Tuning the Magnetization of Manganese (II) Carbonate by Intracrystalline Amino Acids

Interfacial Supra-Assembly of Copolymer Nanoparticles Enables the Formation of Nanocomposite Crystals with a Tunable Internal Structure

It is highly desirable but technically challenging to precisely control the spatial composition and internal structure of crystalline nanocomposite materials, especially in a one-pot synthetic route. Herein, we demonstrate a versatile pathway to tune the spatial distribution of guest species within a host inorganic crystal via an incorporation strategy. Specifically, well-defined block copolymer nanoparticles, poly(methacrylic acid)x-block-poly(styrene-alt-N-phenylmaleimide)y [PMAAx-P(St-alt-NMI)y], are synthesized by polymerization-induced self-assembly. Such anionic nanoparticles can supra-assemble onto the surface of larger cationic nanoparticles via an electrostatic interaction, forming colloidal nanocomposite particles (CNPs). Remarkably, such CNPs can be incorporated into calcite single crystals in a spatially controlled manner: the depth of CNPs incorporation into calcite is tunable. Systematic investigation indicates that this interesting phenomenon is governed by the colloidal stability of CNPs, which in turn is dictated by the PMAAx-P(St-alt-NMI)y adsorption density and calcium ion concentration. This study opens up a general and efficient route for the preparation of a wide range of crystalline nanocomposite materials with a controlled internal composition and structure.

Synergistic Effect of Hydroxyl and Carboxyl Groups on Promoting Nanoparticle Occlusion within Calcite

Direct occlusion of guest nanoparticles into host crystals enables the straightforward preparation for various of nanocomposite materials with emerging properties. Therefore, it is highly desirable to elucidate the 'design rules' that govern efficient nanoparticle occlusion. Herein, a series of sterically-stabilized nanoparticles are rationally prepared, where the surface stabilizer chains of such nanoparticles are composed of either poly(methacrylic acid), or poly(glycerol monomethacrylate), or poly((2-hydroxy-3-(methacryloyloxy)propyl)serine). Systematic investigation reveals that hydroxyl groups and carboxyl groups play a synergistic role in driving nanoparticle incorporation into calcite crystals, where the hydroxyl groups enhance colloidal stability of the nanoparticles and the carboxyl groups provide binding sites for efficient occlusion. The generality of these findings is further validated by extending it to polymer-stabilized gold nanoparticles. This study demonstrates that precision synthesis of polymer stabilizers comprising of synergistic functional groups can significantly promote nanoparticle occlusion, thus enabling the efficient construction of organic-inorganic hybrid materials via nanoparticle occlusion strategy.