4th Biennial International Workshop in Russia “Fullerenes and Atomic Clusters”. St. Petersburg, October 4-8, 1999.
FORMATION OF LANGMUIR-BLODGETT FILMS FROM THE FULLERENE C60 WITH THE GRAFTED POLYMER CHAINS
S.I. Goloudina and B.M.Ginzburg
Electrotechnical University, Microtechnology and Diagnostics Centre;
Institute for Problems in Mechanical Engineering, Russia
Langmuir-Blodgett films made from Ceo fullerene with grafted polymer chains-polysterene and polyethylene oxide- are obtained for the first lime- The Langmuir-Blodgett films are obtained by the transfer of Langmuir films onto the substrates of single-crystal silicon. The Langmuir-Blodgett films and the single-layer Langmuir-Blodgett films of C60 with grafted polysterene are nonuniform over the thickness and form a network consisting of aggregates with a size of < 6mkm. The Langmuir films of C60 with grafted polyethylene oxide are much more uniform.
Thanks to elasticity of the films of C60 with grafted polyethylene oxide (in contrast to the brittle Langmuir films of C60 and C70 with grafted polysterene), they are easily transferred to a solid substrate by Langmuir-Blodgett method. The films were transferred by only moving the substrates upward, i.e., a so-called Z-type transfer was observed.
The transfer coefficient (equal to the ratio) of the change in area of a monolayer at the time of transfer to the area of the substrate surface) was 0.9-1.0 in the transfer of the first layer and then gradually decreased.
The transfer pressure corresponded to different degrees of compression of the Langmuir films. The Langmuir-Blodgett films (10 and 20 layers), obtained at a pressure of 10 mN/m, had wetting angles for water of 70 - 75°, while the films obtained at a pressure of 20 mN/m had a wetting angle of 90°. It can be supposed that increasing the pressure causes changes in the structure of the film and in the surface free energy. Inspection under an optical microscope did not reveal any visible disruption of the uniformity of the films.
S.I. Goloudina and B.M.Ginzburg. Formation of langmuir-blodgett films from the fullerene C60 with the grafted polymer chains // 4th Biennial International Workshop in Russia “Fullerenes and Atomic Clusters”. St. Petersburg, October 4-8, 1999, p. 289