Related Experiment Video
Updated: Jun 30, 2026
09:26
Synthesis and Characterization of Supramolecular Colloids
Published on: April 22, 2016
Particle and substrate charge effects on colloidal self-assembly in a sessile drop
Qingfeng Yan1, Li Gao, Vyom Sharma
1Singapore-MIT Alliance, N3.2-01-36, 65 Nanyang Drive, Singapore 637460.
Langmuir : the ACS Journal of Surfaces and Colloids
|September 24, 2008
Summary
Surface charge significantly influences colloidal sphere ordering during self-assembly. Interactions with substrates control sphere mobility, impacting crystal growth and leading to ordered or disordered structures based on chemical conditions.
Area of Science:
- Colloid and Surface Science
- Materials Science
- Nanotechnology
Background:
- Colloidal self-assembly is crucial for fabricating ordered nanomaterials.
- Controlling self-assembly processes is key to achieving desired material properties.
- Understanding the role of surface interactions is vital for predictable assembly.
Purpose of the Study:
- To investigate the impact of surface charge on colloidal sphere ordering during solvent evaporation.
- To elucidate the mechanisms governing colloidal crystal growth in a sessile drop.
- To correlate self-assembly behavior with interparticle and substrate interactions.
Main Methods:
- Direct video monitoring of dynamic colloidal self-assembly in a sessile drop.
- In situ observation of colloidal sphere movement and arrangement.
- Systematic variation of surface charge and surfactant conditions.
Main Results:
- Surface charge critically affects colloidal sphere mobility during convective self-assembly.
- Ordered and disordered colloidal crystal growth patterns were observed.
- Self-assembly outcomes depend on Coulombic and hydrophobic interactions between spheres and substrates.
Conclusions:
- Surface charge and substrate interactions are key determinants of colloidal self-assembly outcomes.
- Tailoring chemical conditions allows control over the ordering of colloidal spheres.
- This study provides insights into designing self-assembled colloidal structures.
More Related Videos
Related Concept Videos
01:29The Colloidal State
The formation of a colloidal system is exemplified by an aqueous solution containing Cl− ions is introduced to another containing Ag+ ions, resulting in the precipitation of solid AgCl as extremely tiny crystals. Instead of settling out as a filterable precipitate, these crystals remain suspended in the liquid, showcasing a colloidal system.A colloidal system involves colloidal particles within the approximate range of 1 to 1000 nm in at least one dimension, dispersed in a medium called the...
01:09Colloidal precipitates
The high insolubility of some precipitates can result in an unfavorable relative supersaturation. This can lead to colloidal particles with a large surface-to-mass ratio, where adsorption is promoted. For instance, in the precipitation of silver chloride, silver ions are adsorbed on the surface of the colloidal particles, forming a primary layer. This layer attracts ions of opposite charge (such as nitrate ions), forming a diffuse secondary layer of adsorbed ions. This electric double layer...
03:22Colloids
Children at play often make suspensions such as mixtures of mud and water, flour and water, or a suspension of solid pigments in water known as tempera paint. These suspensions are heterogeneous mixtures composed of relatively large particles that are visible to the naked eye or can be seen with a magnifying glass. They are cloudy, and the suspended particles settle out after mixing. On the other hand, a solution is a homogeneous mixture in which no settling occurs and in which the dissolved...
01:16Precipitate Formation and Particle Size Control
In precipitation gravimetry, the precipitating agent should react specifically or selectively with the analyte. While a specific reagent reacts with the analyte alone, a selective reagent can react with a limited number of chemical species.
The obtained precipitate should be either a pure substance of known composition or easily converted to one by a simple process, such as ignition or drying. In addition, the precipitate should be insoluble and easily filterable. In general, filterability...
The obtained precipitate should be either a pure substance of known composition or easily converted to one by a simple process, such as ignition or drying. In addition, the precipitate should be insoluble and easily filterable. In general, filterability...
01:17Colloids and Suspensions
Children at play often make suspensions such as mixtures of mud and water, flour and water, or a suspension of solid pigments in water known as tempera paint. These suspensions are heterogeneous mixtures composed of relatively large particles visible to the naked eye or seen with a magnifying glass. They are cloudy, and the suspended particles settle out after mixing. The suspended particles in a suspension settle out after some time of mixing. The separation of particles from a suspension is...
01:06Coagulation
Colloidal solids are solid particles suspended in solution. They are usually negatively charged, attracting a compact primary layer of positively charged ions, which attract more counterions to form an electrical double layer. Electrostatic repulsion between the charged double layers prevents the particles from colliding, stabilizing the colloids. These solids are often undesirable because they can contain toxins that are difficult to remove. Coagulation is a technique that helps aggregate and...