Colloid Surfactants for Emulsion Stabilization

Kim, Jinwoong; Lee, Daeyeon; Shum, Ho Cheung; Weitz, David A.

doi:10.1002/adma.200800484

Cited by 285 publications

(271 citation statements)

References 38 publications

Supporting

Mentioning

265

Contrasting

Unclassified

Order By: Relevance

“…The larger, rough sides of the particles are located outside of the clusters similar to the hydrophilic head group of surfactant micelles. These interactions together with their overall cone-like shape make our colloids a realization of "colloidal surfactants" (29), which in analogy to molecular surfactants form "colloidal micelles". Similar micelle-like clusters have been observed by Granick et al for colloidal Janus-particles, whose surfaces are half hydrophilic and half hydrophobic (13,14).…”

Section: Resultsmentioning

confidence: 99%

“…During polymerization, roughness is achieved through adsorption of smaller polystyrene spheres at the surface. Using these particles in a seeded emulsion polymerization yields rough spheres with a smooth protrusion after phase separation (26)(27)(28)(29). The synthesis protocol is sketched schematically in Fig.…”

Section: Resultsmentioning

confidence: 99%

“…1B. The protrusion size is continuously tunable by adjusting the monomer concentration during synthesis (26)(27)(28)(29). Colloidal particles with protrusions larger than the seed particles (protrusion radius 1.66 μm, pd 3.4 %; seed particle radius 1.2 μm, pd 4.2%; roughness diameter 182 nm, pd 22%; long axis 4.70 μm, pd 3.2%) were synthesized as well to demonstrate the effect of particle geometry on the assembled structures (Fig.…”

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Surface roughness directed self-assembly of patchy particles into colloidal micelles

Kraft

Smallenburg

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

332

314

View full text Add to dashboard Cite

Colloidal particles with site-specific directional interactions, so called "patchy particles", are promising candidates for bottomup assembly routes towards complex structures with rationally designed properties. Here we present an experimental realization of patchy colloidal particles based on material independent depletion interaction and surface roughness. Curved, smooth patches on rough colloids are shown to be exclusively attractive due to their different overlap volumes. We discuss in detail the case of colloids with one patch that serves as a model for molecular surfactants both with respect to their geometry and their interactions. These one-patch particles assemble into clusters that resemble surfactant micelles with the smooth and attractive sides of the colloids located at the interior. We term these clusters "colloidal micelles". Direct Monte Carlo simulations starting from a homogeneous state give rise to cluster size distributions that are in good agreement with those found in experiments. Important differences with surfactant micelles originate from the colloidal character of our model system and are investigated by simulations and addressed theoretically. Our new "patchy" model system opens up the possibility for self-assembly studies into finite-sized superstructures as well as crystals with as of yet inaccessible structures.anisotropic colloids | depletion interactions | Monte-Carlo simulations N ature has mastered the self-assembly of simple basic subunits into complex, functional structures with outstanding precision. Examples include biological membranes and viruses, which exhibit excellent control over the assembled structures with respect to their functionalities, shapes or sizes. However, the interactions between the building blocks, in the case of viruses, the protein subunits, are often complex and it remains challenging to identify the key elements for guiding and controlling the selfassembling process. By mimicking such self-assembly processes on a colloidal scale, insights into the paramount elements that control the assembly can be obtained in situ and applied to build up superstructures with new and desirable properties.Colloidal particles with site-specific directional interactions, so called "patchy particles", are promising candidates for bottom-up assembly routes towards such complex structures with rationally designed properties (1-3). The size and geometry of the patches together with the shape of the interparticle potential are expected to determine the formed structures and phases, which may range from empty liquids (4) and crystals (5-7) to finite-sized clusters (1, 2, 8-11), and lead to novel collective behavior (12).Recent experimental approaches to assemble colloidal particles at specific sites include hydrophobic-hydrophilic interactions (6,7,(13)(14)(15), and lock-and-key recognition mechanisms (16). With a wide variability of colloidal shapes available today, the ultimate challenge is to identify general methods to render specific areas of the colloids attractive or ...

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Surface roughness directed self-assembly of patchy particles into colloidal micelles

Kraft

Smallenburg

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

332

314

View full text Add to dashboard Cite

show abstract

“…Janus particles were initially introduced by Casagrade et al in 1989, [21] but it took the mention of Janus grains in de Gennes' Nobel Lecture [23] in 1991 to bring these particles to the general attention of researchers worldwide. Over the last two decades, many fabrication methods for Janus particles have been developed, [14] including scalable ones, and the particles are now being implemented in new technologies such as emulsions, [44,45] electronic paper, [46][47][48] tunable liquid optics, [49] sensors [50] and microrheological probes. [51][52][53] Fabrication methods for various types of Janus particles, ranging from bicompartmental and dumbbell-like to half-rasberry, arconand snowman-like particles, have been comprehensively reviewed by Perro and co-workers.…”

Section: Definition Of the Term Patchy Particlementioning

confidence: 99%

Fabrication, Assembly, and Application of Patchy Particles

Pawar

Kretzschmar

2010

Macromol. Rapid Commun.

450

411

View full text Add to dashboard Cite

The site‐specific engineering of colloidal surfaces has provided a powerful approach to pushing the boundaries of today's materials research. The resulting surface‐anisotropic and patchy particles have become the center of vital research areas, ranging from the need for large‐scale fabrication techniques to exploring new applications of these materials. This Review summarizes patchy particle fabrication techniques, including but not limited to particle and nanosphere lithography and glancing‐angle deposition. The variety of existing patchy particle fabrication techniques is revealed and the need for a scalable approach to high‐volume patchy particle production is identified. Ongoing modeling efforts describing patchy particle interactions and properties are reviewed as potential predictive tools. Research endeavors that deal with the directed assembly of patchy particles in electric and magnetic fields, as well as with supraparticular assembly through chemical interactions, are discussed. The Review is concluded with a note on the future application of patchy particles as phoretic motors.magnified image

show abstract

“…[6][7][8][9][10][11][12] Since the late 1980s researchers aim at exploiting the remarkable properties of dissymmetrical particles and, by extension, of particles exhibiting partial segregation between two components. 9, 13-18 Nanophase segregation of bi-component organic shells, or self-assembled monolayers (SAMs), on nanoparticles is a straightforward way to reach such asymmetric nano-objects.…”

Section: Introductionmentioning

confidence: 99%

Nanophase Segregation of Self-Assembled Monolayers on Gold Nanoparticles

et al. 2017

View full text Add to dashboard Cite

Nanophase segregation of a bi-component thiol self-assembled monolayer is predicted using atomistic molecular dynamics simulations and experimentally confirmed. The simulations suggest the formation of domains rich in acid-terminated chains, on one hand, and of domains rich in amide-functionalized ethylene glycol oligomers, on the other hand. In particular, within the amide-ethylene glycol oligomers region, a key role is played by the formation of inter-chain hydrogen bonds. The predicted phase segregation is experimentally confirmed by the synthesis of 35 and 15 nm gold nanoparticles functionalized with several binary mixtures of ligands. An extensive study by transmission electron microscopy and electron tomography using silica selective heterogeneous nucleation on acid-rich domains to provide electron contrast supports simulations and highlights patchy nanoparticles with a trend towards Janus nano-objects depending on the nature of the ligands and the particle size. These results validate our computational platform as an effective tool to predict nanophase separation in organic mixtures on a surface and drive further exploration of advanced nanoparticle functionalization.

show abstract

Colloid Surfactants for Emulsion Stabilization

Cited by 285 publications

References 38 publications

Surface roughness directed self-assembly of patchy particles into colloidal micelles

Surface roughness directed self-assembly of patchy particles into colloidal micelles

Fabrication, Assembly, and Application of Patchy Particles

Nanophase Segregation of Self-Assembled Monolayers on Gold Nanoparticles

Contact Info

Product

Resources

About