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Aggregation of Elongated Colloids in Water.
Lei Wu1, Carlos P Ortiz1, Douglas J Jerolmack1
1Department of Earth and Environmental Science and ‡Department of Physics and Astronomy, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
Langmuir : the ACS Journal of Surfaces and Colloids
|December 10, 2016
Summary
Particle shape significantly influences colloidal aggregation. Elongated particles like asbestos and glass rods form noncompact aggregates, differing from spherical particle dynamics. This finding aids environmental contaminant transport prediction.
Area of Science:
- Colloid and Surface Science
- Environmental Science
- Materials Science
Background:
- Colloidal aggregation is well-studied for spherical particles.
- The impact of particle shape on aggregation is less understood.
- Many industrial and environmental colloids are elongated.
Purpose of the Study:
- To investigate how particle shape affects colloidal aggregation kinetics and structure.
- To compare aggregation of elongated colloids (asbestos, glass rods) with spherical colloids.
- To determine the influence of material properties versus shape on aggregation.
Main Methods:
- Laboratory experiments on aqueous diffusion and aggregation.
- Used natural asbestos fibers and synthetic glass rods (aspect ratio ~5:1).
- Included control experiments with similar-sized glass spheres (~1 μm).
Main Results:
- Elongated particles formed noncompact aggregates.
- Aggregation rates and morphologies differed significantly from spherical monomers.
- Asbestos and glass rod results were similar, highlighting shape's primacy.
- Findings suggest applicability to other elongated colloids like carbon nanotubes/fibers.
Conclusions:
- Particle shape is a primary factor in colloidal aggregation dynamics.
- The aggregation behavior of elongated colloids deviates from classical models.
- Results improve predictions of environmental colloidal contaminant transport and fate.
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