Pentaerythritol-based polyether dendrimers at the air-water interface

Surface pressure versus area isotherms and film relaxation experiments of Langmuir films of second generation, pentaerythritol-based polyether dendrimers were recorded to study the behavior of these molecules at the air-water interface. These dendrimers form highly compressible films at molecular areas between 200 and 700 Angstrom(2) and undergo a collapse to a multilayer film at a surface pressure of approximately 17 mN/m and surface area of 200 Angstrom(2). Empirically, the collapse is found to involve three relaxation times when fit with a series of exponentials. Increasing the temperature from 5 to 20 degrees C increases the collapse rate and the extent of collapse during compression and slightly decreases the collapse pressure from 17.4 to 16.5 mN/m.