H2S Gas Sensitivity of Doped SbP Monolayer:First Principle Study

The sensing behaviors of monolayer antimonide phosphorus (SbP) for hydrogen sulfide (H2S) are investigated by means of the density functional theory. In this paper, we calculated the best adsorption configuration, charge transfer, adsorption distance, band gap, electronic structure and recovery time of H2S on the SbP monolayer and mental-doped SbP (X-SbP). The calculated results indicate that Al atom replaces Sb atom of SbP (Al-Sb-SbP), adsorption capacity was greatly increased, but the covalent bond formed between the gas molecules and the substrate was not suitable for sensing materials. And though Co or Ni atom could improve the interactions between H2S gas and SbP sheets, the recovery time was too long. It was also not suitable for the sensor material of H2S gas. However, for Pd doped SbP, Pd-Sb and Pd-P doping all exhibit excellent gas sensing performance for H2S gas with the adsorption energy of -0.677eV and -0.520eV, the charge transfer 0.1113e and 0.0930e, the recovery time 0.19s and 5.30×10-4 s, respectively. These characters made Pd-SbP suitable for H2S gas sensing material. Which further analysis we knew that these changes were mainly due to the orbital hybridization between the s, p orbitals of Pd atom and the p orbitals of S atom. Theoretical studies show that Pd-doped SbP is a promising H2S gas sensing materialread more

Dong Li, Xiaolei Li, Tengfei Wang, Lu Li and Junkai Wang

Comparative Study on Sodium Storage Properties of Two CNTs and a Novel CNT Design

Density functional theory (DFT) is employed to research three carbon tubes (CNTs), SWCNT, N-NiCNT, and N-CoCNT. The first two structures synthesized by other groups and N-NiCNT has better sodium storage properties as sodium-ion battery (SIB) anode than SWCNT, the last one is a designed structure. Here, the intrinsic cause why N-NiCNT has better performance than SWCNT has been located at molecular and atomic levels, meanwhile the potential of N-CoCNT as anode candidate is predicted. The researched properties that determine the electrochemical performances involve in structure stability, frontier molecular orbital, partial density of state analysis, and sodiation barrier comparison. The results indicate that the lower sodiation barrier, expanding transfer space, more stable structure stability of N-NiCNT should be responsible for its better sodium storage performance, which consists with the experimental results. In addition, the designed N-CoCNT anode is a promising candidate as SIB anode owing to better stability, lower barrier, and strong N-Co interaction than N-NiCNTread more

Tingting Xu, Xiaohua Xie, Huisheng Huang and Xinwei Zhao

Electrocatalytic Oxidation Performance of PbO2 Composite Electrode Doped with MXenes

In this study, a two-dimensional transition metal carbon/nitride (MXenes) method was used to enhance the electrocatalytic oxidation behavior of PbO2 electrode. A novel composite electrode was prepared by doping the modified MXenes into PbO2 material. The electrochemical performance was tested by electrochemical workstation. The typical cationic red X-GRL was treated by electrochemical oxidation, and the electrochemical oxidation performance of the material electrode was investigated. The results demostrated that the dyes were removed by the oxygen evolution reaction at the electrodes doped with modified MXenes by passing current. The charge transfer resistance is 12.56. The electrodes have remained stable after 20 cycles of charging and discharging. And the removal rate of cationic red X-GRL was as high as 95.19% in 120 min. A high-efficiency composite electrode was developed in this study, which increased the electrode's performance as well as wastewater degradation efficiency, and lay the groundwork for future research into doping MXenes to improve the performance of other materials. Hence, electrode materials doped with two-dimensional structured MXenes were candidates for the removal of contaminants, especially in the field of electrochemical catalysisread more

Xinyu Zhang, Jiajun Li, Ming Guo, Kaijie Ni, Ronghui Wu and Zhiyan Hu

Use of 1D [Pr(BTC)(H2O)6] MOF as a Filler for Fabrication of Matrimid® based MMMs

Selection of good filler-polymer pair results in improved gas separation performances. Present study deals with fabrication of Matrimid based hybrid or mixed matrix membranes (MMMs) by using three weight loadings (10, 20 and 30 wt. %) of 1D rod shaped nanoporous [Pr(BTC)(H2O)6] metal organic framework (MOF). The fourier transform infrared (FTIR) spectrophotometric analysis indicated the bonding of lanthanide metal ion with the linker and thus formation of the MOF, and further revealed that the structure of MOF remained intact after incorporation into the polymer matrix. Powder X-ray (PXRD) analysis revealed purity and crystallinity of the MOF while the PXRD results for the MMMs indicated that crystallinity of the MOF remained unaffected after fabrication of the MMMs. The Scanning electron microscopy (SEM) results gave an indication of the formation of the MOF in same morphology as it is previously reported. Additionally, nice distribution and well adherence of the additive particles throughout the polymer matrix was observed while the interfacial voids were visibly absent. The MOF and the MMMs were thermally stable and crystallinity of MOF particles remained intact after dispersion into polymer matrix. The Brunauer Emmett Teller (BET) surface area of the MOF was also obtained that indicated its permanent porosity. The prepared MMMs were flexible enough to handle for all analysis. These findings led to conclude that a proper polymer-filler pair was made that produced defect free MMMs. The prepared MMMs can be evaluated in future for their performance towards separation of different gases after modification of the pore of the fillerread more

Asma R. Tariq, Misbah Sultan, Tariq Mahmud, Ghayoor Abbas Chotana, Muhammad Rizwan Dilshad, Asim Laeeq Khan, Muhammad Imran, Saadia Rashid Tariq and Prof. Dr. Klaus Müller-Buschbaum

The Influence of pH of Float on the Dyeability of Polyester Fabric

Disperse dyes are essentially non – ionic, exhibit poor solubility in water, and they can be used in the form of water dispersion. Polyester fibres are resistant to dilute aqueous acids and alkaline solutions and pH value does not provide a crucial impact on the dyeing mechanism; however, many disperse dyes undergo degradation if the pH is uncontrolled during aqueous dyeing. In order to minimize the possibility of dye hydrolysis, the dyeing is carried out in a slightly acidic medium, and pH is usually adjusted with acetic acid. In this work, the quantity of disperse dyes (Sinten Gelb P-5GL and Sinten Scharlach P-3GL) applied to polyester knitwear was investigated as a function of pH. The sorption capacity of polyester knitwear was monitored by using reflection curves and CIELab system, according to Swiss software Sandoz (based on spectrophotometry). The acetic acid was used for dyebath pH adjustment. The results showed that the maximum uptake of Sinten Gelb P-5GL and SintenScharlach P-3GL dyes by polyester knitwear occurred at pH 4.64 (0.2924%) and 6.20 (0.1860%), respectively. According to reflection curves in the range (max = 400-700 nm), the effect of pH on the sorption of Sinten Gelb P-5GL was more significant than one for Sinten Scharlach P-3GL, when concentration of dye is constant (0.4%). The CIELab values for three illuminants (daylight, light – bulb and incandescent) showed a significant dependence between pH float and hue and intensity of polyester knitwear dyeing with disperse dyesread more

Milena Miljković, Sandra S. Konstantinović, Vojkan M. Miljković, Milena Nikodijević and Dušan Trajković

Synthesis, Characterization and Application of Karak Bentonite Clay-Graft-Poly (Acrylamide/Co- Acrylic Acid) Superabsorbent Composite and its Adsorption Study for Selected Heavy Metals

A novel superabsorbent composite (SAC) based on bentonite, acrylamide and acrylic acid was synthesized. The effects of bentonite quantity, initiator content on the grafting degree and on the water absorbency for the samples were studied. Synthesis mechanism, morphology and thermal properties of the SAC were characterized. FTIR results confirmed the presence of acrylamide/ acrylic acid onto bentonite backbone while TGA showed that introduction of 70 % bentonite to polymer increases thermal stability. The SAC was also tested in the removal of heavy metal in aqueous solution where kinetics analyses were performed using Langmuir adsorption isotherm. The optimum adsorption capability of heavy metal ions onto bentonite-based SAC from solution was 92, 48 and 91 % for Pb++, Ni++, and Cu++ respectively. The unique characteristics of these SAC such as its slow-release and water-retention capability, nontoxicity in soil, environmentally friendly and high capacity for the removal of heavy metals might be very valuable in agriculture and environmental studiesread more

Shaheen Wali, Manzoor Iqbal Khattak and Mahmood Iqbal Khattak

Determination of Diclofenac Sodium in Pharmaceutical Preparations by Computational Image Scanning Densitometry

Diclofenac sodium is a nonsteroidal anti-inflammatory drug which cures by reducing substances in the body that cause pain and inflammation. There is always a risk of heart attack and stroke in case of taking excess of the drug. In present study a simple, fast and cost-effective method is devised for the assay of diclofenac sodium in locally available pharmaceutical preparations. The method is based on the reaction of the drug with 2, 4-DNPH (2, 4-Dinitro phenyl hydrazine). Micro-quantities of the drug gave green coloured spots when mixed with 2,4-DNPH on a pre-coated TLC plate, in the presence of potassium iodate and lithium hydroxide. The spots were scanned by using a flatbed scanner and the images obtained were computationally quantified with the help of custom-made software to measure the optical density. The reaction parameters were optimized, and the results were compared with the standard spectrophotometric methodread more

Waheed-uz-Zuman, Rida Ayub, Amara Dar and Jamil Anwar

Organic-Exchanged Silicotungstic Acid Compounds as Efficient and Environmental-Friendly Catalysts for Synthesis of Glycerol Monolaurate

A series of organic-exchanged silicotungstic acid catalysts were synthesized by changing the variety and amount of organic compounds. The structure, thermal stability and acidic properties of the catalysts were characterized by FT-IR, XRD, TGA and 31P-MAS NMR. The catalytic performances of the catalysts were investigated on the selective esterification of lauric acid with glycerol to glycerol monolaurate. Among the various catalysts, [QuH]1H3SiW12O40 with molar ratio of quinoline to silicotungstic acid of 1:1 showed excellent activity and reusability due to strong Brønsted acidity and “pseudo-liquid” catalytic modes. The optimal conditions optimized by response surface methodology were as follows: the molar ratio of glycerol to lauric acid was 5.3:1, the amount of catalyst was 4.8 wt%, the reaction temperature was 424 K, and the reaction time was 1.5 h. Under these conditions, the average yield of glycerol monolaurate was 79.7%, which was basically consistent with the values predicted by the mathematical model. Moreover, the kinetic data of this reaction were fitted to a second-order kinetic model and the apparent activation energy Ea was 52.35 kJ / molread more

Li Ran, Deng Yunli, Wu Siliang, Liao Jiayi, Tang Xiujuan, Han Xiaoxiang

Synthesis, Characterization, Antimicrobial and Anticarcinogenic Activity of Quinazoline Derivatives

The reaction of β-dicarbonyl compounds as ethyl acetoacetate with hydrazines is a well-established route for the creation of pyrazole derivatives. In this research, 4-hydrazinoquinazoline (4) reacted with ethyl acetoacetate in boiling ethanol it gives ethyl 3-oxobutanoate quinazolin-4-yl-hydrazone (5). Cyclization of the compound (5) in the presence of glacial acetic acid is passed to form 4-(5-hydroxy-3-methyl-1H-pyrazol-1-yl)quinazoline(6). Furthermore, the reaction of phenylisothiocyanate compounds with hydrazines is a well-established way for the synthesis of tetrazinoquinazoline (8). The new compounds are confirmed by elemental analysis, nuclear magnetic resonance, infrared, and mass spectra. In-vitro anti-tumor evaluation of the new compounds across three cell lines HepG2 (liver carcinoma), HCT-116 (colon carcinoma), and MCF-7 (breast carcinoma) indicats high anti-tumor activity. In addition, antimicrobial activity of specific synthesized compounds are screened against four bacterial species. Amongst four, two Gram-negative are Escherichia coli, Pseudomonas aeuroginosa and gram-positive as Staphylococcus aureus and Bacillus subtilis. The antibacterial activity of Compounds (5) and (6) are greater comparing to standard drug (Amphicillin).read more

Fatma A. M. Mohamed, Bi Bi Zainab Mazhari, Mona F. Warrad, Hesham A. M. Gomaa, Asmaa T. Ali, Shaimaa Salah Eldeen Hussein and Hendawy Om

Pro-Neurogenic Potential of Daphne mucronata Royle

The petroleum ether soluble and insoluble fractions of the methanol extract of air dried stem extract of Daphne mucronata and a pure compound daphnin obtained from the more active petroleum ether insoluble fraction were evaluated for the pro-neurogenic activity on cortical and hippocampal primary cell cultures prepared from the neonatal mice brain. It showed significant proliferation of the cells as assessed by MTT assayread more

Perveen Bano, Kanwal Iftikhar, Kinza Rafi, Bina Shaheen Siddiqui, Shabana Usman Simjee, Sabira Begum