Advanced Materials Letters

Abstract Magnesium oxide nanoparticles have emerged as a potential candidate for meeting ends of various problems due to its unique properties such as biodegradability, non-toxicity, inhibition of biofilm growth and degradation of harmful dyes such as methyl violet and many more. Along with its easy synthesis by methods such as sol-gel technique, precipitation method, and green synthesis, it is widely applicable for toxic waste remediation, antibacterial materials, removal of industrial pollutants and also used in anti-arthritic and anti-cancer activities. Prior reviews have laid focus on singular domains whereas our review clubs three major domains i.e., clinical, agricultural and environmental that are involved in the day to day life of plants as well as animals. Besides the above information, properties, synthesis, nanotoxicity and future perspectives of magnesium oxide nanoparticles have also been elaborated in this review.

Abstract Deacetylation of chitin affords chitosan, a polymer, widely studied for its pharmaceutical and nonpharmaceutical applications. The hurdle in comprehending these applications is its limited solubility. Carboxymethylation of chitosan helps to surmount this hurdle with its improved solubility in water. Though there is ample of research related to carboxymethyl chitosan (CMC) the focused review of the topic is unavailable. Hence an attempt is made in this review to cover the recent findings pertaining to synthesis, characterization of CMC and its applications especially in pharmaceutical field. CMC has been synthesized by ways as direct alkylation, reductive alkylation, Michael addition and characterized by FTIR, NMR spectroscopy, and DSC, titrimetry, viscometry, gel permeation chromatography, X-ray diffraction and capillary zone electrophoresis. The carboxymethyl group can be present at O or N or both the atoms of chitosan molecule. The CMC possess modulated physical and biological properties as chelating, sorption, moisture retention, cell functioning antioxidant, antibacterial, antiapoptotic etc. CMC is used in sustained or controlled release drug delivery, pH responsive drug delivery, DNA delivery as permeation enhancer etc. CMC can be further modified with alkylation, acylation, and grafting. Carboxyalkylation of chitosan yield carboxyethyl, carboxybutyl chitosans. These analogues of CMC may be helpful in substantiating the applications of chitosan.

Abstract Herein, we are reporting a novel biological approach for the formation of zinc oxide (ZnO) nanoparticles using Maddar (Calotropis procera) latex at room temperature. X-Ray diffraction (XRD) pattern reveals the formation of ZnO nanoparticles, which shows crystallinity. Transmission electron microscopy (TEM) suggested particles size and shape in the range of 5-40 nm. Scanning electron microscopy (SEM) image reveals that the particles are of spherical and granular nature. UV-Vis absorption shows characteristic absorption peak of ZnO nanoparticles. Photoluminescence (PL) studies were performed to emphasize its emission properties. This simple and cost-effective biological approach for the formation of ZnO NPs has a promising application in biosensing, electronics and photonics.

Abstract All the elastic, mechanical and thermal properties of Gd-doped ZnO nanorods (NRs) have studied using interaction potential model. Gd-doped ZnO nanorods are hexagonal wurtzite structure. The characteristic features of elastic characteristics of Gd-doped ZnO NRs imply that this is mechanically stable. For mechanical characterization, bulk modulus (B), shear modulus (G), Young's modulus (Y), Pugh's ratio (B / G), Poisson’s ratio and anisotropic index are evaluated using second order elastic constants. For the investigation of anisotropic behaviour and thermophysical properties, ultrasonic velocities and thermal relaxation time have been also calculated along with different orientations from the unique axis of the crystal. The mechanical properties of the Gd-doped ZnO nanorods are better than at 6% Gd amount due to minimum attenuation. The obtained results are analyzed to explore the characteristic of ZnO nanorods. Computed elastic, ultrasonic and thermal properties are correlated to evaluate the microstructural behaviour of the materials useful for industrial applications

Abstract Nowadays, nanotechnology has grown to be an important research field in all areas including medicinal chemistry. The size, orientation and physical properties of nanoparticles have reportedly shown to change the performance of any material. For several years, scientists have constantly explored different synthetic methods to synthesize nanoparticles. On the contrary, the green method of synthesis of nanoparticles is easy, efficient, and eco-friendly in comparison to chemical-mediated or microbe-mediated synthesis. The chemical synthesis involves toxic solvents, high pressure, energy and high temperature conversion and microbe involved synthesis is not feasible industrially due to its lab maintenance. Since, green synthesis is the best option to opt for the synthesis of nanoparticles, therefore the nanoparticles were synthesized by using aqueous extract of Moringa oleifera and metal ions (such as silver). Silver was of particular interest due to its distinctive physical and chemical properties. M. oleifera leaf extract was selected as it is of high medicinal value and it does not require any sample preparation and hence is cost-effective. The fixed ratio of plant extract and silver ions were mixed and kept at room temperature for reduction. The color change from yellow to reddish brown confirmed the formation of nanoparticles. Further, the synthesized nanoparticles were characterized by UV, EPMA, XRD and FTIR data. The antimicrobial activity of synthesized nanoparticle has also been examined in gram positive and gram negative bacteria and encouraging results are in hand.