Interpolymer Complexes Based on the Core/Shell Micelles. Interaction of Polystyrene-block-poly(methacrylic acid) Micelles with Linear Poly(2-vinylpyridine) in 1,4-Dioxane Water Mixtures and in Aqueous Media

Abstract

The size and structural changes of nanoparticles formed after the addition of poly(2-vinylpyridine), PVP, to block copolymer micelles of polystyrene-block-poly(methacrylic acid), PS-PMA, were studied by light scattering and atomic force microscopy. Due to the strong hydrogen bonding between PVP and PMA segments, complex structures based on the core/shell micelles form in mixed selective solvents. As proven by a combination of light scattering and atomic force microscopy, individual PS-PMA micelles are "glued" together by PVP chains. The dialysis against solvents with a high content of water results in transient increase in polydispersity and turbidity of originally clear solutions. However, the precipitated polymer material dissolves in basic buffers and stable soluble nanoparticles reform in aqueous media. The behavior of their solutions was studied in a broad pH range by light scattering, atomic force microscopy and capillary zone electrophoresis.

Polyion Complex Nanomaterials from Block Polyelectrolyte Micelles and Linear Polyelectrolytes of Opposite Charge. 2. Dynamic Properties

“…19 We and others have shown that under such conditions nonstoichiometric BIC are formed, which have a multilayer structure with a hydrophobic nonionic core, insoluble polyion complex layer, and hydrophilic shell of the excessive polyelectrolyte. [12][13][14][15][16][17][18] It was of interest to compare such complexes with soluble nonstoichiometric IPEC formed by linear homopolymers. 4 Unlike BICs, nonstoichiometric IPECs usually do not form core-shell aggregates.…”

“…Interaction of PSMs with oppositely charged linear polyelectrolytes, such as PEVP or poly(sodium carboxylates), can lead to formation of water-soluble nanosized complexes. [12][13][14][15][16][17][18][19] Such complexes have a multilayer structure with a hydrophobic nonionic core, intermediate water-insoluble polyion complex layer, and surrounding hydrophilic shell of the excessive polelectrolyte. [12][13][14][15][16][17][18] Previous work 19 has studied the dispersion stability of such BICs in aqueous media as a function of the composition and chemical nature of the reacting polyelectrolytes.…”

Multilayer Polymeric Nanoparticles Based on Specific Interactions in Solution: Polystyrene-block-poly(methacrylic acid) Micelles with Linear Poly(2-vinylpyridine) in Aqueous Buffers

“…Finally, a dialysis of turbid water-rich mixtures in basic aqueous buffers results in the dissolution of polymer complexes in the form of soluble nanoparticles. Our previous study also shows that PS-PMA/PVP nanoparticles with a various PVP-to-PMA ratio are stable in a broad range of pH [3].…”

“…In our recent article [3], we described a simple strategy how one can prepare relatively stable micelles containing both weak polyacid, that is, poly(methacrylic acid) (PMA), and weak polybase, that is, poly(2-vinylpyridine) (PVP), with kinetically frozen polystyrene (PS) core, by dialysis from 1,4-dioxane-rich solutions into water. We took advantage from the fact that PMA forms a very stable complex with PVP in organic media, e.g., in 1,4-dioxanerich aqueous solvents.…”

“…The classical methods used in our work are represented by static and dynamic light scattering (SLS and DLS) and atomic force microscopy (AFM) for overall characterization, similarly as in our recent article [3]. The new approach of the present study includes less common experimental methods as pyrene-fluorescence measurements for studying of hydrophobic nanodomains within the micelles and capillary zone electrophoresis (CZE) to reveal a structure and charge of the micellar shell.…”