Muhammad Ahsan Shafique

A simple microwave assists aqueous route to synthesis CuS nanoparticles and further aggregation to spherical shape

The aggregation of CuS nanoparticles during synthesis by a hassle-free aqueous route under microwave irradiation gave remarkable spherical shape, utilizing Cu(CH3COO)2·H2O as the source of copper and Na2S2O3·5H2O, as sulfur source; these materials were used without assistance of any surfactant or template. An X-ray powder diffraction pattern proved that the product is hexagonal CuS phase. The morphologies of the product were observed by scanning electron microscopy. Thermal behavior, different solid state, and chemical conversion in CuS with respect to temperature were studied by DSC/TGA, which confirmed the thermal oxidation of CuS and its conversion into CuO then to Cu2O.

Effect of doping concentration on absorbance, structural, and magnetic properties of cobalt-doped ZnO nano-crystallites

Controlled conduction of magnetic spins is desired for data processing in modern spintronic devices. Transition metal-doped ZnO is a potential candidate for this purpose. We studied the effects of cobalt doping on structural, absorbance, and magnetic properties of ZnO nano-particles. Different compositions (Zn0.99Co0.1O, Zn0.97Co0.3O, and Zn0.95Co0.5O) of cobalt-doped ZnO were fabricated using metallic chlorides by co-precipitation method. XRD revealed standard ZnO wurtzite crystal structure without lattice distortion due to impurities but showed presence of additional phases at higher doping ratios. Fourier transformed infrared spectroscopy also confirmed the standard ZnO profiles at lower doping ratios but additional phases at higher doping. Vibrating sample magnetometer showed soft ferromagnetic behavior for low impurity samples and harder ferromagnetic behavior for higher doping at room temperature. A simultaneous differential scanning calorimetry/thermo gravimetric analysis was performed to study the phase variations during crystallization.

2-[(E)-3-Phenyl­prop-2-en­yl]-1,2-benzisothia­zol-3(2H)-one 1,1-dioxide

In the crystal structure of the title compound, C16H13NO3S, the benzisothiazole group is almost planar (r.m.s. deviation for all non-H atoms excluding the two O atoms bonded to S = 0.009 Å). The dihedral angle between the fused ring and the terminal ring is 13.8 (1)°. In the crystal, molecules are linked through intermolecular C—H⋯O contacts forming a chain of molecules along b.

Improved cell viability and hydroxyapatite growth on nitrogen ion-implanted surfaces

ABSTRACT Stainless steel 306 is implanted with various doses of nitrogen ions using a 2 MV pelletron accelerator for the improvement of its surface biomedical properties. Raman spectroscopy reveals incubation of hydroxyapatite (HA) on all the samples and it is found that the growth of incubated HA is greater in higher ion dose samples. SEM profiles depict uniform growth and greater spread of HA with higher ion implantation. Human oral fibroblast response is also found consistent with Raman spectroscopy and SEM results; the cell viability is found maximum in samples treated with the highest (more than 300%) dose. XRD profiles signified greater peak intensity of HA with ion implantation; a contact angle study revealed hydrophilic behavior of all the samples but the treated samples were found to be lesser hydrophilic compared to the control samples. Nitrogen implantation yields greater bioactivity, improved surface affinity for HA incubation and improved hardness of the surface.

STUDY OF NICKEL ION RELEASE IN SIMULATED BODY FLUID FROM C+-IMPLANTED NICKEL TITANIUM ALLOY

Nickel ion release from NiTi shape memory alloy is an issue for biomedical applications. This study was planned to study the effect of C+ implantation on nickel ion release and affinity of calcium phosphate precipitation on NiTi alloy. Four annealed samples are chosen for the present study; three samples with oxidation layer and the fourth without oxidation layer. X-ray diffraction (XRD) spectra reveal amorphization with ion implantation. Proton-induced X-ray emission (PIXE) result shows insignificant increase in Ni release in simulated body fluid (SBF) and calcium phosphate precipitation up to 8×1013ions/cm2. Then Nickel contents show a sharp increase for greater ion doses. Corrosion potential decreases by increasing the dose but all the samples passivate after the same interval of time and at the same level of VSCE in ringer lactate solution. Hardness of samples initially increases at greater rate (up to 8×1013ions/cm2) and then increases with lesser rate. It is found that 8×1013ions/cm2 (≈1014) is a safer limit of implantation on NiTi alloy, this limit gives us lesser ion release, better hardness and reasonable hydroxyapatite incubation affinity.

4-Methyl-N-{4-[(5-methyl-1,2-oxazol-3-yl)sulfamo-yl]phen-yl}benzene-sulfonamide.

In the title compound, C17H17N3O5S2, the dihedral angle between the two benzene rings is 81.27 (8)° and the heterocyclic ring is oriented at 9.1 (2) and 76.01 (9)° with respect to these rings. Molecules are connected via N—H⋯N and N—H⋯O hydrogen bonds, generating an R 2 2(8) motif, into chains running along the [001] direction. There is also an intramolecular C—H⋯O hydrogen bond completing an S(6) ring motif. The polymeric chains are interlinked through intermolecular C—H⋯O hydrogen bonds.

Methyl 4-{[(4-methyl­phen­yl)sulfon­yl]amino}­benzoate

In the molecule of the title compound, C15H15NO4S, the dihedral angle between the two rings is 88.05 (7)°. The methyl ester group is nearly coplanar with the adjacent ring [dihedral angle = 2.81 (10)°], whereas it is oriented at 86.90 (9)° with respect to the plane of the ring attached to the –SO2– group. Weak intramolecular C—H⋯O hydrogen bonding completes S(5) and S(6) ring motifs. The molecules form one-dimensional polymeric C(8) chains along the [010] direction due to N—H⋯O hydrogen bonding and these chains are linked by C—H⋯O hydrogen bonds, forming a three-dimensional network.