Publications


Title : An Overshoot-Hump in a pi-A Curve and the Cooperative Aggregation among Dinitrophenyl Moieties in Phospholipids at an Air/Water Interface

Language: English
Type: Article
Authors: Masakazu Makino, C. Sasaki, K. Nakamura, Mamoru Kamiya and Kenichi Yoshikawa
Journal: Progress in Colloid and Polymer Science
ISSN: 0340-255X
Volume: 106
Year: 1997
Actual year: 1997
Pages: 215-218
doi:   10.1007/bfb0111019
Abstract: We observed the surface pressure (pi) - surface area (A) curves of the DNP-DPPE monolayers at an air/water interface. An overshoot-hump and an inflection point were markedly shown in the pi-A curve with a successive compression. To elucidate the mechanism of the characteristic changes in the curve, we measured the absorption spectra of the thin film which was deposited on a quartz plate using a Langmuir-Blodgett (LB) technique. It was found that the maximum peak in the spectrum shifted to longer wavelengths at 3 nm in the subsequent overshoot-hump, and that the peak intensity increased threefold after the inflection point. Therefore, it was considered that the overshoot-hump indicated a change of the conformation of the dinitrophenyl moiety in the DNP-DPPE molecule at an air/water interface, and that the inflection point reflected a collapse of the DNP-DPPE monolayer, respectively. To explain the mechanism of the overshoot-hump, we established a kinetic model which included a cooperative aggregation process between DNP-DPPE molecules during compression. The overshoot-hump was successfully reproduced with the help of computer simulation on the basis of this kinetic model.

"An Overshoot-Hump in a pi-A Curve and the Cooperative Aggregation among Dinitrophenyl Moieties in Phospholipids at an Air/Water Interface"

Masakazu Makino, C. Sasaki, K. Nakamura, Mamoru Kamiya and Kenichi Yoshikawa, Progress in Colloid and Polymer Science, 106, 215-218 (1997)