Publications

CCDC 896479: 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.

Amino-bridged covalent organic Polycalix[4]arenes for ultra efficient adsorption of iodine in water

Effect of Embedment of MWCNTs for Enhancement of Physical and Mechanical Performance of Medium Density Fiberboard

In this research work effect of embedment of multiwall carbon nanotubes (MWCNTs) on the physical and mechanical properties of medium density fiberboard (MDF) have been investigated. The MWCNTs were embedded in urea formaldehyde resin (UF) at 0, 1.5%, 3% and 5% concentrations by weight for the manufacturing of nano-MDF. The addition of these nanoparticles enhanced thermal conductivity by 24.2% reduced curing time by 20% and controlled formaldehyde emission by 59.4%. The internal bonding (I.B), modulus elasticity (MOE), modulus of rupture (MOR), thickness swelling (Ts) and water absorption (WA) properties were improved significantly by 21.15%, 30.2%, 28.3%, 44.8% and 29% respectively as compared to controlled MDF.

The DFT investigations of the electron injection in hydrazone-based sensitizers

Redox behavior, chromatographic and spectroscopic characterization of some reactive π-conjugated 4′-tricyanovinylhydrazone dyes

The electrochemical reduction mechanism of 4′-nitrotricyanovinylhydrazone in DMF–B-R buffer to the corresponding [(4-hydroxyamino)phenyl]methamine <italic>via</italic> 2H⁺/2e⁻ reduction of (<italic>E</italic>)-<italic>N</italic>-(1-(4-hydroxyamine)phenylethylidene)methamine is proposed.

Synthesis and Sensor Activity of a PET-based 1,8-naphthalimide Probe for Zn2+ and pH Determination

Covalent organic frameworks promoted single metal atom catalysis: Strategies and applications

2-[(2-Hydroxynaphthalen-1-yl)methylideneamino]-5,6,7,8-tetrahydro-4<i>H</i>-cyclohepta[<i>b</i>]thiophene-3-carbonitrile

Two independent mol-ecules, A and B, comprise the asymmetric unit of the title compound, C(21)H(18)N(2)OS, with the difference in the angle of orientation between the naphthalene ring system and the mean plane of the cyclo-heptyl ring [16.13 (1) in A and 11.48 (5)° in B], being evident. The cyclo-heptyl ring adopts a distorted chair conformation in each mol-ecule with r.m.s. deviations of 0.2345 (4) (A) and 0.2302 (4) Å (B). Intra-molecular O-H⋯N hydrogen bonding generates planar six-membered S(6) loops with r.m.s. deviations of 0.0099 (1) (A) and 0.0286 (1) Å (B).

Grafting polyisoprene onto surfaces of nanosilica via RAFT polymerization and modification of natural rubber

In this contribution, we reported the investigation of natural rubber (NR) reinforced by silicon dioxide‐ graft ‐polyisoprene (SiO 2 ‐ g ‐PIP) core–shell nanoparticle. First, the hydroxyl on the surface of the SiO 2 nanoparticles was reacted with 2‐methyl‐2‐[(dodecylsulfanylthiocarbonyl) sulfanyl] propanoic acid to produce trithioester‐capped SiO 2 (denoted as SiO 2 ‐CTA). SiO 2 ‐CTA was used as a nanoparticle chain transfer agent, and SiO 2 ‐ g ‐PIP core–shell nanoparticles were synthesized via reversible addition‐fragmentation chain transfer polymerization (RAFT). The results of FTIR spectroscopy and TGA showed that the grafting weight of the PIP block in SiO 2 ‐ g ‐PIP was 2.1 wt%. SiO 2 ‐ g ‐PIP and SiO 2 were simultaneously incorporated into NR. The curing properties of the NR compounds showed that the vulcanization rates of the NR/SiO 2 ‐ g ‐PIP compounds were much higher than those of NR/silica compounds. The results of scanning electron microscopy showed that SiO 2 microdomains in the NR/SiO 2 ‐ g ‐PIP vulcanizate were much better disperse and distribute than SiO 2 microdomains in the NR/SiO 2 composite. The filler–rubber interaction of the NR/SiO 2 ‐ g ‐PIP composite endowed the composite with improved mechanical properties. POLYM. ENG. SCI., 59:1167–1174 2019. © 2019 Society of Plastics Engineers

Albizia chevalier based Ag nanoparticles: Anti-proliferation, bactericidal and pollutants degradation performance

Photochromic properties of 1′,3′,3′‐trimethyl‐6‐nitrospiro[2H‐1‐benzopyran‐2,2′‐indoline] doped in PMMA and epoxy resin thin films

Purpose The purpose of this paper is to evaluate the photochromic performance of photochromic compounds in polymer matrices. Design/methodology/approach The poly(methyl methacrylate) (PMMA) and epoxy resin doped with photochromic spirobenzopyran were prepared and the effects of ultraviolet (UV) irradiation were studied using spectrophotometer. The reversible reaction was effected using white light. Photochemical fatigue resistance of these films was also studied. Findings Irradiation of colourless 1′,3′,3′‐trimethyl‐6‐nitrospiro[2H‐1‐benzopyran‐2,2′‐indoline] spiropyran (SP) doped in PMMA and epoxy resin with UV light (366 nm) results in the formation of an intense purple‐red coloured zwitterionic photomerocyanine (PMC). The reverse reaction was photochemically induced by irradiation with white light. Photocolouration of SP doped in PMMA follows a first‐order rate equation ( k =0.0011 s −1 ), while that doped in epoxy resin deviates from linearity. It was found that photobleaching follows a first‐order equation in both matrices. The photobleaching rate constant of PMC in both matrices is the same and equals 0.0043 s −1 . Spirobenzopyran doped in PMMA shows better fatigue resistance than that doped in epoxy resin. Research limitations/implications The PMMA and epoxy resin polymers doped with photochromic spirobenzopyran described in the present paper were prepared and studied. The principle of study established can be applied to any type of polymer or to any type of photochromic compounds. Practical implications The photochromic materials developed can be used for different applications, such as coatings and holography. Originality/value The method developed may be used to enhance the performance of photochromic materials.

CCDC 845500: 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.

?Chemical Constituents of Three Launea and One Crepis Species

The essential oil of Salvia aegyptiaca was analysed by GC/ MS technique. Eighteen compounds were identified. It was found that the essential oil comprises 40% terpenoidal constituents, opposite to 32% fat derivatives. The major terpenoidal component was 1(10)- aristolene (19.3%). From the non-volatile matter, ?-amyrin, lupeol, ?-sitosterol, stigmasterol, ?-sitosterol-?-D-glucopyranoside and stigmasterol-?-Dglucopyranoside as well as 3?-hydroxy-24-alkylcarboxylate-12- oleanan-28-oic acid. Fatty acids esters were isolated and identified by spectral means

Carbon Nanotubes and Graphene Powder based Multifunctional Pressure, Displacement and Gradient of Temperature Sensors

This work presents the fabrication and investigation of the multiwalled carbon nanotubes (MWCNTs) and graphene pristine powders based multifunctional pressure, displacement and gradient of temperature sensors. The effect of pressure on the resistance, Seebeck coefficient , thermoelectric voltage and current of the sensors was measured by changing pressure from 0 to 1.65 kgf/cm2, while the effect of temperature gradient on the resistance, thermoelectric voltage and current of the sensors was measured up to the temperature gradient of 34–36°C. Dependence of the resistance on longitudinal compressive displacement up to 100 μm was investigated. It was found that the resistance, Seebeck coefficient and thermoelectric voltage of the CNT and graphene powders decreased with increasing pressure, while the thermoelectric current increased with pressure. Moreover, with increasing temperature gradient and average temperature a considerable increase was observed in thermoelectric current and voltage, while the increase in resistances was moderate. The increase in longitudinal displacement resulted in the compression of the samples that caused to decrease the resistances of the samples, especially in the case of samples made from CNT and graphene both. The simulation of the experimental results was carried out by using of linear functions and the results of simulations were in good agreement with experimental results.

A novel highly selective electrochemical chlorobenzene sensor based on ternary oxide RuO₂/ZnO/TiO₂ nanocomposites

A novel electrochemical (EC) chlorobenzene (CBZ) sensor was fabricated using a ternary oxide RuO₂/ZnO/TiO₂ nanocomposite (NC)-decorated glassy carbon electrode (GCE). The nanoparticles (NPs) were synthesized by a wet-chemical method and characterized by X-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), and ultraviolet-visible (UV-vis) spectroscopy. The synthesized RuO₂/ZnO/TiO₂ NC was layered as thin film on a GCE with Nafion (5% suspension in ethanol) adhesive, and the as-prepared sensor was subjected to CBZ analysis using an electrochemical approach. The calibration of the proposed CBZ sensor was executed with a linear relation of current <i>versus</i> concentration of CBZs known as the calibration curve. The sensitivity (32.02 μA μM^-1 cm^-2) of the CBZ sensor was calculated from the slope of the calibration curve by considering the active surface area of the GCE (0.0316 cm²). The lower detection limit (LD; 98.70 ± 4.90 pM) was also calculated at a signal-to-noise ratio of 3. Besides these, the response current followed a linear relationship with the concentration of chlorobenzene and the linear dynamic range (LDR) was denoted in the range of 0.1 nM to 1.0 μM. Moreover, the CBZ sensor was found to exhibit good reproducibility, reliability, stability, and fast response time. Finally, the sensing mechanism was also discussed with the energy-band theory of ternary doped semiconductor materials. The sensing activity of the proposed sensor was significantly enhanced due to the combined result of depletion layer formation at the heterojunction of RuO₂/ZnO/TiO₂ NCs as well as the activity of RuO₂ NPs as oxidation catalysts. The proposed CBZ sensor probe based on ternary oxide RuO₂/ZnO/TiO₂ NCs was developed with significant analytical parameters for practical application in monitoring the environmental pollutants of CBZs for the safety of environmental fields on a large scale.

ChemInform Abstract: Synthesis of Taurine‐Containing Peptides, Sulfonopeptides, and N‐ and O‐Conjugates.

A magnetic electrochemical immunosensor for the detection of phosphorylated p53 based on enzyme functionalized carbon nanospheres with signal amplification

A nanomaterial-based disposable immunosensor was developed for detection of phosphorylated protein using enzyme functionalization of carbon nanospheres as amplification labels.

Physicochemical and Nonlinear Optical Properties of Novel Environmentally Benign Heterocyclic Azomethine Dyes: Experimental and Theoretical Studies

Novel heterocyclic azomethine dyes were prepared by the reaction of anthracene-9-carbaldehyde with different heterocyclic amines under microwave irradiation. Structures of the azomethine dyes were confirmed by the elemental analysis, mass spectrometry and several spectroscopic techniques. We studied absorbance and fluorescence spectra of the azomethine dyes in various solvents. They are found to be good absorbers and emitters. We also report photophysical properties like, extinction coefficient, oscillator strength, stokes shift and transition dipole moment. This reflects physicochemical behaviors of synthesized dyes. In addition, their intramolecular charge transfer and nonlinear optical properties, supported by natural bond orbital technique, were also studied computationally by density functional theory. The negative nonlinear refractive index and nonlinear absorption coefficient were measured for these dyes using the closed and open aperture Z-scan technique with a continuous wave helium-neon laser. These are found to vary linearly with solution concentration.