European Polymer Congress - 2005. Russia, Moscow, 27.06.2005-01.07.2005
LANGMUIR-BLODGETT FILMS OF RIGID-ROD POLYIMIDE: FORMATION AND APPLICATION
Svetlana Goloudina1*, Viktor Luchinin1, Vyacheslav Pasyuta1, Valentina Sklizkova2, Vladislav Kudryavtsev2
1
State Electrotechnical University (Ulyanova),
2
Institute of Macromolecular Compounds RAS,
Langmuir–Blodgett (LB) multilayer films of rigid-rod polyimide (PI) based on polyamic acid (PAA BPDA-oTD) alkylammonium salt with two multichains of tert. amine (o, o', o''- trihexadecanoyltriethanolamine) were obtained. PI films were formed by the thermal and chemical imidization of LB prepolymer films. Important specific features of the obtained PI are high thermal stability (a 5% weight loss at 560°C) and a low temperature expansion coefficient (0.5×10-5K-1). The characterization of LB films before and after imidization was carried out by various methods such as small angle X-ray scattering (SAXS), X-ray reflection, electron diffraction, ellipsometry, optical and atomic-force microscopy (AFM). It was shown that stable monolayers of densely packed prepolymer chains were formed on the water surface. Polyamic acid salt (PAAS) monolayers were transferred onto silicon substrates. The Y-type structure was observed for the surface pressure in the monolayer ranging within 20–35 mN/m. The results of SAXS and X-ray reflection showed that the orientation of aliphatic chains in the PAAS LB films depends on the deposition surface pressure. The AFM images showed a nano-domain structure of the PAAS and the PI LB films. A considerable difference between the morphology of PAAS LB films prepared at different deposition surface pressure and the morphology of PI obtained by chemical and thermal imidization was found. Thermal imidization leads to the formation of more densely packed polymer chains as revealed by the ellipsometry measurements.
An ultrathin PI membrane on a metal grid matrix was obtained by the Langmuir–Blodgett method for the first time. The PI film on a nickel grid (40×40 µm mesh size) for electron microscopy was formed. The thickness of this film was 70-130 nm. The ratio of the membrane thickness to the grid mesh reaches 1:1000 [1].
Modification of SiO2 surface by the PI films with the thickness of 1.5-4.5 nm lead to increasing negative and positive charges stability [2].
1. V.V.Luchinin, S.I.Goloudina, V.M.Pasyuta, M.F.Panov, I.V.Gofman, V.P.Sklizkova, V.V.Kudryavtsev. Technical Physics Letters, Vol. 31, No. 4, 2005, pp. 341–342.
2. RU 2193255, H01L 21/18, 2002. V.V.Luchinin, D.A.Kozodaev, S.I.Goloudina, V.M.Pasyuta, A.V.Korlyakov, V.I.Zakrgevsky, V.V.Kudryavtsev, V.P.Sklizkova
This work was carried out with partial support of RFBI.
Svetlana Goloudina, Victor Luchinin, Vyacheslav Pasyuta, Valentina Sklizkova, Vladislav Kudryavtsev / Langmuir-Blodgett films of rigid-rod polyimide: Formation and application // European polymer congress. Under the sponsorship of European Polymer Federation, Moscow State University, Russian Academy of Sciences, Russian Foundation of Basic Research. Moscow. 2005. P6.2-6.