The interaction of amphiphilic alternating copolymers of sodium maleate and dodecyl vinyl ether (Mal/C12) with a nonionic surfactant, Triton X-100 (TX), was investigated by frontal analysis continuous capillary electrophoresis (FACCE). The binding isotherms obtained from FACCE data were indicative of weak cooperative interaction for all the polymers examined. The cooperative interaction was also analyzed by the Hill model, and the results were compared with the previous results on the interaction of statistical copolymers of sodium 2-acrylamido-2-methylpropanesulfonate and N-dodecylmethacrylamide with TX. 1. Introduction Interactions between amphiphilic polymers and surfactants have attracted increasing interest from researchers in the last two or three decades because they are considered as simple model systems for colloid-colloid interactions, which are important in biological systems and various applications [1–7]. The interactions of amphiphilic polymers with surfactants have been investigated so far by various techniques [1], including equilibrium dialysis [8, 9], turbidimetry [10–12], viscometry [10, 13, 14], light scattering [10, 15], and fluorescence [10, 13, 15–17]. Frontal analysis continuous capillary electrophoresis (FACCE) is a powerful tool to investigate the association equilibrium of colloidal species because it allows ones to obtain binding isotherms, which are fundamental data for detail understanding on colloid-colloid interactions, in a short time period using a small amount of samples [18]. FACCE has been utilized mainly for binding equilibrium of protein-polymer systems [19–28]. To our knowledge, however, FACCE studies on the polymer-surfactant interaction have been still scarce [29, 30]. In the preceding study, the interaction of statistical copolymers of sodium 2-acrylamido-2-methylpropanesulfonate and N-dodecylmethacrylamide {A/C12(x), where x denotes the mol% content of N-dodecylmethacrylamide} with a nonionic surfactant, Triton X-100 (TX, Scheme 1), was investigated by FACCE [29]. The binding isotherms obtained using the FACCE data indicated that the binding of TX was weakly cooperative for the whole x range (x = 10–60 mol%) and A/C12(x) polymers of x > ca. 50？mol% exhibited higher cooperativity than did A/C12(x) copolymers of x < ca. 40？mol%. In this work, we have further studied on the interaction of an alternating copolymer of sodium maleate and dodecyl vinyl ether (Mal/C12, Scheme 1) with TX and compared the Mal/C12-TX interaction with the our previous study in order to investigate the effect of the polymer structure on
References
[1]
J. C. T. Kwak, Polymer-Surfactant Systems, vol. 77, Marcel Dekker, New York, NY, USA, 1998.
[2]
B. J？nsson, B. Lindman, K. Holmberg, and B. Kronberg, Surfactants and polymers in aqueous solution, Wiley & Sons, Chichester, UK, 1998.
[3]
R. S. Farinato and P. L. Dubin, Colloid-Polymer Interactions. From Fundamentals to Practice, Wiley & Sons, New York, NY, USA, 1999.
[4]
F. M. Winnik, H. Ringsdorf, and J. Venzmer, “Interactions of surfactants with hydrophobically modified poly (N-isopropylacrylamides). 1. Fluorescence probe studies,” Langmuir, vol. 7, no. 5, pp. 905–911, 1991.
[5]
F. M. Winnik, H. Ringsdorf, and J. Venzmer, “Interactions of surfactants with hydrophobically modified poly (N-isopropylacrylamides). 2. Fluorescence probe studies,” Langmuir, vol. 7, no. 5, pp. 912–917, 1991.
[6]
E. D. Goddard and P. S. Leung, “Interaction of cationic surfactants with a hydrophobically modified cationic cellulose polymer,” Langmuir, vol. 8, no. 5, pp. 1499–1500, 1992.
[7]
F. M. Winnik, S. T. A. Regismond, and E. D. Goddard, “Interactions of cationic surfactants with a hydrophobically modified cationic cellulose polymer: a study by fluorescence spectroscopy,” Colloids and Surfaces A, vol. 106, no. 2/3, pp. 243–247, 1996.
[8]
C. Holmberg and L. O. Sundel？f, “Temperature dependence of hydrodynamic properties and surfactant-polymer interaction in solution. The EHEC/SDS/water system,” Langmuir, vol. 12, no. 4, pp. 883–889, 1996.
[9]
C. Holmberg, S. Nilsson, and L. O. Sundel？f, “Thermodynamic properties of surfactant/polymer/water systems with respect to clustering adsorption and intermolecular interaction as a function of temperature and polymer concentration,” Langmuir, vol. 13, no. 6, pp. 1392–1399, 1997.
[10]
A. Hashidzume, T. Ohara, and Y. Morishima, “Coacervation of hydrophobically modified polyanions by association with nonionic surfactants in water,” Langmuir, vol. 18, no. 24, pp. 9211–9218, 2002.
[11]
H. Bu, A. L. Kj？niksen, A. Elgsaeter, and B. Nystr？m, “Interaction of unmodified and hydrophobically modified alginate with sodium dodecyl sulfate in dilute aqueous solution,” Colloids and Surfaces, A, vol. 278, no. 1-3, pp. 166–174, 2006.
[12]
A. L. Kj？niksen, A. Laukkanen, H. Tenhu, and B. Nystr？m, “Anomalous turbidity, dynamical, and rheological properties in aqueous mixtures of a thermoresponsive pvcl-g-c11eo42 copolymer and an anionic surfactant,” Colloids and Surfaces A, vol. 316, no. 1–3, pp. 159–170, 2008.
[13]
O. Anthony and R. Zana, “Interactions between water-soluble polymers and surfactants: Effect of the polymer hydrophobicity. 2. Amphiphilic polyelectrolytes (polysoaps),” Langmuir, vol. 12, no. 15, pp. 3590–3597, 1996.
[14]
G. Zhao, C. C. Khin, S. B. Chen, and B. H. Chen, “Nonionic surfactant and temperature effects on the viscosity of hydrophobically modified hydroxyethyl cellulose solutions,” Journal of Physical Chemistry B, vol. 109, no. 29, pp. 14198–14204, 2005.
[15]
A. Hashidzume, M. Mizusaki, K. Yoda, and Y. Morishima, “Interaction of unimolecular micelles of hydrophobically modified polyelectrolytes with nonionic/ionic mixed surfactant micelles,” Langmuir, vol. 15, no. 12, pp. 4276–4282, 1999.
[16]
O. Anthony and R. Zana, “Interactions between water-soluble polymers and surfactants: effect of the polymer hydrophobicity. 1. Hydrophilic polyelectrolytes,” Langmuir, vol. 12, no. 8, pp. 1967–1975, 1996.
[17]
M. Mizusaki, Y. Morishima, and P. L. Dubin, “Interaction of pyrene-labeled hydrophobically modified polyelectrolytes with oppositely charged mixed micelles studied by fluorescence quenching,” Journal of Physical Chemistry B, vol. 102, no. 11, pp. 1908–1915, 1998.
[18]
J. Y. Gao, P. L. Dubin, and B. B. Muhoberac, “Measurement of the binding of proteins to polyelectrolytes by frontal analysis continuous capillary electrophoresis,” Analytical Chemistry, vol. 69, no. 15, pp. 2945–2951, 1997.
[19]
R. K. Hallberg and P. L. Dubin, “Effect of pH on the binding of β-lactoglobulin to sodium polystyrenesulfonate,” Journal of Physical Chemistry B, vol. 102, no. 43, pp. 8629–8633, 1998.
[20]
J. Y. Gao, P. L. Dubin, and B. B. Muhoberac, “Capillary electrophoresis and dynamic light scattering studies of structure and binding characteristics of protein-polyelectrolyte complexes,” Journal of Physical Chemistry B, vol. 102, no. 28, pp. 5529–5535, 1998.
[21]
J. Y. Gao and P. L. Dubin, “Binding of proteins to copolymers of varying hydrophobicity,” Biopolymers, vol. 49, no. 2, pp. 185–193, 1999.
[22]
T. Hattori, R. Hallberg, and P. L. Dubin, “Roles of electrostatic interaction and polymer structure in the binding of β-lactoglobulin to anionic polyelectrolytes: measurement of binding constants by frontal analysis continuous capillary electrophoresis,” Langmuir, vol. 16, no. 25, pp. 9738–9743, 2000.
[23]
T. Hattori, K. Kimura, E. Seyrek, and P. L. Dubin, “Binding of bovine serum albumin to heparin determined by turbidimetric titration and frontal analysis continuous capillary electrophoresis,” Analytical Biochemistry, vol. 295, no. 2, pp. 158–167, 2001.
[24]
E. Seyrek, P. L. Dubin, C. Tribet, and E. A. Gamble, “Ionic strength dependence of protein-polyelectrolyte interactions,” Biomacromolecules, vol. 4, no. 2, pp. 273–282, 2003.
[25]
M. Girard, S. L. Turgeon, and S. F. Gauthier, “Quantification of the interactions between beta-lactoglobulin and pectin through capillary electrophoresis analysis,” Journal of Agricultural and Food Chemistry, vol. 51, no. 20, pp. 6043–6049, 2003.
[26]
E. Seyrek, T. Hattori, and P. L. Dubin, “Frontal analysis continuous capillary electrophoresis for protein-polyelectrolyte binding studies,” Methods in Molecular Biology, vol. 276, pp. 217–228, 2004.
[27]
T. Hattori, S. Bat-Aldar, R. Kato, H. B. Bohidar, and P. L. Dubin, “Characterization of polyanion-protein complexes by frontal analysis continuous capillary electrophoresis and small angle neutron scattering: Effect of polyanion flexibility,” Analytical Biochemistry, vol. 342, no. 2, pp. 229–236, 2005.
[28]
G. Pouliquen and C. Tribet, “Light-triggered association of bovine serum albumin and azobenzene-modified poly(acrylic acid) in dilute and semidilute solutions,” Macromolecules, vol. 39, no. 1, pp. 373–383, 2006.
[29]
A. Hashidzume, S. I. Watanabe, and Y. Morishima, “Cooperative binding of nonionic surfactant to hydrophobically modified polyanions as studied by frontal analysis continuous capillary electrophoresis,” Langmuir, vol. 23, no. 4, pp. 2191–2197, 2007.
[30]
C. Diab, F. M. Winnik, and C. Tribet, “Enthalpy of interaction and binding isotherms of non-ionic surfactants onto micellar amphiphilic polymers (amphipols),” Langmuir, vol. 23, no. 6, pp. 3025–3035, 2007.
[31]
D. Taura, A. Hashidzume, and A. Harada, “Macromolecular recognition: interaction of cyclodextrins with an alternating copolymer of sodium maleate and dodecyl vinyl ether,” Macromolecular Rapid Communications, vol. 28, no. 24, pp. 2306–2310, 2007.
[32]
D. Taura, A. Hashidzume, Y. Okumura, and A. Harada, “Cooperative complexation of α-cyclodextrin with alternating copolymers of sodium maleate and dodecyl vinyl ether with varying molecular weights,” Macromolecules, vol. 41, no. 10, pp. 3640–3645, 2008.
[33]
M. Ueda, A. Hashidzume, and T. Sato, “Unicore—multicore transition of the micelle formed by an amphiphilic alternating copolymer in aqueous media by changing molecular weight,” Macromolecules, vol. 44, no. 8, pp. 2970–2977, 2011.
[34]
B. Staggemeier, Q. R. Huang, P. L. Dubin, Y. Morishima, and T. Sato, “Determination of the compositional distribution of copolymers by frontal analysis continuous capillary electrophoresis,” Analytical Chemistry, vol. 72, no. 1, pp. 255–258, 2000.
[35]
B. Zhang, T. Hattori, and P. L. Dubin, “Observation of compositional heterogeneity in poly(styrene sulfonate) using frontal analysis continuous capillary electrophoresis,” Macromolecules, vol. 34, no. 19, pp. 6790–6794, 2001.
[36]
B. Zhang, G. F. Kirton, and P. L. Dubin, “Compositional heterogeneity in anionic/nonionic mixed micelles observed by frontal analysis continuous capillary electrophoresis,” Langmuir, vol. 18, no. 12, pp. 4605–4609, 2002.
[37]
J. Collet, C. Tribet, and P. Gareil, “Use of neutral surfactants for the capillary electrophoretic separation of hydrophobically modified poly(acrylic acids),” Electrophoresis, vol. 17, no. 7, pp. 1202–1209, 1996.
[38]
S. F. Y. Li, Capillary Electrophoresis. Principles, Practice, and Applications, vol. 52, Elsevier, Amsterdam, The Netherlands, 1992.
[39]
N. M. van Os, J. R. Haak, and L. A. M. Rupert, Physico-Chemical Properties of Selected Anionic, Cationic and Nonionic Surfactants, Elsevier, Amsterdam, Netherlands, 1993.
[40]
K. Shirahama, K. Kameyama, and T. Takagi, “Bimodality in the dodecylpyridinium bromide-sodium dextran sulfate system as observed by an electrophoretic method,” Journal of Physical Chemistry, vol. 96, no. 16, pp. 6817–6820, 1992.
[41]
A. Y. Tret'yakova, A. V. Bilalov, and V. P. Barabanov, “Potentiometric study of the binding of sodium dodecyl sulfate by vinylpyridine-based synthetic cationic polyelectrolytes in aqueous media,” Vysokomolekulyarnye Soedineniya, Seriya A, vol. 34, no. 5, pp. 86–90, 1992.
[42]
I. Satake and J. T. Yang, “Interaction of sodium decyl sulfate with poly(l-ornithine) and poly(l-lysine) in aqueous solution,” Biopolymers, vol. 15, no. 11, pp. 2263–2275, 1976.
[43]
K. Hayakawa and J. C. T. Kwak, “Surfactant-polyelectrolyte interactions. 1. Binding of dodecyltrimethylammonium ions by sodium dextransulfate and sodium poly(styrenesulfonate) in aqueous solution in the presence of sodium chloride,” Journal of Physical Chemistry, vol. 86, no. 19, pp. 3866–3870, 1982.
[44]
S. Kosmella, J. K？tz, K. Shirahama, and J. Liu, “Cooperative nature of complex formation in mixed polyelectrolyte-surfactant systems,” Journal of Physical Chemistry B, vol. 102, no. 34, pp. 6459–6464, 1998.
[45]
K Shirahama, “The nature of polymer-surfactant interactions,” in Polymer-Surfactant Systems, J. C. T. Kwak, Ed., pp. 143–191, Marcel Dekker, New York, NY, USA, 1998.
[46]
P. Linse, L. Piculell, and P. Hansson, “Models of polymer-surfactant complexation,” in Polymer-Surfactant Systems, J. C. T. Kwak, Ed., pp. 193–238, Marcel Dekker, New York, NY, USA, 1998.
[47]
A. V. Hill, “A new mathematical treatment of changes of ionic concentration in muscle and nerve under he action of electric currents, with a theory as to their mode of excitation,” Journal of Physiology, vol. 40, pp. 190–224, 1910.
[48]
B. H. Zimm and J. K. Bragg, “Theory of the phase transition between helix and random coil in polypeptide chains,” The Journal of Chemical Physics, vol. 31, no. 2, pp. 526–535, 1959.
