Deck C Flashcards
Micelle definition
thermodynamic, random, and non-hierarchical process with molecular length scale.
Main micelle formation driving force
Hydrophobic interactions
Micelle formation process (increasing surfactant concentration)
- Surface and diluted
- Surface and paired dilution
- Monolayer surface (1st) and micelle formation (CMC)
- Monolayer surface and aggregate formation (CMC+)
CMC
Critical Micelle Concentration
The monomer concentration where the first micelle begins to appear
Important micelle parameters
- CMC
- Aggregation number
- Degree of counterion binding on the surface of micelles
CMC range and Micelle diameter
micro to milli molar
2-20 nm
Aggregation number
The number of surfactant or polymer molecules within a micelle (10-10,000)
Degree of Counterion binding
The ratio of counterion bound on the micelle surface to the whole concentration of counterion in the system
CMC Calculation of Mixed Micelle
1/CMC = MoleFraction_A/CMC_A + MoleFraction_B/CMC_B
HLB Calculation of Mixture
HLB = [MoleFraction_A*HLB_A + MoleFraction_B * HLB_B]/M_mix
Qualities of a bilayer monomer
Usually 2 tails
Needs to be cylindrical
Bolaform Surfactant
two head groups connected by hydrophobic tails
Bilayer formation process
Well defined CMC
Finite size
Thermodynamically driven
All micelles for a given surfactant are relatively the same size which is dictated by the size of the polymer.
What determines the unique planar-like structure of a bilayer
molecular geometry of its monomer
Vesicle size
20 nm - 50 um
Thickness of each single layer is 3-5 nm
