Langmuir Monolayer

Langmuir Monolayer helps to prepare and investigate thin monomolecular films, that widely used in scientific and industrial research. Particularly, this application is useful for preparation of lipid monolayers at air-water interface.

This app is a part of Bio- Chemistry and Chemical Engineering Lab Pack including several apps dealing with chemical solutions, reaction equilibrium and kinetics, acid base neutralisation reaction, titration, and liposome and monolayer preparation.

The application supports calculation of final molar concentration, volume, moles and average molar weight of mixture of up to three independent solutions with their optional dilution. Finally, based on calculated parameters of the solution, the application calculates the area per molecule available upon preparation of thin monomolecular film on the given subphase.

First activity, "Mixing solutions", makes it easy to parameterize and prepare complex mixture of several stock solutions.
Second activity, "Analysis", helps with parameterization of monolayer film composed of preliminary prepared complex solution.

Layout of "Mixing solutions". Three input rows are corresponding to the three optional initial stock solutions (of the same or different solutes), which are going to be mixed to produce the final complex solution. Each row consists of the following data fields: solution name (mostly named after main solute), solutes' molar weight, molar concentration in the initial solution and the volume of the initial solution. Last cell represents molar fraction of the particular solute, that will be calculated automatically upon pressing “done” or “enter” key in the keyboard, and may be adjusted later to get the desired component ratio.
Last row represents final solution parameters. First comes the volume of pure solvent that optionally can be added to dilute the solution, then the Total Molarity and Total solution volume, that can be adjusted at any time, on condition that molar concentrations of the initial solution/s are provided.

Layout of "Analysis". The activity window divided to data panel (left) and results panel (right):

The data panel parameters:
Total Concentration: Total solution components’ (lipids, etc..) concentration. Automatically uploaded from Mixing solutions activity and can be corrected at any time.
Added Volume: Solution volume that actually used for monolayer preparation.
Trough Area: Total area of the subphase (water, etc..) surface available for monolayer (in square cm).

The results panel parameters:
Number of Molecules: Total number of components’ molecules in monolayer.
Number of Moles: Total number of components’ moles in monolayer.
Area per Molecule: Average surface area available for single molecule (in square angstroms).

Additional application features.

•Application includes database for storing molecular weights of the frequently used compounds.

•Solution name field is input sensitive and may be auto completed with information stored in the database.

•The application is fully interactive: all system parameters are updated immediately after any input from user (if it is sufficient, otherwise warning will be shown).

•If molecular weights (Mw, units "g/mole") of solutes are provided as well, then the average Mw can be calculated, which is important for monolayer preparation.

Important points.

•The user should follow the simple rule to ensure proper functionality: all known data should be provided in the following order (Only yellow fields are editable): solution or solute nicknames (optional)-> Mw -> initial concentrations (must!)-> volumes (if known)-> molar ratios (if known)-> Total Molarity (if known)-> Total Volume (if known).

•If user updates molar ratios (percent only), program will not start calculations until sum of the ratios will be 100% exactly and obviously, not before than initial concentrations are provided.

•Application assigns dot as a decimal separator.