Self-Assembly and pH-Responsiveness of ABC Miktoarm Star Terpolymers

Abstract

This work deals with the self-assembly in water of ABC miktoarm star terpolymers consisting of hydrophobic poly(-caprolactone), hydrophilic poly(ethylene oxide) (PEO), and pH-sensitive poly(2-vinylpyridine) (P2VP). A variety of experimental techniques were used, including dynamic light scattering, transmission electron microscopy, and zeta potential. Special attention was paid to the pH dependency of the supramolecular self-assemblies. A key observation is the capability of the miktoarm terpolymers to form micelles stable over the whole range of pH, although a transition was observed from neutral to highly positively charged nanoobjects upon decreasing pH.

Water-Soluble Stimuli Responsive Star-Shaped Segmented Macromolecules

“…pH sensitivity was exhibited from another μ-ABC star terpolymer, consisting of a ionizable P2VP arm, and the hydrophobic PCL and hydrophilic PEO arms [55]. In low pH values, this miktoarm star was able to form micelles comprised of PCL hydrophobic cores surrounded by a mixed corona containing hydrophilic PEO and and positively charged protonated P2VP arms.…”

Self‐Assembly and Photoresponsivity Property of Amphiphilic ABA Triblock Copolymers Containing Azobenzene Moieties in Dilute Solution

“…The micelles are believed to be composed of PA6C blocks as the core and PEG blocks as the corona. Considering the relative lengths of PEG to PA6C, these aggregates could be considered to be more like flowerlike micelles, [14] shown in Figure 3(A). With continuous addition of water, at the ratio of water/THF being 0.30:1, corresponding to point b in Figure 2(B), the polymer chains form mainly vesicle-like aggregates with a size of around 500 nm, shown in Figure 3(B).…”

“…[5] In general, the molecular architecture of block copolymers has a decisive impact on the shape of the aggregate morphology whatever the selective solvent, organic solvents, or water. [14] The diblock copolymers are of popular in investigating their self-assembly behavior in dilute solution, as we known, they form generally fairy small spherical core-shell micelles with a core protected by a shell of solvated blocks. It has been recognized that triblock copolymers can provide an important role in making the phase diagrams more complicated than those observed for diblock copolymers in solution.…”

Temperature‐Sensitive (BA)(AC)2 Miktoarm Star Diblock Copolymer Based on PMMA, PPEGMA, and PNIPAm

“…[1][2][3][4][5][6][7] Compared with their linear counterparts, star polymers exhibit unique morphologies, properties, and functions, [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] especially miktoarm star polymers. [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] This is because a miktoarm star polymer combines different polymer arms into a molecule through a single core. For example, Liu et al [ 15 ] synthesized the ABC miktoarm polymer poly(ethylene oxide)-poly(2-(diethylamino)ethyl methacrylate)-poly(methacrylic acid) (PEG-PDEA-PMAA).…”

“…In high pH solution (basic conditions) the deprotonated P2VP blocks could collapse from the corona onto the core to form PEGcorona and PCL/P2VP-core micelles. [ 16 ] He and coworkers synthesized ABC miktoarm star polymer polystyrenepoly( N -isopropylacrylamide)-poly(2-(dimethylamino)ethyl methacrylate) (PSt-PNIPAm-PDMAEMA). The PSt-PNIPAm-PDMAEMA copolymer could self-assemble into micelles with a PSt-core and PNIPAm/PDMAEMA-shell in aqueous solution.…”