Temperature Of Ultrasonic Bath Research Articles

3D-printed microfluidics under ultrasonic cooling crystallization for nano-precipitation of ezetimibe: Effect of process parameters and PBD approach

The current research focuses on the antisolvent precipitation of Ezetimibe (EZB) via microfluidics under continuous ultrasonic cooling crystallization. One factor at a time was applied to study the effect of parameters: organic-aqueous flow rate ratio (1:2–1:5), EZB concentration (2.5–12.5, mg/mL), polymer concentration (0.025–0.3, % w/v), ultrasonic frequency (22–42, kHz), ultrasonic bath temperature (10–25, °C), ultrasonic amplitude (20–100, %), confluence angle of micromixer inlet (90°–180°) on the particle size (PS, nm), % yield, % encapsulation efficiency (% EE), and % dissolution rate (% DR). A PBD (Plackett–Burman design) was also employed for the screening studies of influencing factors for aforementioned responses. PS, Zeta potential (ZP, mv), Field Emission Gun Transmission Electron microscope (FEG-TEM), and X-ray diffraction (XRD) were analyzed for raw EZB and nano-precipitated EZB. An average EZB PS of 101 ± 1.1 nm, PDI of 0.027 ± 0.01, 80 ± 1.7 % yield, 78.83 ± 0.5 % DR, 90.67 ± 0.1 % EE, and −20 mV ZP were obtained under best parametric condition. FEG-TEM revealed the final nano EZB morphology was likely to be elongated cuboidal or rod-shaped. An approximately 5-fold increase in %DR was observed for the confluence angle of 90° (├ shaped) micromixer as compared to raw EZB. However, 94.14 % decreament in avg EZB PS was achieved for the confluence angle of 90° (├ shaped) micromixer and utilizing ultrasonic microfluidic system (USMS) under cooling crystallization as a process intesification approach.

Ultrasonic assisted extraction of water-soluble vitamins from minor components of bee pollen with deep eutectic solvents (DESs) as green solvent

In this study, different deep eutectic solvents (DESs) were used for vitamin extraction from bee pollen. The DES combination with the highest total amount of individual vitamins was choline chloride: ethylene glycol (molar ratio 1:2). The response surface method was then used to optimize the extraction conditions. The independent variables used for optimization were ultrasonic power, time, and temperature, while the dependent variables were the total individual amino acids, total individual phenolic compounds, and total individual vitamin contents. Spectrophotometric analyses and antimicrobial activity were also determined in the extracts. In addition, AGREEprep, ComplexGAPI and BAGI tools were used to evaluate the greenness of the method. The results obtained with DES were compared with water, ethanol, and methanol extracts, which were considered control groups. As a result of optimization, the optimum conditions were found to be 75 % for ultrasonic power, 71.5 min for sonication time, and 40 °C for ultrasonic bath temperature. The model’s composite desirability value (d) was found to be 0.81. The predicted value and the experimental values were close to each other. Furthermore, the most dominant vitamin in DES extracts was ascorbic acid, the most dominant amino acid was proline, and the most dominant phenolic compound was myricetin. The amounts of these compounds were higher than those obtained from water, ethanol, and methanol extracts. The spectrophotometric analysis results obtained higher yields with DES compared to the control groups. Antimicrobial activity analysis showed that pollen extracts prepared using choline chloride: ethylene glycol had a weak inhibitory effect for Gram-positive and Gram-negative bacteria but not yeast-like fungal strains. In conclusion, DES has been successfully used to extract vitamins and other bioactive compounds from bee pollen. The results obtained showed that DESs can be an alternative to organic solvents for the extraction of vitamins, which are among the minor components of bee pollen. Besides, the potential of the application different DESs for more efficient extraction of vitamins and components with important pharmaceutical properties from bee pollen needs to be evaluated in detail.

New fabric phase sorptive extraction for nondestructive analysis of heritage textile samples

Several types of pesticides used in museum collections over time become dangerous for people who may handle textile articles treated with such substances. In the case of the analysis of ancient, modern, and contemporary textile materials, it is particularly important to keep the artifacts intact, as they cannot be replaced. The need to use micro- or nondestructive techniques led to the development of methods such as solid-phase microextraction (SPME), liquid‒liquid dispersive microextraction (DLLME), and single-droplet microextraction (SDME). In this paper is described an optimized extraction method of three pesticides (malathion, methoxychlor, and permethrin) by creating a non-destructive solid phase extraction system on a textile support, abbreviated FPSE – 100 % cotton fabric coated with a sol-gel solution prepared from a polymer (PEG or PDMS). To obtain a suitable FPSE, the following parameters were evaluated: polymer selection (individual or mixture of polymers), acid catalyst (trifluoroacetic acid, acetic acid and hydrochloride acid), amount of polymer (1.0 g, 2.5 g or 5.0 g), polymerization time (30 min, 120 min and 240 min), ultrasonic bath temperature (40 °C and 70 °C), and type of bath to obtain the sol-gel (ultrasonic bath, water bath with stirring and mechanical stirrer). To complete the FPSE optimization, the influence of pesticide extraction time on FPSE and desorption from FPSE in ethyl acetate was also assessed.The pesticides extraction yields obtained for the laboratory textile samples are in the range of 52.7 %–128.0 %. The technique proposed in the manuscript proved to be effective as a nondestructive tool for evaluating and quantifying the presence of pesticides in textile museum collections. The approach described here reduces heritage object damage due to sampling compared to methods commonly employed and may represent a starting point for future research.

Extraction of citronella oil from lemongrass (Cymbopogon winterianus) by sequential ultrasonic and microwave-assisted hydro-distillation

The Ultrasonic and Microwave-Assisted Hydro-Distillation (US-MAHD) method is a process combination of ultrasonic-assisted extraction (UAE) and microwave-assisted hydro-distillation (MAHD) carried out sequentially. This method aims to improve the UAE and MAHD methods in extracting citronella oil. This study evaluates the performance of US-MAHD in the extraction of citronella oil from the citronella plant. Extraction is conducted for 90 min at various solvent-plant ratios (v/m) (10:1, 12:1, 14:1), ultrasonic bath temperature (30 °C, 40 °C, 50 °C), and power of microwave oven (150 W, 300 W, 450 W). US-MAHD yields a maximum yield of citronella oil of 1.82 mg/g when extracting lemongrass plant with a combination of ultrasonic bath temperature of 30 °C, a solvent-plant ratio of 10:1, microwave power of 300 W, and time of 90 min. All quality parameters of the oil produced have met ISO 3848:1976 standard. Extraction of citronella oil using the US-MAHD method produces higher yields than the UAE and MAHD methods under the same operating conditions. The yields of citronella oil from the US-MAHD, UAE, and MAHD methods are 1.82, 0.92, and 1.48 mg/g, respectively. SEM analysis of residual lemongrass plant shows more cell wall damage which indicates more oil release from the plant matrix.

Temperature-controlled exfoliation of graphite oxide: studies of defects and transport properties of graphene oxide

The quality, structural defects, and transport properties of GO can be tailored by maintaining ultrasonic bath temperature. Herein, the effect of temperature-controlled exfoliation on the structural defects and transport properties of the resulting graphene oxide (GO) sheets are examined. The large crystallite size (12.23 nm) and low defect density (2.16 × 1011 cm−2) are found at 20 °C exfoliations. Highly oriented GO sheets were exfoliated at 20 °C which was confirmed through Bernal-stacking proportions (∼30%). Furthermore, electrical transport properties are high at 10 °C exfoliation temperature while optimum at other temperatures, calculated through impedance spectroscopy. Comparatively, smooth, wrinkle-free, and lesser bulges are found at 20 °C and 30 °C exfoliation temperatures.

Simultaneous Determination of REEs in Coal Samples Using the Combination of Microwave-Assisted Ashing and Ultrasound-Assisted Extraction Methods Followed by ICP-OES Analysis

The world during the COVID-19 pandemic has led to extensive use of virtual activities by means of electronic devices, which are made up of rare earth elements (REEs). This means that quantitative knowledge of REEs in various resources is crucial for the development of effective recovery methods. Therefore, this report describes a simple microwave assisted ashing followed by ultrasound-assisted extraction (MAA-UAE) for quantitative determination of REEs in coal samples using inductively coupled plasma-optical emission spectroscopy (ICP-OES). Firstly, coal samples were ashed at 55 °C for 4.5 h to form white ashes, which were then treated with dilute HNO3 acid under ultrasonication to enhance the extraction of REEs. The quantitative recoveries (86–120%) of REEs were obtained when 1 mol L−1, 0.1 g, 40 °C, 20 min, and high frequency were applied for [HNO3], sample mass, ultrasonic bath temperature, extraction time, and ultrasonic bath frequency, respectively. The method detection limits of the proposed MAA-UAE method were between 0.0075 and 0.59 µg g−1 with satisfactory precision (<5%). The concentration levels of REEs in South African coals ranged from 1.4 to 105 µg g−1, suggesting that this coal can be a resource for REEs.

Novel and green ultrasonic-assisted liquid–liquid microextraction method based on a nanopolymer for extraction of ferulic acid, gallic acid, cinnamic acid and rutin from vegetable oils

A novel, simple, sensitive and green ultrasonic-assisted liquid–liquid microextraction method based on a synthetic citric acid–glycerol nanopolymer solution was used for the extraction of antioxidant acids (ferulic, cinnamic, gallic acid and rutin) in five kinds of oil samples from vegetables. The synthetic nanopolymer from citric acid and glycerol with absolute molar ratio was synthesized, and its specifications were characterized by (FTIR, DLS, GPC, AFM and NMR). Its solution as a green extractor for oil samples was added to n-hexane containing analytes. Then, the extraction was speeded up by using ultrasonic. After the extraction, phase separation (rich phase/n-hexane phase) was accomplished by using a centrifugation. Rich phase in lower phase was removed by a micro-syringe and injected to reverse-phase HPLC with UV detector. Volume of nanopolymer solution, concentration of nanopolymer, extraction time and temperature of ultrasonic bath were optimum conditions and obtained by response surface methodology. This method has good linear calibration ranges between 0.7 and 1300 μg L−1, coefficients of determination (r2 > 0.9831) and low limits of detection between 0.05 and 0.81 μg L−1. This method was successfully used to determine target analytes in oil samples of olive, almond, sesame, hazelnut and edible with satisfactory inter–intraday precision and recoveries (93.4–107.1%).

Response Surface Methodology Optimization of Ultrasonic-Assisted Extraction of Acer Truncatum Leaves for Maximal Phenolic Yield and Antioxidant Activity.

This study is the first to report the use of response surface methodology to improve phenolic yield and antioxidant activity of Acer truncatum leaves extracts (ATLs) obtained by ultrasonic-assisted extraction. The phenolic composition in ATLs extracted under the optimized conditions were characterized by UPLC-QTOF-MS/MS. Solvent and extraction time were selected based on preliminary experiments, and a four-factors-three-levels central composite design was conducted to optimize solvent concentration (X1), material-to-liquid ratio (X2), ultrasonic temperature (X3) and power (X4) for an optimal total phenol yield (Y1) and DPPH• antioxidant activity (Y2). The results showed that the optimal combination was ethanol:water (v:v) 66.21%, material-to-liquid ratio 1:15.31 g/mL, ultrasonic bath temperature 60 °C, power 267.30 W, and time 30 min with three extractions, giving a maximal total phenol yield of 7593.62 mg gallic acid equivalent/100 g d.w. and a maximal DPPH• antioxidant activity of 74,241.61 μmol Trolox equivalent/100 g d.w. Furthermore, 22 phenolics were first identified in ATL extract obtained under the optimized conditions, indicating that gallates, gallotannins, quercetin, myricetin and chlorogenic acid derivatives were the main phenolic components in ATL. What’s more, a gallotannins pathway existing in ATL from gallic acid to penta-O-galloylglucoside was proposed. All these results provide practical information aiming at full utilization of phenolics in ATL, together with fundamental knowledge for further research.

Determination of photoinitiator 4-methylbenzophenone in milk by cloud point extraction

An efficient and easy sample pretreatment methodology was proposed for the detection of photoinitiator 4-methylbenzophenone from milk before high-performance liquid chromatography. Appropriate conditions for demulsification were studied. The parameters affecting cloud point extraction, such as concentration of Tween-20, electrolyte salt, equilibration temperature, and time, have been investigated. When the spiked level was 200-1000 μg/kg, the average addition standard recovery was 99.14-105.98% with the optimum cloud point extraction conditions (concentration of Tween-20, 138 g/L; mass of anhydrous sodium sulfate, 0.75 g; equilibration temperature, 65°C; equilibration time, 30 min). To decrease the detection limits, further work about the organic solvent, shaking time, and ultrasonic parameters was carried. When the spiked level was 10-100 μg/kg, the average addition standard recovery was 70.40-106.91% with the optimum cloud point extraction and enrichment conditions (optimum cloud point extraction conditions; volume of cyclohexane, 30 mL; shaking time, 20 min; time of ultrasonic, 20 min; temperature of ultrasonic bath, 45°C).

Structural and electrical properties of nickel–iron thin film on copper substrate for dynamic random access memory applications

Using pulse electrodeposition technique, nano crystalline NiFe films were deposited on conductive copper substrates, under galvanostatic mode in an ultrasonic field at different conditions such as pulse current magnitude, deposition time and ultrasonic bath temperature. As-prepared NiFe/Cu thin films were characterized for phase analysis, surface morphology, surface roughness and resistivity measurements. The results show that the use of ultrasonic bath at room temperature has reduced the surface roughness, resistivity, average grain size and crystallite size of NiFe/Cu thin films. The resistivity is reduced with increasing deposition current from 44.2 µΩ cm at 40 mA to 33.0 µΩ cm at 100 mA. On the other hand, a significant drop of the resistivity from 35.7 to 9.4 µΩ cm is observed if the deposition time was reduced from 5 to 3 min.

Physical and electrical characteristics of NiFe thin films using ultrasonic assisted pulse electrodeposition

Nickel iron (NiFe) thin films were prepared on the copper substrate by ultrasonic assisted pulse electrodeposition under galvanostatic mode. Careful control of the thin films deposition is essential as the electrical properties of the films could be greatly affected, particularly if low quality films are produced. The preparation of NiFe/Cu thin films was aimed to reduce the grain size of NiFe particles, surface roughness and electrical resistivity of the copper substrates. Various parameters were systematically studied including current magnitude, deposition time and ultrasonic bath temperature. The optimized conditions to obtain NiFe permalloy, which subsequently applied to all investigated samples, were found at a current magnitude of 70mA deposited for a duration of 2min under ultrasonic bath temperature of 27°C. The composition of NiFe permalloy was as close as Ni 80.71% and Fe 19.29% and the surface roughness was reduced from 12.76nm to 2.25nm. The films electrical resistivity was decreased nearly sevenfold from an initial value of 67.32μΩcm to 9.46μΩcm.

Simple one-pot sonochemical synthesis of copper sulphide nanoparticles for solar cell applications

Copper sulphide nanoparticles for solar cell applications were synthesized by a single step sonochemical method using copper acetate and thiourea as precursors. The effects of sonication time, ultrasonic bath temperature and annealing temperature on particle properties were studied. Synthesized particles were characterized using scanning electron microscope, transmission electron microscope, X-ray diffraction spectrophotometer and UV–visible spectrophotometer. The particles were found to be a mixture of chalcocite, covellite and djurleite. The optical band gap of the particles was found to be in the range of 1.6–2.1eV. Heat treatment of the particles was found to give rise to needle shaped particles while a bath temperature of 55°C yielded few nanoplates.

Optimization of Ultrasonic-Assisted Acid Extraction of Mercury in Muscle Tissues of Fishes Using Multivariate Strategy

A simple and rapid ultrasound-assisted extraction procedure was developed for the determination of total mercury (Hg) in muscle tissues of freshwater fish species. A Plackett-Burman experimental design was used as a multivariate strategy for the evaluation of the effects of variables, such as presonication time (without ultrasonic stirring), sonication time, ultrasonic bath temperature, nitric acid concentration, hydrochloric acid concentration, and sample mass of muscle tissues. Some variables showed a significant effect on recovery, and they were further optimized by a 2(3) + star central composite design that involved 16 experiments. The validation was carried out by analysis of certified reference material DORM-2 (dog fish muscles); for comparative purposes, an acid digestion induced by microwave energy was used. Cold vapor atomic absorption spectrometry was used for the determination of total Hg. No significant differences were established between the analytical results and the certified values (paired t-test at P > 0.05). The LOD and LOQ of Hg were 0.133 and 0.445 microg/kg, respectively, which demonstrated the high sensitivity of the proposed procedure for the determination of Hg at trace levels. The Hg concentrations in the muscle tissues of 10 freshwater fish species were found in the range of 35.3-67.8 microg/kg on a dried basis, which were within the permissible limit of the World Health Organization.

Evaluation of an ultrasonic acid digestion procedure for total heavy metals determination in environmental and biological samples

In this study, a sample preparation method based on ultrasonic assisted acid digestion (UAD) has been evaluated for total heavy metals (Cd, Cr, Ni and Pb) determination in different environmental (soil, sediment and sewage sludge), and biological (fish muscles, vegetables and grains) samples, using electrothermal atomic absorption spectrometry (ETAAS). The investigated parameters influencing UAD such as presonication time, sonication time, temperature of ultrasonic bath, and different acid mixtures were fully optimized, whereas power was maintained constant at 100% of nominal power of ultrasonic bath. Six different sets of above parameters were applied on six certified reference materials (CRMs) having different matrices. The accuracy of the method was also tested by comparing the results with those obtained from conventional hot plate assisted acid digestion method on same CRMs. Analytical results for HMs by both methods showed no significant difference at 95% confidence limit ( p < 0.05). Recoveries of HMs ranging from 96.2% to 102% and 96.3% to 98.6% were obtained from biological and environmental samples, respectively. The average relative standard deviation of UAD method varied between 3.5% and 8.2%, depending on the analyte.

Towards cleaner degreasing method in industries: ultrasound-assisted aqueous degreasing process in leather making

Studies on ultrasound-assisted processes are gaining importance due to its effectiveness and facilitating green method in processing. Degreasing of skin/hide prior to tanning process is an important unit operation. Presence of large amounts of natural fat at the interior of skin/hide matrix makes degreasing process a challenging one. Conventionally, organic solvent and/or detergent based degreasing process are employed leading to environmental problems. In the present paper, the use of power ultrasound in aqueous degreasing process has been studied and compared with different degreasing systems. Glutaraldehyde pre-tanning has also been employed for carrying out the degreasing process at ultrasonic bath temperature. The results indicate that there is a significant increase in the degreasing efficiency due to the application of ultrasound. About 2-fold increase in fat removal has been observed due to the use of ultrasound as compared to control under the given process conditions. Comparing the degreasing efficiencies of the solvent with aqueous based ultrasonic processes, about 80% of the solvent degreasing efficiency could be obtained for aqueous degreasing process. This novel ultrasonic process helps in making aqueous degreasing process a viable option, which is eco-friendly even dispensing with temperature control measures.

Determination of Toxic Elements in Muscle Tissues of Five Fish Species Using Ultrasound‐Assisted Pseudodigestion by Electrothermal Atomic Absorption Spectrophotometry: Optimization Study

A simple and rapid method is described for the determination of As, Cd, and Pb in muscle tissue of five freshwater fish species by ultrasound‐assisted pseudodigestion (USD). A Plackett‐Burman experimental design was used as a multivariate strategy for the evaluation of the effects of varying several variables at once. The variables such as sonication time (ST), sample mass of muscle tissues (SM), temperature of ultrasonic bath (T), nitric acid (A1), and mixture of acid and oxidant (A2) have been studied. From these studies, some variables showed significant effect on % recovery, and they were further optimized by a 23+star central composite design, which involved 16 experiments. Optimum values of the variables were selected for the development of USD to determine the contents of As, Cd, and Pb in muscle tissue of five fish species, used as bioindicators for Lake Manchar (Sindh, Pakistan) to know whether consumption of these fishes threatens human health. The determination of three toxic elements under study was carried out by electrothermal atomic absorption spectrometry (ETAAS). The accuracy of the optimized procedure was evaluated by analysis of certified reference materials DORM‐2 (Dogfish Muscle Certified Reference Material for Trace Elements) and by comparison with conventional wet acid digestion methodology. No significant differences were observed for p=0.05 when comparing the values obtained by the proposed USD method and conventional digestion method (CDM) (paired t‐test). The average relative standard deviation of the USD method varied between 4.05%, 7.53%, and 4.55% for As, Cd, and Pb, respectively (n=10).

Application of factorial design in optimization of ultrasonic-assisted extraction of aluminum in juices and soft drinks

A sample preparation method based on ultrasound-assisted pseudo-digestion of Al from Juices and soft drink samples under ultrasonic effect has been described. A Plackett–Burman experimental design was used as a multivariate strategy for the evaluation of the effects of varying several variables at once. The effects of five different variables preintensification time (without ultrasonic stirring), intensification time in ultrasonic bath (UB), temperature of UB, two acid mixtures (HNO 3–H 2SO 4–H 2O 2 and HNO 3–H 2O 2), on the recovery of Al have been investigated. From these studies, certain variable showed up as significant, and they were optimized by a using 2 3 + star central composite design, which involved 16 experiments. The best conditions for pseudo-digestion were as follows: a preintensification time 10 min, intensification time 20 min, volume of acid mixtures 3.0 ml and temperature of ultrasonic bath 80 °C. A conventional acid digestion on electric hot plate was used to obtain total Al for comparative purpose. Final solutions obtained from both methods, were analysed by electrothermal atomic absorption spectrometry. Analytical results for the Al by ultrasound-assisted pseudo-digestion, and conventional wet digestion methods showed a good agreement, thus indicating the possibility of using ultrasonic-assisted digestion sample preparation instead of intensive treatments inherent with the acid digestion methods on electric hot plate. The procedure proposed allowed the determination of Al with detection limit (3 ά/ s) 10 μg l −1.

Power ultrasound-assisted cleaner leather dyeing technique: influence of process parameters.

The application of power ultrasound to leather processing has a significant role in the concept of "clean technology" for leather production. The effect of power ultrasound in leather dyeing has been compared with dyeing in the absence of ultrasound and conventional drumming. The power ultrasound source used in these experiments was ultrasonic cleaner (150 W and 33 kHz). The effect of various process parameters such as amount of dye offer, temperature, and type of dye has been experimentally found out. The effect of presonication of dye solution as well as leather has been studied. Experiments at ultrasonic bath temperature were carried out to find out the combined thermal as well as stirring effects of ultrasound. Dyeing in the presence of ultrasound affords about 37.5 (1.8 times) difference as increase in % dye exhaustion or about 50% decrease in the time required for dyeing compared to dyeing in the absence of ultrasound for 4% acid red dye. About 29 (1.55 times) increase in % dye exhaustion or 30% reduction in time required for dyeing was observed using ultrasound at stationary condition compared with conventional dynamic drumming conditions. The effect of ultrasound at constant temperature conditions with a control experiment has also been studied. The dye exhaustion increases as the temperature increases (30-60 degrees C) and better results are observed at higher temperature due to the use of ultrasound. Presonication of dye solution or crust leather prior to the dyeing process has no significant improvement in dye exhaustion, suggesting ultrasound effect is realized when it is applied during the dyeing process. The results indicate that 1697 and 1416 ppm of dye can be reduced in the spent liquor due to the use of ultrasound for acid red (for 100 min) and acid black (for 3 h) dyes, respectively, thereby reducing the pollution load in the effluent stream. The color yield of the leather as inferred from the reflectance measurement indicates that dye offer can be halved when ultrasound is employed to promote dyeing. Scanning electron microscopy analysis of the cross section of the dyed leather indicates that fiber structure is not affected due to the use of ultrasound under the given process conditions. The present study clearly demonstrates that ultrasound can be used as a tool to improve the rate of exhaustion of dye, reduce pollution load in the spent effluent liquor, and improve the quality of leather produced. The study also offered provision to employ optimum levels of chemicals and increases percentage exhaustion for a given time, thereby limiting the pollution load in the tannery effluent, which is of great social concern.