Surface dilational moduli of poly (ethylene oxide), poly (methyl methacrylate), and their blend films

Surface dilational moduli of latex-particle monolayers spread at air–water interface

“…We note that the magnitude of E 00 is larger than that of E 0 for all surface pressures examined, indicating that the latex-particle monolayer spread at the air-water interface behaves as liquid-like viscoelastic matter. However, poly(vinyl acetate) (PVAc) [14,15], poly(methyl methacrylate) (PMMA) [15,16], and poly(ethylene oxide) [16] spread at the air-water interface behave as solid-like viscoelastic materials, for which E 0 is larger than E 00 , irrespective of the surface pressure.…”

“…Among the former methods, a simple oscillatory barrier compression-expansion method permits the imposition of an oscillatory dilational strain on a spread monolayer and the measurement of the surface dilational modulus through the use of a surface pressure measurement apparatus. Recently, such a method has been used to obtain the surface dilational moduli of monolayers of proteins [7][8][9], polymers [10][11][12], and blend polymers [13][14][15][16] spread at the air-water interface.…”

Nonlinear dynamics in experimental devices with compressed/expanded surfactant monolayers

“…If local equilibrium is assumed, then the system should exhibit reversible dynamics in the compression/expansion cycles. In particular, the experiments carried out by Hilles et al (2007) show that the oscillatory motions of the barriers lead to hysteresis cycles, whose area increases with the strain amplitude; see also the experimental results by Kato and Kawaguchi (2012) and Kobayashi and Kawaguchi (2013). This irreversible behavior is sometimes attributed to non-equilibrium effects related to physico-chemical properties of the surfactant, like for example phase-changes in the monolayer.…”

“…Equations (25)-(27) apply in the limit co ~ 1, which is relevant in some experimental runs (Kato andKawaguchi 2012, Kobayashi andKawaguchi 2013) and will be pursued elsewhere. Here, instead, we further simplify these equations, concentrating in the limit ««1,…”

“…Equations ( 25)-( 27) apply in the limit ω ∼ 1, which is relevant in some experimental runs (Kato andKawaguchi 2012, Kobayashi andKawaguchi 2013) and will be pursued elsewhere.…”