Saba Jamil

First Principle Study of Electronic and Non-Linear Optical (NLO) Properties of Triphenylamine Dyes: Interactive Design Computation of New NLO Compounds

In this study, density functional theory and time-dependent density functional theory are used to determine how the size of π-conjugated system influences the absorption spectra and non-linear optical (NLO) properties of dyes. Double and triple bonds, as well the benzene rings, are used in conjugated systems. The results of the theoretical computation show that the absorption spectra are gradually broadened and red-shifted with increases in the conjugation length. Theoretical examination of the NLO properties was performed on the key parameters of polarizability and hyperpolarizability. A notable increase in the non-linear optical response was observed with an increase in the conjugation length of the π-spacer.

Synthesis of Self-Assembled Co3O4 Nanoparticles with Porous Sea Urchin-Like Morphology and their Catalytic and Electrochemical Applications

Novel self-assembled cobalt oxide nanoparticles with sea urchin-like morphology were synthesized using a solvothermal method. It was observed that the product consists of a tube-like arrangement of nanoparticles arising from a base. The base is formed by the arrangement of nanoparticles in the form of dense aggregates. A series of comparative experiments were performed over different time intervals to investigate the mechanism of formation of this morphology. The electrochemical performance of an electrode prepared based on this product was analysed by cyclic voltammetry, chronopotentiometry, and alternating current impedance. The electrochemical study shows that the prepared electrode possesses high capacitance and offers very low resistance against the flow of electrons. The product was used as a catalyst for the reduction of nitrobenzene in aqueous medium. The value of the apparent rate constant of catalysis was found to be as high as previously reported values.

Solvent-Dependent Non-Linear Optical Properties of 5,5′-Disubstituted-2,2′-bipyridine Complexes of Ruthenium(ii): A Quantum Chemical Perspective

In this research article, we reported solvent effects on non-linear optical (NLO) properties of 5,5′-disubstituted-2,2′-bipyridine complexes of ruthenium. The polarizability (α) and hyperpolarizability (β) were calculated in the gas phase. Benzene (ϵ (dielectric constant) = 2.3), THF (ϵ = 7.52), dichloromethane (ϵ = 8.93), acetone (ϵ = 21.01), methanol (ϵ = 33.00), and water (ϵ = 80.10) were used by density functional theory. These solvents cover a wide range of polarities. The results of theoretical investigation showed that the non-linear optical properties were significantly increased with the increase in solvent polarity. The results of this study also showed that similarly to structural modifications, polarity of the medium may play a significant role in modulating the NLO properties.

First Synthetic Study of Cube-Like Cobalt Hydroxystannate Nanoparticles as Photocatalyst for Drimarene Red K-4BL Degradation and Fuel Additive

This research article describes the development of a simple and sensitive approach with less runtime for the estimation of photo degradation of an anthraquinone dye drimarene red K-4BL in the presence of newly synthesized nano catalyst. Hydrothermal approach is used to synthesize cobalt hydroxystannate by using precursor salts of chloride i.e. stannic chloride, cobalt chloride and sodium hydroxide is used as a precipitating agent. Various techniques were used to analyze the product. Two major applications of synthesized nanocubes are investigating the efficiency of modified fuel and as a photocatalyst for dye degradation. Anthraquinone dye (drimarene red K-4BL) is degraded by the newly synthesized nanoparticles which is used as a catalyst in aqueous medium. In the presence of sun irradiation at different concentrations of hydrogen peroxide and catalyst, kinetics of photo catalytic degradation of dye is monitored on ultra violet visible spectrophotometer. Efficiency of modified fuel is analyzed by studying the various parameters such as flash point, fire point, pour point and cloud point, etc. at different dosage of Cobalt hydroxystannate. By changing the dosage of the catalyst, values of these parameters changed significantly.Graphical Abstract

Synthesis and adsorption properties of flower-like layered double hydroxide by a facile one-pot reaction with an eggshell membrane as assistant

In this paper, flower-like layered double hydroxides were synthesized with eggshell membrane assistant. The as-prepared samples were characterized by a series of techniques including X-ray diffract...

Synthetic Study and Merits of Fe 3 O 4 Nanoparticles as Emerging Material

Iron (III) oxide magnetic nanoparticles have provided us a multitude of new tools to explore biological and other scientific systems on small length scales. The opening up of single cell or single molecule phenomena to experimental investigations present an important step forward and promises to yield new insights. This review depicts some important and most commonly used methodologies for the engineering of iron oxide magnetic nanoparticles including superparamagnetic iron oxide nanoparticles and ultra-small superparamagnetic iron oxide nanoparticles, important features of these synthesis methods and their applications in different fields of life proving it as an emerging material. Most important task in nanoscale synthesis of iron oxide is to control morphology and contain it within a narrow size distribution. These processes include sol–gel method, hydrothermal method, sonochemical method, co-precipitation and micro emulsion methods. These processes are essentially highly controlled to fabricate the desire material with appropriate properties. Synthesis of mono disperse nanometer-sized magnetic particles of metal alloys and metal oxides is an active research area because of their potential technological ramifications ranging from ultrahigh-density magnetic storage media, to biological imaging. Size, size distribution, shape, and dimensionality are important for the properties of these magnetic materials. Nanoparticles of various iron oxides (Fe3O4 and ç-Fe2O3 in particular) have been widely used in a range of biological applications. Iron oxide magnetic nanoparticles can be designed to exhibit novel and significantly improved physical, chemical and biological properties, phenomena and strategies as a result of the limited size of their constituent particles.Graphical AbstractIron oxide nanoparticles can be designed to exhibit novel and significantly improved physical, chemical and biological properties, phenomena and strategies as a result of the limited size of their constituent particles by using various methodologies.

In vitro antibiofilm and anti-adhesion effects of magnesium oxide nanoparticles against antibiotic resistant bacteria: Antibiofilm potential of MgO NPs

The aim of the current investigation was to determine the antibacterial and antibiofilm potential of MgO nanoparticles (NPs) against antibiotic‐resistant clinical strains of bacteria. MgO NPs were synthesized by a wet chemical method and further characterized by scanning electron microscopy and energy dispersive X‐ray. Antibacterial activity was determined by broth microdilution and agar diffusion methods. The Bradford method was used to assess cellular protein leakage as a result of loss of membrane integrity. Microtiter plate assay following crystal violet staining was employed to determine the effect of MgO NPs on biofilm formation and removal of established biofilms. MIC values ranged between 125 and 500 μg/mL. Moreover, treatment with MgO NPs accelerated rate of membrane disruption, measured as a function of leakage of cellular proteins. Leakage of cellular protein content was greater among gram‐negative bacteria. Cell adherence assay indicated 25.3–49.8% inhibition of bacterial attachment to plastic surfaces. According to a static biofilm method, MgO NPs reduced biofilm formation potential from 31% to 82.9% in a time‐dependent manner. Moreover, NPs also significantly reduced the biomass of 48, 72, 96 and 120 hr old biofilms (P < 0.05). Cytotoxicity experiments using a neutral red assay revealed that MgO NPs are non‐toxic to HeLa cells at concentrations of 15–120 μg/mL. These data provide in vitro scientific evidence that MgO NPs are effective and safe antibiofilm agents that inhibit adhesion, biofilm formation and removal of established biofilms of multidrug‐resistant bacteria.

Photocatalytic degradation of reactive black 5 on the surface of tin oxide microrods

A simple co-precipitation technique is proposed for synthesis of tin oxide (SnO2) microrods. Stannous chloride and urea were used during synthesis. X-ray powder diffraction (XRD) analysis revealed that the annealed product consists of SnO2 microrods having tetragonal unit cells, while scanning electron microscopy (SEM) analysis revealed the rod-like morphology of a synthesized product. These synthesized microrods are used as photocatalyst for the degradation of reactive black 5 (RB5). Degradation kinetics of RB5 are monitored under daylight in different concentrations of hydrogen peroxide (H2O2) and catalyst. The percentage of RB5 conversion is also calculated at various concentrations of hydrogen peroxide and catalyst which demonstrate that RB5 shows high catalytic degradation at high concentrations of hydrogen peroxide and catalyst.

DFT Molecular Simulation for Design and Effect of Core Bridging Acceptors (BA) on NLO Response: First Theoretical Framework to Enhance Nonlinearity Through BA

The effect of nature of carbazole like groups on polarizability and hyperpolarizability of organic dyes has been investigated in this article. Quantum chemical methodologies are used to compute the electronic structures, UV–visible absorption spectra and non-linear optical response. The computed results indicate that the polarizability, oscillator strength, light harvesting efficiency and hyperpolarizability of isoindigo bridging acceptor (BA4) is greater than that of phthalimide bridging acceptor (BA1). The simulated absorption spectra show that the wavelength of dye with BA4 group is red-shifted as compared to that of dye with BA1 group. These results indicate that the BA4 group can effectively improve the non-linear optical response. These theoretical frameworks might be useful to design other organic dyes as these are the first quantum mechanical models to enhance nonlinearity through BA.Graphical AbstractQuantum mechanical design based on A–π–CorA–π–A combination to enhance NLO response.