Cu(II) and Gd(III) doped boehmite nanostructures: a comparative study of electrical property and thermal stability

The present article reports the effect of transition (Cu2+) and rare earth metal (Gd3+) ion doping on structural, microstructural and electrical properties of boehmite nanoparticles. Rietveld refinement is adopted here to refine the x-ray diffractograms for further analyzing the microstructural details and their alteration due to the incorporation of foreign cations. This is probably the first time when dielectric properties of these doped boehmite samples having been reported herein. These samples show remarkably high dielectric constant values which corroborate that doping enhances the microstrain values inside the orthorhombic structure and results in higher crystallographic defects. Enhancement in defect sites causes the augmentation of relative permittivity and ac conductivity. Temperature stability has also been enhanced significantly in our Cu-doped sample. The present study enables us to determine a relationship between crystalline deformation and electrical properties of nanomaterials which may be highly beneficial in fabricating cost-effective energy harvesting devices

Click-Chemistry-Assisted Alteration of Glycosaminoglycans for Biological Applications

This short review describes the assistance of click chemistry in the chemical modification of glycosaminoglycans. Through an alkyne-azide 1,3-dipolar cycloaddition reaction, the chemically and physiologically stable triazole unit connects glycosaminoglycans with other labelled or attached functionalities. The synthesized glycosaminoglycan (GAG) conjugates act as drug carriers, forming hydrogels or nanohydrogels for localized drug delivery or injectable GAGs and so on. These are used in research on antithrombotic agents, protein binding, and hepatocyte growth factors, as well as in mechanistic studies of glycosaminoglycans biosynthesis and wound healing. 1 Introduction 2 Synthetic Modification of GAGS 3 Click Chemistry 4 Modification of GAGS Applying Click Chemistry 5 Conclusions 6 Abbreviation

Towards the enantioselective synthesis of anti-HIV agents litseaverticillols C and K from D-glucose

The first enantioselective synthesis towards the litseaverticillols C and K has been achieved, from D-glucose, using the ring closing metathesis (RCM) and Wittig reactions as key steps

In Situ-Grown Cdot-Wrapped Boehmite Nanoparticles for Cr(VI) Sensing in Wastewater and a Theoretical Probe for Chromium-Induced Carcinogen Detection

In modern society, massive industrialization escalates environmental degradation by liberating various contaminants into the environment. Hexavalent chromium is a heavy metal that is being discharged from tannery and other industries, resulting in various carcinogenic diseases. This study reports a carbon dot (cdot)-based fluorometric probe for detecting hexavalent chromium in water. This is the very first time that cdots are tailored over the boehmite nanoparticle's surface using an in situ approach. Validation of formation of the nanocomposite has been discussed in detail employing the Rietveld refinement-based X-ray crystallography method. Vibrational spectroscopy and electron microscopy of the sample authenticate the nucleation process and the growth mechanism. The Stern-Volmer approach and time-resolved fluorescence measurements justify the sensitivity of the sensor (similar to 58 nM), and selectivity is analyzed by exposing the material to different ionic environments. Density functional theory (DFT) is applied herein to analyze the origin of fluorescence and the sensing mechanism of the probe, which shows that photoinduced electron transfer is responsible for the turn-off-based sensing of Cr(VI). The molecular docking simulation is carried out to ensure the binding of cdots to the binding pocket of the glutathione enzyme, which is responsible for treating reactive oxygen species-mediated DNA damage due to elements such as hexavalent chromium. Time-dependent density functional calculations show that the fluorometric probe is capable of detecting Cr(VI) in living cells making it an early stage chromium-mediated carcinogen detector

Development of a Cu(I) doped boehmite based multifunctional sensor for detection and removal of Cr(VI) from wastewater and conversion of Cr(VI) into an energy harvesting source

This article reports a copper doped boehmite (CBH) based nano-material which is capable of detecting and removing hexavalent chromium simultaneously. Basic characterization has been performed to determine its phase purity, particle size (similar to 20 nm), morphology and surface properties (surface area 15.29 m(2) g(-1) and pore diameter 3.9 nm) by using some basic characterization tools. The Rietveld refinement method has been adopted to analyze the microstructural details of the synthesized nanostructure. Photoinduced electron transfer (PET) based quenching of fluorescence is mainly responsible for chromium sensing in this case. This nanosensor is exceptionally sensitive (limit of detection similar to 6.24 mu M) and merely selective towards hexavalent chromium ions. Industrial wastewater samples have also been used here to demonstrate the real life applicability of this material, which shows the same trend. This fluoro-sensor gains its multi-functionality when it comes to the adsorption based removal of Cr(VI) from wastewater. The synthesized material shows a remarkably high adsorption rate (similar to 85% in just 5 minutes) due to its sponge-like porous structure. Adsorption of hexavalent chromium from wastewater enhances the dielectric constant of this material significantly (similar to 7.93 times). Ionic polarization-dependent enhancement of the dielectric constant resulting from industrial wastewater treatment is a quite unmarked approach. Very low tangent loss with augmented dielectric permittivity makes this nano-material desirable for energy harvesting applications. Previously many articles have reported the sensing and removal of various industrial effluents. Keeping this in mind, this work has been designed and, apart from sensing and removal, it provides a new insight into energy harvesting from wastewater

Particle size mediated investigation of various physicochemical properties of kaolinite clay for fabricating the separator layer of green capacitors

This article reports size fractionation of a natural clay namely kaolinite for fabricating cost-effective green separator material for energy storage devices. kaolinite is reportedly biocompatible and abundantly available in nature, which makes it cost-effective. Such a low-cost clay is found to be in the nano regime when treated in a ball-milling machine for a prolonged duration (12 h). The enhancement in porosity and surface area have also been observed in the treated nano-clay, which subsequently renders it's dielectric constant (similar to 5000 at 40 Hz frequency) remarkably. Henceforth, it can be argued that crystallinity and aspect ratio (S/V) has a prominent impact on the electrical properties of this natural clay. Cyclic voltammetry and galvanostatic charging-discharging measurements depict high specific capacitance (similar to 185 F g(-1)) in the nano-clay sample without the presence of any redox peak making it a good separator material. The slow electrical discharge rate also approves the storage property of this clay sample quite effectively. Abundance, augmented permittivity with a relatively low tangent loss, high specific capacitance and significant resistivity through the material make this nano-clay material a promising `green' dielectric separator for energy storage applications