Effect Of Solvent Volume Research Articles

Yield Optimization for The Extraction of Organic Compounds from Okra Leaves Wastes

An important area of research is the extraction of organic chemicals from plants and herbs. Considering the fact that the extracts have numerous commercial and pharmacological uses. Furthermore, limiting the optimal working region is made easier by employing an appropriate experimental design. Solvent extraction is the technique most frequently used to separate organic components from plants. However, the conditions of extracting solvent that is utilized greatly affects the yields of the extract and, as a result, the organic activities of the plant parts. This research deals with the extraction of solid organic compounds from the okra leaves using water as a solvent. A Soxhlet apparatus was used for the extraction process. The influence of extraction time, solvent volume, and okra powder mass on the yield percentage was optimized. Two mathematical models were suggested: second-order polynomials and power models. A higher correlation coefficient was obtained with the polynomial model. The maximum extraction yield was obtained at optimum values of 200.3 min, 29.07 g, and 290.7 ml for time, okra powder mass, and solvent volume, respectively. It is evident from mathematical formulas that the impact of time was less significant than the effects of solvent volume and powder mass. On the other hand, the power model and the second-order quadratic interaction model had correlation coefficients of 0.4849 and 0.9707, respectively.

Effect of solvent volume on the properties of ZnWO4 nanoparticles and their photocatalytic activity for the degradation of cationic dye

In this paper, we report the photocatalytic degradation performance of zinc tungstate (ZnWO4) nanoparticles prepared by co-precipitation technique by the effect of increasing the volume of solvent (30 ml−90 ml). The well defined x-ray diffraction peaks confirmed the formation of pure monoclinic phase zinc tungstate with wolframite structure. The vibrational bands corresponding to W-O bond stretching and bending vibrations in WO6 group are occurred at 714 and 615 cm−1, which indicates the good crystallinity and relatively low concentration of defects in ZnWO4. The photoluminescence emission peak observed at 380 nm region is due to the electronic transition of Zn-WO4. The optical energy band gap decreases (3.19 eV−3.16 eV) as the volume of the solvent increases (30–90 ml) which may be due to the reducing interaction of metal–oxygen orbital. The photocatalytic activity of wolframite ZnWO4 nanoparticles was investigated by the decomposition of methylene blue (MB) dye pollutant under ultra-violet (UV) lamp (254 nm) irradiation at room temperature. The highest dye removal efficiency of 81% was noticed for ZnWO4 nanoparticles synthesized with 30 ml volume of solvent, which may be due to the presence of more active species and nanopores on the surface.

Competition between Hydrogen and Halogen Bonds: The Effect of Solvent Volume

The effect of crystallization method and solvent volume on the competition between hydrogen and halogen bond formation was investigated through co-crystallization experiments carried out by adding ...

Effect of solvent on the key properties of Al doped ZnO films prepared by nebulized spray pyrolysis technique

In current work, the Al doped ZnO thin films (AZO) were deposited onto glass substrates by nebulized spray pyrolysis technique using different volume of solvents (5 ml–15 ml). The effect of solvent volume on the structural, optical, morphological and electrical properties were studied. X-ray diffraction pattern confirmed that all the films are polycrystalline in nature and have hexagonal wurtzite structure with (101) plane orientation. The structural parameters such as crystallite size, dislocation density, micro strain, texture coefficient and number of crystallites per unit area were calculated from X-ray diffraction data. AFM images showed that all the AZO films have spinous and granulous structures. The transmittance values of the films were as high as 88% in the visible region from 400 to 700 nm. The band gap values of AZO thin films are found in the range from 3.34 to 3.28 eV for 5 ml–15 ml, respectively. Optical constants such as extinction coefficient, refractive index and skin depth were calculated from reflectance and absorbance spectra. The electrical properties of the thin films were studied by Hall-Effect measurements and found as n-type conductivity with high carrier concentrations (n) 3.54 × 1020 cm−3 and low resistivity (ρ) 4.37 × 10−3 Ω-cm at 15 ml solution.

Facile preparation of hierarchical nanostructured CuInS2 counter electrodes for dye-sensitized solar cells

CuInS2 (CIS) thin films have been synthesized onto the glass substrates for different solvent volumes (10, 30, 50 and 70 ml) by nebulizer spray technique. The effect of solvent volume on the structural, morphological, compositional, optical and electrical properties of CIS thin films has been investigated. X-ray diffraction patterns suggest that the obtained CIS films are polycrystalline with the tetragonal structure. The surface morphology of the prepared CIS films purely depends on the solvent volume. The elemental quantitative investigation and the stoichiometric ratio of the CIS thin films were verified from XPS and EDS. High absorbance with the optical band gap of 1.13 eV was obtained at the higher solvent volume. All the deposited CIS thin films exhibited p-type semiconducting behavior with the high electrical conductivity and carrier concentration. CIS thin films deposited onto the FTO substrate were used as a counter electrode (CE) in dye-sensitized solar cells. CIS CEs possessed high electrocatalytic behavior and fast electron charge transfer at the CE/electrolyte interface. The CIS CE prepared using 50 ml solvent volume generated high energy conversion efficiency of about 3.25%.

Evaluation of the physical, optical, and electrical properties of SnO2: F thin films prepared by nebulized spray pyrolysis for optoelectronics

Fluorine-doped tin oxide (SnO2:F, FTO) thin films were prepared by the nebulized spray pyrolysis technique on glass substrates using tin(IV) chloride pentahydrate (SnCl2·5H2O) and ammonium fluoride (NH4F) as source materials. Different volumes of solvent were used to prepare the spray solution, and their effects on structural, optical, morphological, and electrical properties were investigated. X-ray diffraction patterns revealed the polycrystalline tetragonal structure of FTO films. FESEM images demonstrated well-aligned trigonal-shaped nano-grains. Optical band gap values were estimated to be in the range of 3.71–3.66 eV by Tauc’s plot. The effects of solvent volume on the resistivity, conductivity, carrier concentration, mobility, and figure of merit of FTO films were examined. The lowest electrical resistivity and sheet resistance values were 1.90 × 10−4 Ω cm and 4.96 Ω/cm, respectively.

Effect of solvent volume on the physical properties of spray deposited nano needle structured Sn2S3 thin films

Nanostructured Sn2S3 thin films were deposited by spray pyrolysis technique from spraying solution having different values of solvent volume (10, 20, 30 and 40 ml) on glass substrates maintained at 400 °C. XRD studies showed that all the films exhibit orthorhombic crystal structure with a (2 1 1) preferential orientation. SEM images reveal that the Sn2S3 films prepared from higher solvent volumes exhibited uniformly distributed nanoneedled grains. The optical band gap was blue shifted from 2.06 to 2.21 eV with increase in solvent volume. The photoluminescence spectra endorsed the lesser defect crystalline nature of the as-deposited Sn2S3 films. The obtained results infer that the film coated with 30 ml solvent volume exhibited better physical properties.

Role of solvent volume on the structural and transparent conducting properties of SnO2: Zn films

Zinc doped tin oxide (ZTO) films were deposited from starting solutions having different solvent volumes (10, 20 … 50 mL), using a simplified spray pyrolysis technique. The effects of solvent volume on the structural, electrical, optical and surface morphological properties were investigated. From the structural studies, it is observed that the preferential orientation is along the (200) plane for lower solvent volumes and it turns in favour of (101) plane for the higher solvent volume levels (40 and 50 mL), indicating the stable p-type conductivity. Electrical studies show that the sheet resistance (Rsh) increases as the solvent volume increases. The minimum sheet resistance (4.32 kΩ/sq.) is obtained in the case of minimum solvent volume (10 mL). The Hall measurements reveal that the type inversion takes place beyond 30 mL of solvent volume. The optical transmittance increases as the solvent volume is increased and it is found to be in the range of 80–95 %.

Effect of solvent volume on properties of SnO2:Al films

Aluminium doped tin oxide films (ATO) were deposited from starting solutions having different solvent volumes (10, 20, …, 50 mL), using a simplified spray pyrolysis technique and the effect of solvent volume on the structural, optical and electrical properties was investigated. Structural studies revealed that Al3+ incorporation into the Sn4+ sites of the SnO2 lattice is gradually increased with increasing solvent volume. The variation in the preferential orientation factor f (110) as a function of solvent volume is discussed in detail. From electrical studies, it is found that the sheet resistance Rsh is minimum (3·98 kΩ sq−1) when the solvent volume is minimum, and Rsh increases as the volume of the solvent increases. The gradual decline in the intensity of the peak at 411 nm of the photoluminescence spectra indicated the decrease in the density of oxygen vacancies. The optical transmittance in the visible region is higher (85%) for higher solvent volume.

Effect of solvent volume on the physical properties of aluminium doped nanocrystalline zinc oxide thin films deposited using a simplified spray pyrolysis technique

Aluminium doped zinc oxide (AZO) thin films were deposited by employing a low cost and simplified spray technique using a perfume atomizer from starting solutions having different volumes (10, 20,…,50mL) of solvent. The effect of solvent volume on the structural, electrical, optical, photoluminescence (PL) and surface morphological properties was studied. The electrical resistivity of the AZO films is remarkably influenced by the variation in the solvent volume. The X-ray diffraction profiles clearly showed that all the films have preferential orientation along the (002) plane irrespective of the solvent volume. The crystallite size was found to be in the nano range of 35–46nm. The optical transmittance in the visible region is desirably high (>85%). The AFM images show columnar morphology with varying grain size. The PL studies revealed that the AZO film deposited from 50mL of solvent volume has good quality with lesser defect density.

Effect of solvent volume on the physical properties of sprayed fluorine‐doped zinc oxide thin films

AbstractFluorine‐doped zinc oxide (FZO) films were deposited from aged starting solutions having different solvent volumes (10, 20, 30, 40 and 50 ml) using a simplified spray pyrolysis technique. The electrical studies showed that the resistivity is minimum (4.68 × 10–2 Ω cm) for lowest solvent volume (10 ml) and the value progressively increased with the increase in the solvent volume indicating that the fluorine incorporation increases with solvent volume. The systematic study clearly showed that the spray flux rate plays a crucial role in determining the electrical, optical, surface and structural properties of the FZO films. The optical transparency is found to be gradually increased (from 85 to 95%) as the volume of the solvent increases. The scanning electron microscope images depicted that the decrease in the spray flux rate caused an enhancement in the grain size. The X‐ray diffraction profile clearly showed that all the films have preferential orientation along the (002) plane with hexagonal wurtzite structure. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Effect of solvent volume on the physical properties of undoped and fluorine doped tin oxide films deposited using a low-cost spray technique

Undoped and fluorine doped tin oxide films were deposited from starting solutions having different values of solvent volume (10–50 ml) by employing a low cost and simplified spray technique using perfume atomizer. X-ray diffraction studies showed that there was a change in the preferential orientation from (2 1 1) plane to (1 1 0) plane as the volume of the solvent was increased. The sheet resistance ( R sh) of undoped SnO 2 film was found to be minimum (13.58 KΩ/□) when the solvent volume was lesser (10 ml) and there was a sharp increase in R sh for higher values of solvent volume. Interestingly, it was observed that while the R sh increases sharply with the increase in solvent volume for undoped SnO 2 films, it decreases gradually in the case of fluorine doped SnO 2 films. The quantitative analysis of EDAX confirmed that the electrical resistivity of the sprayed tin oxide film was mainly governed by the number of oxygen vacancies and the interstitial incorporation of Sn atoms which in turn was governed by the impinging flux on the hot substrate. The films were found to have good optical characteristics suitable for opto-electronic devices.

Optimization of a microwave-assisted extraction method for the analysis of polychlorinated biphenyls in ash samples

An alternative method for the extraction of polychlorinated biphenyls (PCBs) in ash samples, which is less time and solvent consuming than Soxhlet extraction, is presented. A study was carried out to evaluate the possibilities of microwave-assisted extraction (MAE) to determine exactly which parameters affect the efficiency of the process, since direct extrapolation of extraction conditions for PCBs in other solid matrices, failed when applied to coplanar congeners in ash samples. Influence of the organic solvent on the yield of the extraction was first evaluated using two ash samples with different percentages of carbon. Once the extraction solvent was fixed, the effects of solvent volume, extraction temperature and extraction time were investigated using an experimental design. It was found that the volume of organic solvent played a more important role in the extraction efficiency than the other factors. In the optimal conditions microwave extractions were performed at 110 °C, for 10 min and using 30 ml of toluene. Recoveries higher than 80% were obtained for all the highly chlorinated congeners, including coplanar species, in a spiked ash sample containing a relatively high concentration of carbon. The proposed method was also applied to the determination of PCBs in a reference material of urban dust. Recoveries were similar to those obtained for spiked ash samples.

Improved solvent trapping of volatiles in supercritical fluid extraction by pressurizing the collection vial

The high flow rates that result after decompression make the trapping of analytes one of the more difficult aspects of a supercritical extraction. By elevation of the pressure on the collection vial, the flow may be reduced and trapping efficiency improved, considerably. The effects of different collection vial pressures were evaluated. The best results were obtained at 25 atm. With the collection vial at 25 atm, the trapping efficiencies of different solvents were then investigated. Also considered were the effects of solvent volume, extraction flow rate, collection solvent geometry, and restrictor temperature. For a 30 min extraction--with the restrictor line at 200 degrees C--quantitative recoveries were obtained with analytes as volatile as chlorobenzene (approximately 90%) in 1 mL of solvent. Mild precooling of the collection vessel allowed quantitative recoveries to be obtained down to benzene (94.2%).

Recovery of phenytoin from an enteral nutrient formula

The recovery of phenytoin from phenytoin oral suspension dispersed in an enteral nutrient formula was determined. The study was conducted in two phases. In phase 1, diluted phenytoin oral suspension was added to 10 1-mL samples of full-strength Osmolite and 10 1-mL samples of a distilled water control solution to produce a theoretical concentration of 10 micrograms/mL. The samples were filtered through an ultrafiltration membrane and assayed for phenytoin concentration by a homogeneous enzyme-multiplied immunoassay technique. In phase 2, varying amounts of diluted phenytoin oral suspension were added to 30-mL quantities of half-strength Osmolite or control solution to determine the effect of phenytoin concentration on recovery of phenytoin; also, a constant amount of diluted phenytoin oral suspension was added to 30-, 60-, and 90-mL quantities of half-strength Osmolite or control solution to determine the effect of solvent volume on recovery of phenytoin. Duplicate samples of each phase 2 mixture were filtered and assayed in the same manner as phase 1 samples. The mean concentration of phenytoin in phase 1 samples was 3.70 +/- 0.28 microgram/mL for Osmolite and 9.87 +/- 0.27 microgram/mL for control solution; this difference was significant. The percentage of phenytoin recovered from phase 2 samples of Osmolite increased with increasing phenytoin concentration and decreased with increasing volumes of Osmolite. The decreased recovery of phenytoin from the enteral nutrient formula used in this study has potential clinical importance, but further research in humans is needed to substantiate these in vitro observations.

Numerical Simulation of the Behaviour of Enriched Gas Injected Alternately With Water In Horizontal Miscible Floods

Abstract An investigation was made of the effects of solvent:water injection ratios, length of injection cycles and solvent volume injected on solvent bank movement and sweep efficiency when enriched gas is injected alternately with water in horizontal miscible floods. A two-dimensional three-phase reservoir simulator incorporating a nine-point finite-difference formulation was used in this study. Introduction The work reviewed here was undertaken to improve understanding of the performance of the enriched gas (solvent) water bank in horizontal hydrocarbon miscible floods. Of particular interest were:solvent-water bank propagation;the effect of varying soivent:water ratio;injection cycle size effects;the effects of solvent volume injected;zonal areal sweep;producing characteristics after solvent breakthrough; andinjection fluid distribution into a layered system. Assumptions and Limitations Basic data representative of an existing horizontal hydrocarbon miscible flood were used throughout the study. Basic reservoir parameters and the oil-water relative permeability curves are included as Table I and Figure I respectively. The solvent-oil relative permeability curves were derived from an assumed fractional flow equation used to simulate miscible displacement as noted on Figure 2. For the model work conducted, it was assumed that the oil-water relative permeability curve held for solvent-water as well. This assumption implies that oil and solvent have the same flow behaviour. The solvent-oil mixing zone is neglected. It was also assumed that there was no' hysteresis in the oil-water relative permeability curve. The formation studied is moderately oil-wet, resulting in hysteresis in the water relative permeability curve. There is negligible hysteresis in the oil relative permeability curve. As the results presented in this study are intended to be qualitative, these assumptions would not affect the conclusions. Three-phase relative permeability was handled by entering the water-oil relative permeability curve (Fig. 1) as a waterhydrocarbon phase curve. The relative permeability of the hydrocarbon phase was then divided between oil and solvent by the solvent?oil relative permeability curve (Fig. 2). Two reservoir simulators were used: an areal black oil and a radial coning black oil model. Both are two-dimensional and capable of handling three fluid phases. The black oil model was used in two configurations. A homogeneous I-D configuration was used to investigate the mechanism of alternate solvent-water injection and yield a qualitative understanding of the process. A' homogeneous 2--D areal configuration was us!'d to investigate areal sweep effects. The coning model was used to investigate cyclic production after solvent breakthrough and the effects of permeability contrast in injection wellbores on solvent:water ratio. The radial configuration was useful in simulating viscous effects near the wellbore and pressure changes in the inter-well area. Published data(1) have shown that the 9-point finite difference formulation is required to eliminate grid orientation effects under adverse mobility ratio conditions. The 9-point formulation was used for this study because an adverse mobility ratio existed during each cycle when the injection was switched from low-mobility water to high mobility solvent.

Effect of solvent volume and solvent equilibration time on Whatman filter paper No. 20

Effect of solvent volume and solvent equilibration time on Whatman filter paper No. 20