Silver Nitrate Research Articles

Fluoride-Ion-Responsive Sol–Gel Transition in anL-Cysteine/AgNO3 System: Self-Assembly Peculiarities and Anticancer Activity

Supramolecular hydrogels based on low-molecular-weight compounds are a unique class of so-called “soft” materials, formed by weak non-covalent interactions between precursors at their millimolar concentrations. Due to the variety of structures that can be formed using different low-molecular-weight gelators, they are widely used in various fields of technology and medicine. In this study, we report for the first time an unusual self-assembly process of mixing a hydrosol obtained from L-cysteine and silver nitrate (cysteine–silver sol—CSS) with sodium halides. Modern instrumental techniques such as viscosimetry, UV spectroscopy, dynamic light scattering, zeta potential measurements, SEM and EDS identified that adding fluoride anions to CSS is able to form stable hydrogels of a thixotropic nature, while Cl−, Br− and I− lead to precipitation. The self-assembly process proceeds using a narrow concentration range of F−. An increase in the fluoride anion content in the system leads to a change in the gel network morphology from elongated structures to spherical ones. This fact is reflected in a decrease in the gel viscosity and a number of gel–sol–gel transition cycles. The mechanism of F−’s interaction with hydrosol includes the condensation of anions on the positive surface of the CSS nanoparticles, their binding via electrostatic forces and the formation of a resulting gel carcass. In vitro analysis showed that the hydrogels suppressed human squamous carcinoma cells at a micromolar sample concentration. The obtained soft gels could have potential applications against cutaneous malignancy and as carriers for fluoride anion and other bioactive substance delivery.

Antimicrobial Properties of Newly Developed Silver-Enriched Red Onion–Polymer Composites

Antimicrobial Properties of Newly Developed Silver-Enriched Red Onion–Polymer Composites

Assembly and Disassembly of Supramolecular Hypervalent Iodine Macrocycles via Anion Coordination.

This study explores the dynamic self-assembly and disassembly of hypervalent iodine-based macrocycles (HIMs) guided by secondary bonding interactions. The reversible disassembly and reassembly of HIMs are facilitated through anion binding via the addition of tetrabutylammonium (TBA) salts or removal of the anion by the addition of silver nitrate. The association constants for HIM monomers with TBA(Cl) and TBA(Br) are calculated and show a correlation with the strength of the iodine-anion bond. A unique tetracoordinate hypervalent iodine-based compound was identified as the disassembled monomer. Last, the study reveals the dynamic bonding nature of these macrocycles in solution, allowing for rearrangement and participation in dynamic bonding chemistry.

The effects of silver nitrate as antimicrobial agent in rubber latex films to reduce hospital acquired infections

The effects of silver nitrate as antimicrobial agent in rubber latex films to reduce hospital acquired infections

Evaluation of toxicity of Vitex negundo L. synthesized silver nanoparticles against Aedes aegypti

Dengue, chikungunya, and zika are some of the fatal diseases that are causing a high number of deaths. Therefore, this work is designed to provide an effective control measure against these species of mosquito. Vitex negundo L. leaves were used to synthesize silver nanoparticles (AgNPs), which were proven to have significant larvicidal and pupicidal activity when tested against the developmental stages of Aedes aegypti. The nanoparticles were synthesized using silver nitrate, and the synthesized nanoparticles were characterized using techniques such as UV-visible spectrometry, Fourier Transform Infrared Spectrometry, and X-ray diffraction to confirm the presence of nanoparticles. The conditions for the larval hatchability from the first instar to adult stages were optimized at different pH ranges with three water sources: reverse osmosis water, tap water, and stagnant water. The LC50 of the subjected stages was found to be 441.43, 308.74, and 490.66 µl/L for the third and fourth instar and pupal stages of A. aegypti, respectively. The plant secondary metabolites were utilized as ligand compounds to target mosquito juvenile hormone-binding protein. Our study attempted to identify a plant-based nanomaterial that showed promising results in controlling larval development.

Silver Complexes of Miconazole and Metronidazole: Potential Candidates for Melanoma Treatment

Melanoma, arguably the deadliest form of skin cancer, is responsible for the majority of skin-cancer-related fatalities. Innovative strategies concentrate on new therapies that avoid the undesirable effects of pharmacological or medical treatment. This article discusses the chemical structures of [(MTZ)2AgNO3], [(MTZ)2Ag]2SO4, [Ag(MCZ)2NO3], [Ag(MCZ)2BF4], [Ag(MCZ)2SbF6] and [Ag(MCZ)2ClO4] (MTZ—metronidazole; MCZ—miconazole) silver(I) compounds and the possible relationship between the molecules and their cytostatic activity against melanoma cells. Molecular Hirshfeld surface analysis and computational methods were used to examine the possible association between the structure and anticancer activity of the silver(I) complexes and compare the cytotoxicity of the silver(I) complexes of metronidazole and miconazole with that of silver(I) nitrate, cisplatin, metronidazole and miconazole complexes against A375 and BJ cells. Additionally, these preliminary biological studies found the greatest IC50 values against the A375 line were demonstrated by [Ag(MCZ)2NO3] and [(MTZ)2AgNO3]. The compound [(MTZ)2AgNO3] was three-fold more toxic to the A375 cells than the reference (cisplatin) and 15 times more cytotoxic against the A375 cells than the normal BJ cells. Complexes of metronidazole with Ag(I) are considered biocompatible at a concentration below 50 µmol/L.

Electrochemical polymerization of PEDOT:PSS with graphene oxide and silver nanoparticles for antibacterial coating and SERS detection

This study involved the use of electrochemical polymerization to coat poly(3,4-ethylenedioxythiophene) (PEDOT), polystyrene sulfonate (PSS) and graphene oxide (GO) onto SUS316L stainless steel substrates, aiming to produce PEDOT:PSS and GO@PEDOT:PSS films. Following this, Ag@PEDOT:PSS and GO/Ag@PEDOT:PSS films were developed through the electrochemical deposition of silver nitrate. Electrochemical impedance spectroscopy (EIS) indicated that adding GO increased the impedance of film, while AgNPs deposition decreased it, thereby enhancing conductivity. Films with AgNPs showed surface enhanced Raman scattering (SERS) effects, as assessed using malachite green (MG). Compared to films without GO, the GO/Ag@PEDOT:PSS films exhibit enhanced conductivity and SERS detection performance due to the negatively charged functional groups on the GO surface forming a continuous layer of AgNPs. Moreover, antibacterial capabilities were evaluated through bacterial attachment and inhibition zone assays. Both Ag@PEDOT:PSS and GO/Ag@PEDOT:PSS films were effective in inhibiting bacterial adhesion, achieving up to 99.4 % and 99.0 % inhibition, respectively. In the inhibition zone assays, the GO/Ag@PEDOT:PSS film showed a 1.33 times increase in antibacterial efficacy compared to Ag@PEDOT:PSS. Furthermore, the effectiveness of electrodepositing antibiotics on these substrates was investigated, confirming optimal antibacterial performance. This efficacy is attributed to the synergistic interaction between silver nanoparticles and antibiotics, potentially reducing the need for antibiotics. The findings of this study highlight its significant potential for applications in antibacterial treatments and biomedical detection.

Maize leaves as a precursor for the synthesis of greened silver nanocomposite and nanoparticles

This study is aimed at the synthesis of nanoparticles (NPs) and nanocomposite (NC) using maize leave as precursor. Silver NPs (AgNPs) and AgNCs were synthesized from silver nitrate and maize leave extract using green approach. The maize leave NPs (AgNPs) and the maize leave NCs (AgNCs) were characterized using Fourier Transform infrared (FTIR), scanning electron microscopy (SEM), energy dispersion x-ray (EDX), Brunauer–Emmett–Teller (BET) surface area measurement, and dynamic light scattering (DLS) particle size analysis. The phytochemical analysis revealed the presence of tannin, oxalate, and flavonoids in appreciable quantity, which have proven to be a powerful reducing agent that facilitates the reduction of silver ions for the synthesis of silver NPs and silver nano composites. FTIR revealed that all the peaks identified in AgNPs and AgNCs belong to the characteristic bands of reducing compounds such as flavonoid compounds. The SEM-EDX results showed that the peaks observed from 2.9 to 3.1 Kev in the spectra indicate the presence of elemental silver as it is reduced from Ag+ to Ag. DLS analysis results showed that the average size and polydispersity index (PdI) of the synthesized AgNPs and AgNCs were 42.30 and 68.29 nm, 0.691 and 0.270, respectively. The single point BET surface area (m2/g) obtained for AgNPs and AgNCs were 223.3 and 209.5, respectively. The results showed maize leave as a potential precursor for the preparation of NPs and NCs.

Antibacterial and antiviral PA6-AgNPs microfibers for application as a filter element in facial respirators

Polymeric microfibers are very interesting materials that can be associated with other nanomaterials aiming to obtain specific properties and be used in a wide range of applications. In this study, we prepared different formulations of polyamide 6 (PA6) containing silver nanoparticles (AgNPs) and produced microfibers by solution blow spinning technique for its use as a filter element in a face respirator. The obtained samples were then characterized by field emission gun-scanning electron microscopy (FEG-SEM), energy dispersion spectroscopy (EDS), ultraviolet–visible diffuse reflectance spectroscopy (UV–Vis DRS), water contact angle (WCA), thermogravimetric analysis (TGA), and respirability and antibacterial, antiviral and cytotoxicity assays. In general, the microfibers were well dispersed and the AgNPs were evenly distributed throughout the samples, reflecting a hydrophilic character and good thermal stability, with a maximum weight loss of 2.9 % attributed to the evaporation of water molecules. The sample produced with a concentration of 10 mmol/L of silver nitrate presented acceptable levels of resistance to respiration. Concerning the microbiological analyses, the results showed that samples evidenced antibacterial effect against Escherichia coli and Staphylococcus aureus, forming inhibition halos of up to 4 mm in disk diffusion assays and inhibiting bacterial growth in liquid medium assays, as well as antiviral effect against betacoronavirus MHV-3, promoting a reduction of up to 99.9 % of viral particles. Moreover, the samples presented cytotoxicity on the first and second days, whereas on the seventh day some of the extracts did not show cytotoxic activity, indicating that the cells adapted to the culture medium. Considering the data set and the simple process of obtaining the microfibers, it was possible to conclude that this material can be applied as a filter element in a face respirator as well as in a variety of products with antibacterial and antiviral purposes.

Comparison between silver nitrate and table salt in the treatment of umbilical granuloma.

Objective: To compare the efficacy of table salt with silver nitrate in the treatment of umbilical granuloma presenting to the neonatal unit/paediatric department KTH. Study Design: Randomized Controlled Trial Setting: Neonatal Unit of Khyber Teaching Hospital. Period: November 2019 to November 2022. Methods: A total of 120 patients who presented to the neonatal unit/paediatric department, aged 15-60 days were enrolled in this study via consecutive sampling. Seventy-five patients each, were allocated to two groups, Group A (common salt) and Group B (silver nitrate). Sixteen patients from Group A whereas, in Group B, 17 patients were lost to follow-up. Results: A total of 58 out of the remaining 117 patients were female whereas 59 patients were male. Treatment response was recorded for both groups. The cure rate was greater among Group B (93%) as compared to Group A (88%) but there was no statistically significant difference between Group A and B in treatment response (p= 0.35). Conclusion: Table salt is a cheaper, easily accessible, and safe alternative to topical silver nitrate in the treatment of umbilical granuloma.

Bio-fabrication and Characterization of Green Synthesized Nanoparticles from Commercial Honey

Green approaches to nanoparticle synthesis offer sustainable and environmentally friendly alternatives, avoiding hazardous chemicals typical in traditional methods. This study characterizes nanoparticles (NPs) synthesized from silver nitrate (AgNO3) and iron oxide (Fe2O3) using commercial honey as a reducing and capping agent. Characterization revealed significant disparities between silver NPs (AgNPs) and iron NPs (FeNPs). AgNPs had a larger particle size (Z-average: 3115.67 nm) compared to FeNPs (Z-average: 1813 nm). AgNPs showed a monodisperse population, while FeNPs had a slightly broader size distribution. Additionally, AgNPs had a higher particle concentration (mean count rate: 505.17 kcps) than FeNPs (mean count rate: 296.65 kcps). Both AgNPs and FeNPs displayed negative surface charges, at -6.499 mV and -1.652 mV, respectively, where FeNPs exhibit a slightly higher value. Elemental composition analysis by scanning electron microscope – energy dispersive X-ray (SEM-EDX) revealed that AgNPs are primarily composed of silver, carbon, and oxygen, whereas FeNPs consisted mainly of iron, oxygen, and carbon. These findings provide insights into the physical and chemical properties of AgNPs and FeNPs synthesized using commercial honey. Understanding these properties is essential for optimizing synthesis processes and exploring applications in medicine, catalysis, and environmental remediation. The eco-friendly synthesis approach using honey underscores the potential for sustainable nanomaterial production. Further research can explore specific applications and benefits of AgNPs and FeNPs synthesized through this green method, offering an efficient and economical alternative for nanoparticle synthesis.

Argyreia nervosa-driven biosynthesis of Cu-Ag bimetallic nanoparticles from plant leaves extract unveils enhanced antibacterial properties.

Our study specifically explores the biosynthesis of copper-silver bimetallic nanoparticles (Cu-Ag BMNPs) using Argyreia nervosa (AN) plant leaf green extract as a versatile agent for capping, reducing, and stabilizing. This biosynthesis method is characterized by its simplicity and cost-effectiveness, utilizing silver nitrate (AgNO3) and cupric oxide (CuO) as precursor materials. Our comprehensive characterization of the Cu-Ag BMNPs, employing techniques such as X-ray diffraction (XRD), UV-Vis spectrometry, scanning electron microscopy (SEM), Zetasizer, and Fourier transformed infrared spectrometry (FTIR). FTIR analysis reveals biofunctional groups and chemical bands, while SEM and XRD analyses provide morphological and structural details. To evaluate the antimicrobial properties of the Cu-Ag BMNPs, we conducted disc diffusion and minimum inhibitory concentration (MIC) assays against Escherichia coli (E. coli), with results compared to the standard gentamicin antibiotic. It is observed that the 2% and 5% CuO concentrations of AN Cu-Ag BMNPs exhibit substantial antibacterial activity in comparison to AN extract when tested on EPEC. Among these, the Cu-Ag BMNPs at a 2% concentration demonstrate higher antibacterial activity, potentially attributed to the enhanced dispersion of BMNPs facilitated by the lower CuO doping concentration. These two assays showcased the improved antimicrobial activity of Cu-Ag BMNPs, highlighting their synergistic effect, characterized by high MIC values and a broad zone of inhibition in the disc diffusion tests against E. coli. These results emphasize the significant antibacterial potential of the synthesized BMNPs, with a medicinal plant AN leaf extract playing a pivotal role in enhancing antibacterial activity.

Common Salt versus Silver Nitrate for the Treatment of Umbilical Granuloma in Infants: An Open-label, Single-center, Pilot Randomized Controlled Trial

ABSTRACT Aim: This study aims to compare the efficacy and safety of topical application of common salt (CS) in comparison to silver nitrate (SN) for treating infants with umbilical granuloma (UG). Materials and Methods: We conducted an open-label, prospective, single-center, pilot randomized controlled trial. Thirty-seven infants with a clinical UG diagnosis were enrolled between October 2022 and July 2023, excluding those previously treated for UG. Patients were randomly assigned (using the Randomizer® app) to receive either topical CS (applied thrice daily by caregivers at home for 5 days) or SN (applied by pediatric surgeon in clinic and kept under occlusive dressing for 48 h). Patients with partial/no healing received an additional session of the same treatment. Nonresponders transitioned from CS to SN, and vice versa, for two more applications. Healing rates were compared with a significance level of α =0.05. Results: Out of 34 patients (18 CS and 16 SN), 32 successfully completed the trial (17 CS and 15 SN). No significant differences were observed in baseline characteristics. Efficacy rates of CS (19/22; 86.36%) and SN (11/17; 64.71%) did not significantly differ (P = 0.056; 95% confidence interval [CI] −0.4832–0.0502). No major adverse events were reported. CS showed superior healing outcomes in infants below 3 months of age (19/22; 86.36%) compared to SN (11/17; 64.71%) (P = 0.056; 95% CI − 0.4832–0.0502). The timing of umbilical cord detachment did not significantly affect healing rates. Conclusion: Widespread availability, ease of access, suitability for safe home application, and cost-effectiveness make CS a primary treatment option for UG. Larger patient cohorts are needed for conclusive results.

التخليق الحيوي لجسيمات الفضة النانوية باستخدام مستخلصات الشاي الأخضر

اصبح تركيب جسيمات الفضة النانوية بالطرق الخضراء بواسطة النباتات شائعًا بشكل متزايد بسبب ملاءمته للبيئة ، وتوفره ، وفعاليته وكلفته القليلة ، ويمكن التعامل معه بأمان ويمتلك تنوعًا واسعًا من المركبات الفعالة ، مثل مضادات الأكسدة و ومركبات مضادة للميكروبات. في الدراسة الحالية ، تم تصنيع جسيمات الفضة النانوية AgNPs باستخدام المستخلصات المائية والميثانولية لأوراق الشاي الاخضر التي اختزلت نترات الفضة, والتي تم توصيفها باستخدام العديد من التقنيات التحليلية مثل القياس الطيفي المرئي فوق البنفسجي (UV-Vis) ، والتحويل الطيفي بالأشعة تحت الحمراء (FTIR) ، والفحص المجهري الذري (AFM) ، وتشتت الأشعة السينية (XRD) وفحص جهد زيتا. أشارت الملاحظة البصرية إلى أن لون نترات الفضة المائية قد تحول بعد المعاملة بمستخلصات الأوراق وتأكد ذلك بواسطة أطياف UV-Vis. فضلا عن ذلك ، أظهر تحليل AFM أن الجسيمات كانت كروية الشكل ، مفردة أو في مجاميع بمتوسط ​​أحجام 108.3 و 84.76 نانومتر للمستخلصات المائية والميثانولية على التوالي. كذلك, أكدت تقنية XRD الطبيعة البلورية للجسيمات النانوية, وتم تقدير متوسط ​​الحجم وفقًا لمعادلة شيرير اذ بلغت 61.24 و 99.66 نانومتر للمستخلصات المائية والميثانولية (CANPs) على التوالي. بالإضافة إلى قيم زيتا المحتملة كانت-30.31 و -32.33 مللي فولت للمستخلصات المائية والميثانولية CANPs على التوالي.

Preparation of silver nitroprusside nanoparticles for enhanced acid red 94 removal from effluent: A study on synergistic adsorption and photocatalytic processes, with toxicological assessment

Toxic dye pollution in water is an urgent global environmental issue. The synergistic action of adsorption and degradation has shown great removal effects for treating toxic dyes in aqueous environments. Silver ions and nitroprusside salts exhibit excellent antimicrobial, anticancer, and biocompatibility properties and are widely used in the pharmaceutical field; however, their application in environmental treatment has not been extensively explored. Hence, we prepared novel and highly efficient silver nitroprusside nanoparticles (Ag2[Fe(CN)5NO] NPs) through a one-pot reaction using sodium nitroprusside and silver nitrate for the first removal of acid red dye (AR 94). Furthermore, Ag2[Fe(CN)5NO] NPs were characterized using various analytical techniques. The Ag2[Fe(CN)5NO] NPs have both cubic and rod-like structures with a size of 107.46 ± 34.54 d.nm, the PDI is 0.263 ± 0.018 and the zeta potential is −46.9 ± 0.026 mV. In addition, the synergistic adsorption and degradation performance of Ag2[Fe(CN)5NO] NPs was evaluated. The removal efficiencies of Ag2[Fe(CN)5NO] NPs on AR 94 can reach more than 95 % under natural light irradiation and optimal reaction conditions of 60 mg/L AR 94 dye concentration, pH 6, temperature 45 °C, and time 6 h. After 5 cycles of recycling, the removal efficiency remained above 90 %. The aqueous solution obtained after removing AR 94 demonstrated no adverse effects on Zea mays L. seed growth. It also exhibited low toxicity to Artemia salina. These results emphasize the potential of Ag2[Fe(CN)5NO] NPs as an efficient and environmentally friendly material for the removal of dyes from aqueous environments.

Sustainable in situ synthesis of silver/titanium dioxide/organofunctional trialkoxysilane nanocomposite coatings on cotton fabric to tailor superior multifunctional protective properties

Multifunctional properties are crucial for the production of high-quality technical textiles. In this study, a cotton fabric with simultaneously superior UV-protection, self-sterilisation, photocatalytic self-cleaning and flame retardant properties was produced using a sol–gel/hydrothermal process, in which titanium(IV) isopropoxide (TTIP) as a titanium dioxide (TiO2) precursor was combined for the first time with mixtures of organofunctional trialkoxysiloxanes, i.e., 3-(trihydroxysilyl)propyl methylphosphonate (TPMP) as a P-based flame retardant and dimethyloctadecyl [3-(trimethoxysilyl)propyl]ammonium chloride (SiQAC) or aminopropyltriethoxysilane (APTES) as the antimicrobial, biobarrier-forming precursors. The latter was used in two increased concentrations of APTES1 and APTES2. A sol–gel/hydrothermal approach was employed with a small amount of silver nitrate (AgNO3) added during the hydrothermal treatment to produce Ag-loaded TiO2. The results of scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDS), X-ray diffraction spectroscopy (XRD), inductively coupled plasma mass spectroscopy (ICP MS) and Fourier-transform infrared spectroscopy (FT-IR) confirmed the successful functionalisation of TiO2 by TPMP, SiQAC and APTES through the formation of Si–O–Ti bonds and the well-dispersed Ag/TiO2/TPMP/SiQAC, Ag/TiO2/TPMP/APTES1 and Ag/TiO2/TPMP/APTES2 coatings on the surface of the cotton fabric. The type of biobarrier-forming precursor significantly influenced the formation of the Ag species after the Ag loading of TiO2. The presence of SiQAC induced the formation of AgCl crystals, while APTES controlled the formation of silver nanoparticles (Ag NPs), which was more pronounced at the lower APTES1 concentration. The interactions between the coating components significantly influenced the functional protection performance, with the highest level of cooperation achieved in the Ag/TiO2/TPMP/SiQAC and Ag/TiO2/TPMP/APTES1 coatings, which exhibited the best overall multifunctionality, albeit with certain drawbacks. While the Ag/TiO2/TPMP/APTES1 coating provided excellent UV protection for the cotton, this was only improved by the Ag/TiO2/TPMP/SiQAC coating. At the same time, the Ag/TiO2/TPMP/APTES1 coating impaired the development of the char barrier by TPMP, which is due to the formation of Ag NPs. Nevertheless, both coatings showed high photocatalytic self-cleaning performance, complete self-sterilisation activity and improved burning behaviour.

Study on the microstructure and adsorption mechanism of different silver-based iodine adsorbents

To further clarify the iodine adsorption mechanism of three-dimensional ordered macroporous silver-silica (3DOM-SA) composite aerogel, based on the establishment of the relationship between pore structure and adsorption properties, the kinetic analysis of the adsorption process of gaseous iodine was carried out, and a comprehensive comparison was made with silver nitrate impregnated silica (AgS) which has been applied in engineering. The results show that the adsorption of gaseous iodine by 3DOM-SA and AgS fits well with the pseudo-second-order and pseudo-first-order kinetic model, corresponding to the main roles played by chemical adsorption and physical adsorption. The iodine adsorption capacity of 3DOM-SA (925 ± 46 mg/g) is much larger than that of AgS (64 ± 11 mg/g) due to the 3DOM structure and more dispersed nano-active components.

The Effect of Aminocyclopropane Carboxylic Acid (ACC) and Silver Nitrate (AGNO3) on Green Super Rice Seedlings for Submergence Tolerance

This internship reported titled as “The effect of Aminocyclopropane Carboxylic acid (ACC) and Silver Nitrate (AGNO3) on green super rice seedlings for submergence tolerance” aimed to identify submergence tolerant rice genotypes and the role of two chemicals i.e. Aminocyclopropane Carboxylic acid (ACC) and Silver Nitrate (AGNO3) in enhancing submergence tolerance of rice. The trial comprised a pot experiment that was conducted at the experimental field of National Agriculture Research Council (NARC) to evaluate the effect on various newly developed lines of green super rice for submergence tolerance. The experiment was designed in randomized complete block within three replications. The treatments consisted of eleven rice genotypes and two chemicals. Five plants of each genotype were transplanted in to pots which were then treated with ACC, AGNO3 or control (without any chemical). Both these chemicals were applied after one week of transplantation. The data were collected before submergence, after seven days of submergence and after fourteen days of submergence on various agronomic parameters including plant height, leaf length and number of leaves. The results indicated that plant height of genotype NRPC-7 resulted in the tallest plants among all the tested genotypes. Greater leaf length was observed in NRPC-9 in control treatments while maximum number of leaves under the treatment of ACC was observed in genotype NRPC-8. It was concluded that the above-mentioned genotypes were highly tolerated to submergence and can be used in breeding program for submergence tolerant variety development

Physiological and molecular responses of basil (Ocimum basilicum) to silver stress: a comparison between silver nanoparticles and silver nitrate treatments

Physiological and molecular responses of basil (Ocimum basilicum) to silver stress: a comparison between silver nanoparticles and silver nitrate treatments

Enhancing concrete durability in chloride-rich environments through manual application of healing agents

Concrete structures in chloride-rich environments are prone to deterioration, especially when ions can intrude via cracks towards the steel reinforcement. Self-healing concrete could significantly extend the service life of reinforced concrete. Hence, selecting appropriate healing agents to improve the durability is a critical challenge for the construction industry. This study investigates the use of three potential healing agents: water-repellent agent (WRA), sodium silicate (SS), and polyurethane (PU). The agents are tested separately under two conditions: exposure to a 3.3 % NaCl concentration at 20 °C and exposure to cyclic freeze-thaw conditions. The agents are manually injected into the cracks and evaluated for their healing efficiency using the capillary absorption test and microscopy analysis. Additionally, their resistance to freeze-thaw cycles by monitoring mass loss and chloride bulk diffusion is measured using sprayed silver nitrate, titration, and EDX mapping. The results demonstrate the effectiveness of PU in completely preventing chloride ingress and withstanding the freeze-thaw cycles. On the other hand, WRA showed a significant reduction in scaling, being the only healing agent to keep scaling below the appropriate scaling level of 1 kg/m2. Although WRA had the best performance in the scaling test and prevented chloride ingress, some influence was observed from the freeze-thaw cycles with regard to chloride ingress. Samples treated with SS performed better than the reference samples but did not show the same effectiveness as samples treated with PU or WRA in preventing chloride ingress. Overall, the study highlights the potential of healing agents in improving the durability of concrete structures in chloride-rich environments, with PU and WRA being the most promising for further development and optimization.