Rachid Ahfir; Mohammed Filali
Abstract
We investigate thermodynamic and structural properties of positively charged O/W microemulsion spherical nanodroplets, suspended in salt water and decorated with telechelic polymers PEO-m and PEO-2m at low and high volume fraction F (6.98%, 26.5%) by using Small Angle Neutron Scattering (SANS). We describe ...
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We investigate thermodynamic and structural properties of positively charged O/W microemulsion spherical nanodroplets, suspended in salt water and decorated with telechelic polymers PEO-m and PEO-2m at low and high volume fraction F (6.98%, 26.5%) by using Small Angle Neutron Scattering (SANS). We describe and propose an effective pair potential interaction between charged colloidal particles in solution both with and without added telechelic polymers PEO-m or PEO-2m.We solve Ornstein-Zernicke (OZ) integral equation in the Hypernetted Chain (HNC) closure relation to obtain the pair correlation function g(r) and the structure factor S(q). A good agreement is found between the experimental and numerical spectra assuming the interaction potentials to be the sum of attractive and repulsive contributions in terms of decoration or bridging of the nanodroplets by the PEO polymer chains.
Atul B. Lavand; Yuvraj S. Malghe
Abstract
Nanosized bare, C and N doped as well as C, N co-doped ZnO nanopowders were prepared using microemulsion method. Synthesized powders were characterized using X-ray diffraction(XRD), Fourier transform infrared spectrophotometer (FTIR), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy ...
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Nanosized bare, C and N doped as well as C, N co-doped ZnO nanopowders were prepared using microemulsion method. Synthesized powders were characterized using X-ray diffraction(XRD), Fourier transform infrared spectrophotometer (FTIR), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), CHNS analyzer, photoluminescence spectrophotometer and UV-visible spectrophotometer. XRD study shows that C, N co-doped ZnO have hexagonal wurtzite structure. UV-visible spectral study reveals that C and N co-doping improves photo absorption capacity in visible region. Visible light photocatalytic degradation of malachite green was carried out using nanosized bare, C doped and C, N co-doped ZnO. C, N co-doped ZnO exhibits better visible light photocatalytic activity as compared to pure and C doped ZnO. Also the photocatalyst prepared is stable and can be reused repeatedly.
Atul B. Lavand; Yuvraj S. Malghe
Abstract
Nanosized bare and carbon (C)-doped TiO2 were prepared using reverse micro-emulsion method. Synthesized powders were characterized with the help of X-ray diffractometer (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), energy dispersive X-ray spectroscope (EDX) and UV-visible ...
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Nanosized bare and carbon (C)-doped TiO2 were prepared using reverse micro-emulsion method. Synthesized powders were characterized with the help of X-ray diffractometer (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), energy dispersive X-ray spectroscope (EDX) and UV-visible spectrophotometer. EDX study reveals that as calcination temperature increases amount of C on TiO2 decreases. SEM and TEM images show that TiO2 particles are spherical in shape and after increasing the calcination temperature size of particle increases. Particle size of TiO2 obtained from TEM data varies between 10 to 17nm. Visible light photocatalytic degradation of 2,4,6-trichlorophenol (TCP) aqueous solution was carried out using nanosized bare as well as C-doped TiO2. UV-visible spectrophotometer and high pressure liquid chromatography (HPLC) techniques were used to analyze the concentration of TCP during the degradation process. In presence of visible light C-doped TiO2 obtained after calcination of precursor at 300°C shows better photocatalytic activity. Parameters affecting the photocatalytic process such as calcination temperature, amount of catalyst and TCP concentration are investigated. TCP photocatalytic degradation process was optimized. It is observed that to get better photocatalytic activity optimum amount of photocatalyst and concentration of TCP solution required are 1.0 gL -1 and 20 mg L -1 respectively. Reusability study indicates that C doped TiO2 prepared in the present work is highly stable and reusable photo catalyst.
Suman Rana; Gunjan Verma;P. A. Hassan
Abstract
Solubilization of solid lipids in oil-in-water microemulsion is an important step in the preparation of lipid nanoparticles. Oil in water microemulsion has been prepared using Tween-80 (T-80) as a surfactant and isopropyl myristate (IPM) as an oil phase with a view to utilize them for the preparation ...
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Solubilization of solid lipids in oil-in-water microemulsion is an important step in the preparation of lipid nanoparticles. Oil in water microemulsion has been prepared using Tween-80 (T-80) as a surfactant and isopropyl myristate (IPM) as an oil phase with a view to utilize them for the preparation of Solid Lipid Nanoparticles (SLN). The microstructure of the microemulsions were evaluated using laser light scattering studies. From light scattering studies, it was observed that the intensity of scattered light increases on increasing the concentration of IPM at a fixed concentration of T-80 (15%), reflecting an increase in the size of the micelles. Dynamic light scattering studies show that the hydrodynamic diameter of the micelles increases on increasing the concentration of IPM. Phospholipon® 90 G (lipid) solubilized microemulsions were prepared using 1:1 w/w mixture of lipid and IPM as the oil phase. DLS studies suggest that addition of lipid did not alter the size of microemulsion droplets significantly.
S. Gupta; R. Gabrani;S. Dang; J.K. Sahni; J. Ali
Abstract
Natural products are important sources for new drug development. Though antibiotic therapies are first line of treatment for vaginal infections but prolonged use results in various side effects, hence there is a need to develop alternative therapies based upon natural products. Green tea powder (GTP) ...
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Natural products are important sources for new drug development. Though antibiotic therapies are first line of treatment for vaginal infections but prolonged use results in various side effects, hence there is a need to develop alternative therapies based upon natural products. Green tea powder (GTP) has been reported to exhibit anti-microbial activity and has synergistic effect with some antibiotics. Conversely, the role of GTP against vaginal infections has not been explored extensively. GTP is safe even at high doses but exhibits poor oral bioavailability. Encapsulation of GTP in a microemulsion (ME) vehicle would protect it against degradation. Aim of this study is to formulate GTP loaded MEs for vaginal application and to assess its efficacy against various vaginal pathogens. UV analysis of the GTP was done and solubility studies in various oils, surfactants and co-surfactants were carried out to select various phases of MEs. Titrations were carried out with various oil:Smix ratios and the data obtained was used to plot pseudo-ternary phase diagrams. The emulsion regions which corresponded to particle less, transparent regions and within GRAS limits were subjected to thermodynamic stability studies. Droplet size of thermodynamically stable MEs was found to be in nanometre range. Escherichia coli and Staphylococcus epidermidis were found to be sensitive to GTP and its ME via disc diffusion assay.
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