The key difference between steric and electrostatic stabilization is that steric stabilization is applied to both aqueous and non-aqueous systems, whereas electrostatic stabilization is applied only to aqueous systems.
We can combine steric stabilization and electrostatic stabilization to maintain nanoparticle stability in solutions. These types of stabilization are generally provided through ionic surfactants. If we use a polymeric surfactant, both steric and electrostatic stabilizing effects tend to combine in one molecule. Steric stabilization is a process in which adsorbed nonionic surfactants or polymers produce a strong repulsion between the particles and droplets in a dispersion. Electrostatic stabilization, on the other hand, is the mechanism in which the attraction forces (Van der Waals) are counterbalanced by the repulsive Coulomb forces that are acting between the negatively charged colloidal particles.
CONTENTS
1. Overview and Key Difference
2. What is Steric Stabilization
3. What is Electrostatic Stabilization
4. Steric vs Electrostatic Stabilization in Tabular Form
5. Summary – Steric vs Electrostatic Stabilization
What is Steric Stabilization?
Steric stabilization is a process in which adsorbed nonionic surfactants or polymers produce a strong repulsion between the particles and droplets in a dispersion. This term is also used in nanotechnology. The adsorption of large molecules, including surfactants or polymers, on the nanoparticle surface can prevent aggregation, and this process is called steric stabilization. In other words, it is the reduction in particle interaction via a surface steric barrier.
The importance of steric stabilization is a leading factor when using polymeric amphiphiles as surfactants that can cover and stabilize the globules by adsorbing them onto the external interface. The steric stabilization tends to arise as a result of polymer adsorption onto the surface of particles.
Figure 01: Steric Stabilization and Gel Network Stabilization in Colloids
According to steric stabilization criteria, the dispersant tail has to be soluble in the polymer or be compatible with it. Moreover, solubility is usually based on the principle “like dissolves like”. This means the dispersant tail and the polymer need to have a similar polarity and similar solubility parameter.
What is Electrostatic Stabilization?
Electrostatic stabilization can be described as the mechanism in which the attraction forces (Van der Waals) are counterbalanced by the repulsive Coulomb forces that are acting between the negatively charged colloidal particles.
A colloidal stabilizer is a type of stabilizer that can provide a significant repulsion between the individual dispersed particles, which makes the hetero-phase system kinetically stable. This is typically accomplished by electrostatic or steric stabilization.
What is the Difference Between Steric and Electrostatic Stabilization?
Steric stabilization and electrostatic stabilization are two related terms. Steric stabilization is a process in which adsorbed nonionic surfactants or polymers produce a strong repulsion between the particles and droplets in a dispersion. Electrostatic stabilization, on the other hand, is the mechanism in which the attraction forces are counterbalanced by the repulsive Coulomb forces that are acting between the negatively charged colloidal particles.
The key difference between steric and electrostatic stabilization is that steric stabilization is applied to both aqueous and non-aqueous systems, whereas electrostatic stabilization is applied only to aqueous systems.
Below is a summary of the difference between steric and electrostatic stabilization in tabular form for side by side comparison.
Summary – Steric vs Electrostatic
Steric stabilization is a process in which adsorbed nonionic surfactants or polymers produce a strong repulsion between the particles and droplets in a dispersion. Electrostatic stabilization, on the other hand, is the mechanism in which the attraction forces (Van der Waals) are counterbalanced by the repulsive Coulomb forces that are acting between the negatively charged colloidal particles. The key difference between steric and electrostatic stabilization is that steric stabilization is applied to both aqueous and non-aqueous systems, whereas electrostatic stabilization is applied only to aqueous systems.
Reference:
1. “Steric Stabilization.” An Overview | ScienceDirect Topics.
Image Courtesy:
1. “ComparisonStericStab-ShearThinningFluids2” By SunKart at English Wikipedia (CC BY 3.0) via Commons Wikimedia