Related Experiment Video
Updated: Jul 23, 2025
06:31
Studying Surfactant Effects on Hydrate Crystallization at Oil-Water Interfaces Using a Low-Cost Integrated Modular Peltier Device
Published on: March 18, 2020
6.4K
Effect of Colloidal Surface Charge on Desiccation Cracks
Sanket Kumar1,2,3, Madivala G Basavaraj2,3, Dillip K Satapathy1,3
1Soft Materials Laboratory, Department of Physics, IIT Madras, Chennai 600036, India.
Langmuir : the ACS Journal of Surfaces and Colloids
|July 14, 2023
Summary
Colloid drying cracks differ based on particle charge. Positively charged colloids form wider, more spaced cracks that grow faster than negatively charged ones, influenced by particle interactions.
Area of Science:
- Colloid science
- Materials science
- Surface chemistry
Background:
- Desiccation cracks form in colloidal deposits during drying.
- Crack patterns are influenced by material properties and drying conditions.
- Understanding crack formation is crucial for material stability and applications.
Purpose of the Study:
- To investigate the effect of colloid polarity and surface charge density on desiccation crack nucleation and growth kinetics.
- To correlate crack patterns with particle arrangement and interactions.
Main Methods:
- Controlled drying of colloidal suspensions with varying surface charges.
- Microscopic analysis of crack patterns (spacing, opening).
- Kinetic analysis of crack growth over time.
Main Results:
- Positively charged colloid deposits exhibit higher crack spacing and opening compared to negatively charged ones.
- Crack growth kinetics are faster for positively charged particle deposits.
- Decreasing surface charge density increases crack spacing, opening, and widening rate.
Conclusions:
- Colloid surface charge and polarity significantly influence desiccation crack formation and kinetics.
- Particle arrangement, driven by substrate-particle and particle-particle interactions, dictates distinct crack patterns.
- Surface charge density is a key parameter controlling crack characteristics in drying colloids.
More Related Videos
Related Concept Videos
01:09Colloidal precipitates
625
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...
625
03:22Colloids
17.6K
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...
17.6K
01:09Theories of Dissolution: The Danckwerts' Model and Interfacial Barrier Model
343
Various dissolution theories provide insight into the factors that influence the dissolution rate. Danckwerts' Model suggests that turbulence, rather than a stagnant layer, characterizes the dissolution medium at the solid-liquid interface. In this model, the agitated solvent contains macroscopic packets that move to the interface via eddy currents, facilitating the absorption and delivery of the drug to the bulk solution. The regular replenishment of solvent packets maintains the...
343
01:23Factors Affecting Dissolution: Particle Size and Effective Surface Area
895
Dissolution kinetics, an essential aspect of oral drug delivery, is significantly influenced by the drug's particle size. According to the Noyes-Whitney dissolution model, the dissolution rate correlates directly with the drug's surface area. The larger the surface area, the higher the drug's solubility in water, leading to a faster drug dissolution rate. Reducing particle size increases the effective surface area, enhancing the dissolution process. Micronization and nanosizing are...
895
02:57Surface Tension, Capillary Action, and Viscosity
28.1K
Surface Tension
The various IMFs between identical molecules of a substance are examples of cohesive forces. The molecules within a liquid are surrounded by other molecules and are attracted equally in all directions by the cohesive forces within the liquid. However, the molecules on the surface of a liquid are attracted only by about one-half as many molecules. Because of the unbalanced molecular attractions on the surface molecules, liquids contract to form a shape that minimizes the number...
The various IMFs between identical molecules of a substance are examples of cohesive forces. The molecules within a liquid are surrounded by other molecules and are attracted equally in all directions by the cohesive forces within the liquid. However, the molecules on the surface of a liquid are attracted only by about one-half as many molecules. Because of the unbalanced molecular attractions on the surface molecules, liquids contract to form a shape that minimizes the number...
28.1K
01:20Microcracking in Concrete
151
Microcracking in concrete refers to the tiny cracks that can form within the material even before any external load is applied. These microcracks typically occur at the interface between the coarse aggregate and the hydrated cement paste, often as a result of differential volume changes prompted by variations in stress-strain behavior, as well as thermal and moisture movement. Initially, these microcracks remain stable and do not grow substantially until the concrete is stressed to about 30...
151