Addition Of Chloride Research Articles

Spectral investigation, TD-DFT study, Hirshfeld surface analysis, NCI-RDG, HOMO-LUMO, chemical reactivity and NLO properties of 1-(4-fluorobenzyl)-5-bromolindolin-2,3‑dione

In a previous study, the 1-(4-fluorobenzyl)-5-bromolindolin-2,3‑dione (FBID) molecule was synthesized by adding isatin and K2CO3 to acetonitrile, followed by the addition of 4-fluorobenzyl chloride. The resulting mixture was filtered, concentrated, then solidified with n-hexane, and recrystallized in water. In the present study, a combination of theoretical and experimental methods is employed to evaluate and understand the structural and vibrational properties of FBID: FT-IR, UV–Vis as well as 1H and 13C NMR chemical shifts using GIAO approach. All calculations were performed applying the DFT method, with B3LYP functional and 6–311G(d,p) basis set. The HOMO-LUMO energy gap revealed a good charge transfer interaction in FBID molecule. Also, the HOMO and LUMO energies have been exploited to describe the global chemical reactivity. At the same method and level, it has been demonstrated that the studied compound has NLO properties. The estimated NBO, atomic charges and the molecular electrostatic potential map indicated that the sites around the oxygen atoms of the FBID molecule are the most reactive. The contribution of intermolecular interactions was analysed via Hirshfeld surface analysis. In order to identify the different types of all possible interactions in our system, the reduced density gradient (RDG) method was used to characterize and evaluate the nature of these interactions as strong repulsion (steric effect), strong attraction (hydrogen bond), or weak interaction (Van der Waals).

MOISTURE-HARVESTING LIZARD SKINS AS AN INSPIRATON FOR PERFORMATIVE BUILDING ENVELOPES IN ARID CLIMATES

Research on shape-shifting adaptive architectural skins has recently focused on bio-inspired programmable materials. Only a few studies however examine the microstructure of living organisms, especially in terms of morphological adaptation in harsh climatic conditions. This paper explores the microstructure of moisture-harvesting lizard skins, specifically the Trapelus species of the Agamidae family in North-East Africa, as an inspiration for programmable materials in adaptive building skins in the arid climate of Egypt. The paper investigates the ability to improve the durability and morphological capabilities of programmable materials based on surface formation, utilizing digital fabrication techniques. A series of physical experiments were conducted on different samples of 3D printed wood filament under several humidity conditions, as a single layer, with textured patterns, and with the addition of potassium chloride as a moisture-harvesting chemical composite. The paper concluded that materials composed of textured patterns and moisture-harvesting chemical composites exhibited the highest moisture retention, therefore leading to advantages in its use in adaptive building skins in arid climates, through a wide variety of design possibilities for performative building envelopes.

The corrosion properties of steel in pore solutions obtained from alkali‐activated mortars

AbstractAlkali‐activated materials (AAMs) are considered a promising alternative to materials made from ordinary Portland cement (OPC). Other than considering the durability of the material itself, the use of AAMs for reinforced concrete elements also raises the question of steel corrosion processes in these materials, which are still relatively unknown. Three different alkali‐activated mortars were prepared for this study, based on either fly ash, slag, or metakaolin. Pore solutions were then extracted from each mortar and chemically analyzed. Electrochemical techniques were used to study the corrosion of steel in synthetic pore solutions containing varying concentrations of chlorides. In parallel, the same corrosion tests were performed in a generic pore solution representing OPC mortar. It was shown that the chemical composition differed in each pore solution tested, thus affecting the corrosion properties of the steel. The addition of chloride also had a varying effect on the corrosion properties of the steel in each type of pore solution tested. This study provided a basic overview of the corrosion behavior and mechanisms of the various AAM environments in comparison to that of OPC.

Photochemical transformation of anthracene (ANT) in surface soil: Chlorination and hydroxylation

To reveal the fate of anthracene (ANT) in soil, the photodegradation behavior of ANT was systematically studied using SiO2 to simulate a soil environment. Under xenon lamp irradiation, more than 90% of ANT loaded on SiO2 could be removed after 240 min. Moreover, the effects of water content, chloride ions (Cl-) and humic acid (HA) were examined. It was found that the presence of water and HA can significantly inhibit the photolysis of ANT on SiO2, while the addition of chloride alone has no obvious effect. However, when water is present, the inhibition effect of chloride became more obvious. According to radical quenching experiments and electron paramagnetic resonance (EPR) spectra, hydroxyl radicals (•OH) and chlorine radicals (Cl•) were formed in the system. Possible reaction pathways were speculated based on products identified by mass spectrometry. ANT was attacked by •OH to form hydroxylated products, which can be further hydroxylated and oxidized with the final formation of ring-opening products. ANT directly excited by light may also react with Cl• to produce chlorinated polycyclic aromatic hydrocarbons (Cl-PAHs). Finally, the experimental results were verified on real soil. This study provides important information for understanding the photochemical transformation mechanism of ANT at the soil/air interface.

Insights into the enhanced electrokinetic remediation of lead and cadmium contaminated soil with the composite electrolyte of citric acid and calcium chloride

ABSTRACT Electrolyte is one of the critical factors for the efficient and green implementation of electrokinetic remediation (EK). Modelling of enhanced EK in the complex heavy metal contaminated soils was designed. Enhanced electrokinetic remediation experiments with composite electrolyte (citric acid + calcium chloride) were conducted to investigate their influence on the removal of cadmium (Cd) and lead (Pb), depletion of soil cations, and electric energy consumption. The results indicated that the removal efficiency of lead and cadmium rose from 10.8% and 14% to 15.1% and 22.5%, at the same time, the power consumption increased from 140.4 to 402 Wh since calcium chloride was added to citric acid. With the extension of time, the highest removal of Pb and Cd were 58% and 99.2%, respectively, in the section of S1 where soil pH was 2.5. The dominant cations (detected) in the pore water of the soil were Ca2+, Mg2+, and Mn2+, which was more evident with the extension of time. Lead-cadmium transmission efficiency under the electric field was lowered because the ratio of the heavy metal ions to the total amount of cations was very low, especially with the addition of calcium chloride.

Cs4PbI6-Cl Nucleation Seeds Assisted Highly-Oriented Inorganic CsPbI3 Perovskites for Efficient Perovskite Solar Cells

Inorganic cesium lead triiodide (CsPbI3) perovskites show high potential for photovoltaic applications due to their suitable bandgap and excellent thermal stability. However, the photovoltaic performance of CsPbI3 perovskite solar cells (PSCs) is significantly restricted by unsatisfactory crystal quality and serious nonradiative recombination. Herein, chloride additives, such as dimethylammonium chloride (DMACl), ammonium chloride (NH4Cl), and methylammonium chloride (MACl), are applied to ameliorate the crystallization of CsPbI3 perovskite films. The results reveal that DMACl could form a low-solubility complex (Cs4PbI6-Cl) in the precursor as seeds to induce crystallization during solvent evaporation and simultaneously passivate perovskite surface with residual DMA+. Consequently, the DMACl-CsPbI3 perovskite film with highly oriented crystals and suppressed nonradiative recombination is realized. With these advantages, the inorganic PSC with high efficiency of 18.62% is demonstrated and exhibits good stability. This work provides insight into the crystallization of CsPbI3 perovskite films for the development of high-performance all-inorganic PSCs.

Narrow Near-Infrared Emission from InP QDs Synthesized with Indium(I) Halides and Aminophosphine.

Nonpyrophoric aminophosphines reacted with indium(III) halides in the presence of zinc chloride have emerged as promising phosphorus precursors in the synthesis of colloidal indium phosphide (InP) quantum dots (QDs). Nonetheless, due to the required P/In ratio of 4:1, it remains challenging to prepare large-sized (>5 nm), near-infrared absorbing/emitting InP QDs using this synthetic scheme. Furthermore, the addition of zinc chloride leads to structural disorder and the formation of shallow trap states inducing spectral broadening. To overcome these limitations, we introduce a synthetic approach relying on the use of indium(I) halide, which acts as both the indium source and reducing agent for aminophosphine. The developed zinc-free, single-injection method gives access to tetrahedral InP QDs with an edge length > 10 nm and narrow size distribution. The first excitonic peak is tunable from 450 to 700 nm by changing the indium halide (InI, InBr, InCl). Kinetic studies using phosphorus NMR reveal the coexistence of two reaction pathways, the reduction of transaminated aminophosphine by In(I) and via redox disproportionation. Etching the surface of the obtained InP QDs at room temperature with in situ-generated hydrofluoric acid (HF) leads to strong photoluminescence (PL) emission with a quantum yield approaching 80%. Alternatively, surface passivation of the InP core QDs was achieved by low-temperature (140 °C) ZnS shelling using the monomolecular precursor zinc diethyldithiocarbamate. The obtained InP/ZnS core/shell QDs that emit in a range of 507-728 nm exhibit a small Stokes shift (110-120 meV) and a narrow PL line width (112 meV at 728 nm).

Extraction and purification of lectins from mushroom and study its agglutination activity

Lectin is a type of protein that found in most common kinds of nutrients. The human body is unable to digest it, therefore lectin passes through a gastrointestinal tract and linked to sugar. It is importance lactin bind to have an immune response, as it gains the body’s immunity, meaning it is used as an antioxidant. To extract lactin protein from mushroom, the worked utilized 1 kg of mushroom for all three steps. The first step involved cell destruction and extraction by transferring 1kg of mushroom into distilled water (100 mL), and the addition of sodium chloride (11.7 g) in mixer then filtered by gauzes and filter paper. The second step includes precipitation process using five different concentrations of ammonia sulphate of (20, 40, 60, 80, 100 %) for 50 mL of the extract mushroom. The final step involved dialysis by semipermeable membrane made of cellulose acetate or nitrocellulose. The result of extraction process is indicated by spectrophotometer from measurement the sample that precipitated using ammonia sulphate. Moreover, the extracted, the purified lectin protein from fungi was utilized as antibiotic against diseases.

Corrosion of alloy 690 in simulated steam generator chemistry with boiling-effect of chloride and sulfate impurities

Enrichment of impurities occurs in steam generators of nuclear plants due to intense boiling conditions prevailing within them. In this work, deposition and release of chloride and sulfate impurities were studied using a dedicated water circulation loop with Alloy 690 as steam generator tubing. Electrochemical impedance spectroscopy was employed to follow in-situ the corrosion behavior in non-boiling, boiling and after-boiling conditions. Deposition/release of impurities is quasi-first-order vs. concentration. Interpretation of electrochemical impedance data using an updated version of the Mixed-Conduction Model allows to obtain reaction orders of oxide growth and corrosion release with respect to chloride and sulfate additives.

Modified Solid Electrolyte Interphases with Alkali Chloride Additives for Aluminum–Sulfur Batteries with Enhanced Cyclability

AbstractAluminum–sulfur batteries employing high‐capacity and low‐cost electrode materials, as well as non‐flammable electrolytes, are promising energy storage devices. However, the fast capacity fading due to the shuttle effect of polysulfides limits their further application. Herein, alkaline chlorides, for example, LiCl, NaCl, and KCl are proposed as electrolyte additives for promoting the cyclability of aluminum–sulfur batteries. Using NaCl as a model additive, it is demonstrated that its addition leads to the formation of a thicker, NaxAlyO2‐containing solid electrolyte interphase on the aluminum metal anode (AMA) reducing the deposition of polysulfides. As a result, a specific discharge capacity of 473 mAh g−1 is delivered in an aluminum–sulfur battery with NaCl‐containing electrolyte after 50 dis‐/charge cycles at 100 mA g−1. In contrast, the additive‐free electrolyte only leads to a specific capacity of 313 mAh g−1 after 50 cycles under the same conditions. A similar result is also observed with LiCl and KCl additives. When a KCl‐containing electrolyte is employed, the capacity increases to 496 mA h g−1 can be achieved after 100 cycles at 50 mA g−1. The proposed additive strategy and the insight into the solid electrolyte interphase are beneficial for the further development of long‐life aluminum–sulfur batteries.

Polyacrylamide/EDTA-modified chitosan/graphene oxide hydrogels as an adsorbent and supercapacitor for sustainable applications

Due to high security and versatility, hydrogels have attracted great interest in sustainable applications such as wastewater treatment and energy storage. However, the poor adsorption capacity as an adsorbent and the low conductivity as an electrolyte seriously restrict the sustainable application of hydrogels. Here, we prepare nanocomposite hydrogels (PAAm/CS-EDTA/GO) by mixing ethylene diamine tetraacetic acid (EDTA)-modified chitosan (CS) and graphene oxide (GO) in crosslinking polymerization of acrylamide (AAm). Nanocomposite gives PAAm/CS-EDTA/GO hydrogel excellent mechanical properties (e.g., fracture energy of ∼1208 kJ∙m−3). EDTA, CS and GO support rich and special adsorption sites for the removal of metal ions and dyes. The addition of lithium chloride (LiCl) makes PAAm/CS-EDTA/GO/Li hydrogel have anti-freezing and anti-dehydration properties. Interestingly, the synergy of CS-EDTA and GO increases the conductivity of the hydrogel. The supercapacitor assembled by PAAm/CS-EDTA/GO/Li hydrogel electrolyte shows high capacitance and temperature tolerance. Our work provides a route for the rational development of adsorption materials and energy storage devices for sustainable applications.

Electroless deposition of Ni-W-Mo-Co-P films as a binder-free, efficient and durable electrode for electrochemical hydrogen evolution

In this study, the manufacture of Ni-W-Mo-Co-P, Ni-Mo-Co-P, Ni-W-Co-P, Ni-W-Mo -P, Ni-Co-P, Ni-Mo-P, Ni-W-P, and Ni-P alloying coatings through electroless method on the copper substrate was investigated. The elemental and structural tests showed that the alteration of the Ni-P electroless basic bath composition by introducing sodium tungstate, sodium molybdate, and cobalt chloride additives enabled the deposition of alloying coatings. Linear Sweep Voltametry (LSV) tests revealed that the Ni-W-Mo-Co-P sample (NWMCP) coated in an alkaline bath with 18 g/l Nickel (II) sulfate, 12 g/l Ammonium acetate, 12 g/l Sodium citrate, 12 ml Lactic acid, 12 g/l Sodium hypophosphite, 8 g/l Sodium tungstate, 0.2 g/l Sodium molybdate, and 10 g/l Cobalt (II) chloride was featured with the best electrocatalytic properties with η10 = −41, η20 = −46, η100 = −67 mV and tafel slope of 38 mV.dec−1. Scanning Electron Microscope (SEM) observations and Cyclic Voltametry (CV) electrochemical tests showed that morphology had a negligible effect on electrocatalytic performance of the coating. In addition, the presence of alloying elements improved the coating intrinsic properties by changing its electronic structure. Electrocatalytic stability was assessed using chronoamperometry, cyclic voltammetry, and stepwise chronoamperometry tests, introducing NWMCP sample a durable electrode generation with good stability.

Influence of the polymerization method on the properties of fibrin matrices

Highlights. We have proposed and patented a method for obtaining fully autologous fibrin without the use of exogenous thrombin, which can be implemented within the framework of a personalized approach in tissue engineering. Such fibrin, in addition to lower risk of infection and inflammation, possesses greater strength and resistance to degradation, as well as better hemocompatibility compared to fibrin polymerized with exogenous thrombin, which is an undoubted advantage when used as a coating for small-diameter vascular grafts.Background. Autologous fibrin can be used as a coating to impart biomimetic properties to various polymers used in vascular tissue engineering. Traditionally, fibrinogen polymerization is performed with the addition of exogenous thrombin and calcium chloride. Our patented method of obtaining fibrin without the use of exogenous thrombin allows us to obtain a completely autologous material that does not have the risk of infection. The differences in methods polymerization can change the fibrin properties.Aim. To compare the most important properties of vascular tissue engineering of fibrin obtained by various methods: using endogenous thrombin and exogenous thrombin in vitro.Methods. The fibrinogen precipitate was obtained with ethanol precipitation method using low concentration of ethanol. The content of fibrinogen in the precipitate was normalized to a final concentration in fibrin of 30 mg/mL. Polymerization of fibrin polymerized with exogenous thrombin was performed by adding 50 U/ mL and 0.2% calcium chloride to the thrombin precipitate, fibrin polymerized by activation of endogenous thrombin only by adding 0.2% calcium chloride. The strength properties of the samples were tested on a Z tensile tester (Zwick/ Roell). The structure of fibrin was studied using scanning electron microscopy, a quantitative analysis of the size of pores and fibers, the density of branching points was carried out. The quantitative content of FXIII in plasma and the resulting precipitate was determined by ELISA. FXIII activity was studied by the formation of γ-γ crosslinks by SDS-PAGE, the resistance of samples to proteolytic and fibrinolytic degradation. The ability of fibrin polymerized by activation of endogenous thrombin and fibrin polymerized with exogenous thrombin to activate contact coagulation and platelet aggregation was evaluated.Results. Thinner fibers predominated in the structure of the fibrin polymerized by activation of endogenous thrombin samples, while the samples were distinguished by greater strength and stiffness. The described features may be associated with a more efficient activation of FXIII, which is confirmed by the formation of a larger number of γ-γ dimers in fibrin polymerized by activation of endogenous thrombin samples, as well as resistance to proteolytic degradation compared to fibrin polymerized with exogenous thrombin. Moreover, fibrin polymerized by activation of endogenous thrombin samples in vitro activated platelets less than fibrin polymerized with exogenous thrombin.Conclusion. The method for obtaining and polymerizing fibrin using endogenous thrombin makes it possible to obtain a completely autologous material that has better physical and mechanical properties, resistance to proteolytic degradation and lower thrombogenicity compared to traditional fibrin polymerization.

One-pot liquefaction of cellulose to ethyl levulinate via 1-sulfonic acid-3-methyl imidazolium trichlorozincate as Brønsted-Lewis catalyst

The direct conversions of cellulose to ethyl levulinate (EL) via Brønsted acidic ionic liquid (BAIL), Lewis acidic ionic liquid (LAIL), and Brønsted-Lewis acidic ionic liquid (BLAIL) conducted in this study is a sustainable approach. Initially, BAIL 1-sulfonic acid-3-methyl imidazolium chloride [SMIM][Cl] was prepared by the mixing of 1-methylimidazole, dry dichloromethane, and chlorosulfonic acid. Then, Lewis acidic site was provided to the BAIL by the addition of zinc chloride (ZnCl2), to synthetize BLAIL 1-sulfonic acid-3-methyl imidazolium trichlorozincate, [SMIM][ZnCl3]. Meanwhile, LAIL 1-butyl-3-methyl imidazolium trichlorozincate [BMIM][ZnCl3] was prepared by the addition of ZnCl2 to a neutral 1-butyl-3-methyl imidazolium chloride [BMIM][Cl]. These three catalysts were then characterized and employed in the one-pot liquefaction process that was conducted in a stainless-steel batch reactor at 180 ˚C for 10 hr, by charging 0.6 g of cellulose, 40 mL of ethanol and 3 g of catalyst. A parameter study, mainly temperature (120–200) °C, time (2–10) hr, and cellulose loading (0.2–1.0) g, were then conducted to determine the selected parameters to obtain high EL yield. Among the employed ionic liquids (ILs), BLAIL [SMIM][ZnCl3] exhibited the highest catalytic activity, which was contributed mainly by its co-existence of Brønsted and Lewis acidic sites as detected in Fourier-Transform Infrared (FTIR) analysis, and its high acidic value. The maximum EL yield (20.27 wt%) was obtained under conditions of 180 °C, 6 hr, 0.6 of cellulose, and 3 g of [SMIM][ZnCl3]. The outcome of this study provides an insight on the potential of novel [SMIM][ZnCl3] in facilitating the direct cellulose ethanolysis to EL.

Investigation of the hydration process and biological activity of a novel nanosilver incorporated dicalcium silicate based retrograde filling material.

Although several materials have been used for retrograde filling following apical surgeries, there is no consensus on a single best material. Tricalcium silicate-based types of cement have been developed as root-end filling materials mainly due to tricalcium silicate's hydraulic properties. However, its unfavorable setting characteristics and minimal antimicrobial properties have necessitated the introduction of new additives into the existing commercially available materials. To design an affordable product based on a dicalcium silicate with a shorter set time, minimal cytotoxic complications, and enhanced antibacterial activity, we developed a new endodontic cement from pure raw materials, intending to satisfy the prerequisites of ideal retrograde material. The composition of the experimental calcium silicate-based cement included the addition of calcium chloride and silver nanoparticles in varying concentrations. Structural characterization was carried out using energy dispersive analysis by X-rays using scanning electron microscope (EDAX SEM) and hydration characteristics were performed using an X-ray diffractometer (XRD). The experimental material was further evaluated for biocompatibility using MTT ([3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide)assay and antibacterial activity was evaluated using an agar diffusion test against Enterococcus faecalis. The structural characterization and hydration characteristics revealed that the experimental cement was dicalcium silicate based with favorable biocompatibility and enhanced antibacterial activity. Tricalcium silicate based mineral trioxide aggregate (MTA) also had favourable biocompatibility, however, its antibacterial activity was significantly decreased when compared to the novel cement. All hydraulic cements that are available in the dental market are predominantly tricalcium silicate-based materials. There has been no evidence in the literature to date wherein it has been explored whether a dicalcium silicate-based hydraulic cement can solely be used in root-end cavities. The findings of the study revealed a dicalcium silicate based retrograde filling material with favourable biocompatibility exhibited immediately as well as in the set samples. Incorporation of silver nanoparticles boosted the antibacterial activity when compared to that of ProRoot MTA. This material could potentially reinstate the usual hype created with tricalcium silicate types of cement since dicalcium silicate cements also exhibit similar properties.

Broth Characteristics of Broiler Chicken, Free-Range Chicken, and IPB D1 Chicken

Broth is a product made from beef or poultry by cooking ingredients rich in protein and water, with or without the addition of spices, vegetable fat and sodium chloride. This study aims to determine the physicochemical properties including crude protein, ash, fat, carbohydrates, water activity, and pH as well as organoleptic tests of three types of broth from different chicken meat, namely broiler, free-range chicken, and IPB-D1 chicken. An organoleptic test was performed using quantitative descriptive analysis (QDA). The results showed that the different types of chicken strains did not significantly affect the value of water content, ash content, protein content, pH value and viscosity. The descriptive quantitative analysis (QDA) test followed by the ANOVA test showed that the difference in the types of chicken strains has no significant effect on the sensory attributes of chicken taste, salty taste, tastelessness, bitter aftertaste, and carnation aftertaste. Chicken broth made from native chicken gave the best characteristicresults for the analysis of physicochemical and organoleptic properties.

Geochemical techniques to identify fluid sources in highly pressured casing-casing annuli (CCA)

The buildup of high pressure in the casing-casing annulus (CCA) threatens well integrity and can cause serious incidents in case of left untreated. Either, trapped water in the cement column or a dynamic water inflow represent potential fluid sources for the elevated CCA pressure. This study presents a sequential methodology to determine the provenance of CCA effluent as trigger for high pressure in newly drilled wells. Single fluid types, multicomponent mixing, and secondary fluid alteration processes were identified through inorganic geochemical techniques; in detail by monitoring the hydrochemical (major, minor, and trace elements) and stable isotopic (δ2H, δ18O) relationship between fluid candidates. As a proof-of-concept, geochemical signatures of CCA effluent from three wells were linked with potential source candidates, i.e., utilized drilling fluids (mud filtrate, supply water) from the prospect well site, groundwater from Lower - Upper Cretaceous aquifers, and Upper Jurassic - Upper Triassic formation waters from adjacent wells and fields. The detection of geochemical affinities of CCA water with groundwater from a Lower Cretaceous aquifer postulates one single lithological unit as source for active groundwater inflow. Nonreactive elements (Na+, Cl−) and environmental isotopes (δ2H, δ18O) were found to be most suited tools for primary fluid identification. The 2H/1H and 18O/16O ratios of supply water and mud filtrate are generally close to global meteoric water and Tertiary groundwater composition, while formation water from Mesozoic units (Cretaceous, Jurassic, and Triassic) can individually be distinguished through increasing ratios in δ18O and δ2H. Compositional anomalies in SO42− and K+, and extreme alkaline conditions for CCA water indicate the occurrence of secondary fluid alteration processes, likely caused by the contact of inflowing groundwater with alkaline minerals in the cement column or by fluid mixing with residuals of potassium chloride (KCl) additives from the drilling process. The geochemical techniques from this study facilitate the detection of high CCA pressure and fluid leakages sources. As a practical benefit, workover engineers are enabled to plan for potential remedial actions prior to moving the rig to affected well sites; thereby significantly reducing operational costs. Appropriate remedial solutions can be induced for safe well abandonment, plus to resume operation at the earliest time.

Evaluation of sugar beet pectin viscosity, surface activity, conductivity and zeta potential in sodium chloride aqueous solutions

Application of hydrocolloids is highly dependent on their structural and conformational properties. Molecular weight, macromolecular geometry, hydrophobicity and electric charge are, therefore, often researched. In the presented study, influence of sodium chloride on conformation and structure of sugar beet pectin in aqueous solutions was first time thoroughly characterized. Viscosity, surface tension, specific conductivity, zeta potential and pH of sugar beet pectin aqueous solutions were monitored and measured following the addition of sodium chloride. Relative viscosity of sugar beet pectin aqueous solutions decreased by up to 29.19% following the addition of sodium chloride. The highest decrease in relative viscosity values was noticed at the lowest sodium chloride concentrations used (0.2 g L−1 to 2 g L−1). The corresponding changes at the lowest sodium chloride concentrations used were also noticed in the obtained specific conductivity curves. Calculated diameter of sugar beet pectin macromolecule decreased by 19.98% following the addition of 10 g L−1 sodium chloride. Surface tension values of sugar beet pectin aqueous solutions were strongly influenced by the addition of sodium chloride. Decrease in zeta potential of sugar beet pectin aqueous solutions with addition of sodium chloride was observed. Presented results suggested that the addition of sodium chloride to sugar beet pectin aqueous solution could cause conformational changes of macromolecular chain suggesting possible transition from linear to globular conformation.

Study on the changing pattern of the salt-freeze swelling force of sulfate saline soil containing sodium chloride under variable temperature environment

The salt-freeze swelling forces generated by sulfate saline soils when experiencing changes in ambient temperature can cause a large degree of damage to building foundations, endangering the safety of people's lives and property. We performed an experimental study on the change of salt-freeze swelling force under different conditions of salt content, cooling rate, and chlorine-sulfur ratio by using the self-developed salt-freeze swelling force test device in combination with the methods of indoor tests and mathematical statistics. The findings revealed that: The growth rate of the salt-freeze swelling force was positively correlated with the salt content. The salt-freeze swelling force of soils increased first and then decreased as the temperature decreased, and the maximum reduction reached 71.7%, which could be divided into three stages: rapid growth, slow growth, and fallback. The rate of temperature reduction had a significant impact on the deviation of the salt-freezing swelling force, and the two were positively correlated. The addition of sodium chloride could effectively inhibit the occurrence of salt-freeze swelling. Considering the economy and applicability, 0.3 is recommended to be considered as the chlorine-to-sulfur ratio in soils with CSR≥0.3; in soils with CSR<0.3, 0.3 and 0.1 are recommended to be considered for soils with high salt content (S>2%) and low salt content (S ≤ 2%), respectively. The final salt-freeze swelling force of sulfate-saline soils and sulfate-saline soils containing sodium chloride was predicted using a specific model, and its accuracy was confirmed by comparing it with previous studies.

Band Engineering of Photocatalytic BiVO4 with Modified Vanadium States via Potassium Chloride Addition during Hydro-Thermal Synthesis and Post-Annealing

The monoclinic BiVO4 in a powder state was prepared via a hydrothermal method, with the addition of KCl as a structure-directing agent. The as-prepared sample was calcined at different temperatures (400–600 °C), either in the air or in Ar gas. It is found that, though the morphology and crystal structure mostly remain unchanged, the bandgap properties are modified during calcination. A detailed analysis of the surface chemical states and optical absorption properties reveals the involvement of tetravalent vanadium ions and oxygen vacancies as the cause of the band modification. The bandgap properties are to be found tunable via changing the calcination condition, as well as the KCl concentration in the precursor. The photocatalytic properties of BiVO4 samples are greatly enhanced with the addition of KCl in the precursor, but degraded by post-annealing, where the residual Cl in the calcined sample may act as an inhibitor. The enhanced photoactivity is explained in terms of favorable faceting, bandgap modification, and heterojunction of BiVO4/BiOCl.