Study of the Effects of SiO2 Nanoparticles Concentration on the TiO2 Nanoparticles Suspensions Stabilization

TiO2 nanoparticles (NPTiO2) suspensions are in several ecosystems and residue treatment processes or disposal systems due to their large industrial use and handling. The interactions of the NPTiO2 with NPSiO2 have special interest due to their strong ability to maintain high TiO2 nanoparticles concentration in suspension and promote nanoparticles clustering. These characteristics are used either in cleaning systems or in production of nanoparticles solution for several applications in the food industry or medicine. In this study, suspensions of NPTiO2 and NPSiO2 are synthetized and their stabilizations are discussed. A base TiO2 nanoparticles suspension was synthetized and the initial concentrations of SiO2 nanoparticles (NPSiO2) were changed in order to determine the effects of presence of SiO2 nanoparticles on the stabilization and clustering size. Zeta potential and concentrations measurements were carried out throughout the time and correlated with the initial concentrations of the base suspensions. In this study, the concentrations, zeta potential and pH are measured to estimate the stability of the suspensions. The clustering size, obtained by nanoparticle tracking analysis (NTA), are also monitored and discussed. Results of column soil experiments are discussed and compared under similar conditions with literature data.

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Dispersion and stability of titanium dioxide nanoparticles in aqueous suspension: effects of ultrasonication and concentration

Water Science & Technology ◽

10.2166/wst.2012.545 ◽

2013 ◽

Vol 67 (1) ◽

pp. 147-151 ◽

Cited By ~ 22

Author(s):

J. Qi ◽

Y. Y. Ye ◽

J. J. Wu ◽

H. T. Wang ◽

F. T. Li

Keyword(s):

Titanium Dioxide ◽

Zeta Potential ◽

Tio2 Nanoparticles ◽

Titanium Dioxide Nanoparticles ◽

Aqueous Suspension ◽

Solution Chemistry ◽

Hydrodynamic Diameter ◽

Nanoparticles Dispersion ◽

Nanoparticles Concentration ◽

Nanoparticles Suspension

The increasing applications of titanium dioxide (TiO2) nanoparticles raise concerns about their potential environmental impacts. To investigate the fate and transport of TiO2 nanoparticles in aqueous suspension, ultrasonication is widely used for the dispersion of TiO2 nanoparticles in laboratory-scale studies. There is a pressing need for detailed information on the dispersion and stability of TiO2 nanoparticles. This study investigated the change of size, zeta potential, and pH of TiO2 nanoparticles aqueous suspension under different conditions of ultrasonication and concentrations. It was found that the hydrodynamic diameter of TiO2 nanoparticles decreased with increasing suspension concentration and remained stable for more than 1 hour after sonication, which is enough for experimental research. The pH decreased with increasing nanoparticles concentration. Ultrasonication remarkably improved zeta potential to be above 15 mV for all the samples. Therefore, 20 minutes of ultrasonication (180 W) is sufficient for the dispersion of this rutile TiO2 nanoparticles suspension, which can remain stable for more than 1 hour. However, the optimum sonication time for TiO2 nanoparticles dispersion is influenced by many factors, such as TiO2 nanoparticles concentration, solution chemistry, and sonicator parameters.

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STUDY OF BETULIN STABILITY BY ELECTROKINETIC POTENTIAL DETERMINATION

Леса России и хозяйство в них ◽

10.51318/fret.2021.68.16.008 ◽

2021 ◽

pp. 63-67

Author(s):

Г.И. Мальцев

Keyword(s):

Aqueous Solution ◽

Zeta Potential ◽

Food Industry ◽

Colloidal Particle ◽

Electrokinetic Potential ◽

Energy Costs ◽

Particle Charge ◽

The Stability ◽

Time And Energy ◽

Biological Actions

Исследование стабильности бетулина методом определения электрокинетического потенциала. На сегодняшний день бетулин интересен в области медицины, косметики и пищевой промышленности, ведь он обладает огромным спектром биологических действий. Из него можно получить производные, которые, в свою очередь, имеют определенное хорошо выраженное действие и используются для производства различных медикаментов. И чтобы интенсифицировать процесс очистки и фильтрования бетулина для экономии времени и затрат на энергию, необходимо узнать его заряд коллоидной частицы и стабильность в водном растворе. Для этого было проведено определение электрокинетического потенциала. Найден ξ-потенциал бетулина в водном растворе, который показал, что с увеличением концентрации водного раствора бетулина вероятность разрушения дисперсии и возможность образования хлопьев при добавлении коагулянта или флогулянта повышаются. Определен заряд поверхности коллоидной частицы бетулина. Investigation of the stability of betulin by the method of determining the electrokinetic potential.Today betulin is interesting in the field of medicine, cosmetics and food industry, because it has a huge range of biological actions. From it, you can get derivatives, which in turn have a certain well-defined effect and are used for the production of various medicines. In order to intensify the process of cleaning and filtering betulin to save time and energy costs, we need to know its colloidal particle charge and stability in an aqueous solution. To do this, we conducted a method for determining the electrokinetic potential. we determined the zeta potential of betulin in an aqueous solution, which showed that with an increase in the concentration of betulin in water, the probability of destruction of the dispersion and the possibility of flocculation when adding a coagulant or flogulant increases. We determined the surface charge of a colloidal betulin particle.

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Impact of Humic Acid on the Charge Behavior and Coagulation of TiO2 Nanoparticles Suspension

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.726-731.2384 ◽

2013 ◽

Vol 726-731 ◽

pp. 2384-2388 ◽

Cited By ~ 1

Author(s):

Feng Gong ◽

Li Zhu Zhang ◽

Li Wang

Keyword(s):

Humic Acid ◽

Zeta Potential ◽

Removal Efficiency ◽

Ph Value ◽

Fate And Transport ◽

High Concentration ◽

Water Treatment Process ◽

The Stability ◽

The Impact ◽

Nanoparticles Suspension

In order to understanding of the fate and transport of TiO2 nanoparticles (Nps) in the water treatment process, this study focused on the impact of humic acid (HA) on the aggregation and charge behavior of TiO2 Nps, and investigated the removability of TiO2 Nps stabilized by HA during the coagulation process. Malvern Zetasizer nanoZS measured the changes of size and zeta potential of HA capped TiO2 Nps (HA-TiO2). Uv-vis spectrometer examined the aggregation behavior of TiO2 and HA-TiO2 NPs at different pH value. Jar tests were conducted to evaluate the removal efficiency of TiO2 NPs. HA adsorbed on the surface of TiO2 Nps could decrease the zeta potential values and enhance the stability of TiO2 Nps. TiO2 Nps could be effectively removed by aluminum sulfate (AS) under favorable condition. HA could influence the removal of TiO2 Nps during the coagulation processes. Low concentration of HA rejected the removal efficiency of TiO2 Nps, however, high concentration of HA promoted removing effectiveness.

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Effect of Nitric Acid Concentrations on Synthesis and Stability of Maghemite Nanoparticles Suspension

The Scientific World JOURNAL ◽

10.1155/2014/589479 ◽

2014 ◽

Vol 2014 ◽

pp. 1-6 ◽

Cited By ~ 6

Author(s):

Irwan Nurdin ◽

Mohd Rafie Johan ◽

Iskandar Idris Yaacob ◽

Bee Chin Ang

Keyword(s):

Nitric Acid ◽

Zeta Potential ◽

Narrow Particle Size Distribution ◽

Maghemite Nanoparticles ◽

X Ray Diffraction ◽

Transmission Electron ◽

The Stability ◽

Xrd Patterns ◽

Nanoparticles Suspension

Maghemite(γ-Fe2O3)nanoparticles have been synthesized using a chemical coprecipitation method at different nitric acid concentrations as an oxidizing agent. Characterization of all samples performed by several techniques including X-ray diffraction (XRD), transmission electron microscopy (TEM), alternating gradient magnetometry (AGM), thermogravimetric analysis (TGA), dynamic light scattering (DLS), and zeta potential. The XRD patterns confirmed that the particles were maghemite. The crystallite size of all samples decreases with the increasing concentration of nitric acid. TEM observation showed that the particles have spherical morphology with narrow particle size distribution. The particles showed superparamagnetic behavior with decreased magnetization values at the increasing concentration of nitric acid. TGA measurement showed that the stability temperature decreases with the increasing concentration of nitric acid. DLS measurement showed that the hydrodynamic particle sizes decrease with the increasing concentration of nitric acid. Zeta potential values show a decrease with the increasing concentration of nitric acid. The increasing concentration of nitric acid in synthesis of maghemite nanoparticles produced smaller size particles, lower magnetization, better thermal stability, and more stable maghemite nanoparticles suspension.

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The Influence of Heating and Photosensitization on the Stability of Lutein- Loaded Lipid-Core Nanocapsules

Current Bioactive Compounds ◽

10.2174/1573407216666200211094654 ◽

2020 ◽

Vol 16 (9) ◽

pp. 1340-1345

Author(s):

Aelson A.S. Brum ◽

Médelin M. da Silva ◽

Priscilla P. dos Santos ◽

Allana V.S. Brasil ◽

Karina Paese ◽

...

Keyword(s):

Activation Energy ◽

Light Scattering ◽

Dynamic Light Scattering ◽

Zeta Potential ◽

Singlet Oxygen ◽

Food Industry ◽

Entrapment Efficiency ◽

Average Diameter ◽

Lipid Core ◽

The Stability

Background: Despite lutein is unstable in light, heat, and oxygen, it is a good quencher of singlet oxygen. The present study evaluated the stability of lutein (92% of purity) in Lipid-core Nanocapsules (Lutein-LNC) prepared through interfacial deposition of preformed polymer, during photosensitization (5-25°C) and heating (70-90°C). Methods: The Lutein-LNC was characterized and presented a polydispersity index of 0.11, an average diameter of 191 nm (dynamic light scattering), zeta potential of -9.14 mV and entrapment efficiency of 100%. Results and Discussion: During photosensitization and heating, Lutein-LNC exhibited activation Energy (Ea) of 24.67 kcal/mol and 9.96 kcal/mol, respectively, and these values of Lutein-LNC were higher than free lutein values, reported in other studies for both experiments. Conclusion: The results obtained in this study suggested that nanotechnology can improve the stability of lutein for future applications in the food industry.

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An Experimental Investigation on Thermal Conductivity and Viscosity of Graphene doped CNTs /TiO2 Nanofluid

International Journal of Automotive and Mechanical Engineering ◽

10.15282/ijame.17.3.2020.16.0620 ◽

2020 ◽

Vol 17 (3) ◽

Author(s):

A.M. Zetty Akhtar ◽

M.M. Rahman ◽

K. Kadirgama ◽

M.A. Maleque

Keyword(s):

Thermal Conductivity ◽

Zeta Potential ◽

Base Fluid ◽

Minimum Quantity Lubrication ◽

Cutting Fluid ◽

Cutting Zone ◽

Observation Method ◽

The Stability ◽

The Relationship ◽

Zeta Potential Analysis

This paper presents the findings of the stability, thermal conductivity and viscosity of CNTs (doped with 10 wt% graphene)- TiO2 hybrid nanofluids under various concentrations. While the usage of cutting fluid in machining operation is necessary for removing the heat generated at the cutting zone, the excessive use of it could lead to environmental and health issue to the operators. Therefore, the minimum quantity lubrication (MQL) to replace the conventional flooding was introduced. The MQL method minimises the usage of cutting fluid as a step to achieve a cleaner environment and sustainable machining. However, the low thermal conductivity of the base fluid in the MQL system caused the insufficient removal of heat generated in the cutting zone. Addition of nanoparticles to the base fluid was then introduced to enhance the performance of cutting fluids. The ethylene glycol used as the base fluid, titanium dioxide (TiO2) and carbon nanotubes (CNTs) nanoparticle mixed to produce nanofluids with concentrations of 0.02 to 0.1 wt.% with an interval of 0.02 wt%. The mixing ratio of TiO2: CNTs was 90:10 and ratio of SDBS (surfactant): CNTs was 10:1. The stability of nanofluid checked using observation method and zeta potential analysis. The thermal conductivity and viscosity of suspension were measured at a temperature range between 30˚C to 70˚C (with increment of 10˚C) to determine the relationship between concentration and temperature on nanofluid’s thermal physical properties. Based on the results obtained, zeta potential value for nanofluid range from -50 to -70 mV indicates a good stability of the suspension. Thermal conductivity of nanofluid increases as an increase of temperature and enhancement ratio is within the range of 1.51 to 4.53 compared to the base fluid. Meanwhile, the viscosity of nanofluid shows decrements with an increase of the temperature remarks significant advantage in pumping power. The developed nanofluid in this study found to be stable with enhanced thermal conductivity and decrease in viscosity, which at once make it possible to be use as nanolubricant in machining operation.

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Insights into Potent Therapeutical Antileukemic Agent L-glutaminase Enzyme Under Solid-state Fermentation: A Review

Current Drug Metabolism ◽

10.2174/1389200221666200421122147 ◽

2020 ◽

Vol 21 (3) ◽

pp. 211-220 ◽

Cited By ~ 1

Author(s):

Chandrasai Potla Durthi ◽

Madhuri Pola ◽

Satish Babu Rajulapati ◽

Anand Kishore Kola

Keyword(s):

Solid State ◽

Solid State Fermentation ◽

Food Industry ◽

Energy Requirement ◽

Production Studies ◽

Wide Range ◽

Hybridoma Technology ◽

Bacteria And Fungi ◽

The Stability ◽

Glutaminase Activity

Aim & objective: To review the applications and production studies of reported antileukemic drug L-glutaminase under Solid-state Fermentation (SSF). Overview: An amidohydrolase that gained economic importance because of its wide range of applications in the pharmaceutical industry, as well as the food industry, is L-glutaminase. The medical applications utilized it as an anti-tumor agent as well as an antiretroviral agent. L-glutaminase is employed in the food industry as an acrylamide degradation agent, as a flavor enhancer and for the synthesis of theanine. Another application includes its use in hybridoma technology as a biosensing agent. Because of its diverse applications, scientists are now focusing on enhancing the production and optimization of L-glutaminase from various sources by both Solid-state Fermentation (SSF) and submerged fermentation studies. Of both types of fermentation processes, SSF has gained importance because of its minimal cost and energy requirement. L-glutaminase can be produced by SSF from both bacteria and fungi. Single-factor studies, as well as multi-level optimization studies, were employed to enhance L-glutaminase production. It was concluded that L-glutaminase activity achieved by SSF was 1690 U/g using wheat bran and Bengal gram husk by applying feed-forward artificial neural network and genetic algorithm. The highest L-glutaminase activity achieved under SSF was 3300 U/gds from Bacillus sp., by mixture design. Purification and kinetics studies were also reported to find the molecular weight as well as the stability of L-glutaminase. Conclusion: The current review is focused on the production of L-glutaminase by SSF from both bacteria and fungi. It was concluded from reported literature that optimization studies enhanced L-glutaminase production. Researchers have also confirmed antileukemic and anti-tumor properties of the purified L-glutaminase on various cell lines.

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Anthocyanins Recovered from Agri-Food By-Products Using Innovative Processes: Trends, Challenges, and Perspectives for Their Application in Food Systems

Molecules ◽

10.3390/molecules26092632 ◽

2021 ◽

Vol 26 (9) ◽

pp. 2632

Author(s):

Henrique Silvano Arruda ◽

Eric Keven Silva ◽

Nayara Macêdo Peixoto Araujo ◽

Gustavo Araujo Pereira ◽

Glaucia Maria Pastore ◽

...

Keyword(s):

Food Systems ◽

Food Industry ◽

Biological Properties ◽

Extraction Techniques ◽

Naturally Occurring ◽

Current Review ◽

Natural Colorants ◽

Conventional Extraction ◽

The Stability ◽

By Products

Anthocyanins are naturally occurring phytochemicals that have attracted growing interest from consumers and the food industry due to their multiple biological properties and technological applications. Nevertheless, conventional extraction techniques based on thermal technologies can compromise both the recovery and stability of anthocyanins, reducing their global yield and/or limiting their application in food systems. The current review provides an overview of the main innovative processes (e.g., pulsed electric field, microwave, and ultrasound) used to recover anthocyanins from agri-food waste/by-products and the mechanisms involved in anthocyanin extraction and their impacts on the stability of these compounds. Moreover, trends and perspectives of anthocyanins’ applications in food systems, such as antioxidants, natural colorants, preservatives, and active and smart packaging components, are addressed. Challenges behind anthocyanin implementation in food systems are displayed and potential solutions to overcome these drawbacks are proposed.

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The Effect of pH and Storage Temperature on the Stability of Emulsions Stabilized by Rapeseed Proteins

Foods ◽

10.3390/foods10071657 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1657

Author(s):

Karolina Östbring ◽

María Matos ◽

Ali Marefati ◽

Cecilia Ahlström ◽

Gemma Gutiérrez

Keyword(s):

Zeta Potential ◽

Storage Temperature ◽

Emulsion Stability ◽

Press Cake ◽

Strong Impact ◽

Soy Lecithin ◽

Rapeseed Protein ◽

Rapeseed Proteins ◽

Precipitation Ph ◽

The Stability

Rapeseed press cake (RPC), the by-product of rapeseed oil production, contains proteins with emulsifying properties, which can be used in food applications. Proteins from industrially produced RPC were extracted at pH 10.5 and precipitated at pH 3 (RPP3) and 6.5 (RPP6.5). Emulsions were formulated at three different pHs (pH 3, 4.5, and 6) with soy lecithin as control, and were stored for six months at either 4 °C or 30 °C. Zeta potential and droplet size distribution were analyzed prior to incubation, and emulsion stability was assessed over time by a Turbiscan instrument. Soy lecithin had significantly larger zeta potential (−49 mV to 66 mV) than rapeseed protein (−19 mV to 20 mV). Rapeseed protein stabilized emulsions with smaller droplets at pH close to neutral, whereas soy lecithin was more efficient at lower pHs. Emulsions stabilized by rapeseed protein had higher stability during storage compared to emulsions prepared by soy lecithin. Precipitation pH during the protein extraction process had a strong impact on the emulsion stability. RPP3 stabilized emulsions with higher stability in pHs close to neutral, whereas the opposite was found for RPP6.5, which stabilized more stable emulsions in acidic conditions. Rapeseed proteins recovered from cold-pressed RPC could be a suitable natural emulsifier and precipitation pH can be used to monitor the stability in emulsions with different pHs.

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Viability of Lactobacillus casei ATCC 393 and properties in Andean blackberry suspensions with probiotic and prebiotic characteristics

DYNA ◽

10.15446/dyna.v86n210.72929 ◽

2019 ◽

Vol 86 (210) ◽

pp. 179-186

Author(s):

Zaira Tatiana Marin Arango ◽

Misael Cortés Rodriguez ◽

Olga Ines Montoya Campuzano ◽

Julio Cesar Arango Tobón

Keyword(s):

Zeta Potential ◽

Mass Fraction ◽

Lactobacillus Casei ◽

Food Industry ◽

Functional Foods ◽

Total Solid ◽

Dependent Variables ◽

Solids Suspension ◽

Probiotic Microorganism ◽

Spray Dried

Food industry has grown in recent years mainly due to the supply of functional foods with probiotics and prebiotics. The viability of Lactobacillus casei and the properties of blackberry suspensions added with inulin were evaluated using a central design composed of the following factors: mass fraction of total solid blackberry concentrate (XTSBC) (0.103-0.120), [McFarland] (6-10), inulin (2.78-3.68%), and mass blackberry concentrate (BC)/mass inoculum (R) (5-20); and the dependent variables: moisture (M), pH, acidity, °Brix, total solids suspension (TSS), viscosity (μ), zeta potential (z), and Log CFU/g. Results of the experimental optimization of multiple responses were: XTSBC (0.103), [McFarland] (10), inulin (3.12%w/w), and R (18.5); being the dependent variables: M=86.7±0.0%, pH=2.74±0.01, acidity=3.1±0.0%, °Brix=11.0±0.1%, TSS=13.3±0.0%, µ=1288.0±20.1 cP, z=-13.3±0.3 mV and Log CFU/g=7.8±0.5. The probiotic microorganism Lb. casei ATCC 393 presents an adaptability in suspensions based on BC and inulin, which guarantee its viability and a possible use for obtaining an innovative spray-dried product.

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