Ultrasonic Cavitation Treatment Research Articles

Degradation of Congo Red Using Periodate, Activated by Ultrasound and Iron(II)

The periodate, activated by the combination of ultrasound and Fe(II), was used for oxidative degradation of an anionic diazo dye of congo red (CR). The effect of the main factors (the initial pH, the molar ratio of CR:KIO4:FeSO4, the amount of Fe(II), and the specific power of ultrasonic cavitation treatment) on its degradation efficiency was analyzed.

Mechanical Damage to Coal and Increased Coal Permeability Caused by Water-Based Ultrasonic Cavitation

Coalbed methane (CBM), recognized as a sustainable and environmentally friendly energy source, plays a crucial role in mitigating global climate change and advancing low-carbon energy solutions. However, the prevalence of low-permeability coal seams poses a significant challenge to effective CBM extraction. Improving coal permeability has emerged as a viable strategy to address the issue of low-permeability coal. Conventional CBM stimulation methods fall short in overcoming this obstacle. In contrast, the enhanced technique of CBM extraction by water-based ultrasonic cavitation holds great promise due to its use of high energy intensity, safety, and efficiency. Nevertheless, the inadequate theoretical framework for managing this technology impedes its widespread adoption for large-scale applications. This study investigated the impact of water-based ultrasonic cavitation treatment on coal’s properties and permeability through mechanical testing and permeability measurements conducted before and after treatment. This study also explored the process by which this technology, known as WUC-ECBM, improves coal’s mechanical properties and permeability. The findings suggest a potential stimulation technique (WUC-ECBM) for use in CBM extraction, and its physical mechanism.

Ultrasonic cavitation strengthening and generation of superhydrophobicity for the surface of in situ (ZrB2 + Al2O3)/AA6016 matrix composite

To enhance the operating stability and durability of the aluminum matrix composite, the superhydrophobic surface is constructed on the substrate of in situ ZrB2 and Al2O3 nano-particle reinforced AA6016 matrix composite. The method incorporating ultrasonic cavitation treatment and low surface energy modification is applied. The performance of the obtained superhydrophobic surface is investigated through comprehensively analyzing micro and nano surface structures, roughness, water contact angle, chemical composition, and mechanical property. The results indicate that the water contact angle and water sliding angle of the specimen treated with cavitation for 9 min and then modified with fluorosilane attain 163.8° and 7.3°, respectively. High superhydrophobicity is accomplished. Long exposure to ultrasonic cavitation treatment results in the shift from hydrophobicity to hydrophilicity. The presence of particle-reinforced phases induces a pinning effect, causing the accumulation and entanglement of dislocations beneath the surface. This phenomenon leads to a 64.7 % increase in surface hardness, and the thickness of the work hardening layer reaches about 300 μm. The obtained conclusions shed light on the preparation of superhydrophobic surface for the aluminum matrix composite, and the application of aluminum matrix composites in harsh environment is expected to be broadened.

Research on Ultrasonic Cavitation Treatment of Milk. An Experimental Approach

Homogenization is a standard milk processing method used to stabilize fat emulsions against gravitational separation. In the dairy industry, high-pressure homogenization is commonly applied, which requires significant energy input to achieve optimal processing conditions. The size and composition of fat globule membranes affect the sensory and rheological properties of secondary dairy products [1]. Recently, ultrasound has been frequently used for milk homogenization [2]. Unlike ultrasound, mechanical mixing does not provide emulsion stability even after prolonged treatment, highlighting the differences between these two technologies. These differences arise due to the varying degrees of fat globule and membrane disruption. However, dairy products with different physicochemical and functional properties can be produced using both ultrasonic treatment and in combination with other traditional homogenization methods.To study the impact of ultrasonic treatment parameters of milk, specifically their different values, on the size of fat inclusions and the stability of milk emulsion over a certain period after treatment.The study employed an experimental method of milk processing using an ultrasonic cavitation unit.The impact of ultrasonic cavitation on the quality of milk homogenization in a steady volume was investigated. Optimal process parameters, specifically the power of the ultrasonic field and treatment time, were experimentally determined. The use of ultrasonic frequency greater than 33 kHz was found to be impractical.It was experimentally proven that ultrasonic cavitation treatment of milk is extremely effective for obtaining homogeneous emulsions. Given that excessive heating (> 65 °C) is undesirable in the production of dairy products from a technological standpoint, a definite advantage of this method is the low-temperature (50 °C) mode compared to traditional processing methods (75–80 °C), which also positively affects the preservation of nutrients.

Degradation of diazine dye safranin T using potassium persulfate activated by ultrasonic treatment and MnFe2O4 spinel nanoparticles

An advanced oxidation process of ultrasound/MnFe2O4/K2S2O8 was developed for the degradation of diazine dye safranin T, according to which potassium persulfate was co-activated by ultrasonic (US) cavitation and MnFe2O4 spinel nanoparticles synthesized via co-precipitation in the ultrasonic field. A synthesis product annealed at a temperature of 4000C, with an average size of MnFe2O4 crystallites of about 7 nm, was used as a catalyst for the decomposition of potassium persulfate. Based on the results of experimental studies on the influence of various factors on the degree and rate constant of safranin T oxidative degradation, as well as considering energy and resource-saving principles, the rational conditions of oxidative degradation were determined as follows: the reaction medium temperature of 600C, the molar ratio of safranin T:K2S2O8=1:100, the catalyst loading of 0.1 g/l, and the specific power of the ultrasonic cavitation treatment of 51.0 W/l. It was established that under such conditions the oxidative degradation degree of safranin T was equal to 98.3%, and the rate constant was 1.510–3 s–1. The changes in the UV-Vis spectra of safranin T, namely a decrease in the intensity of absorption bands, both in the visible (at a wavelength of 520 nm) and in the UV (at a wavelength of 275 nm) regions of the spectrum, confirmed the degradation of safranin T. In addition, the absence of the appearance of new peaks in the visible and UV regions of the spectrum indicated mineralization of the dye.

Effects of ultrasonic cavitation on microstructure and surface properties of Mn–Cu alloy

In the presented study, the effects of ultrasonic vibration on microstructure and surface properties of Mn–Cu alloy were investigated. At the early stage of ultrasonic cavitation treatment, grains of Mn–Cu alloy are refined, nanocrystals and amorphous bands are produced. As the ultrasonic cavitation treatment proceeds, the face-centered cubic structure is transformed into the body-centered tetragonal structure, and the martensitic phase transformation arises. The transformation is accompanied by plastic deformation and the formation of dislocations. The generation of martensite is caused by the stress and strain. Due to grain refinement, dislocations, and generation of martensite, the surface hardness of Mn–Cu alloy is enhanced, and the friction coefficient decreases. The resistance to wear is thereby improved.

Highly sensitive piezoresistive and thermally responsive fibrous networks from the in situ growth of PEDOT on MWCNT-decorated electrospun PU fibers for pressure and temperature sensing

Flexible electronics have demonstrated various strategies to enhance the sensory ability for tactile perception and wearable physiological monitoring. Fibrous microstructures have attracted much interest because of their excellent mechanical properties and fabricability. Herein, a structurally robust fibrous mat was first fabricated by electrospinning, followed by a sequential process of functionalization utilizing ultrasonication treatment and in situ polymerization growth. Electrospun polyurethane (PU) microfibers were anchored with multi-walled carbon nanotubes (MWCNTs) to form conductive paths along each fiber by a scalable ultrasonic cavitation treatment in an MWCNT suspension. After, a layer of poly(3,4-ethylene dioxythiophene) (PEDOT) was grown on the surface of PU fibers decorated with MWCNTs to enhance the conductive conjunctions of MWCNTs. Due to the superior electromechanical behaviors and mechanical reinforcement of PEDOT, the PEDOT/MWCNT@PU mat-based device exhibits a wide working range (0–70 kPa), high sensitivity (1.6 kPa−1), and good mechanical robustness (over 18,000 cycles). The PEDOT/MWCNT@PU mat-based sensor also demonstrates a good linear response to different temperature variations because of the thermoelectricity of the PEDOT/MWCNT composite. This novel strategy for the fabrication of multifunctional fibrous mats provides a promising opportunity for future applications for high-performance wearable devices.

Generation of superhydrophobicity on surface of multiphase aluminum alloy through the combination of ultrasonic cavitation treatment and surface modification

The presented study aims to develop a method that combines ultrasonic cavitation and fluorosilane modification for producing superhydrophobic surface on the aluminum alloy substrate. Micro-nano structures are induced through cavitation erosion at different exposure time, and the samples are further modified using a low surface energy modification method. The results show that ultrasonic cavitation is effective for preparing the surface structures required for superhydrophobicity. The water contact angle of about 140° is obtained through an ultrasonic cavitation treatment of 60 min. After surface modification with fluorosilane, the water contact angle increases to 162.5°, and the water sliding angle is reduced to 3.5°. The microscopic phases with high hardness on the aluminum alloy surface are retained, while the microscopic phases with low hardness are removed. Furthermore, the surface hardness is improved by more than 30 %, and work hardening layers of about 200 µm in thickness are produced beneath the target surface.

Experimental Study on Ultrasonic Cavitation Intensity Based on Fluorescence Analysis

The Ultrasonic cavitation effect has been widely used in mechanical engineering, chemical engineering, biomedicine, and many other fields. The quantitative characterization of ultrasonic cavitation intensity has always been a difficulty. Based on this, a fluorescence analysis method has been adopted to explore ultrasonic cavitation intensity in this paper. In the experiment of fluorescence intensity measurement, terephthalic acid (TA) was used as the fluorescent probe, ultrasonic power, ultrasonic frequency, and irradiation time were independent variables, and fluorescence intensity and fluorescence peak area were used as experimental results. The collapse of cavitation bubble will cause molecular bond breakage and release ·OH, and the non-fluorescent substance TA will form the strong fluorescent substance TAOH with ·OH. The spectra of the treated samples were measured by a F-7000 fluorescence spectrophotometer. The results showed that the fluorescence intensity and fluorescence peak area increased rapidly after ultrasonic cavitation treatment, and then increased slowly with the increase of ultrasonic power, which gradually increased with the increase of irradiation time. They first decreased and then increased with the increase of ultrasonic frequency from 20 kHz to 40 kHz. The irradiation time was the most influential factor, and the cavitation intensity of low frequency was higher overall. The fluorescence intensity and fluorescence peak area of the samples increased by 2–20 times after ultrasonic treatment, which could increase from 69 and 5238 to 1387 and 95451, respectively. After the irradiation time exceeded 25 min, the growth rate of fluorescence intensity slowed down, which was caused by the decrease of gas content and TA concentration in the solution. The study quantitatively characterized the cavitation intensity, reflecting the advantages of fluorescence analysis, and provided a basis for the further study of ultrasonic cavitation.

ОПРЕДЕЛЕНИЕ РЕЖИМОВ УЛЬТРАЗВУКОВОЙ КАВИТАЦИОННОЙ ОБРАБОТКИ МОТОРНОГО ТОПЛИВА

The article considers an example of ultrasonic cavitation created by a piezoelectric emitter. To identify the modes of ultrasonic cavitation treatment, the Qsonica sonicators Q-700 laboratory unit was used. The aim of the work is to determine the modes of ultrasonic treatment of motor fuel to create a cavitation region. Cavitation areas were determined by the area of destruction of aluminum foil samples, 0.008-0.009 mm thick. A sheet of aluminum foil was placed in the test medium parallel and perpendicular to the tip at different distances h, l. In order to identify the intensity of the resulting cavitation, cavitation noise was isolated from the signal of a hydrophone immersed in motor fuel at different distances from the radiator and connected to a multimeter model UT61E. The intensity of cavitation was estimated by the change in the resistance of the medium, R. The following types of motor fuel were used for processing: commercial diesel fuel, biodiesel based on ginger oil, mixed diesel fuel (containing 20% biodiesel). After the study, the foil was dried and the area of destruction was determined. It has been established that the following parameters influence the creation of cavitation – the distance from the radiating surface, intensity, amplitude and time of ultrasonic treatment of the sample.f= f (l, h, I, A, t). Four cavitation areas are defined: the area of active or optimal cavitation, the area of the beginning of cavitation, the area of incipient cavitation, the area of absence of cavitation. Depending on the amplitude and intensity, 6 operating modes are highlighted. It is established that the processing of the used motor fuel should be carried out on the 3 cavitation mode of operation (A =21-40%, I= 12.5-24.8 W / cm2) of the laboratory installation in the used technological volume or in larger volumes with reflective surfaces. It has been found that the cavitation noise in biodiesel is lower than in diesel fuel, since it is more viscous. In viscous liquids, cavitation is less developed and, consequently, the ultrasound absorption coefficient is lower for them. In this regard, it is necessary to design devices for media with a higher viscosity based on the optimal distance from the radiator to the bottom.

Influence of acoustic cavitation on physico-chemical, organoleptic indicators and microstructure of Adyghe cheese produced from cow and goat milk

In this article, we studied the effect of acoustic cavitation on the physicochemical and organoleptic parameters, the microstructure of Adyghe cheese made from cow's and goat's milk, and their mixture. The experimental conditions, optimal modes of ultrasonic cavitation treatment of cow and goat milk, and their mixtures are determined. It was found that high-frequency acoustic cavitation improves the physico-chemical and organoleptic indicators of cheese. The 45 kHz mode, with 17 min a processing time, is optimal, improving the microstructure of cheese, organoleptic, physico-chemical indicators.

Ultrasound cavitation: a reliable non-enzymatic method for adipose-derived mesenchymal stem cell (ADSC) isolation

BackgroundAdipose tissue is known to serve as an abundant and readily accessible source of adipose-derived stem cells (ADSCs) as an alternative to bone marrow. Collagenase is one of the most widely used methods for the isolation of ADSCs from adipose tissue, but it takes a long time, and there are also debates about safety. We propose an ultrasonic cavitation-treated method that can significantly reduce time and avoid the problem of using xenogeneic enzymes in ADSCs isolation.MethodsADSCs were isolated from adipose tissue using the enzyme treatment method and the ultrasonic cavitation treatment method. Cell proliferation was measured using cell viability assay. The expression levels of the surface markers of ADSCs were estimated by real-time PCR. After, ADSCs were cultured in chondrogenic, osteogenic, or adipogenic differentiation medium; the differentiation potential of ADCSs was analyzed by Alcian blue, Alizarin Red S, Oil Red O, and real-time PCR.ResultsThe cells treated with collagenase and ultrasound had similar cell yields and proliferation after isolation. The difference in the expression of surface markers of ADSCs was not statistically significant. ADSCs showed differentiation potential into adipocytes, osteocytes, and chondrocytes, and there was no difference between the enzyme treatment method and the ultrasonic cavitation treatment method. The yield of the ADSC increased in time- and intensity dependently.ConclusionsUltrasound certainly serves as a promising method in advancing ADSC isolation technology.

Visible light-Fenton degradation of tetracycline hydrochloride over oxygen-vacancy-rich LaFeO3/polystyrene: Mechanism and degradation pathways

In this study, the oxygen–vacancy–rich (OV) lanthanum ferrite (LaFeO3) perovskite (also called LFO) was successfully prepared by an ultrasound–assisted sol–gel method and hydrothermally loaded onto polystyrene (PS) to obtain LaFeO3/polystyrene–oxygen–vacancies (LFO/PS–OVs). The structure and properties of LFO/PS–OVs were investigated using scanning electron microscopy–energy dispersive spectroscopy (SEM–EDS), X–ray photo–electron spectroscopy (XPS), photoluminescence spectra (PL) and other characterization methods. The authors also investigated the effects of hydrogen peroxide (H2O2) concentration, catalyst dosage, solution concentration, pH and inorganic anions on the tetracycline hydrochloride (TC) removal efficiency. According to the results, the ultrasonic cavitation treatment and the composite reaction significantly increased the specific surface area of LFO as well as the content of oxygen vacancies and broadened the forbidden band width of LFO. The significant improvement in catalytic activity can be attributed to solving the agglomeration problem of powdered LFO and the introduction of a large amount of OVs. The degradation mechanism was proposed according to the free radical capture experiments and the electron spin resonance (ESR) tests. Based on the DFT calculations and identification of intermediates by LC/MS, the main degradation pathways of TC were proposed. The results showed that reactive oxygen species (ROS) may preferentially attack atoms with the high f0 values of Fukui index. This study gives an insight into the promising application of oxygen–vacancy–rich perovskite/polystyrene composites in environmental remediation.

Highly conductive, stretchable, durable, breathable electrodes based on electrospun polyurethane mats superficially decorated with carbon nanotubes for multifunctional wearable electronics

As smart wearable electronics become commonplace, there exists an unmet need for stretchable, durable and breathable electrodes that can be easily integrated with the electronics and comfortable for the users when used for extended periods. Despite the enormous effort in the development of stretchable electronic materials and structures, limited progress has been made in terms of developing a facile, scalable fabrication process to produce mechanically and electrically robust, breathable conductive electrodes for wearable electronics. Herein, we develop a novel stretchable polymer-carbon nanotube composite electrode based on a fibrous polyurethane mat decorated with conductive carbon nanotubes superficially embedded into individual polyurethane fibers. The fibrous polyurethane mat is fabricated through a facile technique of electrospinning, followed by a scalable ultrasonic cavitation treatment in a carbon nanotubes suspension solution. During ultrasonic cavitation treatment, long carbon nanotubes are embedded into electrospun polyurethane fibers and mechanically interlocked with one other, forming a dense, structurally robust, and electrically stable conductive network surrounding each fiber. The as-fabricated electrodes exhibit several superior properties that are characterized by good stretchability (recoverable stretching rate up to 200 %), high conductivity (low sheet resistance of 30 ∼ 50 Ω/sq), excellent stability (over 20,000 bending and stretching cycles), remarkable durability (capable of ultrasonic washing for over 30 min), and efficient air permeability (22.83 mm s−1 at a pressure difference of 100 Pa). Based on the integrated superior performances, the multifunctional capability of this novel electrode for wearable electronics is demonstrated in applications including thin-film heaters, strain sensors, and wearable energy supply of stretchable supercapacitor electrodes. It is supposed that the developed fabrication process and stretchable electrodes could be a versatile platform for development of flexible and wearable electronics.

Effect of ultrasound fat cavitation versus faradic stimulation on abdominal adiposity during postnatal period section

Background and Purpose: This study examines the effects of ultrasonic fat cavitation versus faradic stimulation on postnatal abdominal obesity. Subjects and Methods: It was a randomized controlled trial. Overall, 40 patients complaining of abdominal adiposity postnatal, aged 25-35 years, were randomized into two equal groups. The control group (A) received sessions of abdominal ultrasonic cavitation treatment three times per week with a frequency of 40 kHz, a power of 45 W, and a duration of 30 minutes, in addition to a balanced diet programme consisting of between 1000kcal and 1200kcal per day for six weeks. The study group (B) received faradic stimulation treatment sessions focusing on their abdomen area three times per week with a duration of 30 minutes, in addition to a healthy diet plan which ranged from 1000kcal to 1200kcal/day for six weeks. Tape measurement was used to assess waist circumference; a digital calliper was used to determine fat thickness, while body analysis was used to evaluate fat percentage in both groups before and after the treatment.

Microbubbles Ultrasonic Cavitation Regulates Tumor Interstitial Fluid Pressure and Enhances Sonodynamic Therapy

Sonodynamic therapy (SDT) is a promising treatment method for solid tumors. However, the high interstitial fluid pressure (IFP) in tumor tissues limits the accumulation of sonosensitizers. In the present study, microbubbles ultrasonic cavitation was used to regulate the tumor’s IFP and evaluate SDT effects. Rabbit VX2 tumor tissues were treated with microbubbles ultrasonic cavitation. The IFP of different tumor parts before and after cavitation was measured by the WIN method. The accumulation of the sonosensitizers hematoporphyrin monomethyl ether (HMME) in tumor tissues was observed using an ultramicro spectrophotometer and laser confocal microscope. Then, tumor-bearing rabbits were treated with SDT once a week for eight weeks and the therapeutic effect was evaluated. After microbubbles ultrasonic cavitation treatment, the tumor’s IFP decreased and the HMME concentration increased. We concluded that microbubbles ultrasonic cavitation can increase HMME accumulation in rabbit VX2 tumors and increase SDT therapeutic effects.

Some control mechanisms of spatial solidification in light alloys

Abstract Two unconventional approaches of controlling the size and distribution of primary particles in aluminium and magnesium alloys are suggested. The first approach uses the ultrasonic cavitation treatment for multiplication of solidification sites for primary crystals by activating catalytic impurities that are present in the melt. The second way, on the contrary, involves elimination of active solidification nuclei by melt overheating with subsequent nucleation of primary particles at a higher undercooling. Both approaches result in refinement of primary crystals.

INCREASING THE ULTRASONIC TECHNOLOGICAL ACTION EFFICIENCY IN THE FOOD RAW MATERIALS PROCESSING

The increase of ultrasonic technological action efficiency at food raw materials processing by taking into account their rheological properties is investigated. We have proved the need to determine the classification characteristics of food media, which are crucial for their processing and reflect the change in ultrasonic treatment. The mode of loading on the emitter, physical characteristics and conditions of exposure to the emitter are among the key features. It was found that acoustically unlimited media with constant and variable physical parameters with constant and variable dimensions have a significant impact on the processing. The efficiency of the oscillations in acoustically unlimited and limited environments is ensured by matching the value of the input resistance with the source of oscillations and with the waveguide system. Physical characteristics of food media, conditions of influence on the emitter are revealed. The identified classification features reflect the main key aspects of improving the efficiency of ultrasonic technological action in the food raw materials processing, which are related to the assessment of the waves’ propagation in the media and the interaction of these waves with the emitter. It is established that the Kelvin-Voigt model is one of the most reliable, it reflects the certain rheological properties of the medium in the conditions of ultrasonic cavitation treatment. Taking into account the conversion of ultrasonic energy, the main stages of the process are identified. The dependences of the amplitude of the sound pressure on the thickness of the fluid treatment layer are established, taking into account the viscosity of the liquid. The dependences of the radius of the cavitation bubble on the amplitude of the sound pressure and the thickness of the liquid layer are revealed. The wave resistance of the medium is studied and analytical dependences are obtained to determine the intensity of the technological process by which the increase of the efficiency of the processes of ultrasonic technological action in the food raw materials processing is realized.

Direct strain distribution and finite-element-analysis simulation of the bonding interface of bamboo laminated lumber with ultrasound-treated bamboo strips

An ultrasonic cavitation treatment was used to increase the permeability of phenol formaldehyde resin adhesive on the surface of bamboo strips, and two-ply laminated bamboo lumber was manufactured. The strain distribution along the bamboo interface under stretching conditions was investigated using the digital image correlation technique. The effect of the ultrasonic treatment on the bamboo strips in terms of the shear strain of the laminated bamboo lumber was investigated, and a finite-element analysis for the bonding interface was carried out to evaluate whether the deformation measurement could predict the mechanical behavior differences of the laminated bamboo lumber. The digital image correlation and shear strength results show that the strain was lower in the bamboo bonding interface after ultrasonic treatment and the shear strength was enhanced due to the increased adhesive penetration. The digital image correlation measurement and finite-element analysis simulation both showed that stress was more concentrated, and the strain value and strain zone width was higher in the carbonized bamboo bonding interface than in the bleached bamboo bonding interface. The finite-element analysis results appeared to be in agreement with the digital image correlation test results.

3D printing-directed flexible strain sensors of accordion-like architecture to achieve ultrastretchability with the assist of ultrasonic cavitation treatment

A new class of accordion-like cellular architecture with sinusoidal struts is designed to enhance the planar stretchability of cellular solids, aiming to fabricate flexible strain sensors with ultrastretchability. The combination manufacturing process of fused deposition modeling (FDM) 3D printing technique and ultrasonic cavitation-enabled treatment was introduced into the fabrication of flexible strain sensors made of thermoplastic polyurethane (TPU) substrate and carbon nanotubes (CNTs). A negative Poisson’s ratio (NPR) architecture made of TPU was firstly 3D-printed by FDM. The ultrasonic cavitation treatment was then conducted on the soft auxetic structure immersing in CNTs liquid, aiming to embed the CNTs into the surface layer of the flexible TPU substrate with NPR configurations. Instead of 3D printing the TPU matrix composite after hybridization inside the matrix material, the hybrid manufacturing procedure can ensure that the intrinsic excellent mechanical properties of TPU are not embrittled. Besides, the sinusoidal struts in accordion-like cellular architectures offer a design route to extend the material property chart to achieve ultrahigh stretchability in lightweight 3D printable flexible polymers for the applications that require combined stretchability, lightweight, and energy absorption such as soft robotics, stretchable electronics, and wearable protection shields.