Molecular Interfaces

From the Content: Condensed phase are the consequence of intermolecular forces
- Van der Waals forces are short range and weak
- Keesom
- Debye
- London
- Overlap repulsion
- Lennard Jones Potential describes intermolecular attractive and repulsive interaction
MD simulations
- Pair correlation Kirkwood buff MD
Surface tension: Molecules at an interface are differently bound as compared to the bulk
- Measuring surface tensions
- Ring technique
- Pendent drop
- Oscillating bubble devices
- Very low surface tensions: Spinning drop
- Facettes of surface tension: Minimizing surface area
- Steiner Network Problem: calculus of variation
Five laws of interfacial engineering: Minimizing surface free energy
- Hamakerer law: The summation of short range intermolecular interaction lead to strong and long range interaction between colloidal objects
- Kelvin law: There is a barrier in forming new phases
- Young law governs the wetting properties
- Laplace law Cuvature matters
- Gibbs law: reducing G by adsorption
Experimental technique
- Surface force apparatus
- AFM colloidal Probe
- X-ray and neutron reflectometry
- QCM
- Optical reflection techniques
- Nonlinear optical technique of the second order
Classical problems seen in the light of new experiments
- Ions at interface
- Ions may adopt a nonmonotoneous concentration profile
- Interfacial water as a sensitive probe
- Hofmeister effects
- Wetting phenomena
- Microstructures surfaces
- Surving under extrem conditios
- Adsorption phenomena
- Illuminating the molecular architecture
Nonequilibrium states and dynamics
- Surface rheology
- Different time scales need different instrumentations
- Langmuir
- Oscillating drop
- Oscillating bubble
- Foams
Assembly: designing complex molecular architecture
- Layer-by layer technique
- Self assembled monolayers
- Stimuli responsive systems
- Adsorption
- What is at the interface
- How much is at the interface isotherm

Hubert Motschmann and Matthias Hofmann, University of Regensburg, Germany.