Keeping drugs under control: Hydrothermally stable, hollow mesoporous silica spheres have a high drug storage capacity, and polyelectrolyte multilayers coated on the spheres act as a switch for drug release which is controlled by the pH or ionic strength of the release medium. The picture shows the release of ibuprofen (IBU) from spheres with and without coatings of sodium polystyrene sulfonate (PSS) and poly(allylamine hydrochloride) (PAH).

We present an in situ reduction method to synthesize a novel structured MnO(2)/mesoporous carbon (MnC) composite. MnO(2) nanoparticles have been synthesized and embedded into the mesoporous carbon wall of CMK-3 materials by the redox reaction between permanganate ions and carbons. Thermogravimetric analysis (TG), X-ray photoelectron spectrum (XPS), X-ray diffraction (XRD), nitrogen sorption, transmission electron microscopy (TEM), and cyclic voltammetry were employed to characterize these composite materials. The results show that different MnO(2) contents could be introduced into the pores of CMK-3 treated with different concentrations of potassium permanganate aqueous solution, while retaining the ordered mesostructure and larger surface area. Increasing the MnO(2) content did not result in a decrease in pore size from the data of nitrogen sorption isotherms, indicating that MnO(2) nanoparticles are embedded in the pore wall, as evidenced by TEM observation. We obtained a large specific capacitance over 200 F/g for the MnC composite and 600 F/g for the MnO(2), and these materials have high electrochemical stability and high reversibility.

Dosierter Wirkstoffeinsatz: Hohle mesoporöse Siliciumdioxidpartikel verfügen über eine hohe Wirkstoffspeicherkapazität, und Polyelektrolyt‐Mehrfachschichten auf der Partikeloberfläche schalten abhängig vom pH‐Wert oder der Ionenstärke die Wirkstoff‐Freisetzung. Das Schema illustriert die Freisetzung von Ibuprofen (IBU) aus Partikeln mit und ohne Beschichtung aus Natriumpolystyrolsulfonat (PSS) und Poly(allylaminhydrochlorid) (PAH).