Abstract
The aqueous two-phase separation system (ATPS) signifies an environmentally responsible approach for the extraction of bioactive compounds from a plants basis, as it is a liquid-liquid ...fractionation technique centred on the inconsistency of two aqueous solutions. In this investigation, various experimental parameters are optimized as the speed of agitation (200, 300 400 and 500 rpm) and solvent ratio (1:1, 2:3 and 3:2) with 20 % (w/w) of Ammonium Sulphate (AMS) salt composition and 30 % (w/w) of Polyethelyene Glycol (PEG). The obtained extract contains alkaloids, flavonoids, tannins, glycosides, acids and total phenolic compounds (TPC). The extracted Oleic acid by the ATPS method was measured with gallic acid equivalent (GAE) of TPC extracted from neem leaves powder. The determined concentration of oleic acid in the practice of TPC is 8.033 mg of GAE/g from the optimized experimental parameter. The optimized results can be cast off for a commercial process on an industrialized scale. Also, the mathematical modelling investigation was done to intent the critical impeller speed (Njs) with the Zwittering model. The identified model calculates the essential speed of agitation (rpm) for maximum extraction yield.
The majority of the naturally occurring antioxidants are obtained from plant sources. The antioxidant activity is mostly exhibited by polyphenols present in the plant cells. Azadirachta Indica (Neem) ...leaves are renowned for their medicinal applications due to their anti-inflammatory, antimalarial, antifungal, antibacterial, antiviral, antioxidant, and anticarcinogenic properties. This work aims to optimize the extraction of Azadirachta Indica (Neem) leaf antioxidants using three-phase partitioning (TPP). The optimized conditions are operating time 15 minutes, slurry ratio 1:30 (g/mL), salt concentration 30% (w/v), aqueous to solvent ratio 1:1.5 (v/v), and stirring speed 400 rpm that infer 74.66% extraction yield. Additionally, ultrasonic pretreatment was also employed to increase the extraction yield up to 86.61%. Sonication pretreatment for 4 min operated at 30 W power, and 75% duty cycle was observed to offer maximum antioxidant extraction about 3.3 mg/g.
•TPC extraction from Azadirachta indica leaves powder.•To understand and establish the useful kinetic expression model by Peleg's model•To optimize and identify significant parameters for maximum ...extraction yield.•Compare the experimental results with conventional batch extraction methods.
The current work deals with ultrasound-assisted extraction (UAE) of the total phenolic compounds (TPC) from A. indica (Neem) leaves powder. Various process parameters have been optimized, including solvent screening, solid/solvent ratio, extraction temperature, particle size, power input, duty cycle, and sound wave frequency. The highest TPC yield of 11.87 mg of GA/g of powder was obtained at a time of 14 min, 70% ethanol as solvent, solid to solvent ratio of 1:30, particle size of 0.2–0.3 mm, extraction temperature of 40ºC, power input of 90 W, and duty cycle of 50%. The experimental outcomes obtained from the UAE have been matched with stirred batch and Soxhlet extraction of TPC, which shows that ultrasound, was relatively better than the traditional method. The UAE method has efficiently decreased the extraction time (14 min) and marginally improved the TPC yield from A. indica leaves. Further, Peleg's mathematical model was studied for the extraction kinetics and to calculate the predicted extraction values of the rate constant, initial rate, and equilibrium concentration for all investigational circumstances. The predicted values obtained from Peleg's mathematical model show a good fit with experimental outcomes.
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Cobalt ferrite is a promising material for many therapeutic applications, photo-catalysis, gas detectors, high-density data storage, etc. Optimization of process parameters has a vital role in ...tailoring its properties. Present work reports effect of precursor pH on the properties of cobalt ferrite nanoparticles dispersed in silica. Crystallite size shows escalation from 16 to 18.5 nm with increase in pH. Many undesired phases were observed at lower precursor pH. Lattice parameter and particle size distribution showed significant impact of pH. Silica matrix showed momentous change in its structure giving a high porosity structure at pH 9. Magnetic parameters show effects due to γ-Fe
2
O
3
phase and pH. Effect on catalytic properties was investigated for the synthesis of 5-(4-chlorophenyl)-1,2,4-triazolidine-3-thione. Structural and morphological changes due to change in pH were found to enhance the catalytic yield considerably. Exquisiteness of the material as a catalyst is that it is magnetically separable and can be reused successively, making it an economic and green catalyst.
Graphical abstract
•Temperature and frequency dependent dielectric properties explored.•Nyquist plot reveal the grain and grain boundary contributions.•The dielectric response exhibits Maxwell – Wagner (M−W) type ...polarization.•Transport properties strongly dependent on temperature and microstructure.•Relaxation time was found to increase with temperature.
Ferroelectrics have been most popular candidates for electro-dielectric applications. Present studies report AC impedance spectroscopic investigations on a typical Pb0.6Ba0.2Sr0.2TiO3 ferroelectric sample. Phase formation was confirmed using X ray diffractometry which showed tetragonal structure with no other impurities. The electro-dielectric behaviour of the system was explored as a function of frequency and temperature. Arrhenius plots were drawn to determine activation energy. Equivalent circuit for the sample was developed to reveal the electrical peculiarities of the samples. Plots of variation of AC conductivity were fitted using Jonscher’s power law. The ferroelectric to paraelectric phase transition was observed at a temperature of 573 K.
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