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Organic compounds containing heteroatoms have been comprehended to exhibit a remarkable tendency towards corrosion mitigation. This corrosion mitigating tendency is enabled by the presence of electron clouds composed of lone pairs, pi-electrons, which allow them to be adsorbed over metallic equivalents. Because of the availability of nitrogen as heteroatoms, these compounds are being extensively used for corrosion diminution. This article looks at a variety of heterocyclic organic compounds like imidazole, triazole, pyridine, pyrazole, quinoline, tetrazole, pyrimidine, purine and pyrrole, having nitrogen as their prime constituent heteroatom for their anti-corrosive properties. The anti-corrosive properties of these nitrogen-based compounds in acidic conditions have been demonstrated using all available experimental techniques such as EIS, PDP and other theoretical investigations such as DFT and MD. Furthermore, the shift in the trend of these compounds inhibitory efficiencies has been noted and underlined here. [ABSTRACT FROM AUTHOR]

A series of facial-Re(CO)3-based acyclic complexes (1–3) possessing N∩O bis-chelating ligands and a triphenylphosphine oxide donor was synthesized and characterized. The most interesting structural feature of these complexes is that both the coordinated ligands are functionalized with external phenyl rings. Single crystal X-ray diffraction analysis confirms that each molecule demonstrates a variety of intermolecular supramolecular interactions via the external phenyl rings. All the complexes displayed strong absorption (ε = 14 000–40 000 M−1 cm−1) over wide visible region (400–600 nm). Due to the interesting structural and photophysical properties of the complexes, a satisfactory DNA binding ability was observed. The binding of the complexes with DNA grooves was confirmed by a significant increase in the absorption intensities of the complexes in the visible region, absorption enhancement of DNA and circular dichroism. [ABSTRACT FROM AUTHOR]

We report a robust synthesis of polymeric plasticiser from the post-consumer plastic waste, i.e. poly(ethylene terephthalate) (PET) and its subsequent use as plasticiser for preparation of nitrile rubber (NBR) and nitrile-PVC rubber blends. PET waste was depolymerised by alcoholysis with the help of 1-decanol. The obtained oligomeric plasticiser was characterised for its chemical structure using Fourier Transform Infrared Spectroscopy and Nuclear Magnetic Resonance. The prepared polymeric plasticiser was then used for the preparation of nitrile and nitrile-PVC blend rubber sheets. NBR and nitrile-PVC blend rubber sheets were also prepared by using dioctyl phthalate as plasticiser. The fabricated sheets were compared for their mechanical properties such as tensile strength, elongation at break, hardness. The effect of ageing on mechanical properties was also analysed. It was observed that the use of polymeric plasticiser resulted in significant improvement in tensile properties and ageing resistance. This eco-friendly synthesis of plasticiser offers its use for high-performance applications. [ABSTRACT FROM AUTHOR]

Abstract A hetero-structured composite with remarkable adsorption performance has drawn more attention owing to its splendid performance in environmental applications. The porosity, stability, and specific surface area of Chitosan can be improved by customizing it with the appropriate bio-polymeric adsorbents, which can also exhibit strong adsorption potential. In the Present study, Chitosan (host) was fabricated via in-situ chemical oxidative polymerization strategy in different ratio. The performance of synthesized composites was tested for the adsorption of Tartrazine dye in a batch mode. Results showed a maximum adsorption efficiency of 99.02 ± 1.980% for CS/Ppy-1:1 and 96.70 ± 1.934% for CS/Ppy-1:2 for the removal of Tartrazine dye under an optimum condition (Initial concentration that is 100 mg/L (CS/Ppy-1:1) and 75 mg/L (CS/Ppy-1:2), pH = 5, Temperature = 25 °C, Adsorbent dose = 10 mg). The adsorption isotherm and kinetic fitted well with the Langmuir model and pseudo-second-order respectively. The thermodynamic study revealed that the adsorption of dye is a spontaneous process. Further, Regeneration investigations showed over 65 ± 0.142% regeneration efficiency with 0.1 M NaOH solution, confirming that the desorption was impeccable. The electrostatic force of interaction, hydrogen bonding, surface complexation, and π − π stacking interactions were all implicated in the dye adsorption mechanism on the CS/Ppy composite. Also, the proposed system treats one of the most complex azo dyes using the efficient binary composite and shows successful regeneration/recyclability of adsorbent upto four successive cycles making it a potential adsorbent for large scale upgradation. [ABSTRACT FROM AUTHOR]

Abstract Interculturally, corrosion has been counted as one of the most expensive factors toward the retrogression of concrete and metallic structures resulting in huge monetary losses and unanticipated loss of life. To a large extent, corrosion-related catastrophes can be avoided by having the ability to monitor corrosion before structural integrity is jeopardized. This paper critically reviews the various accustomed electrochemical techniques utilized for corrosion monitoring in terms of their definition, timeline, experimental set-up, advantages, and shortcomings. Additionally, literature exploiting these techniques as their corrosion detection technique has been focused on here. Furthermore, a comparison between recently reported methods has been made to provide better insights into the research progress in this arena. [ABSTRACT FROM AUTHOR]

A novel Schiff base moiety, ( E )-4-(1-hydrazonoethyl)benzene-1,3-diol (2), and 2,4-dihydroxybenzaldehyde were condensed in a 1 : 1 molar ratio to generate 4-(( E )-1-((( Z )-2,4dihydroxybenzylidene)hydrazono)ethyl)benzene-1,3-diol (L), which was then characterized using high-resolution mass spectrometry (HRMS), 1 H-NMR, 13 C NMR, and single-crystal XRD techniques. UV-vis absorbance measurements were used to determine whether the Schiff base could detect the cupric ions more effectively than the other transition metal ions. When Cu 2+ ions were involved, a new band was observed at 462 nm. From the Job plot, the binding stoichiometry for the anticipated L : Cu 2+ partnership is determined to be 1 : 1. For the purpose of validating structural correlations and absorption data, DFT simulations were performed. Further, docking studies for L indicated high binding affinity for human hemoglobin, providing vital information about the ligand's favorable binding locations inside hemoglobin binding sites and the consequent interactions with HHb. The binding coefficient and limit of detection were found to be 3.02 × 10 4 M -1 and 42.09 nM, respectively. Reversibility of the complex was seen upon the addition of EDTA to the L-Cu 2+ solution, and a colorimetric variation simulating the "INHIBIT" molecular logic gate was seen upon the addition of Cu 2+ and EDTA to L. Furthermore, the chemosensor's potential application in the detection of Cu 2+ in the solid state by chemosensor L also confirms its usefulness in real-world applications emphasizing its versatility and practical utility., Competing Interests: The authors declare that they have no conflicts of interest., (This journal is © The Royal Society of Chemistry.)

Carbon nanodots (CNDs), a fascinating carbon-based nanomaterial (typical size 2-10 nm) owing to their superior optical properties, high biocompatibility, and cell penetrability, have tremendous applications in different interdisciplinary fields. Here, in this Review, we first explore the superiority of CNDs over other nanomaterials in the biomedical, optoelectronics, analytical sensing, and photocatalysis domains. Beginning with synthesis, characterization, and purification techniques, we even address fundamental questions surrounding CNDs such as emission origin and excitation-dependent behavior. Then we explore recent advancements in their applications, focusing on biological/biomedical uses like specific organelle bioimaging, drug/gene delivery, biosensing, and photothermal therapy. In optoelectronics, we cover CND-based solar cells, perovskite solar cells, and their role in LEDs and WLEDs. Analytical sensing applications include the detection of metals, hazardous chemicals, and proteins. In catalysis, we examine roles in photocatalysis, CO 2 reduction, water splitting, stereospecific synthesis, and pollutant degradation. With this Review, we intend to further spark interest in CNDs and CND-based composites by highlighting their many benefits across a wide range of applications.

A new rhodamine based fluorescent and colorimetric chemosensor S1 was synthesized for the selective recognition of Cr 3+ , a trivalent metal ion. The interaction of S1 toward different metal ions has been studied via fluorescence and UV-visible spectroscopy. The studies revealed that the fluorescence and colorimetric changes of chemosensor S1 are prominent for Cr 3+ over other competitive metal ions. Moreover, the chemosensor S1 exhibits 1 : 1 complex formation with Cr 3+ as apparent from the Job's plot and the Benesi-Hildebrand (B-H) plot. Density functional theory (DFT) studies also revealed that the Cr 3+ ion is coordinated to three atoms of S1, which validates the formation of a complex between S1 and Cr 3+ . The limit of detection (LOD) of chemosensor S1 for Cr 3+ was 0.21 μM. Furthermore, to explore the recyclability of S1, ethylenediaminetetraacetic acid (EDTA) was added to the S1-Cr3+ solution. On the addition of EDTA to the solution of S1-Cr3+, the reversibility of the complex was observed, and a colorimetric variation was also observed on the addition of Cr 3+ and EDTA to S1 which mimics the "INHIBIT "molecular logic gate. Chemosensor S1 also demonstrated practical utility through detection of Cr 3+ in the solid state.

A pyridine dicarboxylate Schiff-base DAS was synthesized for cascade colorimetric recognition of Ni 2+ and PPi. The selectivity and sensitivity of chemosensor DAS was investigated through colorimetric and UV-vis studies in MeOH-PBS (5 : 1, v/v, pH = 7.4). The chemosensor formed a 2 : 1 complex with Ni 2+ metal ions with a binding constant of K a = 3.07 × 10 3 M -2 . Besides, a plausible sensing mechanism is confirmed by single crystal X-ray diffraction (SC-XRD), Job's plot and Benesi-Hildebrand plot (B-H plot) experiments. Furthermore, the DAS-Ni 2+ ensemble formed ' in situ ' was used to selectively recognise PPi. The limit of detection (LOD) of DAS for Ni 2+ was found to be 0.14 μM and that of the DAS-Ni 2+ ensemble for PPi was found to be 0.33 μM. Also, the potential of the chemosensor has been applied for solid state detection of Ni 2+ as well as to mimic the 'INHIBIT' logic gate on the addition of Ni 2+ ions and PPi., Competing Interests: The authors have no conflict of interest to declare., (This journal is © The Royal Society of Chemistry.)

Background: In recent years, the delivery of drugs by nanocomposites has emerged as an exciting field of research for bio-imaging tools and targeted cancer treatment. The large surface area and porous volume of mesoporous silica nanocomposites (MSN's) have gained a lot of interest for their application in the delivery of drugs and the magnetic properties of iron oxide (IO) nanocomposites play a key role in the targeted delivery system., Methods: In this study, mesoporous silica encapsulated IO nanocomposites loaded with doxorubicin (DOX) were synthesized for the magnetically guided delivery of anticancer drugs. The synthesis of IO nanocomposites was done through the precipitation method, and then silica encapsulation and drug loading were done by the StÖber method., Results: The magnetically driven delivery of the drug is produced by the encapsulation of magnetically active IO in the mesoporous silica shell. The controlled release of DOX is possible because of the MSN's. TEM images show that the nanocomposites have a spherical morphology and average diameter in the range of 120 nm. Power-XRD data confirm the crystalline nature of nanocomposites. The strong absorption peak was observed in UV-Visible spectroscopy at 490 nm and quenching in fluorescence spectra confirms the encapsulation of DOX in the mesoporous silica shell. VSM data showed the magnetic nature of nanocomposites, with large magnetic susceptibility (74.88 emu/g). The use of DOX/IO@Silica nanocomposites as a sustainable drug release and targeted drug delivery vehicle has been reported here. The pH dependent release of DOX was studied and significant release was observed at lower pH. In-vitro cell viability assay and fluorescence imaging assay have demonstrated that these nanocomposites show significant dose-dependent toxicity to cancer cells in the presence of a magnetic field., Conclusion: In-vitro studies via the MTT assay showed that these synthesized nanocomposites in culture are non-toxic to healthy cells compared to DOX-induced cytotoxicity due its controlled release and can be further strengthened by magnetic guidance. Therefore, due to its optical properties and potential for guided delivery of drug to the targeted site, these nanocomposites are ideal as an anticancer agent and bio-imaging prob., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)