Shape Diagrams

Shape Diagrams is an app that calculates the morphology of various lipids and polymers in aqueous solution.

The app is aimed at chemists who mix pure lipids and polymeric lipids in lab environment. The app shows at which relative concentration the solution forms micelles, vesicles, or for example gyroid phases.

The app calculates the self-assembly shape of a two-component aqueous solution by minimizing the aggregation free energy. The calculations are done in a continuum version of the packing parameter concept [1] based on molecular curvature [2].

The calculations assume the lipids and polymers are in excess water so for example treating gyroid phases at low water concentrations are not accurately described by the app.

The curvatures of some of the lipids and polymers are estimated from computer simulations and may not be accurate. This means that the phases that the app suggests can have a degree of error. The user is advised to also verify the solution phase also by microscopy.

[1] Jacob N. Israelachvili, Intermolecular and Surface Forces, 2011
[2] Wolfgang Helfrich, Elastic properties of lipid bilayers: theory and possible experiments, Zeitschrift für Naturforschung C, 28 (11): 693–703, 1973