Surface Modification of Nano-Copper and its Dispersive Behavior in Water

2008 ◽  
Vol 373-374 ◽  
pp. 670-673
Author(s):  
X.J. Wang ◽  
Dong Sheng Zhu ◽  
X.F. Li ◽  
Nan Wang
Keyword(s):  
Particle Size ◽  
Surface Modification ◽  
Zeta Potential ◽  
Cu Nanoparticles ◽  
Sodium Dodecylbenzenesulfonate ◽  
Absolute Value ◽  
Ph Values ◽  
The Absolute ◽  
The Stability ◽  
Electrostatic Repulsions

In this paper, by measurement of zeta potential and particle size the surface modification of Cu nanoparticles in water was investigated at different pH values and different concentration of sodium dodecylbenzenesulfonate (SDBS) dispersant. The results show that the absolute value of zeta potential has very corresponding relation with particle size, and that the higher the absolute value of zeta potential and the smaller of the particle size are, the better dispersion and stability of copper nano-suspensions system is. It is also found that SDBS can significantly affect the value of zeta potential and particle size by electrostatic repulsions, which lead to the enhancement of the stability of the Cu suspensions, and the optimizing concentration for SDBS in 0.1% copper nano-suspensions is 0.07%, which have the best disperse results.

Influence of SDBS on Stability of Copper Nano-Suspensions

2007 ◽  
Author(s):  
Xinfang Li ◽  
Dongsheng Zhu ◽  
Gang Chen ◽  
Xianju Wang
Keyword(s):  
Heat Transfer ◽  
Zeta Potential ◽  
Cu Nanoparticles ◽  
Transfer Enhancement ◽  
Sodium Dodecylbenzenesulfonate ◽  
Absolute Value ◽  
Ph Values ◽  
The Absolute ◽  
The Stability ◽  
Electrostatic Repulsions

Dispersion and stability of Cu nano-suspensions with dispersant is the important base for the study of rheology and heat transfer enhancement of the suspensions. This paper presented a procedure for preparing a nanofluid which was a suspension consisting of nanophase powders and a base liquids. By means of the procedure, Cu-H2O nanofluids with and without dispersant were prepared, whose sedimentation photographs were given to illustrate the stability and evenness of suspension with dispersant. Dispersion and stability of Cu nanoparticles in water were studied under different pH values and the concentration of sodium dodecylbenzenesulfonate (SDBS) dispersant by the method of zeta potential, absorbency and sedimentation photographs. The results show that zeta potential has very corresponding relation with absorbency, and the higher absolute value of zeta potential and absorbency are, the better dispersion and stability in system is. The absolute value of zeta potential and absorbency are higher at pH 9.5. SDBS can significantly increase the absolute value of the zeta potential of the particle surfaces by electrostatic repulsions, which leads to the enhancement of the stability of the Cu suspensions. The optimizing concentration for SDBS in the 0.1% copper nano-suspensions is 0.07%, which has the best disperse results.

Investigation on Dispersive Behavior of TiO2-H2O Nanofluids

2013 ◽  
Vol 468 ◽  
pp. 49-52
Author(s):  
Xian Ju Wang ◽  
Xin Fang Li ◽  
Zhen Zhang Li ◽  
Fang Lin
Keyword(s):  
Sodium Dodecyl Sulfate ◽  
Zeta Potential ◽  
Mass Fraction ◽  
Sodium Dodecyl ◽  
Absolute Value ◽  
Dodecyl Sulfate ◽  
The Absolute ◽  
The Stability ◽  
Electrostatic Repulsions

This paper investigated the effects of different pH and dispersant concentration on the dispersion of TiO2 H2O by the measuring zeta potential and absorbency. The results show that the absolute value of zeta potential and the absorbency are higher at pH8-10. Sodium dodecyl sulfate (SDS) can significantly increase the absolute value of zeta potential of particle surfaces by electrostatic repulsions, which leads to the enhancement of the stability for TiO2 nanosuspensions. 0.1%(Mass fraction) TiO2 nanosuspensions has the best dispersion at the SDS optimizing concentration 0.045 %. The results also show the zeta potential has good corresponding relation with absorbency, and the higher absolute value of zeta potential and the absorbency are, the better dispersion and stability in system is.

Influence of SDBS on Dispersive Stability of Al2O3 Nano-Suspenions

2008 ◽  
Author(s):  
Dongsheng Zhu ◽  
Xianju Wang ◽  
Xinfang Li
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Ph Value ◽  
Experimental Results ◽  
Dispersion Stability ◽  
Al2o3 Nanoparticles ◽  
Sodium Dodecylbenzenesulfonate ◽  
Electrostatic Repulsions

In this paper, the influence of sodium dodecylbenzenesulfonate (SDBS) on the dispersive behavior of Al2O3 nanoparticles in water are investigated by measuring zeta potential and hydrodynamic sizes of the nanoparticles in suspension at different pHs and different concentration of SDBS. The experimental results show that at different pHs the magnitude of zeta potential has very homologous relation with particle size, the higher magnitude of zeta potential values are, the smaller of the hydrodynamic sizes are, and the better dispersive stability of the nano-suspension is, and that an optimizing pH value of the nano-suspension can induce the highest magnitude zeta potential, then result in the best dispersion stability of the nano-suspension. It is also found that concentrations of SDBS can significantly affect the values of zeta potential and hydrodynamic sizes of the nanoparticles by electrostatic repulsions. Similarity, optimizing concentrations of SDBS can also lead to the highest enhancement of the dispersive stability of the Al2O3 suspension and the optimizing concentration for SDBS is 0.09% in 0.1% Al2O3 nano-suspensions, which have the best disperse results.

Effect of Modified Sludge on the Particles Flocculation and Slurry Stability in the Co-slurry of Sludge and Petroleum Coke

2017 ◽  
Vol 15 (3) ◽  
Author(s):  
Meng Liu ◽  
Xiaobin Zhang ◽  
Liang Zhao
Keyword(s):  
Energy Consumption ◽  
Zeta Potential ◽  
Petroleum Coke ◽  
Reflectance Measurement ◽  
Absolute Value ◽  
Calculation Results ◽  
The Absolute ◽  
The Stability ◽  
Shearing Energy ◽  
Slurry Stability

Abstract Sewage sludge modified by Ca(OH)2 and Fe2(SO4)3 were used as make the slurry with petroleum coke, and changes in the size distribution and a total number of particles in the slurry were determined by Focused Beam Reflectance Measurement (FBRM) to explore the particles flocculation mechanism. In addition, the structural strength of petroleum coke sludge slurry (PCSS) was calculated by two mathematic models to illustrate the how the sludge improves the stability of PCSS. The results indicated that the absolute value of the Zeta potential of PCSS increased with the sludge addition and that PCSS stability improved. However, the absolute value of the Zeta potential decreased and the stability declined after the sludge was modified by Fe2(SO4)3 and Ca(OH)2. Petroleum coke particles were wrapped by sludge flocs, and small particles flocculated during their co-slurry process to form a spatial network structure, effectively prevented the settlement of petroleum coke particles and ultimately improved the stability of slurry. The calculation results obtained by the two mathematic models reveal that the shearing energy consumption per-unit-quality of PCSS using raw sludge is twice or thrice than that of PCWS. However, energy consumption was reduced after the sludge was modified by Fe2(SO4)3.

scholarly journals SYNTHESIS AND STABILITY OF RESVERATROL-CONJUGATED GOLD NANOPARTICLES MODIFIED WITH POLYETHYLENE GLYCOL

2020 ◽  
pp. 230-236
Author(s):  
RADITYA ISWANDANA ◽  
RICHA NURSELVIANA ◽  
SUTRIYO SUTRIYO
Keyword(s):  
Particle Size ◽  
Gold Nanoparticles ◽  
Polyethylene Glycol ◽  
Zeta Potential ◽  
High Performance ◽  
Entrapment Efficiency ◽  
Test Results ◽  
Novel Method ◽  
The Stability ◽  
Phosphate Buffered Saline

Objective: Gold nanoparticles (AuNPs) are highly useful for drug delivery, but their application is limited by their stability as they readily aggregate.This issue can be prevented by adding a stabilizing agent such as resveratrol (RSV), which is a polyphenol derived from plants, that is used to preventcancer. Therefore, we propose a novel method to prepare stable RSV-conjugated nanoparticles modified with polyethylene glycol (RSV-AuNP-PEG).Methods: In the first step, the Turkevich method was used to synthesize the AuNPs. Then, PEG was added as stabilizer agent and conjugated with RSV.The synthesized conjugates were characterized using ultraviolet-visible spectrophotometry, Fourier transform infrared spectroscopy, particle sizeanalysis, and high-performance liquid chromatography.Results: The obtained RSV-AuNP-PEG had a particle size of 83.93 nm with a polydispersity index (PDI) of 0.562 and formed a translucent purple-redfluid in solution. The zeta potential was −22.9 mV, and the highest entrapment efficiency was 75.86±0.66%. For comparison, the RSV-AuNP solutionwas purple and turbid, the particle size was 51.97 nm with a PDI of 0.694, and the zeta potential was −24.6 mV. The stability test results showed thatthe storage stability of RSV-AuNP-PEG was better than that of AuNP-RSV. Further, the RSV-AuNP-PEG was shown to be most stable in 2% bovine serumalbumin (BSA) while the AuNP-RSV was most stable in 2% BSA in phosphate-buffered saline pH 7.4.Conclusion: These results show that modification of RSV-conjugated AuNPs with PEG effectively prevents their aggregation in storage, but only incertain mediums.

scholarly journals Effect of Potato Pulp Pectic Polysaccharide on the Stability of Acidified Milk Drinks

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5632
Author(s):  
Weixuan Sun ◽  
Wenhan Yang ◽  
Yuxue Zheng ◽  
Huiling Zhang ◽  
Haitian Fang ◽  
...  
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Neutral Sugar ◽  
Lower Serum ◽  
Pectic Polysaccharide ◽  
Potato Pulp ◽  
Lower Viscosity ◽  
Stabilizing Effect ◽  
New Ideas ◽  
The Stability

In order to broaden the application of potato pulp pectic polysaccharide (PPP) in stabilizing acidified milk drinks (AMDs) and investigate the stabilizing effect and physical properties of AMDs prepared with PPP, a comparative study was made among PPP, commercial high methoxyl pectin (HMP) and low methoxyl pectin (LMP). The zeta potential, rheology, particle size and serum separation of AMDs were evaluated after preparing with PPP, HMP and LMP, respectively. Results indicated that PPP led to lower serum separation than LMP (14.65% for AMDs prepared with 0.5% PPP compared to 25.05% for AMDs prepared with 0.5% LMP), but still higher than HMP (9.09% for AMDs prepared with 0.5% HMP). However, narrower particle size distribution and lower viscosity of AMDs was achieved by PPP than by LMP and HMP. PPP can electrostatically adsorb on the surface of casein and its abundant neutral sugar side chains would provide steric hindrance to prevent casein flocculation in AMDs. Our results might provide some new ideas for the application of PPP in improving the stability of AMDs.

scholarly journals PHYSICOCHEMICAL CHARACTERIZATION OF PROPRANOLOL-LOADED CHITOSAN NANOPARTICLES FOR A BUCCAL DRUG DELIVERY SYSTEM

2020 ◽  
pp. 243-247
Author(s):  
SIRIPORN KITTIWISUT ◽  
PAKORN KRAISIT
Keyword(s):  
Drug Delivery ◽  
Particle Size ◽  
Zeta Potential ◽  
Drug Delivery System ◽  
Delivery System ◽  
Chitosan Nanoparticles ◽  
Particle Sizes ◽  
Zeta Potentials ◽  
Ph Values ◽  
Buccal Drug Delivery

Objective: This study aimed to characterize the physicochemical properties, including pH, zeta potential, and particle size of propranolol-loaded nanoparticles that were incorporated into a buccal transmucosal drug-delivery system. Methods: An ionotropic gelation technique was used to formulate propranolol-loaded chitosan nanoparticles. Chitosan used as the nanoparticle base, using tripolyphosphate (TPP) as a cross-linking agent. The effects on nanoparticle physical properties, including pH, zeta potential, and particle size were examined when various chitosan [0.150-0.300 % (w/v)] and propranolol contents (0-40 mg) were used during the preparation. The effects of using chitosan solutions with different pH values on nanoparticle properties were also determined. Results: The pH values of all nanoparticles ranged between 4.14–4.55. The zeta potentials of the prepared nanoparticles ranged between 22.6–52.6 mV, with positive charges. The nanoparticle sizes ranged from 107–140 nm, which are within the range of suitable particle sizes for transmucosal preparations. Conclusion: The pH values, zeta potentials, and particle sizes of the nanoparticle formulations were influenced by the concentrations of chitosan and propranolol and by the pH of the initial chitosan solution. The relationships between nanoparticle properties and all factors primarily depended on the ionic charges of the components, especially chitosan. Our study provides beneficial physicochemical knowledge for the further development of chitosan-based nanoparticles containing propranolol for buccal drug delivery systems.

Investigation on the Effect of an Divalent Electrolyte on the Flocculation of SDBS with Al3+

2012 ◽  
Vol 610-613 ◽  
pp. 163-168
Author(s):  
Jie Yan ◽  
Dong Wang ◽  
Fei Fei Yang ◽  
Dong Mei Yao
Keyword(s):  
Surface Tension ◽  
Critical Micelle Concentration ◽  
Zeta Potential ◽  
Anionic Surfactant ◽  
Potential Surface ◽  
Sodium Dodecylbenzenesulfonate ◽  
Molar Ratios ◽  
Ph Values ◽  
Average Size

The effect of an divalent electrolyte Ca2+ on the flocculation of two different concentrations of anionic surfactant Sodium Dodecylbenzenesulfonate (SDBS) with Al3+ has been investigated at different molar ratios Al3+ to SDBS at 298.15 K. The results showed that the flocculation characteristics of 0.01 mol•L-1 SDBS (above the critical micelle concentration CMC) and 0.001 mol•L-1 SDBS (below the CMC) were obviously different with an increase of dosages of Al3+. The z-average size of flocculate of 0.01 mol•L-1 SDBS with Al3+ decreased particularly with the pre-addition of Ca2+，It suggested the formation of the complexion Ca(SDBS)2. At optimization flocculation areas at 298.15K, pH values were all around 3.5 in the flocculation systems SDBS/Al3+ and Ca2+/SDBS/Al3+ whether the SDBS concentration above or below the CMC. The pre-addition of Ca2+ slightly affected other flocculation parameters of SDBS/Al3+ systems such as zeta potential, surface tension, conductivity and pH.

scholarly journals The Effect of the Liposomal Encapsulated Saffron Extract on the Physicochemical Properties of a Functional Ricotta Cheese

Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 120
Author(s):  
Zahra Siyar ◽  
Ali Motamedzadegan ◽  
Jafar Mohammadzadeh Milani ◽  
Ali Rashidinejad
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Encapsulation Efficiency ◽  
Textural Properties ◽  
Constant Concentration ◽  
Soy Lecithin ◽  
Significant Difference ◽  
Saffron Extract ◽  
The Stability ◽  
Potential Stability

In this study, the encapsulation of saffron extract (SE) was examined at four various concentrations of soy lecithin (0.5%–4% w/v) and constant concentration of SE (0.25% w/v). Particle size and zeta potential of liposomes were in the range of 155.9–208.1 nm and −34.6–43.4 mV, respectively. Encapsulation efficiency was in the range of 50.73%–67.02%, with the stability of nanoliposomes in all treatments being >90%. Encapsulated SE (2% lecithin) was added to ricotta cheese at different concentrations (0%, 0.125%, 1%, and 2% w/v), and physicochemical and textural properties of the cheese were examined. Lecithin concentration significantly (p ≤ 0.05) affected the particle size, zeta potential, stability, and encapsulation efficiency of the manufactured liposomes. In terms of chemical composition and color of the functional cheese, the highest difference was observed between the control cheese and the cheese enriched with 2% liposomal encapsulated SE. Hardness and chewiness increased significantly (p ≤ 0.05) in the cheeses containing encapsulated SE compared to the control cheese. However, there was no significant difference in the case of adhesiveness, cohesiveness, and gumminess among different cheeses. Overall, based on the findings of this research, liposomal encapsulation was an efficient method for the delivery of SE in ricotta cheese as a novel functional food.

scholarly journals Characterization and Nanofluid Stability of CoFe2O4-APTES and CoFe2O4-PVA Nanoparticles

2020 ◽  
Vol 78 (1) ◽  
pp. 79-87
Author(s):  
Anis Arisa Roslan ◽  
Hasnah Mohd Zaid ◽  
Siti Nur Azella Zaine ◽  
Mursyidah Umar ◽  
Beh Hoe Guan
Keyword(s):  
Surface Modification ◽  
Zeta Potential ◽  
Performance Studies ◽  
Colloidal Stability ◽  
Amino Silane ◽  
Cobalt Iron Oxide ◽  
One Step ◽  
The Stability ◽  
Surface Modified ◽  
Surface Modified Nanoparticles

Nanofluid contains nanoparticles that enhanced the property of the base fluid. However, the separating layer between the nanoparticles and base fluids may interfere the nanofluids performance. Studies have been made that surface modification of nanoparticles may improve the dispersion of nanoparticles in base fluids. This paper reports the study of the colloidal stability of surface modified nanoparticles using a polymer and an amino-silane. The nanoparticles were prepared by one-step and two-step methods using cobalt iron oxide nanoparticles with brine solution and deionized water as the base fluids. Functionalization by surface modification of the nanoparticles to enhance the nanofluids stability was carried out using (3-aminopropyl) triethoxysilane (APTES) and polyvinyl alcohol (PVA). Characterization using Fourier Transform Infrared (FTIR), Field Emission Scanning Electron Microscope (FESEM) and X-ray Powder Diffraction (XRD) were performed to study the functionality and morphology of the synthesized nanoparticles. The extra IR peaks such as Si-O-Si at 1063 cm-1 for CoFe2O4-APTES and C=O at 1742 cm-1 for CoFe2O4-PVA showed that there are additional elements in the cobalt ferrite due to functionalization. The size of synthesized CoFe2O4-APTES ranged between 15.99 nm to 26.89 nm while CoFe2O4-PVA is from 25.70 nm to 54.16 nm. The stability of the nanofluid were determined via zeta potential measurements. CoFe2O4-APTES nanofluid has zeta potential of -35.7 mV compared to CoFe2O4-PVA at -15.5 mV.

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