Open AccessWetting and dynamics of structured liquid films
Author(s) -
Green Peter F.
Publication year - 2003
Publication title -
journal of polymer science part b: polymer physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.65
H-Index - 145
eISSN - 1099-0488
pISSN - 0887-6266
DOI - 10.1002/polb.10601
Subject(s) - wetting , materials science , copolymer , homogeneous , intermolecular force , chemical physics , substrate (aquarium) , degree of polymerization , thin film , polymerization , molecular dynamics , phase (matter) , polymer chemistry , chemical engineering , composite material , nanotechnology , thermodynamics , polymer , chemistry , molecule , physics , computational chemistry , oceanography , organic chemistry , engineering , geology
The stability of a sufficiently thin, supported, homopolymer film against the development of local thickness fluctuations which can become amplified, eventually leading to structural destabilization of the film, is typically determined by long and short‐range intermolecular forces. In A‐B diblock copolymers, the connectivity between the blocks, the preferential attraction of one block to an external interface, combined with an incompatibility between the A‐B segments, the situation is very different. Two cases, largely dictated by χ N , wher χ is the Flory‐Huggins interaction parameter and N is the degree of polymerization, can arise in thin copolyme films. When χ N is large, thin films exhibit comparatively stable topographical structures, where the dimensions of the topographies normal to the substrate reflect a natural length‐scale associated with phase separation in the material. In the other situation, where χ N is sufficiently small, the copolymer bulk structure is homogeneous. An ordered structure can be induced into the otherwise compositionally homogeneous structure in the vicinity of a substrate. Here, depending on film thickness, a series of transient and stable topographies can develop. Wetting, early stage structural destabilization dynamics leading to the formation of droplets, and late stage coarsening of the droplets are discussed. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 2219–2235, 2003