A pair of oppositely charged diblock copolymers, poly(2-(methacryloyloxy)ethyl phosphorylcholine)-block-poly((3-(methacryloylamino)propyl)trimethylammonium chloride) (PMPC-b-PMAPTAC) and poly(2-(methacryloyloxy)ethyl phosphorylcholine)-block-poly(sodium 2-(acrylamido)-2-methylpropanesulfonate) (PMPC-b-PAMPS), was prepared via reversible addition-fragmentation chain transfer radical polymerization using a PMPC-based macro chain transfer agent. The pendant phosphorylcholine group in the hydrophilic PMPC block has anionic phosphate and cationic quaternary amino groups, which are neutralized within the pendant group. Therefore, the mixing of aqueous solutions of PMPC-b-PMAPTAC and PMPC-b-PAMPS leads to the spontaneous formation of simple core-shell spherical polyion complex (PIC) micelles comprising of a segregated PIC core and PMPC shells. The PIC micelles were characterized using (1)H NMR spin-spin (T2) and spin-lattice relaxation times (T1), diffusion-ordered NMR spectroscopy, static light scattering, dynamic light scattering (DLS), and transmission electron microscopy techniques. The hydrodynamic size of the PIC micelle depended on the mixing ratio of PMPC-b-PMAPTAC and PMPC-b-PAMPS; the maximum size occurred at the mixing ratio yielding stoichiometric charge neutralization. The PIC micelles disintegrated to become unimers with the addition of salts.

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Polymeric micelles consisting of asymmetric triblock copolymers were successfully used for fabrication of robust hybrid nanoparticles with highly biocompatible calcium phosphate shells. The hydrophobic polystyrene core encapsulates hydrophobic fluorescent dyes such as Nile red. The anionic polyacrylic acid provides the site for the mineralization reaction of calcium phosphate. The polyethylene glycol corona stabilizes the hybrid nanoparticles. Fluorescent dyes can be used as imaging agents for determining the location of the nanoparticles and to give an observable indication of drug delivery, while the calcium phosphate shell can enhance the fluorescence of the encapsulated dye.

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A chain transfer agent was immobilized onto the surface of 11-lm diameter silica particles (CPD-SiO 2 ) for use in reversible addition-fragmentation chain transfer (RAFT)-controlled radical polymerization. pH-responsive poly(6-(acrylamido)hexanoic acid) (PAaH)-grafted silica particles (PAaH-SiO 2 ) were prepared via RAFT-controlled radical polymerization using CPD-SiO 2 . Immobilization of the PAaH chains onto the surface of silica particles was confirmed by thermogravimetric analysis, attenuated total reflection-Fourier transfer infrared and scanning electron microscopy measurements. The solubility of PAaH in water is strongly dependent on the pH of the solution. PAaH-SiO 2 was flocculated at pH 3 because of the hydrophobic interaction of the grafted PAaH chains with protonated carboxyl pendant groups. In contrast, PAaH-SiO 2 was dispersed at pH 10 because of electrostatic repulsion between the grafted PAaH chains with pendant carboxylate ions. Millimeter-sized 'liquid marbles' can be prepared using the pH-responsive PAaH-SiO 2 particles. The 'liquid marble' can be transferred intact onto the surface of a neutral or acidic water pool and exhibit long-term stability. When the pH of the water pool becomes alkaline, the 'liquid marble' immediately bursts on the surface of the water pool.

We have developed core-shell-corona-type polymeric micelles that can integrate multiple functions in one system, including the capability of accommodating hydrophobic dyes into core and hydrophilic drug into the shell, as well as pH-triggered drug-release. The neutral and hydrophilic corona sterically stabilizes the multifunctional polymeric micelles in aqueous solution. The mineralization of calcium phosphate (CaP) on the PAA domain not only enhances the diagnostic efficacy of organic dyes, but also works as a diffusion barrier for the controlled release.

We report a novel protocol to prepare titania hollow nanospheres of size about 28 ± 1 nm with micelles of asymmetric triblock copolymers. The hollow particles exhibit unique electrochemical properties in lithium ion rechargeable batteries such as high capacity, very low irreversible capacity loss, and high cycling performance.