Colloidal assembly by directional ice templating

Clustering of colloidal particles near an electrode surface during and after electrophoretic deposition has been reported in the literature [1, 2, 3, 4]. The aggregation of colloidal particles has made the precise assembly of two and three dimensional colloidal crystals possible. In this paper, we demonstrate the use of external electric fields to sensitively tune the interactions between colloidal particles to form ordered structures. The directed assembly of colloidal particles on patterned electrode surfaces is also investigated as a means of building three-dimensional nanostructures. Finally, a new method to map potential energy landscapes of templated substrates using a diffusing colloidal particle as a sensitive local energy probe is described.

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Colloidal assembly by ice templating

Faraday Discussions ◽

10.1039/c5fd00125k ◽

2016 ◽

Vol 186 ◽

pp. 61-76 ◽

Cited By ~ 14

Author(s):

Guruswamy Kumaraswamy ◽

Bipul Biswas ◽

Chandan Kumar Choudhury

Keyword(s):

Size Distribution ◽

Particle Concentration ◽

Colloidal Particles ◽

Cluster Formation ◽

Polymer Chains ◽

Concentration Gradients ◽

Aqueous Dispersions ◽

Colloidal Assembly ◽

Colloidal Clusters ◽

Ice Templating

We investigate ice templating of aqueous dispersions of polymer coated colloids and crosslinkers, at particle concentrations far below that required to form percolated monoliths. Freezing the aqueous dispersions forces the particles into close proximity to form clusters, that are held together as the polymer chains coating the particles are crosslinked. We observe that, with an increase in the particle concentration from about 106 to 108 particles per ml, there is a transition from isolated single particles to increasingly larger clusters. In this concentration range, most of the colloidal clusters formed are linear or sheet like particle aggregates. Remarkably, the cluster size distribution for clusters smaller than about 30 particles, as well as the size distribution of linear clusters, is only weakly dependent on the dispersion concentration in the range that we investigate. We demonstrate that the main features of cluster formation are captured by kinetic simulations that do not consider hydrodynamics or instabilities at the growing ice front due to particle concentration gradients. Thus, clustering of colloidal particles by ice templating dilute dispersions appears to be governed only by particle exclusion by the growing ice crystals that leads to their accumulation at ice crystal boundaries.

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Research on charged colloidal particle propulsion

10.2514/6.1965-72 ◽

1965 ◽

Author(s):

S. HARRIS

Keyword(s):

Colloidal Particle

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Tunable thermo-reversible bicontinuous nanoparticle gel driven by the binary solvent segregation

Nature Communications ◽

10.1038/s41467-020-20701-3 ◽

2021 ◽

Vol 12 (1) ◽

Cited By ~ 2

Author(s):

Yuyin Xi ◽

Ronald S. Lankone ◽

Li-Piin Sung ◽

Yun Liu

Keyword(s):

Phase Separation ◽

Domain Size ◽

Binary Solvent ◽

Colloidal Systems ◽

Colloidal Assembly ◽

Structures And Properties ◽

Wide Range ◽

Equilibrium Process ◽

Equilibrium Structures ◽

Non Equilibrium

AbstractBicontinuous porous structures through colloidal assembly realized by non-equilibrium process is crucial to various applications, including water treatment, catalysis and energy storage. However, as non-equilibrium structures are process-dependent, it is very challenging to simultaneously achieve reversibility, reproducibility, scalability, and tunability over material structures and properties. Here, a novel solvent segregation driven gel (SeedGel) is proposed and demonstrated to arrest bicontinuous structures with excellent thermal structural reversibility and reproducibility, tunable domain size, adjustable gel transition temperature, and amazing optical properties. It is achieved by trapping nanoparticles into one of the solvent domains upon the phase separation of the binary solvent. Due to the universality of the solvent driven particle phase separation, SeedGel is thus potentially a generic method for a wide range of colloidal systems.

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Modeling and theoretical description of magnetic hybrid materials—bridging from meso- to macro-scales

Physical Sciences Reviews ◽

10.1515/psr-2019-0088 ◽

2020 ◽

Vol 0 (0) ◽

Cited By ~ 1

Author(s):

Andreas M. Menzel ◽

Hartmut Löwen

Keyword(s):

Colloidal Particles ◽

Colloidal Particle ◽

Theoretical Description ◽

Point Of View ◽

Material Behavior ◽

Theoretical Point ◽

Mechanical Stiffness ◽

Theoretical Approaches ◽

Theoretical Predictions ◽

Particle Level

Abstract Magnetic gels and elastomers consist of magnetic or magnetizable colloidal particles embedded in an elastic polymeric matrix. Outstanding properties of these materials comprise reversible changes in their mechanical stiffness or magnetostrictive distortions under the influence of external magnetic fields. To understand such types of overall material behavior from a theoretical point of view, it is essential to characterize the substances starting from the discrete colloidal particle level. It turns out that the macroscopic material response depends sensitively on the mesoscopic particle arrangement. We have utilized and developed several theoretical approaches to this end, allowing us both to reproduce experimental observations and to make theoretical predictions. Our hope is that both these paths help to further stimulate the interest in these fascinating materials.

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Construction of nacre-mimetic composites with a “brick-and-mortar” architecture based on structural defects in ice-templating

Materials & Design ◽

10.1016/j.matdes.2021.109668 ◽

2021 ◽

pp. 109668

Author(s):

Yun-Liang Li ◽

Rui-Fen Guo ◽

Zhi-Jie Hu ◽

Ping Shen

Keyword(s):

Structural Defects ◽

Brick And Mortar ◽

Ice Templating

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Combined electrokinetic and shear flows control colloidal particle distribution across microchannel cross-sections

Soft Matter ◽

10.1039/d0sm01646b ◽

2021 ◽

Author(s):

Varun Lochab ◽

Shaurya Prakash

Keyword(s):

Shear Flow ◽

Cross Sections ◽

Lift Force ◽

Shear Flows ◽

Colloidal Particle ◽

Particle Distribution ◽

Particle Migration ◽

Flow Parameters

We quantify and investigate the effects of flow parameters on the extent of colloidal particle migration and the corresponding electrophoresis-induced lift force under combined electrokinetic and shear flow.

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