Hydrochloric Research Articles

Use of nanocelluloses from orange peel and ZnO as hybrid nanofiller in developing functionalized starch nanocomposite for edible coatings

AbstractThis study explores the formulations of orange peel nanocelluloses (NC) with tailored dimensions for the development of functionalized nanocomposites coatings on green chilies. In the present century, the valorization of agro‐waste, specifically orange peel for developing NC facilitated sustainable packaging such as edible films and coatings with improved properties has received importance. As, this approach aligns with the sustainable development goals, including reduced food waste and agro waste. For the work, the derived orange peel celluloses were acid hydrolyzed using sulfuric acid (H2SO4) and hydrochloric acid (HCl) to deliver cellulose nanofibers (CNF) and cellulose nanoparticles (CNP), respectively. The fabricated CNP and CNF were characterized using Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), and thermogravimetric analysis (TGA). The FESEM morphology showed the formation of CNP with diameter ranges from 42.4 to 108 nm and formation of CNF with diameter ranged from 27.4 to 50.5 nm. The creation of the functionalized nanocomposite was done by reinforcing with hybrid nanofillers consisting CNF, CNP consecutively with ZnO in corn starch for tailormade packaging properties in terms of mechanical, physicochemical, optical, thermal properties, and so on. The results reveal improved tensile strength, and reduced water vapor transmission rates of nanocomposite with the addition of hybrid nanofillers. Additionally, green chilies were coated with the functionalized nanocomposites prepared by different concentrations of nanofillers. The storage analysis was performed in terms of weight loss, total chlorophyll content, and microbiological analysis. The developed coatings were found to be effective in extending the shelf life of green chilies. The control samples showed significantly higher weight loss compared to coated ones. The coated samples showed significantly better firmness and total chlorophyll content after 20 days of storage. In comparison to other coatings, NC and ZnO incorporated starch‐based coating was found to be the most effective in maintaining the quality of fresh green chilies throughout the storage. Thus, incorporating NC and ZnO in starch‐based films and coatings presents a promising avenue for sustainable packaging and preservation.Highlights Agro‐waste orange peel was valorized to develop sustainable food packaging. Orange peel‐based nanocellulose was developed using H2SO4 and HCl. Nanocomposite film was developed using hybrid nanofillers. Nanocomposites provide tailored properties due to the nanofillers. Developed nanocomposite was used as edible coatings on green chilies.

Mechanically strong, transparent polyimide composite thin films with a low dielectric constant

Aromatic polyimide is widely used in microelectronics as dielectric packaging layers. There is a high demand to reduce its dielectric constant to meet the fast development of communication technology. Here we report a simple and eco-friendly approach to preparing polyimide films with a lowered dielectric constant by adding silica hollow nanospheres with an average size of 100 nm in an aqueous solution of poly(amic acid) salt, and subsequent film casting and thermal imidization. The silica hollow nanospheres present a uniform distribution in polyimide matrix after surface modification with 3-aminopropyltriethoxysilane. The dielectric constant of the resulting composite films decreases linearly with particle loading till 15 wt% and reaches the lowest value of 2.5. The surface hardness and elastic modulus of the films improve by adding hollow nanospheres, while maintaining high optical transparency, high flexibility and a low coefficient of thermal expansion.

Effect Of The Composition Of The Etching System MF-HCl (M = Li+, Na+, NH4+) on the gas-sensitive properties of Ti3C2Tх/Tioх nanocomposites

The influence of the nature of MF-HCl etching systems (M = Li+, Na+, NH4+) on the process of synthesis of Ti3C2Tx MXenes on the basis of Ti3AlC2 MAX-phase, microstructure, phase purity, interlayer distance, composition of functional surface groups, thermal behavior and yield of the obtained products has been studied. The room temperature sensing properties of Ti3C2Tx receptor layers deposited by microplotter printing were studied with respect to a wide range of gas analytes (H2, CO, NH3, NO2, NO2, O2, benzene, acetone, methane and ethanol). Increased sensitivity to ammonia was revealed for the MXenes obtained by exposure to hydrochloric acid solutions of sodium and ammonium fluorides and to carbon monoxide for the sample synthesized using the LiF-HCl system. High responses (~20–30% to 100 ppm NO2) were observed for all three receptor materials, but sensor recovery processes were significantly hampered. To improve the sensing characteristics, Ti3C2Tx sensing layers were subjected to relatively low-temperature heat treatment in an air atmosphere to form Ti3C2Tx/TiOx nanocomposites. It was found that a high and selective oxygen response at very low operating temperatures (125-175°C) was observed for the MXenes partially oxidized, which is particularly characteristic of the material produced using the HCl-NaF system.

Moderate strategy for efficient recovery of rare earth elements from scintillation crystal waste

The lutetium has been known to be used in medical imaging materials, but its scarcity in the Earth’s crust makes it expensive. In this work, we present a process for efficient lutetium recovery from the lutetium-yttrium oxyorthosilicate crystals (LYSO) waste. The process involves preliminary mechanical activation, followed by rare earth extraction via acid leaching. The key factors for activation and leaching were studied and optimized. The mechanism of mechanical activation promoting rare earth leaching was revealed by employing the characterizations of morphology and crystal structure of LYSO. It was found that the mechanical activation process could destroy the crystal structure of LYSO waste, forming numerous amorphous phases and grain boundaries, which facilitated the breaking of existing bonds and mass transfer of acid. It was also discovered that the formation of silica gel during leaching impedes the leaching of rare earth, and low concentrations of hydrochloric acid, combined with stirring during acid leaching, could reduce the impact of silica gel. Ultimately, following a mechanical activation pretreatment at 300 rpm for 90 min, 98.7 % of lutetium could be leached after 60 min of acid leaching in 3 mol/L hydrochloric acid. This process addresses the problems associated with high energy consumption and excessive usage of acidic and alkaline reagents in conventional recycling techniques. Compared to conventional methods, the mechanical activation-acid leaching method has a minimum economic benefit improvement of 20.8 % in the process of recovery from LYSO waste. It offers an alternative and more energy-efficient and economical recycling route for waste scintillation crystals.

Physico-chemical and microbiological parameters of natural, industrial recycled water and its treatment

Background: Under conditions of anthropogenic impact, the chemical composition of water in surface rivers and groundwater bodies is subjected to pollution, which leads not only to a decrease in water quality, but also to an increase in the number of pathogenic and opportunistic bacteria. Aim: The purpose of this work is to study the physicochemical and microbiological parameters of natural and industrial recycled water before and after treatment with coagulants based on activated aluminum alloys. Materials and methods: As natural waters were analyzed: natural waters from water intake “Almaty SU”, “Medeu” tract, Zhaiyk river, from the well of experimental metallurgical production of IMOB. As recycled water was analyzed water taken from the water treatment unit of deep oil refining production. Turbidity was measured using HACH 2100Q turbidimeter and 2100Qis turbidimeter (USA). Cell morphology of microorganism cultures was studied by light microscopy using a MicroOptix MX-1150 (T) stereoscopic-sotrinocular microscope. Results: An effective and technologically simple method of obtaining aluminum polyoxychloride with the content of the main substance from 33 to 41.0% by Al2O3 and basicity from 55.1 to 66.5% has been developed. The method consists in dissolution of aluminum alloy activated by metal-activators (indium, gallium, tin) in the amount of 0.5–1.0 wt.% of each in 3% HCl. Physico-chemical and microbiological parameters of natural and industrial recycled water have been studied. The efficiency of the obtained aluminum polyoxychloride for treatment and conditioning of drinking water and industrial recycled water was evaluated. Conclusion: Unique alloys with high energy characteristics based on aluminum containing indium, gallium, tin from 0.5–1.0 wt.% have been created. The alloy has high activity in various oxidizing media (water, hydrochloric acid). A technologically simple method of obtaining aluminum polyoxychloride has been developed. Chemical and microbiological composition of natural and industrial recycled water has been studied. Coagulants based on activated aluminum alloys are effective in the processes of conditioning and purification of natural and recycled water from toxic compounds, have bactericidal activity, the level of gram-negative bacteria is reduced to 73%, gram-positive bacteria to 84% and to 96% of other groups of microorganisms. Fungi and yeasts (Mucor, Fusarium) were not detected after water treatment. Efficiency of water turbidity reduction reaches 90–99%, permanganate oxidizability up to 93%.

Oral responsive delivery systems for probiotics targeting the intestinal tract.

The increasing prevalence of health issues, driven by sedentary lifestyles and unhealthy diets in modern society, has led to a growing demand for natural dietary supplements to support overall health and well-being. Probiotic dietary supplements have garnered widespread recognition for their potential health benefits. However, their efficacy is often hindered by the hostile conditions of the gastrointestinal tract. To surmount this challenge, biomaterial-based microencapsulation techniques have been extensively employed to shield probiotics from the harsh environments of stomach acid and bile salts, facilitating their precise delivery to the colon for optimal nutritional effects. With consideration of the distinctive gastrointestinal tract milieu, probiotic delivery systems have been categorized into pH-responsive release, enzyme-responsive release, redox-responsive release and pressure-triggered release systems. These responsive delivery systems have not only demonstrated improved probiotic survival rates in the stomach, but also successful release in the intestines, facilitating enhanced adhesion and colonization of probiotics within the gut. Consequently, these responsive delivery systems contribute to the effectiveness of probiotic supplementation in intervening with gastrointestinal diseases. This review provides a comprehensive overview of the diverse oral responsive delivery systems tailored for probiotics targeting the intestinal tract. Furthermore, the review critically examines the limitations and future prospects of these approaches. This review offers valuable guidance for the effective delivery of probiotics to the intestinal tract, enhancing the potential of probiotics as dietary supplements to promote gastrointestinal health and well-being. © 2024 Society of Chemical Industry.

Boosting Thermogalvanic Cell Performance through Synergistic Redox and Thermogalvanic Corrosion.

Thermogalvanic cells with organic redox couple (OTGCs) have received significant attention for low-grade heat harvesting due to their high thermopower, versatile molecular design, and tailorable physiochemical properties. However, their thermogalvanic conversion power output is largely hindered by slow kinetic rate, which limits practical applications. In this work, we demonstrate a high-performance liquid quinone/hydroquinone (Q/HQ) based OTGC by synergistic coupling redox reaction and thermogalvanic corrosion. By adding hydrochloric acid (HCl) into electrolyte solution, HCl not only boosts intrinsic redox kinetic rate of Q/HQ, but also induces rapid thermogalvanic corrosion of the copper electrode. Notably, these two processes reinforce each other kinetically. Consequently, the Q/HQ-based OTGC exhibits a rapid kinetic rate alongside an increased thermopower, leading to a significantly enhanced power output density. As a result, the Q/HQ-based OTGC achieves an enhanced effective electrical conductivity σeff of 4.22 S m-1 and a record high normalized power density Pmax (ΔT)-2 of 108.7 μW m-2 K-2. This strategy provides a feasible and effective method for development of high-performance OTGCs.

Enantioselective Synthesis of Chiral 1,5-Benzodiazepin-2-ones by Pd-Catalyzed Asymmetric Hydrogenation and Reductive Amination.

The enantioselective synthesis of chiral 4-substituted 4,5-dihydro-1H-[1,5]benzodiazepin-2(3H)-ones via asymmetric hydrogenation catalyzed by the Pd/f-spiroPhos complex in the presence of hydrochloric acid as an additive has been developed, achieving excellent enantioselectivities and high turnover numbers, up to 99% ee and TON = 4600. More significantly, the asymmetric reductive amination of β-keto esters with 1,2-phenylenediamine has also been successfully realized to afford chiral 4-substituted 4,5-dihydro-1H-[1,5]benzodiazepin-2(3H)-ones with comparable enantioselectivities of up to 99% ee.

Thermodynamic Justification for the Effectiveness of the Oxidation—Soda Conversion of Ilmenite Concentrates

This article presents the results of a thermodynamic analysis of the oxidation soda conversion reactions of minerals in ilmenite concentrates in the temperature range of 373–2273 K. The thermodynamic parameters of pseudorutile, pseudobrukite, and the new minerals, zhikinite and spessartine, were calculated for the first time. It has been established that the most important criterion relating to the stability of titanium minerals and related elements, as well as the reaction properties of the structural oxides of metals and silicon, is their degree of oxidation. Oxides of silicon (IV) and manganese have the best reactivity in solid-phase oxidizing alkaline environments (VI). Modeling this process scientifically substantiates the mechanism involved in the destruction of minerals in ilmenite concentrates in the low-temperature region in the presence of atmospheric oxygen and sodium oxide of soda ash, which are decomposed through the absorption of heat and the evaporation of moisture during the dehydration of hydrated minerals of iron and manganese and the dehydration of the soda–ilmenite batch. Tests conducted during pilot metallurgical production at the Institute of Metallurgy and Enrichment (PMP of JSC) confirmed the feasibility of processing high-chromium and siliceous rutile leucoxene ilmenite concentrates, which are unsuitable for traditional pyro- and hydro-metallurgical enrichment methods, through single-stage oxidation soda roasting, followed by the leaching of easily soluble sodium salts of iron and associated impurities with water and a dilute hydrochloric acid solution. The proposed energy-saving method ensures the production of high-purity (>98%) synthetic rutile while eliminating the formation of strong deposits on the lining of roasting units.

Rapid carbonate precipitation induced by carbamate coating: A new approach to form impermeable thin barrier and its mechanism

Various coating strategies have been explored in the past to prevent the ingress of aggressive substances into concrete. However, either the durability or performance is still far from satisfaction. Here, carbamate solutions were prepared by pre-absorbing CO2 into amino acid salts (AASs) to carbonize the surface of cementitious materials. The high concentration of carbonate ions provided by the carbamate induced rapid surface carbonation, resulting in the formation of an AAS-CaCO3 composite barrier with a thickness of 2–3 μm and possessing high micromechanical properties. Additionally, it was observed that the barrier's effectiveness depends on the molecular structures of the amino acids employed. Coatings formed by arginine-based carbamates demonstrated excellent performances, likely due to the highly compacted calcite particles they produced. This easy-to-operate and effective strategy has the potential to open new avenues for the development of highly durable and impermeable coating barriers for practical applications.

Separation of hafnium from zircon leach solution using anion-exchange resin and production of high-purity zirconia for nuclear applications

The ion exchange process using an anion exchange resin (Bio-Rex 5) was employed with batch and column techniques to isolate nuclear-grade zirconium/hafnium from a leach solution of zircon ore. Batch studies were conducted to optimize the conditions for sorption and desorption of Zr(IV) and Hf(IV). The highest separation factor of 10.3 was achieved under equilibrium conditions of 11.0 mol/L HCl, contact time of 30.0 min, solution volume-to-mass of resin ratio of 0.10, and 15 °C. The sorption process for both metals obeyed a pseudo-second-order model and the experimental sorption data was well-described by both Langmuir and Freundlich models. The maximum sorption capacities were determined to be 46.2 mg/g for Zr(IV) and 37.8 mg/g for Hf(IV). The Zr(IV) and Hf(IV) ions were effectively desorbed by 0.1 mol/L nitric and 2.0 mol/L hydrochloric acid solutions, respectively, with total yields of 89.7 % Zr(IV) and 85.8 % Hf(IV) via multistage desorption processes. In both batch and column techniques, the resin exhibited sorption selectivity for Zr and Hf over interfering elements in the hydrochloric acid leach solution of zircon sand. The loaded resin from real leach solution was subjected to desorption, zirconium sulfate precipitation, and calcination at 650 °C, resulting in a pure zirconia powder suitable for nuclear applications. This technique presents a promising effective method for the selective separation and recovery of high-purity zirconium and hafnium from their natural sources.

Fast and Efficient Sensing of Drugs in Water Using Self-Assembling D-Glucamine-Functionalized Naphthalenediimide and 1,8-Naphthalimide Fluorophores.

Fast and sensitive quantification of drugs as emerging pollutants in water bodies is a pressing need in contemporary society, to prevent serious environmental concerns that could negatively impact on human health. This explains the surge of interest in this field, and the need to identify highly selective sensing systems. Addressing this issue, in this work we synthesized two D-glucamine functionalized fluorophores bearing self-assembling cores, as 1,8-naphthalimide and naphthalene diimide. We studied their self-assembly in water solution, and characterized the aggregated formed by determining their stability constant, their morphology and size by scanning electron microscopy, resonance light scattering and dynamic light scattering, as well their solid-state emission ability. Then, we studied their sensing ability, in water, towards pharmaceutically active compounds such as ciprofloxacin, nalidixic acid, carbamazepine and diclofenac sodium salt, by fluorescence investigation. Data collected show that the self-assembling ability is significantly affected by the fluorophore structure, which in turn also determines sensing ability. In particular, the naphtalene diimide-based probe was the most sensitive, with LOD as low as 0.01 μM in the presence of nalidixic acid, which is in line and competitive with more complex sensing systems, recently reported in the literature.

Chemical durability of optical temperature sensors made of tellurite glass: Effect of the alumina concentration

Tellurite glass is an amorphous material commonly doped with rare earth ions for the development of optical temperature sensors. Considering the intrinsic properties of glasses, it is expected that these sensors could be used in acidic environments and withstand temperature changes. However, this has not been fully demonstrated since most of the literature is limited to demonstrate the sensor operation under normal conditions. Additionally, there is a lack of information regarding the chemical durability of these glasses and methods to improve it. In this work, a special tellurite glass composition was proposed for the development of optical temperature sensor. The effect of the alumina concentration on the structure, chemical durability and emission properties of the glasses was evaluated. Chemical durability was assessed by monitoring the weight loss of glass samples after immersion in hydrochloric acid solutions at room temperature, vegetable oil or air at 150 °C. The results indicate that the addition of alumina increases the chemical durability of the glass and improves its emission properties. It was found that the average temperature estimated by the optical sensor had a relative error of 1.3 % due to the degradation of the glass caused by remaining immersed in a 1 N HCl solution for 60 days.

Production of Biopolymer & Preparation of Soap Using Chitin and Chitosan from Brachyura Shell

Collagen, an extracellular protein, was extracted from eggshells using a combination of 5% EDTA, 0.45 M NaCl, 0.2% NaOH, 0.2% H₂SO₄, 0.7% citric acid, and 10% HCl, while chitosan, a naturally occurring polysaccharide, was extracted from crab shells (Brachyura) through demineralization with 1N Hydrochloric acid, deproteinization using 6% sodium hydroxide solution, and deacetylation with 40% NaOH, followed by decolorization using potassium permanganate and oxalic acid. The proximate analysis of chitosan revealed an ash content of 32% and a moisture content of 4.13%, while the protein content of the extracted collagen was found to be 70 µg/dL, with an alternative method indicating 75 µg, equivalent to BSA. The molecular weights of collagen and chitosan were determined to be 300 kilodaltons and 190-310 kilodaltons, respectively, and their purity was confirmed using FTIR analysis. Hydrogels were prepared using a combination of collagen and chitosan and were tested for water absorption capacity and antimicrobial activity, demonstrating that both biomaterials possess significant antimicrobial and antioxidant properties. Additionally, chitosan’s biocompatibility supports its use in creating edible films that can interact with other biopolymers and additives, indicating its potential for various industrial and biomedical applications.

Precision Delivery of Binary Cooperative Nanodrugs Self-Assembled by Berberine Glycyrrhetinic Acid Salts for Hepatocellular Carcinoma Treatment.

Berberine (BB) has demonstrated significant inhibitory effects on tumorigenesis and progression. However, its clinical application is hindered by challenges such as low bioavailability due to limited cell membrane permeability, nontargeted accumulation away from solid tumors, and increased toxicity associated with intravenous administration. To overcome these challenges, a lipophilic salt-forming strategy was employed to enhance lipophilicity, thereby promoting membrane permeability and targetability for tumor accumulation while simultaneously mitigating the toxicity associated with intravenous injection. In vitro findings revealed an almost 10-fold increase in fluorescence intensity with BB-GA NDs compared to BB alone. Furthermore, selective cytotoxicity against tumor cells exhibited a 4-fold elevation compared to normal cells. In vivo results underscored the remarkable tumor-selective accumulation of BB-GA NDs, effectively mitigating the intravenous injection toxicity associated with pure BB. The self-assembly of binary cooperative nanodrugs utilizing berberine glycyrrhetinic acid salts opens up innovative possibilities for drug delivery systems in traditional Chinese medicine.

Anti-Corrosion and Wave-Absorbing Properties of Epoxy-Based Coatings on Q235 Steel

Carbon nanotube/epoxy resin (CNE) coatings and carbon nanotube/carboxy iron powder/epoxy resin (CIE) coatings were applied on the surface of Q235 steel, and their corrosion, absorption properties and other characteristics were measured in this work. The results indicate that the average thickness of a single application was approximately 400 μm, and the surface of the CNE coating was still smooth and intact after a 3000 h copper ion accelerated salt spray test without bubbles, falling off or other corrosion phenomena. The same was true for 28 days of full immersion in solutions of 10% hydrochloric acid (HCl) and 10% sodium hydroxide (NaOH) of the coating. The electrochemical testing exhibited the corrosion current of the CNE coating as being markedly lower than that of Q235 steel, with a protection efficiency of 81.68% for the Q235 steel. The CNE-0.6 coating had the maximum corrosion voltage (−0.390 V), and the CNE-0.3 coating had the minimum corrosion current of 2.07 × 10−6 A·cm2. The adhesion between the coating and Q235 could reach level 0, and the tensile strength of the coating was up to 18.75 MPa. The coating was observed to remain intact and free from detachment upon undergoing a drop test from a height of 50 cm. In addition, the CIE-0.6 coating exhibited an effective absorption band of 9.1 GHz, covering the range from 8.2 to 13.7 GHz, and it achieved a maximum reflection loss of −15.1 dB at a frequency of 8.6 GHz.

Synthesis, characterization and performance of ecofriendly epoxy resin as a highly efficient corrosion inhibition for mild steel in 1m HCl solution

In this study, a novel epoxy resin called tetraglycidyl ether of methyl-α-D-mannopyranoside (TGEMM) was synthesized and investigated for its potential used as a corrosion inhibitor for mild steel in a 1.0 M hydrochloric acid (HCl) solution. The main goal was to evaluate the corrosion inhibition properties of TGEMM using various techniques. The methods used in this research included potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), temperature effect, scanning electron microscopy, energy dispersive X-ray spectroscopy, atomic force microscopy and contact angle measurement. These techniques were chosen to comprehensively assess the corrosion inhibition performance of TGEMM on MS. In this context, the structure of the newly synthesized TGEMM epoxy resin was identified and confirmed using Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). The results obtained from the experiments demonstrated that, at a lower concentration of 10−3 M, TGEMM demonstrated a high inhibitory efficacy of 91.49%, assessed via electrochemical impedance spectroscopy (EIS), and 93.84%, measured via potentiodynamic polarization (PDP), in a 1.0 M hydrochloric acid solution. The PDP data indicated that the TGEMM epoxy resin acted as an anodic inhibitor in the acidic environment. In addition to gain insights into the interaction mechanism and adsorption mode, DFT and MD simulations were conducted, revealing valuable information about the interaction of TGEMM with the mild steel surface.

Dipolar-hollowed α-Fe2O3@Au/Polydopamine nanospindle for photothermal-photodynamic coupling antibacterial and drug-delivery

With the prevalence of drug-resistant bacteria and the waning effects of antibiotics, nanoplatform has become an effective strategy for fighting infections. This work reports a dipolar-hollowed α-Fe2O3@Au/Polydopamine (PDA) nanospindle which possesses both photothermal-photodynamic (PTT-PDT) coupling antibacterial and drug carrying performance. Firstly, the spindle type α-Fe2O3@Au/PDA particle was prepared by a simple one-step strategy and then the dipolar-hollow structure was obtained by controlling etching the inside α-Fe2O3 core with hydrochloric acid. After further loading the photosensitizer zinc phthalocyanine (ZnPc), the dipolar-hollowed α-Fe2O3@Au/PDA-ZnPc nanospindles were obtained. Owing to the dipolar-hollowed interior, the nanospindles are also effective in carrying antitumor drug doxorubicin (DOX) and shows a good drug loading-release behavior. The dipolar-hollowed α-Fe2O3@Au/PDA nanospindles exhibits a high antibacterial performance against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) under near-infrared (NIR) and Xenon lamp irradiation. When α-Fe2O3@Au/PDA-ZnPc nanospindles concentration was increased to 100 μg/mL, the antibacterial rate was close to 100 %. In comparison to the original α-Fe2O3@Au/PDA nanospindles, the product achieved a lower effective antibacterial temperature. This triple-mode therapy (PTT/PDT/Drug) provides an interesting design idea for anisotropic therapeutic nanoplatform which can be applied in low-temperature antibacterial and drug delivery.

Investigating the Inhibitory Effect of Sargassum natans and Sargassum fluitans Extracts on Iron Corrosion in 1.00 mol L−1 HCl Solution

This study deals with the efficacy of extracts of Sargassum natans and Sargassum fluitans, an invasive brown algae present in Guadeloupe, as novel and environmentally friendly corrosion inhibitors for iron in 1 mol L−1 hydrochloric acid solutions. Six different Sargassum extracts (SE) were obtained using Soxhlet extraction with ethyl acetate, acetone, and ethanol, respectively, as solvents; cold successive maceration with chloroform and methanol, respectively; and microwave-assisted extraction with water. Subsequent electrochemical analysis showed that extracts from ethanol and ethyl acetate exhibited remarkable inhibition efficiencies of, respectively, 72.6% and 70.2%, but the better one was the extract of the cold maceration from chloroform with an inhibition efficiency of 92.0%. These findings allow us to focus on the chloroform extract (SEd) in order to see the change happening during the corrosion process via SEM and EDX analyses. Also, NMR analysis was conducted to identify the main chemicals responsible for the anticorrosion effect. The successful demonstration of the corrosion inhibitor effectiveness of extracts of Sargassum natans and fluitans suggests a potentially valuable use for this invasive biomass. These encouraging results warrant further investigation to identify and elucidate the active inhibitors in these extracts to deepen our understanding of their mechanisms for corrosion prevention and potentially expand their utility as an environmentally conscious approach to corrosion control.

CsPbBr3 perovskite nanocrystals-based portable testing device for on-site detection of chloride ions from wastewater

The detrimental effects of chloride (Cl−) ions on industrial wastewater necessitate the in-situ monitoring of Cl−, which is challenging due to the limited availability of field-applicable analytical methodologies. Herein, a novel and compact apparatus (CPB-FC-Cl) was developed for the precise quantification of Cl− in wastewater. This innovative system utilizes the rapid halide exchange of cesium lead bromide (CsPbBr3) perovskite nanocrystals (NCs) with Cl−, a process marked by a pronounced wavelength blueshift and a vivid fluorescence transition from green to blue. The software in the CPB-FC-Cl system automatically identified the fluorescence emission peaks and displayed the Cl− concentration values on the user interface. The detection experiments conducted on actual hydrochloric acid wastewater confirmed the device’s ability to accurately measure Cl− concentrations within 5 min, achieving an accuracy of 98.98 %. The CPB-FC-Cl system exhibited high selectivity in the presence of various coexisting substances in hydrochloric acid wastewater, and its resistance to potential interferences supports its suitability for precise Cl− quantification. The stability of the CPB-FC-Cl system showed an average detection accuracy of 98.96 % over multiple cycles, which underscores its robustness for long-term monitoring applications.