Calcium Chloride Concentration Research Articles

Role of Calcium Chloride on the Eluting Process of Residual Ammonium from Weathered Crust Elution-Deposited Rare Earth Ore Tailings

A large amount of ammonium salt leaching agent will remain in the leaching site of weathered crust elution-deposited rare earth ore (WREOs). The release of residual ammonium (RA) will seriously affect the water system ecology of the mining area, and it is urgent to control it. In this paper, column eluting was used to simulate the eluting process of RA in rare earth (RE) ore tailings, and the effects of calcium chloride concentration, eluting temperature, liquid-solid ratio, eluent pH and eluent flow rate on the eluting process of RA in rare earth ore tailings were discussed. It was found that calcium chloride could effectively elute the RA from ore tailings. Eluting agent pH almost had no effect on the eluting process of RA in the pH range of 4–6, and a greater impact on it at pH 8. The flow rate could effectively enhance the elution efficiency. The optimum conditions were calcium ion concentration of 0.1 mol/L, liquid-solid ratio of 2:1, pH 4–6, flow rate of 0.6 mL/min and elution at room temperature. At this time, the elution efficiency of RA was 91.85%. The eluting process of RA in ore tailings was controlled by the inner particle diffusing according to the kinetic analysis. The reaction order was 0.368, and the activation energy of the reaction is 12.450 kJ/mol. This will provide a theoretical basis and technical support for the efficient eluting process of residual ammonium in the leaching site of WREOs.

Effectiveness of sodium alginate-based coating on the preservation of Da xanh pomelo fresh-cut

Pomelo (Citrus maxima (Burm. f.) Merr) fresh cut has a highly sensitive fruit and has a short shelf life after peeling. The fruits represent high potentials for local consumption and international export. The objective of the study was to focus on the effects of different concentrations of sodium alginate (1%, 1.5% and 2%) combined with fixed concentrations of calcium chloride (2%) and ascorbic acid (2.5%) to biologically active compounds and allowable microbial content on the surface pomelo fresh cut slices. The results showed that the presence of coating has improved several important quality parameters of the fruit. Specifically, the combination of AL (2%) + AA (2.5%) + calcium chloride (2%) Ascorbic acid (AA) has effectively maintained the total polyphenol content and the total ascorbic acid of the pomelo slice samples, thus exhibiting higher DPPH scavenging activity, as compared to control samples. Furthermore, the pomelo coated with alginate showed good conditions for consumption with minimal microbial degradation and describe good acceptance after 6 days of storage.

Developing and Evaluating a Novel Drug Delivery System, Calcium-Alginate Beads loaded with Valsartan

Valsartan is one of the most common drugs used by chronic patients in the management of hypertension, heart failure, and diabetic nephropathy. This present study was conducted with the aim of formulating a long-acting pharmaceutical form by preparing millimeter dimensions’ solid polymeric beads using the Ionotropic Gelation technique by using the polymer “Alginate Sodium” (SA), and Calcium Chloride CaCl2 as a cross-linking agent. Prepared valsartan beads succeeded in the possibility of decreasing dose administration and therefore, reduced immediate release side effects of conventional forms of Valsartan. Valsartan beads were studied using different concentrations of Sodium Alginate and Calcium Chloride to select the optimal formula and then were compared with locally marketed film-coated tables containing Valsartan. The formula (SA 3%, CaCl2 10%) was chosen after conducting several physiochemical tests such as shape and dimensions, swelling index, entrapment efficiency, in vitro drug release, and FTIR. FTIR test showed no chemical bonding between Valsartan and other excipients. Selected beads achieved a high percentage of swelling in phosphate buffer solution pH=6.8. Entrapment efficiency was also high at about 80%. Prepared beads followed the Korsmeyer-Peppas release mechanism, and eventually obtained extended-release beads which slowed drug release for 24h, Compared with the film-coated tablets, the in vitro release of valsartan expired after only one hour.

Statistical and machine learning analysis for the application of microbially induced carbonate precipitation as a physical barrier to control seawater intrusion

Seawater intrusion in coastal aquifers is a significant problem that can be addressed through the construction of subsurface dams or physical cut-off barriers. An alternative method is the use of microbially induced carbonate precipitation (MICP) to reduce the hydraulic conductivity of the porous medium and create a physical barrier. However, the effectiveness of this method depends on various factors, and the scientific literature presents conflicting results, making it challenging to generalise the findings. To overcome this challenge, a statistical and machine learning (ML) approach is employed to infer the causes for the reduction in hydraulic conductivity and identify the optimum MICP parameters for preventing seawater intrusion. The study involves data curation, exploratory analysis, and the development of various models to fit the input data (k-Nearest Neighbours – kNN, Support Vector Regression – SVR, Random Forests – RF, Gradient Boosting – XgBoost, Linear model with interaction terms, Ensemble learning algorithms with weighted averages – EnL-WA and stacking – EnL-Stack). The models performed reasonably well in the region where permeability reduction is sensitive to carbonate increase capturing the permeability reduction profile with respect to cementation level while demonstrating that they can be used in initial assessments of the specific conditions (e.g., soil properties). The best performing algorithms were the EnL-Stack and RF followed by XgBoost and SVR. The MICP method is effective in reducing hydraulic conductivity provided that the various biochemical parameters are optimised. Critical biochemical parameters for successful MICP formulations are the bacterial optical density, the urease activity, calcium chloride concentration and flow rate as well as the interaction terms across the properties of the porous media and the biochemical parameters. The models were used to identify the optimum MICP formulation for various porous media properties and the maximum permeability reduction profiles across cementation levels have been derived.

Preparation, characterization and in vitro digestion of jujube polysaccharide microcapsules

The preparation of jujube polysaccharide microcapsules was investigated in this study. Microcapsule technology was employed to encapsulate jujube polysaccharides, effectively isolating them from external substances and facilitating their smooth passage through the intestinal tract. The objective was to control the release and prolong the release time of the polysaccharides. Additionally, we evaluated the characteristics of these microcapsules and their in vitro solubility and digestive behaviors. The findings demonstrated that the optimal preparation conditions, measured by the encapsulation efficiency, included a sodium alginate concentration of 4% (w/v), a core-to-wall ratio of 1:6, a calcium chloride concentration of 3% (w/v), and a chitosan concentration of 0.5% (w/v). The factors influencing the process ranked in the following order: core-to-wall ratio > sodium alginate concentration > chitosan concentration > CaCl2 concentration. The microcapsules produced under the optimal conditions exhibited a remarkable encapsulation efficiency of 97.29%. The characterization and analysis of the jujube polysaccharide microcapsules confirmed their successful encapsulation, uniform particle size distribution, and robust thermal stability. In addition, swelling and in vitro release trials demonstrated that the jujube polysaccharide microcapsules exhibit excellent swelling characteristics and consistent and prolonged release patterns. These distinct characteristics are anticipated to significantly impact functional food and medicine.

Sustainable, Low‐Cost Sorbents Based on Calcium Chloride‐Loaded Polyacrylamide Hydrogels

AbstractSorbents are promising materials for applications in atmospheric water harvesting, thermal energy storage, and passive cooling, thereby addressing central challenges related to water scarcity and the global energy transition. Recently, hygroscopic hydrogel composites have emerged as high‐performance sorbents. However, many of these systems are fabricated with unsustainable and costly sorbent materials, which hinders their wide deployment. Here, the synthesis of high‐performance, cost‐efficient polyacrylamide hydrogels loaded with unprecedented amounts of calcium chloride is demonstrated. To this end, the swelling procedure of polyacrylamide hydrogels in aqueous calcium chloride solutions is optimized. The achievable salt loading in the hydrogel is characterized as a function of temperature, calcium chloride concentration in the swelling solution, and the hydrogel preparation conditions. The obtained hydrogel‐salt composites are shown to be stable under repeated sorption‐desorption cycling and enable water uptakes of 0.92 and 2.38 grams of water per gram of dry materials at 30% and 70% relative humidity, respectively. The resulting cost‐performance ratio substantially exceeds lithium chloride‐based systems. Further, the mechanistic insights on hydrogel salt interactions can guide the design of sustainable and low‐cost sorbent materials for future applications in water and energy.

Optimization of Malabar Nut (Justicia adhatoda L.) Leaves’ Phenolic Compounds by Alginate Emulsion-gelation Approach using Response Surface Methodology

Background: The encapsulation technique is an effective method for coating bioactive molecules and protecting them against various technological treatment conditions during production processing. Objective: The aim of this study was to optimize the encapsulation conditions of phenolic compounds extracted from Malabar nut (Justicia adhatoda L.) leaves by alginate emulsion-gelation approach using response surface methodology Methods: The ionotropic gelation method was used to encapsulate the phenolic compounds of Malabar nut (Justicia adhatoda L.) leaves. The optimization of this phenolic compounds encapsulation was carried out using response surface methodology through Box˗Behnken design. Four parameters with three levels (-1, 0, +1) were chosen including sodium alginate concentration (2 – 3 - 4%), calcium chloride concentration (4 - 6 - 8%), plant extract-alginate solution ratio (0.02 – 0.11 - 0.2 mg/ml), and gelation time (5 – 12.5 - 20 min). of the total phenolic and flavonoid contents encapsulation efficiency was assessed. Likewise, the antioxidant activity was evaluated using ferric-reducing power (FRP) and free radical scavenging activity (DPPH). Results: The results of response surface methodology analysis using Box˗Behnken design showed that the optimal encapsulation conditions were 3.11% for alginate concentration, 5.74% for calcium chloride concentration, 0.1 mg/ml for the plant extract-alginate solution ratio, and 10.80 min for gelation time. Under these conditions, the optimum values of total phenolic and flavonoid encapsulation efficiency were 86.17% and 75.69%, respectively, 126.75 mg AAE/100 g for ferric reducing power and 97.29% for DPPH. The experimental and prediction results have expressed a high significant level for all responses. Conclusion: The method revealed the validity of elaborated models through response surface methodology optimization processes for phenolic antioxidants encapsulation of Malabar nut (Justicia adhatoda L.) leaves extract.

Feasibility of increasing calcium content of drinking tap water following quality regulations to improve calcium intake at population level

Background Calcium intake is below recommendations in several parts of the world. Improving calcium intake has benefits not only for bone health but also helps to prevent pregnancy hypertension disorders. Calcium concentration of tap water is usually low The aim of the present study was to determine the maximum amount of calcium that can be added to tap water while complying with drinking water local regulations. Methods Tap water samples were collected from the Province of Buenos Aires (Argentina). Physicochemical properties and saturation index were measured. Different incremental concentrations of calcium chloride were added to the experimental aliquots. Results Baseline water had a mean calcium concentration of 22.00 ± 2.54 mg/L, water hardness of 89.9 ± 6.4 mg/L CaCO3, and a saturation index of -1.50 ± 0.11. After the addition of 0.4554 ± 0.0071 g of salt, water hard-ness reached 355.0 ± 7.1 mg/L CaCO3, a calcium concentration of 140.50 ± 2.12 mg/L, and a saturation index -0.53 ± 0.02. Conclusions This study shows that at laboratory level it is feasible to increase calcium concentration of drinking water by adding calcium chloride while complying with national standards. Calcium concentration of drinking tap water could be evaluated and minimum calcium concentration of tap water regulated so as to improve calcium intake in populations with low calcium intake.

PREPARATION OF HEALTH BENEFICIAL PROBIOTIC SOYA ICE -CREAM AND EVALUATION OF QUALITY ATTRIBUTES

Probiotic soya ice cream was prepared by using food grade bacteria Lactobacillus paracasei S1(MF443873) and Lactobacillus rhamnosus KC6 (MF443875). Bacteria have been encapsulated in milk and sodium alginate beads to improve their viability in soya ice -cream. Viable cell number of entrapped probiotic isolates was observed with calcium chloride concentration of 0.1M at pH 7.0, hardening time of 8h. Morphological characterization of microencapsulated beads was done by using SEM. Probiotic soy ice-cream was stored at -20oC for 30 days and was investigated for sensory qualities, microbial count and physicochemical characteristics. Microencapsulated probiotic ice-cream was found more stable during storage as compared to those containing free probiotic microorganisms. As far as physico-chemical characteristics of probiotic enriched soy ice-cream is concerned, though changes in quality attributes viz. pH, ascorbic acid, lactic acid, total soluble solid and antioxidant content during storage interval have been observed but these changes were statistically non- significant.

Screening of Factors Influencing Keratinase Fermentation from Bacillus Haynesii BK1H using The Plackett-Burman Design (PBD)

Keratinase is a class of proteases that degrade keratin into polypeptides and amino acids by breaking peptide and disulfide bonds in keratinous proteins. Protease is one of the largest industrial enzymes, the global protease market is increasing rapidly every year. In previous studies, a keratinase-producing microbe was isolated from Bleduk Kuwu which was identified as Bacillus haynesii BK1H. However, further study needs to be done to optimize the production by observing microenvironmental factors that influence keratinase production. In this study, screening some microenvironmental factors is reported. Screening factors including carbon sources, type and concentration of metal ions, agitation speed, amount of inoculum, pH, and temperature. Screening for these factors was started with the One Factor at A Time (OFAT) method and followed by the Plackett-Burman Design (PBD) method. In this study, sequential work was done: (1) Regeneration of Bacillus haynesii BK1H Microbes, (2) Preparation of Tyrosine Standard Series Solutions, (3) Screening of Factors Affecting Protease Fermentation of Bacillus haynesii BK1H using the One Factor at A Time (OFAT) method. ), and (4) Maintaining Significantly Influential Factors by Using Plackett-Burman Design (PBD). The results of the OFAT approach showed that the best condition for keratinase production was achieved at rice husk concentration, additional carbon source, of 1%; pH of 7; a temperature of 35°C; the amount of inoculum of 1%; agitation speed of 150 rpm; magnesium sulfate concentration of 0.04 g/mL, and calcium chloride concentration of 0.0005 g/m. Justification of those factors using PBD confirmed that only additional rice husk, magnesium sulfate and calcium chloride concentration, and agitation speed were significantly important toward keratinase production at selected experiment level limits.

Development And Components Of Chitosan Primarily Based Microspheres Of Glibenclamide

Development And Components Of Chitosan Primarily Based Microspheres Of Glibenclamide

Formulation and characterization transdermal patches with chitosan-alginate of mangosteen peel (garcinia mangostana l.)

Mangosteen peel extract contains xanthones have an anti-inflammatory effect and accelerated the process of fibroblast proliferation. The xanthones would trigger the formation of collagen which plays an important role in the wound healing process. The preparation of mangosteen peel extract into the trans-dermal patch aims to deliver the active substances through the skin and to the systemic system painlessly. The aims of this research were to formulate and characterize patch trans-dermal mangosteen peel extract. The formulation was characterized by organoleptic, uniformity of thickness and weight, folding resistance, pH, moisture content, drug content, swelling, in vitro drug release test, FTIR spectrum, and morphology by SEM. The patch trans-dermal was prepared using chitosan and sodium alginate by layer by layer using 0,2%, 0,4%, and 0,6�lcium chloride as crosslinker. The enhancement in the concentration of calcium chloride had a significant effect (p<0>300 folds, pH of 5, moisture content of 1,84%, swelling degree value of 3,41%, and penetration test results were found with a percent penetration of 38,87%. The results of the morphological obtained a pore size of 5,88 μm. The results of the FTIR spectrum showed that there was interaction by the presence of a new peak at the wave number of 1622,23 cm-1. It can be concluded that calcium chloride in patch trans-dermal affected physical properties and in vitro drug release of mangosteen peel extract.

Effects of Calcium and pH on Rheological Thermal Resistance of Composite Xanthan Gum and High-Methoxyl Apple Pectin Matrices Featuring Dysphagia-Friendly Consistency.

High-methoxyl apple pectin (AP) derived from apple was employed as the main ingredient facilitating rheological modification features in developing dysphagia-friendly fluidized alimentary matrices. Xanthan gum (XG) was also included as a composite counterpart to modify the viscoelastic properties of the thickened system under different thermal processes. The results indicate that AP is extremely sensitive to thermal processing, and the viscosity is greatly depleted under a neutral pH level. Moreover, the inclusion of calcium ions echoed the modification effect on the rheological properties of AP, and both the elastic property and viscosity value were promoted after thermal processing. The modification effect of viscoelastic properties (G' and G″) was observed whne XG was incorporated into the composite formula. Increasing the XG ratio from 7:3 to 6:4 (AP:XG) triggers the rheological transformation from a liquid-like form to a solid-like state, and the viscosity value shows that the AP-XG composite system exhibits better thermal stability after thermal processing. The ambient modifiers of pH (pH < 4) and calcium chloride concentration (7.5%) with an optimal AP-XG ratio of 7:3 led to weak-gel-like behavior (G″ < G'), helping to maintain the texture properties of dysphagia-friendly features similar to those prior to the thermal processing.

The Isolation, Identification and Immobilization Method of Three Novel Enzymes with Diosgenin-Producing Activity Derived from an Aspergillus flavus.

Diosgenin is an important raw material used in the synthesis of steroid drugs, and it is widely used in the pharmaceutical industry. The traditional method of producing diosgenin is through using raw materials provided via the plant Dioscorea zingiberensis C. H. Wright (DZW), which is subsequently industrially hydrolyzed using a high quantity of hydrochloric and sulfuric acids at temperatures ranging from 70 °C to 175 °C. This process results in a significant amount of unmanageable wastewater, creates issues of severe environmental pollution and consumes high quantities of energy. As an alternative, the enzymolysis of DZW to produce diosgenin is an environmentally and friendly method with wide-ranging prospects for its application. However, there are still only a few enzymes that are suitable for production on an industrial scale. In this study, three new key enzymes, E1, E2, and E3, with a high conversion stability of diosgenin, were isolated and identified using an enzyme-linked-substrate autography strategy. HPLC-MS/MS identification showed that E1, a 134.45 kDa protein with 1019 amino acids (AAs), is a zinc-dependent protein similar to the M16 family. E2, a 97.89 kDa protein with 910 AAs, is a type of endo-β-1,3-glucanase. E3, a 51.6 kDa protein with 476 AAs, is a type of Xaa-Pro aminopeptidase. In addition, the method to immobilize these proteins was optimized, and stability was achieved. The results show that the optimal immobilization parameters are 3.5% sodium alginate, 3.45% calcium chloride concentration, 1.4 h fixed time, and pH 8.8; and the recovery rate of enzyme activity can reach 43.98%. A level of 70.3% relative enzyme activity can be obtained after employing six cycles of the optimized technology. Compared with free enzymes, immobilized enzymes have improved stability, acid and alkaline resistance and reusability, which are conducive to large-scale industrial production.

Influence of biopolymer composition and crosslinking agent concentration on the micro- and nanomechanical properties of hydrogel-based filaments

Hydrogel filaments were manufactured using wet spinning technique, incorporating variations in the concentrations of sodium alginate, gelatin, and calcium chloride (crosslinking agent). The combination of biopolymer concentrations was determined using design of experiments (DoE) approach. The resulting filaments were produced from the developed hydrogels. Tensile and vertical strength analyses of the filaments were conducted using an electromechanical extensor. Atomic force microscopy was employed to evaluate the roughness, viscoelasticity, retraction, and deflection of the hydrogels. By employing DoE, a total of seventeen different combinations of biopolymers and crosslinkers were generated to construct the hydrogels. The filaments exhibited variations in electromechanical traction (measured in kPa) and produced distinct stress peaks. Furthermore, diverse roughness values were observed among the tested materials, with the combinations featuring higher concentrations of sodium alginate displaying the highest Young's modulus. This study demonstrates that manipulating the concentrations of biopolymers and crosslinking agents can modulate the micro and nanomechanical properties of biopolymeric filaments.

Synergistic interaction between hydrocolloids and kinnow peel biowaste for the development of edible fillers using response surface methodology.

Rapidly rising societal awareness about the planet sustainability through developing environmentally friendly and biodegradable alternatives to current impact of plastics waste represents an emerging need for establishing a circular bioeconomy of cleaner, safer, greener, and sustainable future. Until now, no investigation has been done on edible tableware made from leftover fruit peels. Presently, Kinnow mandarin is the most commercially farmed citrus fruit commodity, with the highest production, productivity, and popularity among all horticulture crops worldwide, generating vast quantity of peels ending up as putrefying biowaste that impacts ecosystem health. Sustainable efforts are therefore required in the circular economy to develop a creative and comprehensive strategy to address aforementioned issues, raising profitability, enhancing processing efficiency, and exploring "taste over waste," which contributes to overall sustainability. Therefore, in the current study, we established an approach for transforming the citrus peels biowaste into food-related end products by creating edible fillers, which is a sustainable material in terms of its functional, physical, and microbiological qualities for holding of confectionery products. The optimum level of independent variables with maximum desirability were found to be 0.75% calcium chloride concentration, 1.01% agar concentration, and 10% moisture content. A significant (p < 0.05) effect of process parameters was found in all responses. Model validation revealed that the model developed was accurate, with a prediction error ranging from - 9.96 to 3.28%. The technology developed for biowaste-based biofillers is still in a nascent stage, and it is expected that significant advancements will be made in the bio-refinery industries that can make edible fillers a reality in the future and might be helpful in contributing towards sustainable development. This research also demonstrated an efficient and novel approach towards a "zero-waste."

Effect of Calcium Chloride and Gibberellic Acid on the Vegetative Growth of Two Cultivars of Gladiolus Gladiolus hybrid L.

This study was conducted inside the wooden canopy of the Department of Horticulture and Landscape Engineering / College of Agriculture and Forestry / University of Mosul during the agricultural season 2022-2023. To study the effect of spraying with different concentrations of calcium chloride (0, 500, 1000) mg. L-1 and spraying with gibberellic acid at concentrations of (0, 100, 200) mg. L-1 and the interaction between them in vegetative of two cultivars of Gladiolus Gladiolus hybrid. L. They are Nova lux with yellow flowers and Trader Lux with red flowers. The corms were planted on 17/3/2022, then sprayed 30 days after planting the corms with three sprays and three concentrations of calcium chloride (0,500, 1000) mg.L-1 The plants were also sprayed with gibberellic acid, with three sprays and three concentrations (0, 100, 200), The period between one spray and another was two weeks. The spraying was done with gibberellic acid after 35 days of planting the corms. The study was carried out using a factorial experiment in the design of completed randomized sectors R.C.B.D within split plots with three replications, each experimental unit included (7) cormat for each replicate. The research results of were analyzed statistically with the (SAS) program and tested statistically using Duncan’s multinomial test at the probability level of 0.05. It was found that the red cultivar recorded the largest plant height, which reached 129.905 cm, the largest leaf length, which reached 102.584 cm, and the largest number of leaves, which reached 9,980 leaves. Plant-1, and the largest leaf area of the plant, amounting to 401.656 cm2. plant-1, and the largest dry weight of the leaves, amounting to 12.567 g. The yellow variety plants also recorded the largest values for the percentage of total chlorophyll in the plant, which amounted to 0.984%. The treatment with gibberellic acid at a concentration of 200 mg also resulted. L-1 led to a significant increase in all studied traits.

Cellulose Nanocrystal-Based Emulsion of Thyme Essential Oil: Preparation and Characterisation as Sustainable Crop Protection Tool

Essential oil-based pesticides, which contain antimicrobial and antioxidant molecules, have potential for use in sustainable agriculture. However, these compounds have limitations such as volatility, poor water solubility, and phytotoxicity. Nanoencapsulation, through processes like micro- and nanoemulsions, can enhance the stability and bioactivity of essential oils. In this study, thyme essential oil from supercritical carbon dioxide extraction was selected as a sustainable antimicrobial tool and nanoencapsulated in an oil-in-water emulsion system. The investigated protocol provided high-speed homogenisation in the presence of cellulose nanocrystals as stabilisers and calcium chloride as an ionic crosslinking agent. Thyme essential oil was characterised via GC-MS and UV-vis analysis, indicating rich content in phenols. The cellulose nanocrystal/essential oil ratio and calcium chloride concentration were varied to tune the nanoemulsions’ physical–chemical stability, which was investigated via UV-vis, direct observation, dynamic light scattering, and Turbiscan analysis. Transmission electron microscopy confirmed the nanosized droplet formation. The nanoemulsion resulting from the addition of crosslinked nanocrystals was very stable over time at room temperature. It was evaluated for the first time on Pseudomonas savastanoi pv. savastanoi, the causal agent of olive knot disease. In vitro tests showed a synergistic effect of the formulation components, and in vivo tests on olive seedlings demonstrated reduced bacterial colonies without any phytotoxic effect. These findings suggest that crosslinked cellulose nanocrystal emulsions can enhance the stability and bioactivity of thyme essential oil, providing a new tool for crop protection.

Characterization and Exploration of Placket-Burman-Designed Porous Calcium Carbonate (Vaterite) Microparticles.

The objective of the research was to identify significant variables that impact the porosity-related properties of CaCO3 particles. The Placket-Burman design was employed to screen multiple variables, including pH, molar concentrations of calcium chloride and sodium carbonate, temperature, concentration of Gelucire 44/14, Cremophor RH40, Solutol HS15, Labrasol, mixing rate, reaction time, and order of addition. The response variables were surface area, pore radius, and pore volume. Influential methodologies such as XRD, FTIR, Raman spectroscopy, and TGA were utilized to validate the precipitate type. The BET surface area ranged from 1.5 to 16.14 m2/g, while the pore radius varied from 2.62 to 6.68 nm, and the pore volume exhibited a range of 2.43 to 37.97 cc/gm. Vaterite structures with spherical mesoporous characteristics were observed at high pH, whereas calcite formations occurred at low pH. The order of addition impacted the surface area but did not affect the pore volume. To maximize the surface area, a lower reaction time and molar concentrations of sodium carbonate were found to be advantageous. The pore radius was influenced by the pH, surfactants, and reaction conditions. The sediments were categorized based on the percentage of vaterite formation. The instrumental techniques effectively characterized the precipitates and provided a valuable complementary analysis.

Preparation of porous membrane for moisture absorption from high‐humidity gases

AbstractSuitable air humidity is of great importance for human health, crop growth and the life of buildings. In this work, the polyvinylidene fluoride/calcium chloride (PVDF/CaCl2) porous membranes with rich pore structures for adsorption of high‐humidity gases were prepared using solvent evaporation‐induced phase separation. The results showed that the gap between the PVDF spherical crystals increased with the increase of CaCl2 content, which increased the porosity of the membrane. When the CaCl2 content reached 20 wt.%, the water vapor adsorption capacity of the PVDF/CaCl2 porous membrane was 0.876 and the initial adsorption rate was 0.050 g·g−1·min−1. At this point, the moisture vapor permeance of the membrane was the best at 0.04 g·m−2·h−1·Pa−1, and the dry strength of the PVDF/CaCl2 membrane was 0.397 MPa, which was 1.64 times that of the membrane without CaCl2. This work provides theoretical and technical guidance for the preparation of air dehumidification materials.Highlights The porosity of the membranes increased with increasing of calcium chloride content. The moisture vapor permeance of the M‐20 membrane was the best at 0.04 g·m−2·h−1·Pa−1. The dry strength of the M‐20 membrane was 1.64 times that of the M‐0 membrane.