Related Experiment Video
Updated: Jul 2, 2026
09:26
Synthesis and Characterization of Supramolecular Colloids
Published on: April 22, 2016
Solvent-free synthesis of Janus colloidal particles
Shan Jiang1, Mitchell J Schultz, Qian Chen
1Department of Materials Science and Engineering and Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
Langmuir : the ACS Journal of Surfaces and Colloids
|August 22, 2008
Summary
A new solvent-free method synthesizes Janus colloidal particles efficiently. This technique uses vapor-phase chemical modification at a liquid-liquid interface, creating particles with distinct hydrophobic/hydrophilic or charged surfaces.
Area of Science:
- Materials Science
- Colloid Chemistry
- Surface Chemistry
Background:
- Janus particles possess unique properties due to their two distinct surface chemistries.
- Previous synthesis methods often involve multiple steps, solvents, or lower yields.
Purpose of the Study:
- To develop a simple, solvent-free, and efficient method for large-scale Janus colloidal particle synthesis.
- To create both amphiphilic and dipolar Janus particles using a vapor-phase modification approach.
Main Methods:
- Immobilizing silica particles at a molten wax-water interface.
- Chemically modifying exposed particle surfaces using silane vapor.
- Confirming Janus particle geometry via fluorescence microscopy and flow cytometry.
Main Results:
- Successfully synthesized amphiphilic (hydrophobic/hydrophilic) and dipolar (charged) Janus particles.
- Demonstrated strong adsorption of amphiphilic Janus particles at oil-water interfaces.
- Observed assembly of dipolar Janus particles into chains in aqueous solutions.
Conclusions:
- The developed method offers an efficient and scalable route to Janus colloidal particles.
- The synthesized Janus particles exhibit predictable interfacial behavior and self-assembly properties.
More Related Videos
09:55Preparation of Janus Particles and Alternating Current Electrokinetic Measurements with a Rapidly Fabricated Indium Tin Oxide Electrode Array
Published on: June 23, 2017
11:13Creating Sub-50 Nm Nanofluidic Junctions in PDMS Microfluidic Chip via Self-Assembly Process of Colloidal Particles
Published on: March 13, 2016
Related Concept Videos
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...
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...
01:17Colloids 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...
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...
01:06Coagulation
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...