Poorvesh M. Vyas

FTIR and thermal studies of gel-grown, lead–cadmium-mixed levo tartrate crystals

Metal tartrate compounds find various applications. Lead tartrate is added in gasoline to prevent knocking in motors, and cadmium tartrate crystals possess piezoelectric nature. In the present study, lead–cadmium-mixed levo tartrate crystals were grown using silica hydro gel as growth medium. Long and dendrite-type white crystals were obtained. The crystals were characterized by EDAX, powder XRD, FTIR spectroscopy, TG, DTA, and DSC. The composition of the crystals was determined by EDAX. The FTIR spectra revealed the presence of water molecules, O–H, C–H, C–O, C–C, and C=O functional groups. TG curves suggested that the crystals were thermally unstable and decomposed into oxide through three stages. DTA curves showed endothermic and exothermic reactions.

Synthesis and Characterization of Calcium Tartrate Dihydrate Nanoparticles

Calcium tartrate finds various applications. In the present study, calcium tartrate nanoparticles were synthesized by wet chemical method using surfactant mediated approach. The powder XRD pattern revealed the typical broadening of peaks indicating the nanostructured nature. The average crystallite size was calculated by applying the Scherrers formula to powder XRD pattern and was found in the range of 22.8–23.9 nm. The particle size and morphology of the synthesized nanoparticles was confirmed by using transmission electron microscopy (TEM). FTIR spectroscopy was used to confirm the presence of various functional groups. From TGA, it was found that calcium tartrate nanoparticles remained stable up to 120°C and were having two water molecules associated with them. The results are compared with the bulk crystalline materials available in the literature.

Synthesis and Characterization of Cholesterol Nano Particles by Using w/o Microemulsion Technique

Cholesterol is one of the most abundant and well known steroids in the animal kingdom. Cholesterol rich micro‐emulsions and nano‐emulsions are useful for the treatment of breast cancer and gynecologic cancers. The nano particles of cholesterol and other pharmaceutically important materials have been reported. In the present investigation, the nano particles of cholesterol were synthesized by direct precipitation technique using triton X‐100/water/n‐butanol micro‐emulsion. The average particle size of cholesterol nano particles was estimated by applying Scherrer’s formula to the powder X‐ray diffraction pattern, which was found to be 22 nm. The nanoparticles of cholesterol were observed by using TEM and the particle size was found within the range from 15 nm–31 nm. The distribution of particle size was studied through DLS. The nanoparticles of cholesterol were characterized by using FT‐IR spectroscopy and the force constant was also calculated for O‐H, C‐H and C‐O bonds. The thermal response of nanoparticl...

Surface Micro Topographical and Dielectric Studies of Cholesterol Crystals

Cholesterol is a main component in mammalian cell membranes and lipoproteins. High level of cholesterol in blood can damage arteries and potentially linked with cardiovascular diseases. Cholesterol is also major constituent of gall stones. Cholesterol crystals were grown by single diffusion gel growth technique using neutral silica gel set by acetic acid. Solution of cholesterol prepared in acetone was poured as a supernatant solution on set gel. Transparent, thin, platelet type crystals were grown. Powder XRD and FT IR studies were carried out for the confirmation of crystal system and chemical bonding. The surface micro topographical study was carried out by using SEM and AFM and interesting features were observed. As cholesterol possesses high dielectric constant, it functions as an insulting cover for the transmission of electric impulses in the nervous tissues; therefore, the dielectric study was carried to understand its dielectric behavior in the frequency range from 50 Hz to 5 MHz. The dielectric constant decreased as the frequency of applied field increased. The a.c. conductivity and a.c. resistivity were also calculated.

SYNTHESIS AND CHARACTERIZATION OF n-BUTYL 4-(3,4-DIMETHOXYPHENYL)-6-METHYL-2-THIOXO-1,2,3,4 TETRAHYDROPYRIMIDINE-5-CARBOXYLATE NANOCRYSTALLINE PARTICLES BY WATER/OIL MICROEMULSION METHOD

Various pyrimidine derivatives are well known for their different pharmaceutical applications. The n-butyl 4-(3, 4-dimethoxyphenyl)-6-methyl-2-thioxo-1,2,3,4 tetrahydropyrimidine-5-carboxylate (n-butyl THPM) was synthesized by using n-butylacetoacetate. The n-butyl acetoacetate was obtained by transesterification of ethyl acetoacetate with n-butyl alcohol using Biginelli condensation. The synthesized powder was used to obtain the nanoparticles of n-butyl THPM by using water/oil microemulsion technique. The average particle size was calculated from the powder XRD pattern by applying Scherrers formula. The nanoparticles of n-butyl THPM were observed by Transmission Electron Microscope (TEM). The diameter of the nanoparticles varied from 15 nm to 65 nm. The nanoparticles were also characterized by FT–IR spectroscopy, TG–DTA–DSC and mass spectroscopy. The n-butyl THPM nanoparticles were stable up to 280°C. Thermodynamic and kinetic parameters of decomposition were obtained by applying Coats and Redfern relation to the thermogram. The dielectric study was carried out in the frequency range of 50 Hz to 5 MHz. The dielectric constant, dielectric loss and ac conductivity decreased as the frequency of applied field increased.

(E)-N'-{7-Meth-oxy-spiro-[chromeno[4,3-d]thia-zole-4,1'-cyclo-hexa-n]-2-yl}-N,N-dimethyl-acetimidamide.

In the chromenothiazole ring system of the title molecule, C20H25N3O2S, the pyran ring is in a half-chair conformation. The dihedral angle between the thiazole and benzene rings is 14.78 (6)°. The cyclohexane ring is in a chair conformation. The crystal structure is stabilized by weak intermolecular C—H⋯N and C—H⋯O hydrogen bonds.