Abstract
Rod-coil molecules of 4,4′-bis[4-methyloxypoly(propyleneoxy)-propyloxy-4′-biphenyloxymethy ]biphenyl with 3, 6, 17, and 22 repeating propylene oxide units (CRC-N) have been investigated for their ability to form organized monolayers on a solid surface. We observed a complete spectrum of molecular reorganizations at variable surface pressure for the CRC-17 molecule. These reversible molecular reorganizations, ranging from separated circular micelles composed of 20-30 molecules to a rectangular lattice of circular micelles with the unit cell of 10.6 × 9.7 nm and further to a perfectly ordered lamellar structure with 6.5 nm periodicity, all are induced by the variation of surface area available for the molecule. We suggest that continuous compression results in folding of water-soluble flexible tails and their desorption from the air-water interface into the water subphase. As a result, the effective content of the rod blocks at the air-water interface is changing continuously from 20% for close to zero surface pressure to 50% in the wake of monolayer collapse, initiating molecular reorganizations predicted by the theoretical models. Variable "effective" composition at the air-water interface for constant chemical composition provides an efficient mechanism for initiation of structural reorganizations within the monolayer.
Original language | English |
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Pages (from-to) | 495-499 |
Number of pages | 5 |
Journal | Langmuir |
Volume | 19 |
Issue number | 3 |
DOIs | |
State | Published - Feb 4 2003 |
ASJC Scopus subject areas
- General Materials Science
- Condensed Matter Physics
- Surfaces and Interfaces
- Spectroscopy
- Electrochemistry