Layer-by-layer optical assembly of colloidal particles

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’.

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

Journal of Colloid and Interface Science ◽

10.1016/j.jcis.2018.02.013 ◽

2018 ◽

Vol 518 ◽

pp. 122-129 ◽

Cited By ~ 11

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

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Determinants of Entrapment of R-Phycoerythrin within Ployeletrolyte Microcapsules

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.183-185.1657 ◽

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.

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

Journal of Nanomaterials ◽

10.1155/2014/632068 ◽

2014 ◽

Vol 2014 ◽

pp. 1-7 ◽

Cited By ~ 4

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.

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

Journal of Colloid and Interface Science ◽

10.1016/j.jcis.2014.01.038 ◽

2014 ◽

Vol 421 ◽

pp. 132-140 ◽

Cited By ~ 21

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

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Layer-by-Layer Growth of Attractive Binary Colloidal Particles

Langmuir ◽

10.1021/la8009089 ◽

2008 ◽

Vol 24 (17) ◽

pp. 9273-9278 ◽

Cited By ~ 15

Author(s):

Kwan Wee Tan ◽

Guang Li ◽

Yaw Koon Koh ◽

Qingfeng Yan ◽

C. C. Wong

Keyword(s):

Colloidal Particles ◽

Layer Growth ◽

Layer By Layer

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

International Journal of Biological Macromolecules ◽

10.1016/j.ijbiomac.2020.05.237 ◽

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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Multi-layer films of block copolymer micelles adsorbed to colloidal templates

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2010.0151 ◽

2010 ◽

Vol 368 (1927) ◽

pp. 4293-4311 ◽

Cited By ~ 4

Author(s):

Timothy Addison ◽

Olivier J. Cayre ◽

Simon Biggs ◽

Steven P. Armes ◽

David York

Keyword(s):

Block Copolymer ◽

Colloidal Particles ◽

Thermo Gravimetric Analysis ◽

Layer By Layer ◽

Gravimetric Analysis ◽

Industrial Sectors ◽

Hydrophobic Materials ◽

Block Copolymer Micelles ◽

Copolymer Micelles ◽

Novel Delivery Systems

Alternating layers of cationic and anionic block copolymer micelles have been deposited onto colloidal silica particles using a layer-by-layer approach. The resulting films have been investigated using a number of characterization techniques including zeta potential measurements, dynamic light scattering, thermo-gravimetric analysis and microscopy. The micelles used here demonstrate pH-responsive behaviour both in solution and when adsorbed at interfaces. It has been shown that block copolymer micelles can selectively encapsulate and release hydrophobic materials; therefore, the incorporation of such responsive species within films has the potential to offer increased functionality. The formation of films onto colloidal particles is of great interest as it can provide pathways to direct encapsulation of materials along with surface modification. This study aims to provide new insights into the nature and properties of responsive films. Such studies will allow for the future development of novel delivery systems that have potential application within a number of industrial sectors including personal care products, pharmaceuticals and agro-chemicals.

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Building Two and Three-dimensional Structures of Colloidal Particles on Surfaces using Optical Tweezers and Critical Point Drying

MRS Proceedings ◽

10.1557/proc-705-y6.8 ◽

2001 ◽

Vol 705 ◽

Author(s):

Dirk L. J. Vossen ◽

Jacob P. Hoogenboom ◽

Karin Overgaag ◽

Alfons van Blaaderen

Keyword(s):

Critical Point ◽

Optical Tweezers ◽

Colloidal Particles ◽

Three Dimensional ◽

Silica Shell ◽

Dimensional Structure ◽

Layer By Layer ◽

Two Dimensional ◽

Critical Point Drying ◽

Shell Particles

AbstractWe describe a method for patterning substrates with colloidal particles in any designed two-dimensional structure. By using optical tweezers particles are brought from a reservoir to a surface that carries a surface charge opposite to that of the particles. Using this technique large, two-dimensional patterns can be created, where the pattern can be manipulated on a single particle level. We show that these structures can be dried using critical point drying thus preventing distortions due to surface tension forces. After drying patterned surfaces can be used for further processing, which includes repeating the procedure of patterning. We show some first results of three-dimensional structures created using this layer-by-layer method. The method is generally applicable and has been demonstrated for a variety of (core-shell) colloidal particles including particles that are interesting for photonic applications like high-refractive index (ZnS)-core – silica shell particles, metallodielectric (gold)-core – silica-shell particles, fluorescently labeled particles and small (several nanometers large) gold particles. Particle sizes used range from a few nanometers to several micrometers.

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