The influence of pH and concentration on the zeta potential, hydrophobicity of OVT and the relationship between its structure and interfacial behaviors

2021 ◽  
pp. 1-40
Author(s):  
Linfang Hu ◽  
Leiyan Wu ◽  
Chanjuan Lai ◽  
Mingliang Li ◽  
Wuying Yang
Keyword(s):  
Zeta Potential ◽  
The Relationship ◽  
Influence Of Ph

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

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.

The effects of electrolyte concentration, ion species and pH on the zeta potential and electrokinetic charge density of montmorillonite

Clay Minerals ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 853-861 ◽  
Author(s):  
E. E. Saka ◽  
C. Güler
Keyword(s):  
Zeta Potential ◽  
Charge Density ◽  
Negative Charge ◽  
Electrolyte Concentration ◽  
Great Influence ◽  
Electrolyte Solutions ◽  
Ionic Species ◽  
Positive Sign ◽  
Ion Species ◽  
Influence Of Ph

AbstractIn this study, the influence of pH, electrolyte concentration and type of ionic species (such as LiCl, NaCl, KCl, RbCl, CsCl, CaCl2, AlCl3) on the electrokinetic properties (zeta potential and electrokinetic charge density) of montmorillonite has been quantified. The zeta potential of montmorillonite particles did not change significantly with change in pH. The valencies of the ions have proven to have a great influence on the electrokinetic behaviour of the suspension. There is a gradual decrease in the zeta potential (from —24 mV to —12 mV) with increase in monovalent electrolyte concentration (from 10-4 M to 10-1 M). At any monovalent electrolyte concentration, the magnitude of the zeta potential increased with the electrolytes in the order Li+ > Na+ > K+ > Rb+ > Cs+. The zeta potential of the montmorillonite minerals in CaCl2 solutions illustrated the same behaviour as the monovalent cations. Less negative values were obtained for the CaCl2 electrolyte (∼–10 mV) due to the greater valence of the ions. A sign reversal was observed at an AlCl3 concentration of 5 x 10-4 M, and, at greater concentrations, zeta potential values had a positive sign (∼20 mV).The electrokinetic charge density of montmorillonite showed similar trends of variation in mono and divalent electrolyte solutions. Up to concentrations of ∼10-3 M, it remained practically constant at ∼0.5 x 10-3Cm-2, while for greater electrolyte concentrations the negative charge produced more negative values (–16 x 10-3Cm-2). The electrokinetic charge density of montmorillonite particles was constant at low AlCl3 concentrations, but at certain concentrations it increased rapidly and changed sign to positive.

Investigation on the recycling of sulfuric acid from pretreatment of cellulose for nanocellulose preparation

TAPPI Journal ◽  
2020 ◽  
Vol 19 (2) ◽  
pp. 103-111
Author(s):  
CHAOYU DUAN ◽  
YANGYANG PENG ◽  
SHIYU FU ◽  
LUCIAN LUCIA
Keyword(s):  
Thermal Stability ◽  
Sulfuric Acid ◽  
Zeta Potential ◽  
Surface Properties ◽  
Value Chain ◽  
Solid Residue ◽  
Number Of Cycles ◽  
The Relationship

Sulfuric acid is often used to pretreat cellulose prior to homogenization and conversion to nanocellulose. It would be economically significant to reuse the acid to close the overall value chain loop. The target of this work was to investigate the effect of recovery and recycling frequency of sulfuric acid from the pretreatments on the pretreatment yield of water-insoluble cellulose solid residue, and to explore the relationship between the nanocellulose size prepared by recovery of acid and number of cycles. The surface properties of the nanocelluloses were measured, including content of sulfate groups, absolute zeta potential, crystallinity, and thermal stability.

scholarly journals Surface Response Based Modeling of Liposome Characteristics in a Periodic Disturbance Mixer

Micromachines ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 235 ◽  
Author(s):  
Rubén R. López ◽  
Ixchel Ocampo ◽  
Luz-María Sánchez ◽  
Anas Alazzam ◽  
Karl-F. Bergeron ◽  
...  
Keyword(s):  
Zeta Potential ◽  
Flow Rate ◽  
Size Range ◽  
Physicochemical Characteristics ◽  
Flow Rate Ratio ◽  
Total Flow ◽  
Experimental Conditions ◽  
Periodic Disturbance ◽  
Liposome Size ◽  
The Relationship

Liposomes nanoparticles (LNPs) are vesicles that encapsulate drugs, genes, and imaging labels for advanced delivery applications. Control and tuning liposome physicochemical characteristics such as size, size distribution, and zeta potential are crucial for their functionality. Liposome production using micromixers has shown better control over liposome characteristics compared with classical approaches. In this work, we used our own designed and fabricated Periodic Disturbance Micromixer (PDM). We used Design of Experiments (DoE) and Response Surface Methodology (RSM) to statistically model the relationship between the Total Flow Rate (TFR) and Flow Rate Ratio (FRR) and the resulting liposomes physicochemical characteristics. TFR and FRR effectively control liposome size in the range from 52 nm to 200 nm. In contrast, no significant effect was observed for the TFR on the liposomes Polydispersity Index (PDI); conversely, FRR around 2.6 was found to be a threshold between highly monodisperse and low polydispersed populations. Moreover, it was shown that the zeta potential is independent of TFR and FRR. The developed model presented on the paper enables to pre-establish the experimental conditions under which LNPs would likely be produced within a specified size range. Hence, the model utility was demonstrated by showing that LNPs were produced under such conditions.

The influence of pH and NaCl on the zeta potential and rheology of anatase dispersions

2000 ◽  
Vol 175 (3) ◽  
pp. 349-359 ◽  
Author(s):  
Jan Gustafsson ◽  
Pasi Mikkola ◽  
Mika Jokinen ◽  
Jarl B Rosenholm
Keyword(s):  
Zeta Potential ◽  
Influence Of Ph

The Influence of pH Value and SO42- Concentration on Strength of Cemented Soil

2011 ◽  
Vol 233-235 ◽  
pp. 2006-2010 ◽  
Author(s):  
Xiao Qiang Dong ◽  
Xiao Hong Bai ◽  
Yong Kang Lv ◽  
Peng Ju Han
Keyword(s):  
Compressive Strength ◽  
Ph Value ◽  
Solution Concentration ◽  
Corrosive Environment ◽  
Unconfined Compression ◽  
Cemented Soil ◽  
Set Up ◽  
Relationship Of ◽  
The Relationship ◽  
Influence Of Ph

The pH value and SO42- concentration in corrosive environment may affect mechanical property of cemented soil inturn to cause some serious damage to structure. The results of tests show that the unconfined compression strength is decreasing with the increase of H2SO4 solution concentration, increasing with the increase of pH value. The pH value is increasing and the SO42- concentration is decreasing with the increase of corrosive time. So it is concluded that compressive strength is closely rated with the pH value, SO42- concentration of corrosive environment and corrosive time. Finally a equation is set up based on the relationship of compressive strength and factors affected, which contain the reduced coefficient of compressive strength, pH value, SO42- concentration and corrosive time. The calculated and measured values are close so that the equation could be used in practical design for reference.

scholarly journals Partitioning optimization of proteins from Zea mays malt in ATPS PEG 6000/CaCl2

2007 ◽  
Vol 50 (3) ◽  
pp. 557-564 ◽  
Author(s):  
Graziela Batista Ferreira ◽  
Alex Ferreira Evangelista ◽  
João Baptista Severo Junior ◽  
Roberto Rodrigues de Souza ◽  
José Carlos Curvelo Santana ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Partition Coefficient ◽  
Line Length ◽  
Purification Step ◽  
Two Phase ◽  
Peg 6000 ◽  
The Stability ◽  
The Relationship ◽  
Influence Of Ph ◽  
Tie Line

This work aimed to establish the relationship between the compositions and pH of ATPS PEG 6000/CaCl2 and the proteins partition from maize malt and also to simplify the process optimization in ATPS for a statistical model, established by response surface methodology (RSM). Results showed that these were no influence of pH on the phase diagrams and on the composition of tie line length of PEG 6000/CaCl2 ATPS. SRM analyses showed that elevated pH and larger tie line length were the best conditions for recovering of maize malt proteins. The maximum partition coefficient by PEG 6000/CaCl2 ATPS was about 4.2 and was achieved in ATPS in a single purification step. The theoretical maximum partition coefficient was between 4.1-4.3. The process was very suitable for continuous aqueous two-phase purification due to the stability of proteins (e.g. and -amylases) and could increase their content into middle.

Impact of ZnO Concentration on the Stability of Agglomerates of TiO2 Engineered Nanoparticles: Effects of the pH, Ionic Strength and Zeta Potential

2020 ◽  
Vol 1012 ◽  
pp. 167-172
Author(s):  
Elizabeth Mendes de Oliveira ◽  
Izabella Christynne Ribeiro Pinto Valadão ◽  
Jose Adilson de Castro ◽  
Leonardo Martins da Silval ◽  
Darlene Souza da Silva ◽  
...  
Keyword(s):  
Ionic Strength ◽  
Zeta Potential ◽  
Large Scale ◽  
Soil Column ◽  
Equilibrium Concentration ◽  
Engineered Nanoparticles ◽  
Leaching Experiments ◽  
The Stability ◽  
Potential Interactions ◽  
Influence Of Ph

The stability of nanoparticles in natural aquatic systems is of great interest to the environmental risk assessment. The relevance of this study lies in the fact that nanoparticles are being produced and used in commercial products on a large scale, which makes the need to study its transport through the environment, especially in soil and water important due to their potential interactions with the ecosystems. In this research, the effects of nanoparticles of zinc oxide (NPZnO) in the behavior of nanoparticles of titanium dioxide (NPTiO2) was investigated. The influence of pH, ionic strength and zeta potential of the hazardous nanoparticles into soil landfills are studied using experimental procedures. Leaching experiments were prepared within soil column simulating landfills layers. Leaching experiments were carried out to simulate the capture and attenuation of these nanomaterials in municipal waste landfills. The results found that the presence of NPTiO2 in suspensions increases the stability of the suspensions keeping higher nanoparticles concentrations, while NPZnO promotes rapid sedimentation with lower equilibrium concentration of nanoparticles.

scholarly journals Rapid and Efficient Synthesis of Silver Nanofluid Using Electrical Discharge Machining

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Kuo-Hsiung Tseng ◽  
Heng-Lin Lee ◽  
Chih-Yu Liao ◽  
Kuan-Chih Chen ◽  
Hong-Shiou Lin
Keyword(s):  
Silver Nanoparticles ◽  
Zeta Potential ◽  
Process Parameters ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Silver Ions ◽  
Nano Fluid ◽  
Vis Spectroscopy ◽  
The Stability ◽  
The Relationship

The electrical discharge machining (EDM) system has been proven feasible as a rapid and efficient method for silver nanofluid preparation. This study prepared the silver nano-fluid via EDM and investigated the relationship between its process parameters and product characteristics. The prior study had found that the silver nano-fluid prepared by EDM contained both silver nanoparticles and silver ions. Silver ions had revealed the cause of the high suspension of the silver nanoparticles. To examine the relationship between the stability of silver nanofluid and the process parameters, this study quantified the relationship of process parameters to the material removal rate (MRR) of silver electrode and silver ion output rate (IOR) in the fluid, in order to achieve the most effective process parameter condition. Furthermore, the stability of silver nano-fluid was analyzed by various devices, including UV-Vis spectroscopy, size-distribution, and Zeta-potential analyzer. The effects of MRR, IOR, particle size, Zeta-potential, and optical properties of silver nanofluid under different process parameters are also discussed.

Towards the application of large mordenite particles as Positron Emission Particle Tracking tracers

MRS Advances ◽  
2018 ◽  
Vol 4 (1) ◽  
pp. 21-26
Author(s):  
Daniel S. Parsons ◽  
Andrew Ingram ◽  
Joseph A. Hriljac
Keyword(s):  
Ion Exchange ◽  
Particle Tracking ◽  
Ethanol Concentration ◽  
Particle Morphology ◽  
Cation Concentration ◽  
Positron Emission ◽  
The Relationship ◽  
Influence Of Ph

ABSTRACTIn this study, we report developments towards the application of large zeolite particles, with diameter ca. 40 μm, as tracers in Positron Emission Particle Tracking (PEPT) imaging using 68Ga. The influence of intrapore Na+ and TEA+ (tetraethylammonium) cation concentrations and framework Si/Al ratio on the morphology of mordenite particles has been investigated, advancing understanding of the relationship between these factors. Moreover, the influence of ethanol concentration in the gel during aging on intrapore cation concentration, Si/Al ratio and particle morphology has also been investigated. Additionally, facile ion-exchange between aqueous Ga3+ and intrapore H+ in mordenite has been demonstrated. The influence of pH and gallium speciation on ion-exchange has been investigated to determine favourable conditions for 68Ga3+ uptake by the zeolite.

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