Lecture 15 of 48Week 3
Calculation of Vanderwaal's forces between semi-infinite blocks and Hamaker constant - I
Prof. Basavaraj Madivala Gurappa · IIT Madras
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- Colloids and Surfaces, IIT Madras (at NPTEL)
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All the lectures
- Introduction and motivation
- Colloidal dispersions, terminology and classification
- Stability in colloids
- Source, synthesis and characterisation of colloids
- Characterisation of colloidal particles - I
- Characterisation of colloidal particles - II
- Introduction to forces acting on an individual colloidal particle
- Introduction to interaction between colloidal particles
- Application of Brownian force: Measument of diffusivity and size
- Origin of scattering
- Radiation used to study colloidal systems
- Molecular origin of Van der waals forces
- Vanderwaal interactions between particles
- Problem on scaling of Vanderwaal interactions
- Calculation of Vanderwaal's forces between semi-infinite blocks and Hamaker constant - I
- Calculation of Vanderwaal's forces between semi-infinite blocks and Hamaker constant - II
- Theories of Vanderwaal forces based on bulk properties and calculation of Hamaker constant using bulk properties
- Effect of medium on Vanderwaal's interactions - I
- Effect of medium on Vanderwaal's interactions - II
- Colloid Polymer mixtures
- Colloid polymer mixtures: colloid-solvent interactions & colloid-polymer interactions
- Colloid polymer mixtures: Depletion flocculation
- Colloid polymer mixtures: Depletion stabilisation
- Depletion interactions
- Steric interactions/osmotic repulsion
- Tutorial problem on depletion interactions
- Colloidal Interactions: Introduction to electrostatic interactions/electrical double layer interactions
- Introduction to models of electrical double layer: Helmholtz model/capacitor model
- Review and summary of Helmholtz model (or capacitor model) of electrical double layer
- Models of electrical double layer: Diffuse double layer model/Gouy-Chapman model
- Potential distribution near planar surfaces: Derivation of the Poisson-Boltzmann equation
- Potential distribution near planar surfaces: Solution to the linearised Poisson-Boltzmann equation
- Potential distribution near spherical surfaces: Solution to linearised Poisson-Boltzmann equation
- Comparison of Capacitor model and Diffuse double layer model
- Models of electrical double layer: Gouy Chapman Theory - I
- Models of electrical double layer: Gouy Chapman Theory - II
- Structure of Electrical double layer
- Force of Repulsion between interacting surfaces
- Potential Energy of repulsion between Planar double layers and DLVO Theory
- Zeta Potential and Electrophoretic mobility of an ion
- Electrokinetic Phenomena
- Relation between Electrophoretic mobility and Zeta potential - I
- Relation between Electrophoretic mobility and Zeta potential - II
- Colloidal particles at interfaces:Introduction
- Characterization of Particles at interface
- Experimental Observations -Concept of Electrostatic interactions and Stability at interfaces
- Implications from Surface energy balances & Estimation of energy required for detachment
- Colloidal interactions at interface