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Polysiloxanes at the air/water interface and after transfer onto substrates
Author(s) -
Kalachev Alexei A.,
Litvinov Victor M.,
Wegner Gerhard
Publication year - 1991
Publication title -
makromolekulare chemie. macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 0258-0322
DOI - 10.1002/masy.19910460152
Subject(s) - polydimethylsiloxane , siloxane , mesophase , monomer , evaporation , layer (electronics) , materials science , surface pressure , molecule , chemical engineering , solvent , compression (physics) , condensation , polymer chemistry , composite material , chemistry , polymer , organic chemistry , thermodynamics , liquid crystal , physics , optoelectronics , mechanics , engineering
Abstract Surface/area isotherms, surface potential measurements and FT‐IR data suggest that polydimethylsiloxane (PDMS) forms an uniform layer at the air/water interface, where each oxygen atom of PDMS is in contact with water and the specific area corresponds ca. 20 Å 2 per monomeric unit. Under compression the PDMS‐layer is reversibly folded from 18 to 5 Å 2 /unit and then collapses irreversibly. Collapse pressure and specific area are dependent on the subphase temperature. Polydiethyl‐siloxane (PDES) forms, after spreading, an island‐like structure which is integrated under compression. Thickness and structure of this PDES‐film is a result of several simultaneous processes: spreading of the molecules, evaporation of solvent and PDES‐mesophase formation. The resulting structure is specifically oriented and is obviously different from the PDES‐bulk in its normal mesophase.