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Titanium dioxide (TiO2) nanoparticles are used in a wide variety of products, such as renewable energy resources, cosmetics, foods, packaging materials, and inks. However, large quantities of surfactants are used to prepare waterborne TiO2 nanoparticles with long-term dispersion stability, and very few studies have investigated the development of p...
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Citations
... This focused approach was employed to predict the degradation effect of organic dyes. 49,50 This study aimed to demonstrate that water treatment technology using a focused ultrasonic system is more effective than other methods. Simultaneously, we aimed to determine the optimal conditions of focused ultrasonic equipment for water treatment technology. ...
... Consequently, strong and uniform energy is transmitted inside, and the generation and collapse of cavitation bubbles are repeated. 49,50 When a cavitation bubble collapses, the intense energy latent in the bubble is released outward, and the energy physically and chemically affects the methylene blue molecule. In the experiment, methylene blue samples were circulated through the equipment at a rate of 5.0 mL min −1 using a pump (LongerPump, WT600-1F) to irradiate ultrasonic waves, and cooling water was also circulated at a rate of 10.0 mL min −1 using the same pump to control heat generation and transfer ultrasonic energy to the sample. ...
Textile wastewater accounts for a significant proportion of industrial wastewater worldwide. In particular, dye wastewater accounts for a large proportion and consists of non-degradable dyes, which are substances resistant to biodegradation. Methylene blue is a representative example of such non-degradable dyes. It is not biologically degraded and exhibits toxicity. Various methods for their decomposition are currently being studied. Advanced oxidation processes (AOPs), which generate highly reactive hydroxyl radicals that oxidize and degrade pollutants, have been actively studied. Particularly, the photocatalytic degradation method using TiO2 nanoparticles is one of the most actively studied fields; however, there are still concerns regarding the toxicity of nanoparticles. Research is currently being conducted on AOPs using the cavitation phenomenon of ultrasonic waves. However, achieving high efficiency using existing ultrasonic equipment is difficult. Therefore, in this study, we evaluated a new water treatment technology through AOPs using a focused ultrasonic system with a cylindrical piezoelectric ceramic structure. After determining the optimal conditions for degradation, the degradation process was evaluated as a useful tool for mitigating the toxicity of methylene blue. We found that, under the optimal conditions of 100 W intensity at a frequency of 400 kHz, this system is a helpful instrument for degradation and a new water treatment technology suitable for removing ecotoxicity and genotoxicity.
... In addition, sonication using ultrasonic technology is mainly used to produce nano-sized liposomes [23][24][25][26]. Although bath and horn types of sonication apparatuses are commonly used, they present several disadvantages, such as low energy, non-uniform dispersion, and non-adjustable frequency or power of the ultrasonic waves [27]. In this study, we aim to overcome these disadvantages and use a focused ultrasound device that can control frequency and power, thereby producing uniform dispersion. ...
Liposomes are microspheres produced by placing phospholipids in aqueous solutions. Liposomes have the advantage of being able to encapsulate both hydrophilic and hydrophobic functional substances and are thus important mediators used in cosmetics and pharmaceuticals. It is important for liposomes to have small sizes, uniform particle size distribution, and long-term stability. Previously, liposomes have been prepared using a homo mixer, microfluidizer, and horn and bath types of sonicators. However, it is difficult to produce liposomes with small sizes and uniform particle size distribution using these methods. Therefore, we have developed a focused ultrasound method to produce nano-sized liposomes with better size control. In this study, the liposome solutions were prepared using the focused ultrasound method and conventional methods. The liposome solutions were characterized for their size distribution, stability, and morphology. Results showed that the liposome solution prepared using focused ultrasonic equipment had a uniform particle size distribution with an average size of 113.6 nm and a polydispersity index value of 0.124. Furthermore, the solution showed good stability in dynamic light scattering measurements for 4 d and Turbiscan measurements for 1 week.
... It is noteworthy to observe that the effect of ultra-probe sonication reduced the aggregation and agglomeration of Ag-TiO 2 NPs. The sonication wave from the ultra-probe sonication generated bubble formation, and the collapse of bubbles during irradiation time was called cavitation, inhibiting the aggregation and agglomeration of NPs [38]. The mechanisms of ultra-probe sonication for reducing aggregation or agglomeration of NPs in solution are rupture, erosion, and shattering [39]. ...
... It is generally agreed that the ultrasonic dispersion method is one of the more successful dispersion methods. However, if mechanical energy is used in the dispersion process, it can potentially harm the structure of the nanomaterials; for example, by significantly lowering the aspect ratio of CNT [14,15]. ...
Concrete must be a hydrophilic compound that is easily fabricated by nature. At the nanoscale, mechanical and chemical reactions alter the quality of cement-based substances. Continuous sprinkling of nano-silica solution synthesised with minimal surface solvents has been used to create a superhydrophobic (SH) concrete surface while similarly modifying the surface’s chemical composition and dynamical intrinsic structure. In this study, we examine the impacts of admixtures in SH concrete including nano-based bio-carbonate. The fundamental characteristics and dispersal techniques of nanoparticles often employed in cement-based compounds are reviewed initially in this paper. Investigations of the large contact angle, small slide angle, and carbonated thickness have been employed to analyze the impacts of admixtures. Additionally, the industry and uses of nanoparticles for concrete substances are addressed, and the expense is inventively represented by a survey questionnaire. Finally, this article identifies the obstacles that now occur in the field of research and offers appropriate future viewpoints.
... Physical/mechanical effects accompanying cavitation, namely heating, microjet, and shockwave, play a crucial role in chemical syntheses, e.g., accelerate mass transport, have an impact on morphologies and surface composition, as well as generate nanostructures, e.g., exfoliate layered materials into 2D layered ones [3]. For a detailed explanation, readers are referred to refs [3,5,6]. [6]. ...
... For a detailed explanation, readers are referred to refs [3,5,6]. [6]. Reproduced with permission from ref. [6], licensed under CC-BY. ...
... [6]. Reproduced with permission from ref. [6], licensed under CC-BY. (B) Schematic illustration of the instruments for sonochemical synthesis: (a) cleaning bath [12], (b) probe system [12], (c) horn reactor [14], and (d) longitudinal horn reactor [14]. ...
Ultrasounds are commonly used in medical imaging, solution homogenization, navigation, and ranging, but they are also a great energy source for chemical reactions. Sonochemistry uses ultrasounds and thus realizes one of the basic concepts of green chemistry, i.e., energy savings. Moreover, reduced reaction time, mostly using water as a solvent, and better product yields are among the many factors that make ultrasound-induced reactions greener than those performed under conventional conditions. Sonochemistry has been successfully implemented for the preparation of various materials; this review covers sonochemically synthesized nanoporous materials. For instance, sonochemical-assisted methods afforded ordered mesoporous silicas, spherical mesoporous silicas, periodic mesoporous organosilicas, various metal oxides, biomass-derived activated carbons, carbon nanotubes, diverse metal-organic frameworks, and covalent organic frameworks. Among these materials, highly porous samples have also been prepared, such as garlic peel-derived activated carbon with an apparent specific surface area of 3887 m2/g and MOF-177 with an SSA of 4898 m2/g. Additionally, many of them have been examined for practical usage in gas adsorption, water treatment, catalysis, and energy storage-related applications, yielding satisfactory results.
... To address this issue, ultra-sonic dispersion can be a potential solution that can control aggregation. 16 The supersonic waves can be effectively used to attain the suspension of the nanoparticles in the carrier fluids. The effect of ultrasonication is to break down the large agglomeration of nanoparticles into smaller ones thereby ensuring the stable suspension and more uniform distribution of nanoparticles to the base fluid. ...
Nanofluids are well known for their enhanced thermal properties. In spite of their excellent properties, there are certain hindrances to their applications on large scale. The issue of nanoparticle agglomeration in the base fluid with the consequent stability related issues is one of the main obstacles to the usage of nanofluids. Stability is crucial because the longer the nanofluids remain stable, the better their capacity to retain their thermal properties. Hence there is a need to evolve long-term stable nanofluids. Since there are a lot of factors, which are affecting the stability of the nanofluids, there is a need to optimize the process parameters. In this regard, central composite rotatable design (CCRD) was applied in this study to optimize the independent parameters of stability of ferric oxide nanofluids. For this, the performance of nanofluids was assessed by measuring the nephelometric turbidity units (NTU), based on the independent variables such as percentage of intensity of the nanoparticle, pH of the base fluid, and percentage volume concentration of the surfactant. All the parameters that are affecting individually and mutually were validated statistically using analysis of variance (ANOVA). A regression equation to evaluate the NTU was developed. The obtained results showed that the values predicted by the model and that obtained from the experiments were in good agreement with each other. It is observed that more than 99.65% of the variation could be predicted by the model developed for NTU. The response surface methodology (RSM) has revealed that the ideal process parameters for greater stability of nanofluids are 0.01% particle volume intensity, pH 3.2, and 0.6% surfactant intensity.
... Recently, an ultrasonication system was reported [37] that relies on non-contact ultrasonic dispersion and can provide excellent dispersion stability to dispersed TiO 2 nanoparticles without surfactants. In this study, we used this focused ultrasonic dispersion method to disperse TiO 2 as aggregates of different sizes without a surfactant, and the degradation of MB as a function of the size of TiO 2 aggregates was evaluated. ...
... TiO 2 nanoparticles were dispersed in water without a surfactant and using a highintensity focused ultrasound device (FS-R01K1, FUST Lab, Daejeon, South Korea) [37][38][39]. First, acoustic energy was focused on the center of a rod passing through an ultrasound Nanomaterials 2023, 13, 302 3 of 11 device by a cylindrical piezoelectric ceramic. During this time, a large amount of heat was generated, and the temperature was controlled by the energy transfer medium (cooling water). ...
... The energy was focused until extremely high energy levels were concentrated on the center of the chamber, which dispersed the aggregated TiO 2 colloids passing through the system. The dispersion stability of the water-dispersed TiO 2 suspension obtained through this process could be maintained for a long time without a surfactant [37]. ...
TiO2 is the most commonly used photocatalyst in water treatment. The particle size of TiO2 is an important factor that significantly influences its activity during photocatalytic degradation. In the presence of liquid, the properties of nanopowders composed of exactly the same product clearly differ according to their aggregation size. In this study, TiO2 nanoparticles with a controlled size were fabricated by focused ultrasound dispersion. The high energy generated by this system was used to control the size of TiO2 particles in the suspension. The constant high energy released by cavitation enabled the dispersion of the particles without a surfactant. The activities of the prepared TiO2 photocatalysts for methylene blue (MB) degradation were then compared. The dye degradation effect of the photocatalyst was as high as 61.7% after 10 min when the size of the powder was controlled in the solution, but it was only as high as 41.0% when the aggregation size was not controlled. Furthermore, when the TiO2 concentration exceeded a certain level, the photocatalytic activity of TiO2 decreased. Controlling the size of the aggregated photocatalyst particles is, therefore, essential in water-treatment technologies utilizing TiO2 photocatalytic properties, and adjusting the TiO2 concentration is an important economic factor in this photocatalytic technology. This study contributes to the development of processes for degrading dyes, such as MB, released from wastewater into aquatic environments.
... In this study, a surfactant-free nano-emulsification method was developed using an ultrasonic method that eliminates the disadvantages of using surfactants. Three types of ultrasound equipment were compared: bath, horn, and a focused ultrasound system that our group previously developed [10], and the optimized method for emulsification was examined through particle size analyses. The sizes of the oil particles at various frequencies of 180, 270, and 400 kHz were determined using a focused ultrasound system that disperses the nano oil particles. ...
... To address these drawbacks, we developed a new ultrasonic dispersion method [10]. In this process, the converted acoustic energy is directed toward the center of the system from a cylindrical piezoelectric ceramic element through the surrounding aqueous medium. ...
... Hence, particle size affects both the sedimentation velocity and Brownian motion of particles, both of which affect emulsion stability. Specifically, when particles are sufficiently small that their degree of Brownian motion is greater than their sedimentation (rising) velocity, emulsions are physically stabilized without the use of surfactants or other additives [9,10]. The displacement (velocity) of particles with different sizes suspended in water at 20 • C with a density of 0.9 g/cm 3 and their Brownian motion displacement (velocity) is compared in Table 5 [6,13,14]. ...
Emulsion technology is widely used in the preparation of cosmetics, pharmaceuticals, drug delivery, and other daily necessities, and surfactants are frequently used to prepare these emulsions because of the lack of reliable surfactant-free emulsification techniques. This is disadvantageous because some surfactants pose health hazards, cause environmental pollution, have costly components, and place limitations on process development. In this paper, an efficient method for surfactant-free nano-emulsification is presented. In addition, we discuss the effects of different operating parameters on the oil particle size, as well as the effect of the particle size on the emulsion stability. Specifically, we compared three surfactant-free ultrasonic emulsification technologies (horn, bath, and focused ultrasonic systems). The focused ultrasonic system, which concentrates sound energy at the center of the dispersion system, showed the best performance, producing emulsions with a particle size distribution of 60–400 nm at 400 kHz. In addition, phase separation did not occur despite the lack of surfactants and thickeners, and the emulsion remained stable for seven days. It is expected to be widely used in eco-friendly emulsification processes.
... Transmission electron microscopy (TEM; JEM-ARM200F, JEOL, Freising, Germany) was applied to observe the morphology of titania pigment before and after encapsulation by OSA starch [22]. OTP or non-processed titania pigment (0.01 g) was dispersed in 9.9 mL water and sonicated for 2 min. ...
Titania is a white pigment used widely in papermaking, paints and cosmetic industries.
Dispersion and stabilization of high concentration titania in water-based system remains a great bottleneck in industry nowadays, because aggregation of titania nanoparticles results in severe adverse effects to gloss, opacity, tint strength, color distribution and storage stability of end products. Because kappa-carrageenan (κ-CG) has excellent rheological properties such as emulsification, gelation, stabil�ity and so on, it has the ability to form gel and increase the viscosity of aqueous solution. In this work,
Octenyl succinic anhydride (OSA) starch was utilized as wall material to encapsulate titania pigments using electrostatic spray drying processing. Transmission electron microscopy (TEM) showed that titania pigments were coated by OSA starch, with a final form of nanoparticle. Accelerating stability test found that around 60% OSA starch–titania particles were stably dispersed in κ-CG-based solution. All materials used in this work were natural ingredient, which would be preferred by cosmetic
industry and consumers. The technique used in the present study could potentially be extended to other pigments for similar purpose.
... In addition, the nanoparticles' aggregate as the Zeta potential is lower than +30 mV and higher than −30 mV because the attractive forces may exceed the repulsive forces provided by charged materials. Nanoparticles with Zeta potential higher than +30 mV can resist more against aggregation in solution, being electrically stable (Hwangbo et al., 2021). Therefore, the polyplexes' stability in the physiological environment containing FBS and NaCl was investigated by evaluating the size and Zeta potential of the nanoparticles over 4 h of incubation. ...
Polymer-based nanocarriers requires extensive knowledge of their chemistries to learn functionalization strategies and understand the nature of interactions that they establish with biological entities. In this research, the poly (β-amino ester) (PβAE-447) was synthesized and characterized, aimed to identify the influence of some key parameters in the formulation process. Initially; PβAE-447 was characterized for aqueous solubility, swelling capacity, proton buffering ability, and cytotoxicity study before nanoparticles formulation. Interestingly, the polymer-supported higher cell viability than the Polyethylenimine (PEI) at 100 μg/mL. PβAE-447 complexed with plasmid DNA (pDNA) generated nanocarriers of 184 nm hydrodynamic radius (+7.42 mV Zeta potential) for cell transfection. Transfection assays performed with PEGylated and lyophilized PβAE-447/pDNA complexes on HEK-293, BEAS-2B, and A549 cell lines showed better transfection than PEI. The outcomes toward A549 cells (above 66%) showed the highest transfection efficiency compared to the other cell lines. Altogether, these results suggested that characterizing physicochemical properties pave the way to design a new generation of PβAE-447 for gene delivery.
