Ultrasonic Crystallization Research Articles

Ultrasound treatment of crystalline oil-in-water emulsions stabilized by sodium caseinate: Impact on emulsion stability through altered crystallization behavior in the oil globules

Partial coalescence is a key factor contributing to the instability of crystalline oil-in-water emulsions in products like dressings and sauces, reducing shelf life. The intrinsic characteristics of semi-crystalline droplets, including solid fat content, fat crystal arrangement, and polymorphism, play a pivotal role in influencing partial coalescence, challenging prevention efforts even with emulsifiers like amphiphilic proteins. High-intensity ultrasound (HIU) has emerged as an efficient and cost-effective technology for manipulating bulk fat crystallization, thereby enhancing physical properties. This study specifically investigates the impact of HIU treatment on fat crystallization on protein-stabilized crystalline emulsions, utilizing palm olein stearin (POSt) as the lipid phase and sodium caseinate (NaCas) as the surfactant under various HIU powers (100, 150, 200, 300, and 400 W). Results show that increasing HIU power maintained the interfacial potential (−20 mV) provided by NaCas in the emulsions without significant differences. Higher HIU power induced the most stable polymorphic form (β) in the emulsions. Engagingly, the emulsions at 200 W exhibited better storage stability and slower partial coalescence kinetics. Semi-crystalline globules had more uniform and integral crystal clusters that were distributed tangentially near the droplet boundary, perhaps attributed to intermediate subcooling (40.4 °C) at 200 W. The acoustic energy of HIU significantly translates into thermal effects, influencing subcooling degrees as a dominant factor affecting crystallisation in the emulsions. This study establishes ultrasonic crystallization as a novel strategy for modifying the stability of emulsions containing fat crystals.

Preparation, Characterization, and Bioactivity Evaluation of Polyoxymethylene Copolymer/Nanohydroxyapatite-g-Poly(ε-caprolactone) Composites.

In this work, nanohydroxyapatite (HAp) was functionalized with poly(ε-caprolactone) (PCL), using 1,6-hexamethylene diisocyanate (HDI) as a coupling agent, and then incorporated into the polyoxymethylene copolymer (POM) matrix using the extrusion technique. The obtained POM/HAp-g-PCL composites were investigated using FTIR, DSC, TOPEM DSC, and TG methods. Mechanical properties were studied using destructive and non-destructive ultrasonic methods, wettability, and POM crystallization kinetics in the presence of HAp-g-PCL. Moreover, preliminary bioactivity evaluation of the POM/HAp-g-PCL composites was performed using the Kokubo method. It was found that the introduction of HAp-g-PCL to the POM matrix has a limited effect on the phase transitions of POM as well as on its degree of crystallinity. Importantly, HAp grafted with PCL caused a significant increase in the thermal stability of the POM, from 292 °C for pristine POM to 333 °C for POM modified with 2.5% HAp-g-PCL. If unmodified HAp was used, a distinct decrease in the thermal stability of the POM was observed. Crystallization kinetic studies confirmed that HAp-g-PCL, in small amounts, can act as a nucleating agent for the POM crystallization process. Moreover, incorporation of HAp-g-PCL, although slightly decreasing the mechanical properties of POM composites, improved the crucial parameter in biomedical applications, namely the in vitro bioactivity.

The new achievements in ultrasonic processing of milk and dairy products

The effects of ultrasonic wave vibration, streaming, and cavitation have expanded the usage of ultrasound in milk and dairy industries. This review will look at the latest achievements in ultrasonic processing of milk and dairy products. Given the significant advances in the utilization of ultrasonic processing in milk and dairy products since the millennium, studies have been incorporated into outcome analysis. While ultrasonic crystallization, creaming, and fractionation are advancing faster, interesting achievements in dairy product functionality have emerged. Non-food contact transducers are scalable and better suited for industrial processes. In conclusion, large-scale processing equipment, alone or in combination with other technologies, will help expand ongoing microbial reduction processes.

A Novel Sodium-Ion Batteries: Synthesis and Characterization of Nanostructured Sodium Rhodizonate Cathodes

Several studies have emerged that seek to solve the energy deficit that we face as a society, where energy storage plays an important role. In this regard, Ion-Sodium batteries (Ion-Na) represent an excellent alternative to the Ion-Li batteries currently on the market. These new Ion-Na batteries have adequate charge densities and at a lower cost. Taking this issue into account, there is great interest in studying the composition, structure, and morphology of cathodes as active materials to optimize this type of battery. [i],[ii] .In this study, the synthesis and characterization of sodium rhodizonate nanostructures to be used as cathode material in Sodium-ion batteries was carried out. In a first stage, a two-level factorial design was used as an exploratory stage to evaluate the statistical significance of the variables involved in the synthesis: i) temperature, ii) reaction time, iii) molar ratio of precursors, and iv) addition time. The nanostructuring of the sodium rhodizonate crystals was carried out by the ultrasonic crystallization method and was characterized by X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The electrochemical characterization was performed using cyclic voltammetry, galvanostatic charge/discharge profiles, and cyclability. The results show that the nanostructuring of the material causes an increase in the storage capacity of sodium ions in the sodiation/desodiation process. This shows a strong size-dependence in the Na + ion intercalation process. Finally, these results will allow the generation of causal relationships that lead to the optimization of the electronic properties of alternative Na-ion batteries. [i] Minah Lee, Jihyun Hong, Jeffrey Lopez, Yongming Sun, Dawei Feng, Kipil Lim, William C. Chueh, Michael F. Toney, Yi Cui & Zhenan Bao. Nature Energy, volume 2, pages 861–868 (2017). [ii] R.-E. Dinnebier, H. Nuss, M. Jansen, Disodium rhodizonate: a powder diffraction study, Acta Crystallographica E61 (2005) m2148–m2150.

Ultrasonic protein crystallization: Promoting nucleation in microdroplets through pulsed sonication

Droplet microfluidics allows a higher degree of control over the crystallization conditions than conventional methodologies. To extend this approach, this work explores the synergistic effect of low-frequency pulsed ultrasound on lysozyme crystallization in microdroplets. Pulsed actuation allows control of the crystallization temperature, while the ultrasound effect significantly reduces the induction time and crystal size. Therefore, protein nucleation is enhanced by pulsed sonication without causing precipitation, resulting in uniform crystal size. Finally, the initial supersaturation ratio has a crucial contribution to the crystal size for silent experiments, while a threshold for induction time is observed in ultrasonic crystallization.

Small‐Molecule‐Doped Organic Crystals with Long‐Persistent Luminescence

AbstractTraditional long‐persistent luminescence (LPL) materials, which are based on inorganic systems containing rare elements and with preparation temperatures of at least 1000 °C, exhibit afterglow times of more than 10 h and can be tuned for different applications. However, the development of this field is hindered due to the large thermal energy consumption and the need for nonrenewable resources. Thus, the development of a “green” design and preparation of LPL materials is of some importance. A doped‐crystalline material based on two metal‐free organic small molecules is easily prepared through ultrasonic crystallization at room temperature. It has a high‐quality, single‐crystalline structure, and visible LPL performance with a duration of more than 6 s upon low‐energy photoexcitation. A green, flexible, and convenient screen‐printing technology for controllable pattern anticounterfeiting is then developed from this purely organic material, which improves the prospects for commercial utilization in the future.

Enantioseparation of racemic bupivacaine via ultrasonic-assisted diastereomeric crystallization using 12,14-dinitrodehydroabietic acid

12,14-Dinitrodehydroabietic acid (12,14-dinitroDHAA), a chiral acid obtained by the nitration of optical dehydroabietic acid (DHAA), was successfully employed as resolving agent. The resolution of racemic bupivacaine by ultrasonic-assisted diastereomeric crystallization in ethanol was investigated. The results indicated that ultrasonic-assist can well facilitate resolution of (R,S)-bupivacaine and a higher enantiomeric excess (ee) and yield was obtained for (S)-bupivacaine, and while without ultrasound, the ee value decreases by increasing the crystallization time. A Box-Behnken experimental design with four factors (amount of 12,14-dinitroDHAA, ethanol amount, ultrasonic power and crystallization temperature) combined with response surface methodology (RSM) was applied to explore resolution effects. A second-order polynomial equation was adequate to model the relationship between the ee (or yield) and the dependent variables. When maintaining a lower limit of 90% for the yield of (S)-bupivacaine, the optimal resolution conditions by RSM were 12,14-dinitroDHAA/bupivacaine molar ratio of 1.6, solvent/propranolol ratio of 16.5 mL/g, 63.2 W ultrasonic power and crystallization temperature of 0 °C, respectively. Under the optimal conditions, the experimental ee and yield of (S)-bupivacaine were 69.8% and 87.5%.

Scaling problems and control technologies in industrial operations: Technology assessment

Abstract Calcium and magnesium ions are the major components of scaling in different water sources, especially seawater. Calcium and magnesium scale causes problems in various industrial operations such as reverse osmosis unit, heating unit of multi-stage flash distillation, concentration operation of copper-molybdenum mining industry, cooling water system of power generation industry, and water injection operation of oil and gas production. In general terms, scaling affects the operation performance that leads to increased production, as well as maintenance costs. The pH control, scale inhibitors, and nanofiltration membrane have been implemented by industrial operations to control scale. However, the drawbacks of these technologies may force to seek alternative technologies which could be potential alternatives for scale control. This paper discusses the problems of calcium and magnesium scale affecting various industrial operations when seawater is used. It presents current technologies for scale control such as pH control, scale inhibitors, and nanofiltration. Moreover, the technology assessment (TA) was made to evaluate existing and emerging scale control approaches in the case of reverse osmosis (RO) process. The identification of the emerging technologies of scale control has been performed using bibliometric analysis. The comparison of the technologies was made using House of Quality (HOQ) matrix. The identified emerging technologies are: bioelectrochemical system, biomineralization, biosorbent, microbial desalination cells, step by step deposition and extraction technique, carbon dioxide as a precipitator, gas hydrate, ultrasonic crystallization, and capacitive deionization. The comparison of the technologies has shown that nanofiltration, as a common technology, could be an appropriate approach to ensure feasibility and efficiency of RO process, while emerging technology, microbial desalination cells, could become a potential alternative in the future.

Ultrasonic Irradiation and Seeding To Prevent Metastable Liquid–Liquid Phase Separation and Intensify Crystallization

During the crystallization of complex pharmaceutical molecules, a liquid–liquid phase (LLP) separation phenomenon may occur that could hinder crystallization processes and adversely affect the crystal quality and process robustness. In this study, the LLP separation behavior of a vanillin and water mixture was investigated using a hot-stage microscope and a cooling crystallization process. Thermodynamic stability of phases and the crystallization phase diagram including the metastable zone width, nucleation, and LLP separation were developed. The impact of ultrasound and seeding on LLP separation was investigated and used to optimize the crystallization process. Our results show that the LLP separation may exist in both the stable and metastable zones of the crystallization phase diagram. Ultrasound can effectively promote nucleation, narrow the metastable zone of LLP separation, and inhibit LLP separation within the concentration range of 3.8–4.8 g/100 g water. Moreover, ultrasonic crystallization was op...

Rapid recovery of high content phytosterols from corn silk

BackgroundPhytosterols have important physiological and officinal function.MethodsAn efficient ultrasonic assisted extraction, purification and crystallization procedure of phytosterols was established from corn silk for the first time.ResultsThe orthogonal test was applied to optimize the process parameters and a maximum phytosterols recovery as high as 10.5886 mg/g was achieved by ultrasonic treatment for 55 min with liquid–solid ratio of 12:1 at 35 °C, 220 w. The ultrasonic extraction temperature (T, °C) has the most significant effect on extraction yield of phytosterols. An orthogonal crystallization test was performed and the optimal conditions [crystallization temperature of 8 °C, time of 12 h and solid–liquid ratio of 1:1 (g/ml)] afforded maximum phytosterols purity of 92.76 ± 0.43%.ConclusionsAn efficient extraction and crystallization procedure was established.

Particle Size Control during Ultrasonic Cooling Crystallization of Paracetamol

AbstractThe effect of ultrasound on the crystal size during cooling crystallization of paracetamol was investigated. Sonication was enabled in three distinct stages to define the operating guidelines for crystal size control. In addition, it was identified whether size reduction results from a higher amount of nuclei upon primary nucleation or from enhanced secondary nucleation. The results show that tuning of the ultrasonic power density and exposure time after nucleation results in crystal sizes between 70 and 140 µm. In contrast, the use of ultrasound before nucleation does not affect the size, indicating enhanced secondary nucleation as the main mechanism. Finally, sonication after complete desupersaturation reduces the crystal size by about 30 µm but causes surface erosion.

Agglomeration Control during Ultrasonic Crystallization of an Active Pharmaceutical Ingredient

Application of ultrasound during crystallization can efficiently inhibit agglomeration. However, the mechanism is unclear and sonication is usually enabled throughout the entire process, which increases the energy demand. Additionally, improper operation results in significant crystal damage. Therefore, the present work addresses these issues by identifying the stage in which sonication impacts agglomeration without eroding the crystals. This study was performed using a commercially available API that showed a high tendency to agglomerate during seeded crystallization. The crystallization progress was monitored using process analytical tools (PAT), including focus beam reflectance measurements (FBRM) to track to crystal size and number and Fourier transform infrared spectroscopy (FTIR) to quantify the supersaturation level. These tools provided insight in the mechanism by which ultrasound inhibits agglomeration. A combination of improved micromixing, fast crystal formation which accelerates depletion of the supersaturation and a higher collision frequency prevent crystal cementation to occur. The use of ultrasound as a post-treatment can break some of the agglomerates, but resulted in fractured crystals. Alternatively, sonication during the initial seeding stage could assist in generating nuclei and prevent agglomeration, provided that ultrasound was enabled until complete desupersaturation at the seeding temperature. FTIR and FBRM can be used to determine this end point.

Sono-crystallization kinetics of K2SO4: Estimation of nucleation, growth, breakage and agglomeration kinetics

Application of ultrasound in crystallization has showed improved process characteristics. Although several attempts have been made in the past to study the sono-crystallization kinetics, only nucleation and crystal growth were considered, neglecting breakage and agglomeration of crystals. In this study, an attempt is made for the estimation of the kinetic parameters of all the phenomena occurring simultaneously during sono-crystallization. For this, both conventional and ultrasonic crystallization of K2SO4-water system has been reported. Sono-crystallization experiments were carried out using ultrasonic horn operating at 20 kHz frequency. Reduction in the induction time, reduction in metastable zone width (MSZW), narrowing of crystal size distribution (CSD) were the key observations of sono-crystallization experiments. Population balance equations (PBE) were used to model the crystallization system and the various kinetic parameters have been estimated. The kinetic parameters obtained for conventional crystallization and sonocrystallization were compared. The estimated parameters suggest an increase in nucleation and breakage rate during sono-crystallization. Growth rates were observed to be of the same order of magnitude for both conventional and sonocrystallization. While agglomeration during sono-crystallization was found to be negligible.

Effect of ultrasonication on the dilution crystallization of naproxen

ABSTRACTThis work investigates the use of ultrasonication for the dilution crystallization of naproxen. Naproxen solution was prepared in acetone, while water was used as the anti-solvent. The main objective of this study was to determine the effect of sonication on the thermodynamic properties (solubility, metastable zone width, and induction time) and particle size of naproxen crystals. The use of sonication was compared to conventional stirred crystallization methods. When the solvent ratio (Vacetone/Vwater) is low, no significant difference exists between the naproxen solubility in either the sonicated or stirred solutions. However, at higher solvent ratios (Va/Vw = 9) and at low temperatures (0°C), ultrasonication increases the solubility of naproxen from 0.171 to 0.193 g/mL. Compared to conventional stirred crystallization techniques (the metastable zone width is 0.024 g/mL), ultrasonic crystallization is characterized by a narrower metastable zone (the width is 0.010 g/mL), and with ultrasonic crystallization the induction time decreases by about 50 seconds. During ultrasonic crystallization, the average naproxen particle size is reduced from 22.6 to 10.5 μm by increasing the power and time of ultrasonication. Particle sizes and crystal morphologies obtained using ultrasonication were significantly improved compared to those produced with stirring.

Fractal Interpretation of Ultrasonic Crystallization of Solutions

Fractal Interpretation of Ultrasonic Crystallization of Solutions

Particle Size Control and Crystal Habit Modification of Phenacetin Using Ultrasonic Crystallization

AbstractPower ultrasound is applied for cooling crystallization to control and modify the particle size and crystal habit of an active pharmaceutical ingredient, phenacetin. Operating parameters including sonication intensity and duration, solution concentration, and cooling rate are studied and compared. With respect to mean particle size, the effect of sonication intensity is most significant. In addition, the crystal habit of recrystallized phenacetin is modified substantially and shows an elliptic shape. Recrystallized phenacetin also provides an enhanced dissolution rate compared with the original sample. These results prove that ultrasonic crystallization is an efficient tool for controlling the solid‐state properties of an active pharmaceutical ingredient.

Single-Frequency Ultrasonic Crystallization Monitoring (UCM): Innovative Technique for In-Line Analyzing of Industrial Crystallization Processes

The development, principles, and application of the single-frequency, ultrasonic crystallization monitoring (UCM) technique is discussed. It is shown that the three most important process parameters to control industrial crystallization processes (mean crystal size, suspension density, and liquid concentration) can be monitored simultaneously in-line by means of only one measuring technique holding two sensors. A proof of concept is presented that clearly shows the feasibility and applicability of the UCM method. In demarcation to alternative PAT in the field of industrial crystallization, advantages, potentials, and limits are outlined and discussed with particular reference to the applicability of the technology and the material systems together with the transferability to other substances as well as the scale-up ability of the underlying mathematical model. Additionally, the reliability of the UCM technique is validated by comparing the results with established and commercially available PAT for the solid phase.

Synthesis of Loaded Silver 4A Zeolite Molecular Sieve with Magnetic Cores of SiO<sub>2</sub>/(γ-Fe<sub>2</sub>O<sub>3</sub>- SiO<sub>2</sub>) for Demercuration

It is an effective solution to the problem of agglomeration using the magnetic composite SiO2/(γ-Fe2O3- SiO2) instead of traditional magnetic particles Fe3O4as the core of molecular sieve. The traditional hydrothermal method was utilized by means of adding the magnetic composite particles SiO2/(γ-Fe2O3- SiO2) into the pre-made crystallization liquid. Then, a series of magnetic 4A zeolites with varying contents of SiO2/(γ-Fe2O3- SiO2) were synthesized under the condition of ultrasonic crystallization for 6 hours with the power of 100W and temperature of 70 °C . Afterwards, the characterization tests such as XRD,SEM,TG,IR were carried out; the final result showed that the performance of 4A zeolite molecular sieve with SiO2/(γ-Fe2O3- SiO2) is basically identical with the pure 4A zeolite molecular sieve. The absorption rate was 13.5927μg/g by using the 4A zeolite molecular sieve with SiO2/(γ-Fe2O3- SiO2) for the absorption of mercury. Key words: 4A zeolite molecular sieve; magnetic composite; silver loaded;Demercuration

Ultrasonic crystallization monitoring technique for simultaneous in-line measurement of liquid and solid phase

The mean crystal size, the suspension density and the liquid concentration are the three most important process parameters to quantify the progress of industrial crystallization processes. It will be shown that these parameters can be in-line monitored simultaneously by means of an ultrasonic crystallization monitoring technique (UCM), which will be introduced here in a proof of concept. This process analytical technology (PAT) differs from the known ultrasonic attenuation spectroscopy (UAS). For the UCM the ultrasonic velocity and attenuation were correlated and related to characteristic events during a crystallization process measured at only one frequency (no spectra of frequencies as it is used for UAS). The results shown in this study prepare the ground to establish the UCM as a simple, less complex, robust, universal applicable, inexpensive and, therefore, a winning alternative PAT to monitor and control in-line the solid as well as the liquid phase in the industrial crystallization by means of only one measuring device with two sensors.

Ultrasonic characterization of the crystallization behavior of poly(ethylene terephthalate)

AbstractOn the basis of the previous observations that the ultrasonic signals are sensitive to the crystallization of polymers (Tatibouet and Piché, Polymer 1991, 32, 3147), we have expanded our efforts to study the detail relationship between the ultrasonic signals and crystallization process in this work. The nonisothermal and isothermal crystallization of virgin poly(ethylene terephthalate) (PET) and PET samples after degradation were studied by using a specially designed pressure‐volume‐temperature (PVT) device, with which an ultrasonic detector was combined. The results showed that the evolution of the ultrasonic signals not only can be used to probe the crystallization process but also can qualitatively characterize the crystallization rate, crystallinity, crystallite size, and amorphous. DSC measurement was used to verify such results. Ultrasonic signals could be as a complementary tool to polymer chain movement and well be applied to characterize the crystallization behavior. Furthermore, the ultrasonic measurement has the potential use to characterize crystallization of products in‐line during processing (i.e., injection molding, micromoulding). © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009