Micellization of poly(ethylene glycol)-block-poly(4-vinylpyridine) (PEG114-b-P4VP61) induced by 5,10,15,20-tetrakis-(4-sulfonatophenyl)-porphyrin (TPPS) in acidic solutions were studied by dynamic and static light scattering, atomic force microscope, and UV-vis spectroscopy. The resultant complex micelles had a core-shell structure with the electrostatically complex TPPS/P4VP as the core and the soluble PEG as the shell. The anionic TPPS in the micellar core formed J-aggregates at pH 1.5-2.5 and H-aggregates at pH 3.0-4.0, respectively. Interconversion between the J-aggregates and the H-aggregates was carried out by adjusting the pH value of the micelle solutions. It is worth noting that the micelles showed strong split Cotton effect in the circular dichroism spectra although TPPS and the copolymer were all achiral. The resulting chirality sign could be selected by the hydrodynamic forces of a stirring vortex. Positive or negative chiral signals appeared when stirring clockwise or anticlockwise.

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At room temperature, diblock copolymers of PLA-b-PNIPAM and PEG-b-PLA self-assembled into complex micelles with a PLA core and a mixed PEG/PNIPAM shell. By increasing the temperature, these complex micelles could be converted into a core-shell-corona structure composed of a PLA core, a collapsed PNIPAM shell and a soluble PEG corona, and the PEG chains stretched from the inner core to outside, leading to the formation of PEG channels. The PEG channels could be used for the exchange of substance between the core and the external environment. Compared with core-shell micelles, complex micelles with a core-shell-corona structure could avoid the burst diffusion in the release of ibuprofen and inhibit the degradation of PLA by lipase to a certain extent.

Chiral complex micelles prepared by 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin (TPPS) and the poly(ethylene glycol)-block-poly(4-vinylpyridine) (PEG114-b-P4VP61) in the presence of aspartic acid (Asp), tryptophan (Trp), and lysine (Lys) were investigated in aqueous solutions at pH 2.0. TPPS formed J-aggregates in the micellar core. The morphology and optical properties of the complex micelles depended on the properties of amino acids and the preservation time for the mixed solutions of TPPS and amino acids before adding the copolymer. Prolonging the preservation time, the spherical morphology of the complex micelles remained unchanged in the presence of the Asp. On the contrary, a morphology evolution from sphere to rod took place for Trp and Lys. The intensity of the circular dichroism (CD) signals of the complex micelles increase with the preservation time, and the chirality sign was determined by amino acids. l-Trp and l-Lys led to a negative chirality sign and l-Asp a positive one while the corresponding enantiomers contributed to the opposite sign. Lower concentration of amino acids could not transfer their chirality to the aggregates of TPPS, and at higher concentrations of TPPS, it took more time for the aggregates to express the chiral information on amino acids.