scholarly journals Investigation of Adsorption Capacity of Magnetite Nanoparticles

2021 ◽  
Vol 16 ◽  
pp. 165-171
Author(s):  
V. V. Rodchenko ◽  
Kyaw Ye Ko
Keyword(s):  
Light Scattering ◽  
Zeta Potential ◽  
Colloidal Stability ◽  
Particle Surface ◽  
Decisive Role ◽  
Component Composition ◽  
Hydrodynamic Diameter ◽  
Synthesis Of Nanoparticles ◽  
Air Atmosphere ◽  
Correct Determination

In this work, the preparation of Fe3O4 nanoparticles modified with 3-aminopropyltriethoxysilane (APTES) was carried out under various synthesis modes (in air or in argon). The zeta potential and hydrodynamic diameter of Fe3O4-APTES nanoparticles were determined by the method of dynamic and electrokinetic light scattering. The effect of humic acids on the zeta potential, hydrodynamic diameter and colloidal stability of Fe3O4-APTES at different pH values was established by the method of dynamic and electrophoretic light scattering. It has been shown that changes in the conditions of the synthesis of nanoparticles of one component composition Fe3O4-APTES (argon) and Fe3O4-APTES (air) (in an inert medium and in an air atmosphere, respectively) lead to a change in the charge of the particle surface and a subsequent change in the sorption properties with respect to HA. It was demonstrated that the decisive role in the study of surface properties is played by the purification from low-molecular-weight impurities that can screen the surface of nanoparticles or bind with an indifferent electrolyte. The stage of dispersive post-preparation of samples is also important for the correct determination of the sorption capacity and hydrodynamic diameter of particles.

scholarly journals Surface characterization of nanoparticles using near-field light scattering

2018 ◽  
Vol 9 ◽  
pp. 1228-1238 ◽  
Author(s):  
Eunsoo Yoo ◽  
Yizhong Liu ◽  
Chukwuazam A Nwasike ◽  
Sebastian R Freeman ◽  
Brian C DiPaolo ◽  
...  
Keyword(s):  
Light Scattering ◽  
Zeta Potential ◽  
Surface Characterization ◽  
Colloidal Stability ◽  
Near Field ◽  
Particle Surface ◽  
Superparamagnetic Iron Oxide ◽  
Scattering Intensity ◽  
Potential Applications ◽  
Poly Ethylene

The effect of nanoparticle surface coating characteristics on colloidal stability in solution is a critical parameter in understanding the potential applications of nanoparticles, especially in biomedicine. Here we explored the modification of the surface of poly(ethylene glycol)-coated superparamagnetic iron oxide nanoparticles (PEG-SPIOs) with the synthetic pseudotannin polygallol via interpolymer complexation (IPC). Changes in particle size and zeta potential were indirectly assessed via differences between PEG-SPIOs and IPC-SPIOs in particle velocity and scattering intensity using near-field light scattering. The local scattering intensity is correlated with the distance between the particle and waveguide, which is affected by the size of the particle (coating thickness) as well as the interactions between the particle and waveguide (related to the zeta potential of the coating). Therefore, we report here the use of near-field light scattering using nanophotonic force microscopy (using a NanoTweezerTM instrument, Halo Labs) to determine the changes that occurred in hydrated particle characteristics, which is accompanied by an analytical model. Furthermore, we found that altering the salt concentration of the suspension solution affected the velocity of particles due to the change of dielectric constant and viscosity of the solution. These findings suggest that this technique is suitable for studying particle surface changes and perhaps can be used to dynamically study reaction kinetics at the particle surface.

scholarly journals Biocompatible Lipid Polymer Cationic Nanoparticles for Antigen Presentation

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 185
Author(s):  
Yunys Pérez-Betancourt ◽  
Bianca de Carvalho Lins Fernandes Távora ◽  
Eliana L. Faquim-Mauro ◽  
Ana Maria Carmona-Ribeiro
Keyword(s):  
Zeta Potential ◽  
Methyl Methacrylate ◽  
Colloidal Stability ◽  
Antimicrobial Agents ◽  
Delayed Type Hypersensitivity ◽  
Hydrodynamic Diameter ◽  
Spleen Cells ◽  
Diallyldimethylammonium Chloride ◽  
Ifn Γ ◽  
Dioctadecyldimethylammonium Bromide

Biocompatible lipid polymer nanoparticles (NPs) previously used as antimicrobial agents are explored here as immuno-adjuvants. Poly (methyl methacrylate) (PMMA)/dioctadecyldimethylammonium bromide (DODAB)/poly (diallyldimethylammonium chloride) (PDDA) nanoparticles (NPs) were prepared by emulsion polymerization of methyl methacrylate (MMA) in the presence of DODAB and PDDA, with azobisisobutyronitrile (AIBN) as the initiator. NPs characterization after dialysis by dynamic light-scattering yielded 225 ± 2 nm hydrodynamic diameter (Dz), 73 ± 1 mV zeta-potential (ζ), and 0.10 ± 0.01 polydispersity (P). Ovalbumin (OVA) adsorption reduced ζ to 45 ± 2 mV. Balb/c mice immunized with NPs/OVA produced enhanced OVA-specific IgG1 and IgG2a, exhibited moderate delayed type hypersensitivity reaction, and enhanced cytokines production (IL-4, IL-10, IL-2, IFN-γ) by cultured spleen cells. There was no cytotoxicity against cultured macrophages and fibroblasts. Advantages of the PMMA/DODAB/PDDA NPs were high biocompatibility, zeta-potential, colloidal stability, and antigen adsorption. Both humoral and cellular antigen-specific immune responses were obtained.

scholarly journals Investigation of the Behavior and Mechanism of Action of Ether-Based Polycarboxylate Superplasticizers Absorption on Large Bibulous Stone Powder

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2736
Author(s):  
Zuiliang Deng ◽  
Guimin Lu ◽  
Lefeng Fu ◽  
Weishan Wang ◽  
Baicun Zheng
Keyword(s):  
Infrared Spectroscopy ◽  
Thermogravimetric Analysis ◽  
Zeta Potential ◽  
Mechanism Of Action ◽  
Water Consumption ◽  
Pore Volume ◽  
High Water ◽  
Hydrodynamic Diameter ◽  
Coarse Aggregates ◽  
Polycarboxylate Superplasticizer

The aim of this paper is to study the adsorption behavior of polycarboxylate superplasticizers (PCE) on coarse aggregates with a property of high water consumption (above 2%). The coarse aggregates were ground into a powder to create large bibulous stone powder, and it was observed that significant amounts of the ether-based PCE were absorbed onto large bibulous stone powder. The adsorption rate immediately reached a maximum after 5 min and then gradually decreased until an equilibrium absorption was established after 30 min. Zeta potential, infrared spectroscopy, and thermogravimetric analysis (TGA) measurements confirmed that the polycarboxylate superplasticizer adsorbed on the surface of the stone powder. Hydrodynamic diameter measurements showed that the polycarboxylate superplasticizer molecules were smaller than pore size, and the surface area and pore volume were reduced by the polymer incorporation in the pores.

scholarly journals Development of A Flexible Cell Targeting System Based on Silica Nanoparticles

1998 ◽  
Vol 530 ◽  
Author(s):  
T. Schiimstel ◽  
H. Schirra ◽  
J. Gerwann ◽  
C. Lesniak ◽  
A. Kalaghi-Nafchi ◽  
...  
Keyword(s):  
Silica Nanoparticles ◽  
Electrostatic Interactions ◽  
Particle Concentration ◽  
Biological Function ◽  
Particle Surface ◽  
Cell Types ◽  
Silica Particles ◽  
Hydrodynamic Diameter ◽  
Reaction Conditions ◽  
Physiological Conditions

AbstractCommercially available and synthesized silica particles were fluorescently labeled with FITC and modified to get a wide variety of particle systems with defined size and surface charge. By a variation of reaction conditions particles with diameters of 10 and 80 nm determined with TEM and with zetapotentials between -50 to +30 mV under physiological conditions (pH: 7.4, PBS-buffer) were available.A further molecular shell consisiting of avidin was obtained by binding the molecules to negatively charged particle surfaces through electrostatic interactions. The amount of avidin coupled to the silica particles was 1.7 μg per mg particle. Starting with particles with an hydrodynamic diameter determined with PCS of 260 nm, the size increased to 500 nm, while the zeta potential was altered to -8 mV under physiological conditions.Biotinylated wheat germ agglutinin (bio-WGA) can be bonded to such particles through avidin / biotin complex formation. Up to 2.8 μg lectin per mg particles could be coupled to the particle surface. This leads to a further increase of hydrodynamic diameter to 650 nm. It could be shown by hemagglutination test, that the bonded lectin is still active. No toxic effects of the silica particles were found at 1 wt.-% particle concentration with various cell types (Caco-2, L132). The binding of lectin-particle complexes to cells was increased by a factor of 4.4 in comparison to uncoated particles.In addition it was found that WGA can directly be coupled to the particle surface. An amount of 1.8 μg Lectin per mg particle was determined. The hydrodynamic diameter increases from 260 nm to 432 rm, while a zetapotential of-28 mV was found under physiological conditions.It could be shown, that negatively charged silica nanoparticles are suitable systems to couple various biomolecules retaining their biological function.

scholarly journals Development and Validation of Optical Methods for Zeta Potential Determination of Silica and Polystyrene Particles in Aqueous Suspensions

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 290
Author(s):  
Yannic Ramaye ◽  
Marta Dabrio ◽  
Gert Roebben ◽  
Vikram Kestens
Keyword(s):  
Zeta Potential ◽  
Particle Tracking ◽  
Colloidal Stability ◽  
Optical Methods ◽  
Intermediate Precision ◽  
Electrophoretic Light Scattering ◽  
Measurement Uncertainties ◽  
Development And Validation ◽  
Direct Implementation

Zeta potential is frequently used to examine the colloidal stability of particles and macromolecules in liquids. Recently, it has been suggested that zeta potential can also play an important role for grouping and read-across of nanoforms in a regulatory context. Although the measurement of zeta potential is well established, only little information is reported on key metrological principles such as validation and measurement uncertainties. This contribution presents the results of an in-house validation of the commonly used electrophoretic light scattering (ELS) and the relatively new particle tracking analysis (PTA) methods. The performance characteristics were assessed by analyzing silica and polystyrene reference materials. The ELS and PTA methods are robust and have particle mass working ranges of 0.003 mg/kg to 30 g/kg and 0.03 mg/kg to 1.5 mg/kg, respectively. Despite different measurement principles, both methods exhibit similar uncertainties for repeatability (2%), intermediate precision (3%) and trueness (4%). These results confirm that the developed methods can accurately measure the zeta potential of silica and polystyrene particles and can be transferred to other laboratories that analyze similar types of samples. If direct implementation is impossible, the elaborated methodologies may serve as a guide to help laboratories validating their own methods.

Formulation, Physical and Chemical Stability of Ocimum gratissimum L. Leaf Oil Nanoemulsion

2021 ◽  
Vol 901 ◽  
pp. 117-122
Author(s):  
Netnapa Ontao ◽  
Sirivan Athikomkulchai ◽  
Sarin Tadtong ◽  
Phuriwat Leesawat ◽  
Chuda Chittasupho
Keyword(s):  
Essential Oil ◽  
Zeta Potential ◽  
Chemical Stability ◽  
Polydispersity Index ◽  
Hydrodynamic Diameter ◽  
Potential Value ◽  
Yellow Color ◽  
Leaf Oil ◽  
The Stability ◽  
Physical And Chemical

Ocimum gratissimum L. leaf oil exhibited many pharmacological properties. This study aimed to formulate and evaluate the physical and chemical stability of O.gratissimum leaf oil nanoemulsion. O.gratissimum leaf oil was extracted by hydrodistillation. The major component of the essential oil eugenol, was analyzed by UV-Vis spectrophotometry. Nanoemulsions of O.gratissimum leaf oil were formulated using polysorbate 80, hyaluronic acid, poloxamer 188, and deionized water by phase inversion composition method. The hydrodynamic diameter, polydispersity index, and zeta potential value of O.gratissimum leaf oil nanoemulsion was evaluated by a dynamic light scattering technique. The %remaining of eugenol in the nanoemulsion was analyzed by UV-Vis spectrophotometry. The essential oil extracted from of O. gratissimum leaf oil was a clear, pale yellow color. The %yield of the essential oil was 0.15 ± 0.03% v/w. The size of the nanoemulsion was less than 106 nm. The polydispersity index of the nanoemulsion was ranging from 0.303 - 0.586 and the zeta potential value of the nanoemulsion was closely to zero, depending on the formulation component. O. gratissimum leaf oil at concentrations ranging from 0.002 - 0.012% v/v contained 35 - 41% of eugenol. The size of nanoemulsion was significantly decreased after storage at 4 °C, while significantly increased upon storage at 45 °C. The size of nanoemulsion stored at 30 °C did not significantly change. The %remaining of eugenol in the nanoemulsion was more than 90% after storage at 4 °C and 30 °C for 28 days. The percentage of eugenol remaining in the nanoemulsion stored at 45 °C was more than 85 - 90%, suggesting that the temperature affected the stability of eugenol in the nanoemulsion.

scholarly journals A simple and sensitive sensor for silver ions based on unmodified gold nanoparticles by using dynamic light scattering techniques

2017 ◽  
Vol 95 (12) ◽  
pp. 1267-1272 ◽  
Author(s):  
Zhiyou Xiao ◽  
Anjiang Tang ◽  
Hongsheng Huang ◽  
Ze Wang
Keyword(s):  
Gold Nanoparticles ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
High Sensitivity ◽  
Silver Ions ◽  
Hydrodynamic Diameter ◽  
Optimum Conditions ◽  
Sensitivity And Selectivity ◽  
Sensitive Sensor ◽  
Average Hydrodynamic Diameter

A simple and sensitive assay for Ag+ was developed with unmodified gold nanoparticles (AuNPs) by using dynamic light scattering techniques. Ag+ could induce the oligonucleotide (5′-ATC ACT ATA TCA TAT ACT CAT-3′) to change from a single-stranded structure to a double-stranded structure and desorb from the surface of AuNPs, which triggered the aggregation of AuNPs in the salt solution. The average hydrodynamic diameter of aggregated AuNPs could be detected by using dynamic light scattering techniques. Under the optimum conditions, the average hydrodynamic diameter of AuNPs is proportional to the concentration of Ag+ within the range of 13.3–100.0 nmol/L, with a detection limit of 3.2 nmol/L. The method is easy to operate and has low sample consumption, high sensitivity and selectivity.

Sign in / Sign up

Export Citation Format

Share Document