Specific ζ-Potential Response of Layer-by-Layer Coated Colloidal Particles Triggered by Polyelectrolyte Ion Interactions

Langmuir ◽  
2009 ◽  
Vol 25 (6) ◽  
pp. 3374-3380 ◽  
Author(s):  
J. Irigoyen ◽  
S. E. Moya ◽  
J. J. Iturri ◽  
I. Llarena ◽  
O. Azzaroni ◽  
...  
Keyword(s):  
Colloidal Particles ◽  
Layer By Layer ◽  
Potential Response ◽  
Ζ Potential ◽  
Ion Interactions

Change of Multiple-Layered Phospholipid Vesicles Produced by Electrostatic Deposition of Polymers during Storage

2016 ◽  
Vol 12 (8) ◽  
pp. 763-771 ◽  
Author(s):  
Ji-Yeon Chun ◽  
Jochen Weiss ◽  
Monika Gibis ◽  
Mi-Jung Choi ◽  
Geun-Pyo Hong
Keyword(s):  
Particle Size ◽  
Layer By Layer ◽  
Ζ Potential ◽  
Electrostatic Deposition ◽  
Sedimentation Behavior ◽  
Physicochemical Stability ◽  
Release Study ◽  
Calcein Release ◽  
Liposome Surface ◽  
Positively Charged

Abstract In this study, 1 wt% lecithin (–), chitosan (+), and λ-carrageenan (–) were prepared to manufacture multiple-layered liposomes with optimal formulations developed in a previous study by using layer-by-layer electrostatic deposition. We observed their particle size, ζ-potential, sedimentation behavior, and microstructure for 6 weeks. Multiple-layered liposomes were quenched with calcein to evaluate stability in terms of factors such as encapsulation efficiency and released amount of calcein. The particle size of multi-layered liposomes increased with storage periods and the ζ-potential of multiple-layered liposomes gained a neutral charge. Interestingly, negatively charged layered liposomes were smaller than positively charged layered liposomes and showed a lower polydispersity index. Moreover, the ζ-potential did not apparently change compared to positively charged layered liposomes. For the calcein release study, multiple-layered liposomes significantly sustained quenched calcein more than that observed using non-layered liposomes. This study showed that it was possible to increase the thickness of the liposome surface and to manipulate its charge using chitosan and λ-carrageenan through electrostatic deposition. Results showed that manufacturing negatively charged multiple-layer (over 4-layer) liposomes with charged biopolymer improved the physicochemical stability of liposomes.

scholarly journals Some modification of cellulose nanocrystals for functional Pickering emulsions

2016 ◽  
Vol 374 (2072) ◽  
pp. 20150139 ◽  
Author(s):  
Dorra Saidane ◽  
Emilie Perrin ◽  
Fanch Cherhal ◽  
Florian Guellec ◽  
Isabelle Capron
Keyword(s):  
Charge Density ◽  
Surface Charge ◽  
Cellulose Nanocrystals ◽  
Surface Charge Density ◽  
Colloidal Particles ◽  
Hydroxyl Groups ◽  
Layer By Layer ◽  
Pickering Emulsions ◽  
Simple Method ◽  
Oil Emulsions

Cellulose nanocrystals (CNCs) are negatively charged colloidal particles well known to form highly stable surfactant-free Pickering emulsions. These particles can vary in surface charge density depending on their preparation by acid hydrolysis or applying post-treatments. CNCs with three different surface charge densities were prepared corresponding to 0.08, 0.16 and 0.64 e nm −2 , respectively. Post-treatment might also increase the surface charge density. The well-known TEMPO-mediated oxidation substitutes C 6 -hydroxyl groups by C 6 -carboxyl groups on the surface. We report that these different modified CNCs lead to stable oil-in-water emulsions. TEMPO-oxidized CNC might be the basis of further modifications. It is shown that they can, for example, lead to hydrophobic CNCs with a simple method using quaternary ammonium salts that allow producing inverse water-in-oil emulsions. Different from CNC modification before emulsification, modification can be carried out on the droplets after emulsification. This way allows preparing functional capsules according to the layer-by-layer process. As a result, it is demonstrated here the large range of use of these biobased rod-like nanoparticles, extending therefore their potential use to highly sophisticated formulations. This article is part of the themed issue ‘Soft interfacial materials: from fundamentals to formulation’.

Preparation of PLGA/Rose Bengal colloidal particles by double emulsion and layer-by-layer for breast cancer treatment

2018 ◽  
Vol 518 ◽  
pp. 122-129 ◽  
Author(s):  
María F. Loya-Castro ◽  
Mariana Sánchez-Mejía ◽  
Dante R. Sánchez-Ramírez ◽  
Rossina Domínguez-Ríos ◽  
Noé Escareño ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Treatment ◽  
Rose Bengal ◽  
Colloidal Particles ◽  
Double Emulsion ◽  
Breast Cancer Treatment ◽  
Layer By Layer

Determinants of Entrapment of R-Phycoerythrin within Ployeletrolyte Microcapsules

2011 ◽  
Vol 183-185 ◽  
pp. 1657-1661
Author(s):  
Ye Li ◽  
Heng Jian Zhang
Keyword(s):  
Colloidal Particles ◽  
Fluorescent Protein ◽  
Fluorescent Proteins ◽  
Load Capacity ◽  
Layer By Layer ◽  
Multilayer Adsorption ◽  
Freundlich Model ◽  
Layer Adsorption ◽  
Subsequent Decomposition ◽  
Positively Charged

Micrometer sized polyelectrolyte capsules have been fabricated by employing the layer-by-layer adsorption technique on charged colloidal particles with subsequent decomposition and removal of the core. Based on the permeable properties of capsules, the fluorescent proteins, R-Phycoerythrins are used to examine protein load behaviors. The loading of R-PE on capsules depends on intramolecular electrostatic attraction and intermolecular repulsion interaction. The loading rules on positively charged capsules (PSS/PAH)4and negatively charged capsules (PSS/PAH)4PSS are different, although R-PEs demonstrates the largest load capacity around isoelectric point, which is almost independent of surface charge of the capsules. In the case, driving force of encapsulation of protein into the capsule is hydrophobic mainly, while the fluorescent protein is absorbed on the shell of positively charged capsule (PSS/PAH)4. However, the R-PE was completely encapsulated into negatively charged capsules (PSS/PAH)4PSS. Therefore, compared to the positively charged capsules, negatively charged capsules is more favorable to macromolecules permeating into the capsule interior. Based on the Freundlich model, it can be concluded that capsules take up proteins on surface by multilayer adsorption.

scholarly journals A Novel Oxidation-Reduction Route for Layer-by-Layer Synthesis ofTiO2Nanolayers and Investigation of Its Photocatalytical Properties

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Konstantin Semishchenko ◽  
Valeri Tolstoy ◽  
Artem Lobinsky
Keyword(s):  
Photoelectron Spectroscopy ◽  
Colloidal Particles ◽  
Microprobe Analysis ◽  
Electron Microprobe Analysis ◽  
Colloidal Solution ◽  
Layer By Layer ◽  
Globular Structure ◽  
X Ray ◽  
Oxidation Reduction ◽  
High Area

Layer-by-layer (LbL) synthesis of titanium dioxide was performed by an oxidation-reduction route using a Ti(OH)3colloid and NaNO2solutions. A model of chemical reactions was proposed based on the results of an investigation of synthesized nanolayers by scanning electron microscopy, electron microprobe analysis and X-ray photoelectron spectroscopy, and studying colloidal solution of Ti(OH)3with laser Doppler microelectrophoresis. At each cycle, negatively charged colloidal particles of[Ti(OH)3]HSO4-adsorbed onto the surface of substrate. During the next stage of treatment in NaNO2solution, the particles were oxidized to Ti(OH)4. Photocatalytic activity was studied by following decomposition of methylene blue (MB) under UV irradiation. Sensitivity of the measurements was increased using a diffuse transmittance (DT) method. The investigation revealed strong photocatalytical properties of the synthesized layers, caused by their high area per unit volume and uniform globular structure.

scholarly journals Study of electrostatic parameters of aqueous suspensions for solving the tasks of water treatment and selection of optimal filter media

2021 ◽  
pp. 171-178
Author(s):  
D. V. Charnyi ◽  
E. M. Matseliuk ◽  
Y. A. Onanko
Keyword(s):  
Water Treatment ◽  
Ion Exchange ◽  
Colloidal Particles ◽  
Aqueous Suspension ◽  
Polystyrene Foam ◽  
Treatment Facility ◽  
Filter Media ◽  
Clay Particles ◽  
Ζ Potential ◽  
Initial Stage

Relevance of research. At present, there is a need for a comprehensive study of both physical and chemical parameters of substances, which is the primary source of deteriorating treated water quality, as well as the relevant physical properties of the actual filter media to determine the mechanism of their interaction. Such a parameter of purified water as turbidity is closely related to the electrostatic properties of the colloids contained in water. For a more detailed experimental study of this interaction, an operating water treatment facility was chosen. A preliminary study of the conditions at the Communal Enterprise "Chernivtsivodokanal" in the city of Chernivtsi, Ukraine made it possible to identify the typical problems that need to be immediately addressed.  The study revealed that the main indicator that is critical for the purification of these waters is turbidity, and one of the main growing concerns to be addressed is the replacement of the filter media. Research results. To select optimal filter media, a comprehensive study of the electrostatic parameters of all components in the water treatment process was carried out. Experimental studies of physical quantities that are key to this process were performed. The relationship between the turbidity parameters of the studied waters and the ζ-potential of the colloids contained in them was shown. Seasonal changes in the hydrochemical composition of the treated waters were studied. The connection between electrochemical parameters of clay particles and the processes of their sedimentation in aqueous suspension is given. The dependences of turbidity on time and the ratio of average turbidity values to the minimum and maximum ones at the water intake of the Dniester-Chernivtsi water supply system during 2005-2015 were reviewed and presented. The dynamics of changes in the parameters of turbidity and ζ-potential in the structures of the technological chain of water treatment during the periods of summer-autumn floods and low-water winter period was studied. The effect of the coagulant used at the studied water treatment facility on the electrostatic parameters of the purified colloidal particles, in particular, on changing the structure of the electric double layer of clay particles, which lead to the coagulation and reduction in the treated water turbidity, was analyzed. The optimal conditions of using polystyrene foam and zeolite filter media were determined. Ion exchange properties enabled the zeolite to efficiently remove fine colloidal particles with positively charged cores out of the purified aqueous suspension, which were not completely covered with a layer of potential-forming ions. However, they produced impact only in the short-term initial stage of filtering. Therefore, they cannot be recommended for using for long-term water treatment processes at water treatment facilities. This phenomenon is due to the limited ion exchange adsorption properties of zeolite. The effective filtration of colloidal particles through zeolite in the year-round mode of operation at the studied water treatment facility is mainly associated with the developed outer surface of its grains, which provides mechanical interception and retention of colloidal particles. Conclusions. The connection between the turbidity parameters and colloids ζ-potential of the purified aqueous suspension for the conditions of water quality formation in the upper reaches of the Dniester River has been established. The determined values of the ζ-potential of colloids enabled to find out that the polystyrene foam filter media is more expedient to use during the flood periods, and the application of the zeolite media has a higher efficiency during the low-water periods. The ion exchange properties of zeolite can ensure a high level of water purification during floods; however it can be only efficient at the initial stage of filtration. Effective mechanical interception and retention of colloidal particles in the year-round regime is provided by the developed surface of its grains. The combined polystyrene foam and zeolite filter media is recommended to use to solve the problems of water treatment throughout the year.

Layer-by-layer assembly of polymersomes and polyelectrolytes on planar surfaces and microsized colloidal particles

2014 ◽  
Vol 421 ◽  
pp. 132-140 ◽  
Author(s):  
Marcos Coustet ◽  
Joseba Irigoyen ◽  
Teodoro Alonso Garcia ◽  
Richard A. Murray ◽  
Gabriela Romero ◽  
...  
Keyword(s):  
Colloidal Particles ◽  
Layer By Layer ◽  
Planar Surfaces ◽  
Layer By Layer Assembly ◽  
Layer Assembly

Layer-by-Layer Growth of Attractive Binary Colloidal Particles

Langmuir ◽  
2008 ◽  
Vol 24 (17) ◽  
pp. 9273-9278 ◽  
Author(s):  
Kwan Wee Tan ◽  
Guang Li ◽  
Yaw Koon Koh ◽  
Qingfeng Yan ◽  
C. C. Wong
Keyword(s):  
Colloidal Particles ◽  
Layer Growth ◽  
Layer By Layer

Tailoring assembly behavior of starches to control insulin release from layer-by-layer assembled colloidal particles

2020 ◽  
Vol 160 ◽  
pp. 531-537
Author(s):  
Yiping Zhang ◽  
Shaowen Zhong ◽  
Chengdeng Chi ◽  
Ying He ◽  
Xiaoxi Li ◽  
...  
Keyword(s):  
Insulin Release ◽  
Colloidal Particles ◽  
Layer By Layer ◽  
Assembly Behavior
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