Association in Solution and Adsorption at an Air−Water Interface of Alternating Copolymers of Maleic Anhydride and Styrene

Abstract

The behavior of alternating poly(styrene−maleic anhydride) (SMA) in aqueous solution and at the air−water interface was studied by static and dynamic light scattering, by surface tension measurements, and by transmission electron microscopy (TEM). The variables of interest were the polymer concentration, the molecular weight, and the degree of ionization varied with pH. SMA polymers can associate in aqueous solution. The critical size of SMA in solution ranges from the predicted Gaussian radius of gyration (r g) up to 150 nm. The size of the associates increases with decreasing molecular weight. A maximum in associate size was measured at pH = 6.5, which corresponds to the polymer salt under its monosodium form. A mechanism by which SMA molecules zip together forming a macrocoil made of two molecules in cross section was proposed. SMA molecules also adsorb at the air−water interface, very likely as 2D-coils. An equilibrium links the concentration of SMA in solution and at the air−water interface.

Functional Films of Maleic Anhydride Copolymers under Physiological Conditions

“…This can be attributed to the variation of the ionization state of the copolymer chains together with the high‐interaction strength of the styrene rings leading to a high‐packing density and driving force for the collapse of the films. This observation is in agreement with the recently reported nanocluster formation in solutions of PSMA by changing the pH value 10. For PPMA and PEMA only a slight decrease in swelling is observed.…”

“…In that context, the conformation of the copolymer chains under physiological conditions, i.e., in aqueous electrolyte solutions, is of great interest. In view of the different physicochemical characteristics of the copolymers and their known variation of the ionization state in aqueous solution at varied pH a sensitivity of the chains toward conformational transitions occurs in dependence on the kind of comonomer 8–12. A strong impact of the polymer chain conformation and the availability of reactive groups under physiological conditions can be assumed for the different immobilization strategies of biomolecules onto such surfaces.…”

Nanostructured Complexes of Polyelectrolytes and Charged Polypeptides

“…Among other results, we could show, that the copolyanion of maleic acid with a-methylstyrene (PMA-MS) induced the random coil and that with propylene (PMA-P) resulted in the a-helical conformation, respectively. [8] We suggested therein the existence of preaggregated globular structures of PMA-MS in accordance to [19], which prevented a-helix formation of PLL within PLL/PMA-MS complex particles. Whereas, the unaggregated and more extended structures of PMA-P in solution before complexation with PLL were assumed to favor the a-helical conformation of PLL within PLL/PMA-P complex particles.…”

Polymer–lipid interactions: Biomimetic self-assembly behaviour and surface properties of poly(styrene-alt-maleic acid) with diacylphosphatidylcholines

“…This was perhaps related to the fact that it was mostly ionized in pure water and likely to dissolve in the bulk of the subphase than to spread on the air-water interface. A possible association of PSMA molecules in water was postulated by Garnier and coworkers [32], who proposed a zipper-like association mechanism. They further proposed equilibrium of the SMA polymer chains between the solution and the air-water interface.…”