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Abstract: A biocompatible nanovalve attached to the surface of MCM-41 mesoporous nanoparticles is designed to release encapsulated guest molecules controllably under pH activation. This nanovalve system is comprised of α-cyclodextrin (α-CD) rings that encircle p-anisidino linkers, and can be tuned to respond under specific pH conditions through chemical modification of the linkers. One of the distinctive features of this functional nanovalve system lies in its excellent bio-stability and durability in cell culture medium solution, the binding between the α-CD and p-anisidino groups was not interrupted or disintegrated by the proteins in the DMEM solution without adjusting the pH value. Luminescence spectroscopy demonstrates that the on-command pH-activated system displays very good bio-stability—no drug leakage at pH ∼7.4 and excellent drug release performance not only in H2O but also in cell culture medium at pH ∼5.5. [Copyright &y& Elsevier]

Abstract: A hollow sphere neodymium embedded mesoporous silica material (NEMS) has been synthesized successfully by using neutral 1,12-diaminododecane as template and embedding Nd into the framework simultaneously. It is interesting that a lamellar structured material with MSU-V structure was obtained if only DADD was used as template without embedding of Nd. The synthesized materials were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), BET method, thermal gravimetry/differential thermal analysis (TG/DTA), and X-ray photoelectron spectroscopy (XPS). The hollow sphere morphology was observed by TEM images and clearly revealed the structure of NEMS molecular sieves. Both XRD and XPS results confirmed that the Nd atoms were incorporated into the framework of mesoporous materials. The TG/DTA results verified the good thermal stability of the synthesized NEMS material. The surface area of samples with Si/Nd molar ratio from 10 to 60 reached from 543 to 1103m2 g−1, respectively. It also found that the Nd embedded mesoporous silica material showed good catalytic activity and selectivity towards the oxidation of styrene, proportional to the neodymium content in the catalysts. [Copyright &y& Elsevier]