaining pendent carboxylates are used for gelation by adding calcium salts (CaCl2). Gelation is observed within 30 min producing 93–99% gel fractions that swell in water. Similar gelation occurs in the cultivation medium of green‐fluorescence protein (GFP)‐encoded and COVID‐19 spike protein‐encoded DNA recombinant E.coli in both the absence and presence of isopropyl β‐D‐1‐thiogalactopyranoside (IPTG). Even in the presence of IPTG, fluorescence ascribed to GFP is not observed while the cells are kept at 25 °C for 3 weeks. After solvation by ethylenediaminetetraacetic acid (EDTA), fluorescence intensity at 508 nm is clearly observed and cell preservation at room temperature is thereby demonstrated.

Influence of cation concentration and valence on the structure and texture of spray-dried supraparticles from colloidal silica dispersions

The structure and texture of supraparticles determine their properties and performance, thus playing a critical role in research studies as well as industrial applications. The addition of salts is a well-known strategy to manipulate the colloidal stability of nanoparticles. In this study, this approach is used to tune the structure of spray-dried supraparticles. Three different salts (NaCl, CaCl2, and AlCl3) were added to binary silica (SiO2) nanoparticle dispersions (of 40 and 400 nm in size) to change their colloidal stability by lowering the electrostatic repulsion or enhancing the cation bridging. Dependent on the cation valence of the added salt and the nanoparticle size, the critical salt concentration, which yields nanoparticle agglomeration, is reached at different salt amounts. This phenomenon is exploited to tune the final structure of supraparticles - obtained by spray-drying binary dispersions - from core-shell to Janus-like to well-mixed structures. This consequently also tunes textural properties, like surface roughness and the pore system of the obtained supraparticles. Our results provide insights for controlling the structure of spray-dried supraparticles by manipulating the stability of binary nanoparticle dispersions, and they establish a framework for composite particle design.

Cellulose Nanofiber-Alginate Biotemplated Cobalt Composite Multifunctional Aerogels for Energy Storage Electrodes.

Tunable porous composite materials to control metal and metal oxide functionalization, conductivity, pore structure, electrolyte mass transport, mechanical strength, specific surface area, and magneto-responsiveness are critical for a broad range of energy storage, catalysis, and sensing applications. Biotemplated transition metal composite aerogels present a materials approach to address this need. To demonstrate a solution-based synthesis method to develop cobalt and cobalt oxide aerogels for high surface area multifunctional energy storage electrodes, carboxymethyl cellulose nanofibers (CNF) and alginate biopolymers were mixed to form hydrogels to serve as biotemplates for cobalt nanoparticle formation via the chemical reduction of cobalt salt solutions. The CNF-alginate mixture forms a physically entangled, interpenetrating hydrogel, combining the properties of both biopolymers for monolith shape and pore size control and abundant carboxyl groups that bind metal ions to facilitate biotemplating. The CNF-alginate hydrogels were equilibrated in CaCl2 and CoCl2 salt solutions for hydrogel ionic crosslinking and the prepositioning of transition metal ions, respectively. The salt equilibrated hydrogels were chemically reduced with NaBH4, rinsed, solvent exchanged in ethanol, and supercritically dried with CO2 to form aerogels with a specific surface area of 228 m2/g. The resulting aerogels were pyrolyzed in N2 gas and thermally annealed in air to form Co and Co3O4 porous composite electrodes, respectively. The multifunctional composite aerogel's mechanical, magnetic, and electrochemical functionality was characterized. The coercivity and specific magnetic saturation of the pyrolyzed aerogels were 312 Oe and 114 emu/gCo, respectively. The elastic moduli of the supercritically dried, pyrolyzed, and thermally oxidized aerogels were 0.58, 1.1, and 14.3 MPa, respectively. The electrochemical testing of the pyrolyzed and thermally oxidized aerogels in 1 M KOH resulted in specific capacitances of 650 F/g and 349 F/g, respectively. The rapidly synthesized, low-cost, hydrogel-based synthesis for tunable transition metal multifunctional composite aerogels is envisioned for a wide range of porous metal electrodes to address energy storage, catalysis, and sensing applications.