Surface Characteristics of Comblike Copolymers from Hexadecylacrylamide and Acrylic Acid at the Air/Water Interface

Copolymerization of 2,2,3,3,4,4,5,5-octafluoropentyl acrylate (OFPA) and acrylic acid (AA), OFPA and tert-butyl acrylate (t-BA) in presence ofdibenzylcarbonotrithioate (BTC) and polymeric RAFT-agents was studied, reactivity ratios were calculated. It was shown that type of RAFT-agent can influence on chain microstructure of obtained polymers. Aggregation behavior of obtained amphiphilic copolymers with different microstructures at the air/water interface was characterized by the Langmuir monolayer technique. The effect of the microstructureand subphase pH on the isotherm curves were shown.

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Adsorption of Hydrophobically Modified Poly(acrylic acid) Sodium Salt at the Air/Water Interface by Combined Surface Tension and X-ray Reflectivity Measurements

Langmuir ◽

10.1021/la981481r ◽

1999 ◽

Vol 15 (6) ◽

pp. 2112-2119 ◽

Cited By ~ 38

Author(s):

Frédéric Millet ◽

Michael Nedyalkov ◽

Benjamin Renard ◽

Patrick Perrin ◽

Françoise Lafuma ◽

...

Keyword(s):

Surface Tension ◽

Acrylic Acid ◽

Sodium Salt ◽

Water Interface ◽

X Ray ◽

Hydrophobically Modified ◽

Acid Sodium Salt ◽

Air Water Interface ◽

Poly Acrylic Acid

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Surface characteristics of phosphatidylglycerol phosphate from the extreme halophile Halobacterium cutirubrum compared with those of its deoxy analogue, at the air/water interface

Biochemical Journal ◽

10.1042/bj2610377 ◽

1989 ◽

Vol 261 (2) ◽

pp. 377-381 ◽

Cited By ~ 5

Author(s):

P J Quinn ◽

M Kates ◽

J F Tocanne ◽

M Tomoaia-Cotişel

Keyword(s):

Surface Characteristics ◽

Water Interface ◽

Extreme Halophile ◽

Molecular Area ◽

Counter Ions ◽

Nacl Concentration ◽

Air Water Interface ◽

Decreasing Ph ◽

Compression Isotherms ◽

The Relationship

The relationship between area per molecule and surface pressure of monolayers of phosphatidylglycerol phosphate from extreme halophile Halobacterium cutrirubrum and its deoxy analogue, deoxyphosphatidylglycerol phosphate, spread at an air/water interface was examined. The effect of ionization of the primary and secondary acidic functions of the phosphate groups of the two lipids on surface characteristics of compression isotherms was determined by spreading monolayers on subphases with pH values ranging from below the apparent pKa of the primary ionization (pH 0) to greater than that of secondary ionization (pH 10.9). The limiting molecular area increases with decreasing pH below 2. Ionization of the primary phosphate functions of both phospholipids (with bulk pK1 values close to 4) is associated with a marked expansion of the films, as judged by values of limiting molecular area. Ionization of the secondary phosphate functions causes further expansion of the films, with the apparent pK2 of deoxyphosphatidylglycerol phosphate slightly less than that indicated for phosphatidylglycerol phosphate. Values of surface-compressibility modulus calculated from the surface characteristics of the phosphatidylglcerol phosphate monolayers showed that films spread on subphases with a pH of about the apparent pK1 of the primary phosphate functions were the least compressible. Increasing or decreasing subphase pH caused an increase in compressibility; this effect on compressibility was much less with monolayers of deoxyphosphatidylglycerol phosphate at high pH. The effect of inorganic counter-ions on monolayer characteristics of phosphatidylglycerol phosphate was examined by using subphases of NaCl concentrations varying from 0.01 to 1 M. The limiting molecular area was found to increase exponentially with respect to the subphase NaCl concentration.

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