Analysis of counter ions of cyanine dye in Langmuir-Blodgett films by PIXE

Takashi Watanabe, Keisuke Asai, Kenkichi Ishigure, Akira Morita, Seiji Ito, Toshio Kawanishi

Research output: Contribution to journalArticlepeer-review


Langmuir-Blodgett (LB) films of 1-methyl-1′-octadecylquinocyanine bromide, iodide and perchlorate were prepared from subphases containing NaClO4, KBr and/or KI. Each sample consists of an arachidic cadmium layer and about 100 cyanine dye layers on a Si substrate. Anions incorporated into the film as counter ions from the subphase were analyzed by particle induced X-ray emission (PIXE) using a 2.5 MeV He2+ beam. It was found that the dissociation of the cationic dye molecule in the monolayer at the air/water interface leads to the substitution of counter anions of the dye molecules, and the subsequent incorporation of the counter anions in the LB films. Some of the dissociation constants of cyanine halide dyes were estimated.

Original languageEnglish
Pages (from-to)454-460
Number of pages7
JournalNuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
Issue number3
Publication statusPublished - 2000 Oct


Dive into the research topics of 'Analysis of counter ions of cyanine dye in Langmuir-Blodgett films by PIXE'. Together they form a unique fingerprint.

Cite this