Xiangzhi Cui

Au capped magnetic core/mesoporous silica shell nanoparticles for combined photothermo-/chemo-therapy and multimodal imaging

Uniform Au NRs-capped magnetic core/mesoporous silica shell nanoellipsoids (Au NRs-MMSNEs) were prepared by coating a uniform layer of Au NRs on the outer surface of a magnetic core/mesoporous silica shell nanostructure, based on a two-step chemical self-assembly process. This multifunctional nanocomposite integrate simultaneous chemotherapy, photo-thermotherapy, in vivo MR-, infrared thermal and optical imaging into one single system. The obtained multifunctional nanoellipsoids showed very low cytotoxicity, and the cancer cell uptake and intracellular location of the nanoellipsoids were observed by confocal laser scanning microscopy and bio-TEM. Importantly, the prepared multifunctional nanoellipsoids showed high doxorubicin loading capacity and pH value-responsive release mainly due to the electrostatic interaction between DOX molecules and mesoporous silica surface. Besides, a synergistic effect of combined chemo- and photo-thermo therapy was found at moderate power intensity of NIR irradiation based on the DOX release and the photothermal effect of Au NRs.

Colloidal HPMO Nanoparticles: Silica‐Etching Chemistry Tailoring, Topological Transformation, and Nano‐Biomedical Applications

Hybridization produces the better: Colloidal hollow periodic mesoporous organosilica nanoparticles (HPMO NPs) with tunable compositions and highly hybridized nanostructures are successfully synthesized by a simple, easily scale-up but versatile silica-etching chemistry (alkaline or HF etching) for their applications in nano-fabrication and nano-medicine.

Hollow Mesoporous Carbon Spheres with Magnetic Cores and Their Performance as Separable Bilirubin Adsorbents

Hollow mesoporous carbon spheres with magnetic cores are directly replicated from hollow mesoporous aluminosilicate spheres with hematite cores by a simple incipient-wetness impregnation technique. The amount of magnetic cores and the saturation magnetization value can be easily tuned by changing the concentration of iron nitrate solution used in the synthesis procedure. As-prepared hollow mesoporous carbon spheres with magnetic cores are used as separable bilirubin adsorbents and show very good adsorptive properties. The characteristics of as-prepared composites are examined by XRD, N(2) sorption, TEM, vibrating-sample magnetometry, and UV/Vis spectroscopy.

Direct fabrication of mesoporous zeolite with a hollow capsular structure

We report the direct fabrication of mesoporous zeolite with a hollow spherical/ellipsoidal capsule structure by using conventional TPAOH and CTAB as soft micro- and mesopore generating templates; the mesoporous zeolite shows a high surface area of 717 m(2) g(-1) and small mesopore size of around 3 nm.

Hyaluronic acid-conjugated mesoporous silica nanoparticles: excellent colloidal dispersity in physiological fluids and targeting efficacy

Hyaluronic acid-conjugated mesoporous silica nanoparticles (MSNs-HA) have been synthesized via a facile amidation reaction. This novel strategy can efficiently solve the agglomeration problem of MSNs in physiological fluids. The cellular experiments showed that MSNs-HA is capable of selectively targeting specific cancer cells over-expressing the CD44 protein, leading to rapid and concentration-dependent uptake by the cancer cells through the receptor-mediated endocytosis mechanism. In contrast, no selective targeting of MSNs-HA can be found to the CD44 low-expressing cells, such as MCF-7 and L929 cells. The hydrophobic camptothecin (CPT) drug was encapsulated into MSNs-HA, which showed enhanced cytotoxicity to the Hela cells compared to both free CPT and CPT-loaded MSNs-HA in the presence of excess free HA.

One-step synthesis of sulfur doped graphene foam for oxygen reduction reactions

Sulfur doped graphene foam has been successfully synthesized by a simple solve-thermal method, which exhibited a much enhanced oxygen reduction reaction (ORR) catalytic activity as well as an especially high electrochemical stability, and would be a promising non-metal cathode catalyst for the ORR.

Electrochemical catalytic activity for the hydrogen oxidation of mesoporous WO3 and WO3/C composites

New catalysts for hydrogen oxidation, mesoporous WO3 and WO3/C composites, have been synthesized by a simple one-step casting method using mesoporous silica (KIT-6) as hard template. The materials were characterized with XRD, XPS, TEM and N2 sorption techniques. Cyclic voltammetry (CV) and single cell test for hydrogen oxidation were adopted to characterize the electrochemical performance of the materials. The mesoporous WO3 has a high surface area of 86 m2 g−1 and a well-crystallized framework. This material exhibits stable electrochemical activity for hydrogen desorption/oxidation in half-cell experiments, and after mixing with the appropriate amount of carbon black the resultant mesostructured WO3/C composites show further enhanced electrocatalytic activity and even higher hydrogen oxidation/reduction peak currents than the commercial catalyst 20 wt% Pt/C. The single cell test results indicate that the mesostructured WO3/C composites have clear current output in a proton exchange membrane fuel cell (PEMFC) and exhibit electrochemical catalytic activity toward hydrogen oxidation, and appears to be a potential anode catalyst in PEMFCs.

Dual‐Mesoporous ZSM‐5 Zeolite with Highly b‐Axis‐Oriented Large Mesopore Channels for the Production of Benzoin Ethyl Ether

Dual-mesoporous ZSM-5 zeolite with highly b axis oriented large mesopores was synthesized by using nonionic copolymer F127 and cationic surfactant CTAB as co-templates. The product contains two types of mesopores--smaller wormlike ones of 3.3 nm in size and highly oriented larger ones of 30-50 nm in diameter along the b axis--and both of them interpenetrate throughout the zeolite crystals and interconnect with zeolite microporosity. The dual-mesoporous zeolite exhibits excellent catalytic performance in the condensation of benzaldehyde with ethanol and greater than 99 % selectivity for benzoin ethyl ether at room temperature, which can be ascribed to the zeolite lattice structure offering catalytically active sites and the hierarchical and oriented mesoporous structure providing fast access of reactants to these sites in the catalytic reaction. The excellent recyclability and high catalytic stability of the catalyst suggest prospective applications of such unique mesoporous zeolites in the chemical industry.

SnO2 nanocrystal-decorated mesoporous ZSM-5 as a precious metal-free electrode catalyst for methanol oxidation

A novel precious metal-free electrode catalyst SnO2/m-ZSM-5 nanocomposite has been successfully synthesized. This SnO2/m-ZSM-5 nanocomposite shows high and stable electrochemical catalytic activity for methanol oxidation, which is comparable to Pt/C. The high electrochemical performance has been attributed to the synergetic catalytic effects between the mesoporous ZSM-5 matrix and the loaded SnO2 nanocrystals.

One-step replication and enhanced catalytic activity for cathodic oxygen reduction of the mesostructured Co3O4/carbon composites

Mesostructured Co3O4/C composites of high surface area have been synthesized via a one-step replica route by co-nanocasting cobalt and carbon precursors into mesoporous silica, in which the Co3O4 nanoparticles are homogeneously dispersed in the mesoporous structure of carbon substrates. The mesostructured composites showed relatively high catalytic activities for oxygen reduction reaction (ORR), and that with a Co loading content of 4.3 at% exhibited the best electrochemical performance for ORR. The relatively high catalytic activity is attributed to the effects of the redox couples (Co(3+)/Co(2+)) together with the contribution from the conductive mesoporous carbon substrate.