Publications

Facile synthesis of doped ZnO-CdO nanoblocks as solid-phase adsorbent and efficient solar photo-catalyst applications

The Role of Eliminating PEG from PEG/MCM-41 Composite on the Structural, Textural and Electrical Conductivity Properties of MCM-41

A PEG/MCM-41 composite was synthesized by a simple solution method with polyethylene glycol (PEG) and mesoporous MCM-41. The thermal behavior of the composite was studied using thermogravimetric analysis (TGA) and an in situ electrical conductivity measurement. The results showed that polymer degradation occurs in the temperature range of 300 to 550 °C, and is accompanied by a decrease in the electrical conductivity. Thus, to elucidate the influence of polymer elimination on the structural, textural and electrical conductivity properties of MCM-41, a sample was prepared by calcining the PEG/MCM-41 composite for 3 h at 550 °C in air. Various physico-chemical techniques such as XRD, FT-IR, FE-SEM and N2 physisorption, were used for characterization. It was shown that the calcined solid still exhibits the mesoporous MCM-41 framework with poor ordering. A texture analysis revealed that the PEG/MCM-41 composite formation and the subsequent PEG elimination are accompanied by a loss of the type IV character of the MCM-41 and a sharp decrease in the textural parameters. The observed meso-porosity loss of the MCM-41 as a result of adding and then eliminating the PEG molecules was accompanied by a reduction of the conductivity.

Photo-degradation, thermodynamic and kinetic study of carcinogenic dyes via zinc oxide/graphene oxide nanocomposites

Pollution problem increases with the same face as the industrial development. One of the toxic ingredients of these industrial effluents is the organic dyes. Zinc oxide/Graphene oxide nanocomposite (ZnO-GNc) was synthesized in aqueous solution by mixing ultrasonically various compositions. The prepared ZnO-GNc nanocomposite was characterized by XRD, FTIR, FE-SEM, EDX and TEM. XRD of Graphene oxide (GO) showed their crystalline nature and the average size was 3.54, 18.98 and 15.47 nm for GO, ZnO, and ZnO-GNc respectively. An active toxic and stable dye, Methyl red (MR) was employed as the target pollutant to evaluate the photocatalytic activity of ZnO-GNc. The photocatalytic performance of ZnO-GNc nanocomposite was compared with that of zinc oxide (ZnO) and GO. The effect of some parameters, dye concentration, pH and temperature of dye solution were studied. The kinetic studies show that the process of MR photocatalytic discoloration by ZnO-GNc followed first-order reaction kinetics under different conditions with the rate constant of 2.2 × 10−2 s−1. The possible reasons for the high values of photocatalytic efficiency of the ZnO-GNc may be due to the improved charge passage and separation.

Antibiotic-contaminated wastewater treatment and remediation by electrochemical advanced oxidation processes (EAOPs)

Antibiotics are extensively used in health sectors, animal husbandry, and agriculture, which raises serious concerns nowadays due to their presence in surface water, groundwater, soil, sediment, and plants. Antibiotics in water can cause the accumulation and spread of antibiotic-resistant genes that have a serious impact on the environment. Moreover, due to the refractory and persistent nature of antibiotics, conventional wastewater treatment technologies including physio-chemical and biological treatments are inefficient for antibiotic wastewater treatment. In recent times, Electrochemical Advanced Oxidation Processes (EAOPs) have been reported to be effective in the treatment of antibiotic-contaminated wastewater. These specialized techniques produce very reactive and oxidizing intermediate •OH radicals which readily degrade the antibiotics. In this article three most important EAOPs, Electro Oxidation (EO), Photo Electro Catalytic Oxidation (PEC), and Electro Fenton ( EF ) are reviewed along with their classification, performance in different antibiotics, influencing factors e.g., anode-cathode materials, pH, current density, initial concentration, temperature, and supporting electrolytes. These processes offer eco-friendly, sustainable, cost-effective methods for treating antibiotics. Moreover, the feasibility of EAOPs in industrial wastewater treatment has not been properly established due to toxic intermediates, high cost, incapable to handle a large volume of wastewater, its performance only at ideal conditions, degrade only a few antibiotics, and mass transfer limitations. Consequently, combining membrane separation and conventional biological treatments as pre- or post-treatments of EAOPs can effectively address toxicity reduction and the handling of large volumes of wastewater. In addition, the energy consumption in a single EO process is higher than the combined processes. To constructively write this review, data have been collected from renowned publishers e.g., ScienceDirect, Springer, Willey, American Chemical Society Publications, etc. The possibilities, challenges, and future outlooks for the scale-up and commercialization of existing lab-based EAOPs have been discussed for the sustainable use of EAOPs in treating toxic and bio-persistent antibiotic compounds from wastewater. Furthermore, the research gaps mentioned in this paper can encourage future researchers to utilize the merits of EAOPs and combined processes for achieving high degradation efficiency of antibiotics at low cost and establishing it commercially. • Boron Doped Diamond electrode was highly efficient however it is expensive. • Most EAOPs follow pseudo-first-order reaction kinetics. • Real wastewater treatment was more challenging than synthetic ones with EAOPs. • Coupling EAOPs with other methods could eliminate EAOPs limitations.

One-Pot Synthesis, Spectroscopic and Physicochemical Studies of Quinoline Based Blue Emitting Donor—Acceptor Chromophores with Their Biological Application

CCDC 1519819: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Cut from the Same Cloth: Enamine-Derived Spirobifluorenes as Hole Transporters for Perovskite Solar Cells

To attain commercial viability, perovskite solar cells (PSCs) have to be reasonably priced, highly efficient, and stable for a long period of time. Although a new record of a certified power conversion efficiency (PCE) value over 25% was achieved, PSC performance is limited by the lack of hole-transporting materials (HTMs), which extract positive charges from the light-absorbing perovskite layer and carry them to the electrode. Here, we report spirobifluorene-based HTMs with finely tuned energy levels, high glass-transition temperature, and excellent charge mobility and conductivity enabled by molecularly engineered enamine arms. HTMs are synthesized using simple condensation chemistry, which does not require costly catalysts, inert reaction conditions, and time-consuming product purification procedures. Enamine-derived HTMs allow the fabrication of PSCs reaching a maximum PCE of 19.2% and stability comparable to spiro-OMeTAD. This work demonstrates that simple enamine condensation reactions could be used as a universal path to obtain HTMs for highly efficient and stable PSCs.

Hypophosphatemia in the Intensive Care Unit: Incidence, Predictors and Management

Introduction: Our objectives are to identify the incidence of hypophosphatemia and the associated risk factors. We also want to establish intravenous replacement therapy that is effective for ICU patients. Methods: A prospective observational study assessing adults admitted to ICU in between March and May 2009. All patients without baseline phosphate level and renal failure were excluded. They were evaluated for the occurrence of common risk factors. Association with independent variables that includes age, gender and BMI were verified. Evaluation of IV replacement therapy was done in the treated patients. Results: From 50 patients that were reviewed, nine were excluded. There were 66% male and 34% female with mean age 46.88±17.89. The mean ICU stay was 8.00±6.41 days. The incidence of hypophosphatemia was 29% (n=12/41). Gender and creatinine clearance was found to be significantly different between normophosphatemia and hypophosphatemia patients. There was no significant association for each potential risk factor and the number of risk factors (≥3) with the incidence of hypophosphatemia. Multi-linear regression analysis showed that lactate, creatinine clearance and pH were significant predictors to the serum levels. A significant difference of mean serum phosphate was seen after repletion by total dose of 10, 20 and 40 mmols in the treatment subgroups. Conclusions: The incidence of hypophosphatemia in our ICU was high and comparable to previous studies. None of the commonly reported risk factors is associated with hypophosphatemia in this studied population. Among all significant correlated variables, only pH was found to be a significant predictor for serum phosphate. Baseline phosphate level may guide the initial replacement dose to prevent delay in normalization of serum levels.

(<i>E</i>)-2-Cyano-3-[4-(dimethylamino)phenyl]-<i>N</i>-phenylprop-2-enamide

In the title compound, C(18)H(17)N(3)O, the dihedral angle between the phenyl and benzene rings is 11.22 (14)°. Apart from the methyl H atoms, the mol-ecule is close to planar, with a maximum deviation of 0.145 (3) Å. Intra-molecular C-H⋯O and C-H⋯N inter-actions occur. In the crystal, inversion dimers linked by pairs of N-H⋯N hydrogen bonds occur, resulting in an R(2) (2)(12) ring motif. Further C-H⋯N and C-H⋯O bonds generate R(1) (2)(7) and R(2) (2)(22) motifs and a C-H⋯π inter-action also occurs.

On the loading rate sensitivity of plastic deformation in molecular crystals

The nanoindentation technique is being widely utilized to measure the mechanical properties of small single crystals of molecular materials. However, all the experiments reported hitherto were performed under quasi-static conditions and at relatively low loading rates. “Will the plastic response change if the tests are performed at high strain rates?” is a question we address in this communication. For this, we have examined the strain rate sensitivity of nanoindentation responses on the major faces of four different molecular crystals: L-alanine, saccharin, p-nitroaniline, and sulfathiazole. Experimental results indicate that the measured hardness values are loading rate insensitive. The possible reasons for this insensitivity and implications for applications in pharmaceutical manufacturing are discussed.

Effects of Date Palm fibres loading on mechanical, and thermal properties of Date Palm reinforced phenolic composites

Present research work deals with the various date palm fibres (DPF) loading (0%, 40%, 50%, and 60% by wt%) as reinforced material in phenolic composites. DPF reinforced phenolic composite were manufactured by hand lay-up technique and characterized mechanical (tensile, flexural and impact), morphological, and dynamic mechanical properties to evaluate optimum fibre loading of composites. It is observed that incorporation of 50% DPF loading improved tensile modulus and impact properties but reduce tensile strength, flexural strength and modulus. Scanning electron microscope investigated the interfacial bonding of fibre and matrix in composites. Storage modulus of DPF composites improved and 50% DPF loading illustrated highest storage modulus. Loss modulus increased when DPF was reinforced, 40% fibre loading showed highest Tg for loss modulus but Tg of 50% fibre loading was very close to the composite with 40% fibre loading. Tan delta of DPF composites display low value whereas increasing the fibre loading, the Tg of damping factor were increased. The obtained results concluded that 50% DPF composites have better mechanical and thermal properties with better interfacial bonding between fibres and matrix. This material can be use as insulation material in buildings, false ceiling and walls.

CCDC 1960711: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

(<i>E</i>)-<i>N</i>′-(9-Anthrylmethylidene)-<i>p</i>-toluenesulfonohydrazide

The S-N(H)-N=C linkage in the title mol-ecule, C(22)H(18)N(2)O(2)S, is non-planar [torsion angle = 30.6 (1)°] as the amino N atom is pyramidally coordinated. In the crystal, the amino group acts as a hydrogen-bond donor to an O atom of an adjacent mol-ecule, generating chains running parallel to the b axis.

Manganese(<scp>iii</scp>) acetate-mediated synthesis of <i>N</i>-substituted fulleropyrrolines <i>via</i> the reaction of [60]fullerene with α-monosubstituted acetaldehydes and primary amines

The simple one-step reaction of [60]fullerene with α-monosubstituted acetaldehydes and primary amines in the presence of Mn(OAc)₃·2H₂O under air conditions afforded a series of novel <i>N</i>-substituted fulleropyrrolines with trisubstituted CC bonds in moderate to good yields. The addition of Mn(OAc)₃·2H₂O played a crucial role in the successful synthesis of <i>N</i>-aryl fulleropyrrolines with trisubstituted CC bonds, which would be extremely difficult to prepare by known methods as a result of the decreased nucleophilicity of arylamines due to the p-π conjugation effect. Intriguingly, arylamines displayed abnormally higher reactivity as compared with non-arylamines in the current reaction system by the observation of obviously decreased equivalent of Mn(OAc)₃·2H₂O, higher product yields, and lower reaction temperature probably due to the radical reaction mechanism initiated by Mn(OAc)₃·2H₂O. On the basis of experimental observations, a plausible formation pathway for <i>N</i>-substituted fulleropyrrolines with trisubstituted CC bonds was proposed to elucidate the above-mentioned reaction process.

Sonochemical synthesis of Co2SnO4 nanocubes for supercapacitor applications

Micro concentrations of Ru(III) used as homogenous catalyst in the oxidation of levothyroxine by N-bromosuccinimide and the mechanistic pathway

Turmeric/polyvinyl alcohol Th(IV) phosphate electrospun fibers: Synthesis, characterization and antimicrobial studies

A combined experimental and theoretical investigation of 2-Thienylboronic acid: Conformational search, molecular structure, NBO, NLO and FT-IR, FT-Raman, NMR and UV spectral analysis