Daihua Tang

Oleic acid (OA)-modified LaF3 : Er,Yb nanocrystals and their polymer hybrid materials for potential optical-amplification applications

Oleic acid (OA)-modified LaF3 : Er,Yb nanocrystals (NCs) have been prepared and investigated. The OA-capped nanocrystals have a nearly spherical shape with a mean diameter of 7 nm and show excellent dispersibility in common organic solvents and a PMMA matrix. A 0.25 g ml−1 transparent colloidal solution in toluene can be obtained. The resulting nanocrystal–polymer hybrid materials exhibit strong emission around the 1550 nm telecommunication window when excited at 980 nm and are promising materials for polymer-based optical waveguide amplifiers.

Crystal structure and near-infrared luminescence properties of novel binuclear erbium and erbium–ytterbium cocrystalline complexes

Three binuclear complexes of erbium and ytterbium, Er2(Ba)6(Phen)2, Yb2(Ba)6(Phen)2 and Er1.4Yb0.6(Ba)6(Phen)2 (Ba = benzoate, Phen = 1,10-phenanthroline), were synthesized and structurally characterized, and their luminescent properties examined in detail. Compared with the binuclear complex Er2(Ba)6(Phen)2, the NIR luminescence of the erbium ion in Er1.4Yb0.6(Ba)6(Phen)2 is enhanced because of the coexistence of the ytterbium ion through an ytterbium-to-erbium energy transfer process. The full width at half maximum, centered at 1535 nm in the emission spectrum of Er1.4Yb0.6(Ba)6(Phen)2, is 108 nm, excited at 975 nm, which has potential to enable a wide-gain bandwidth for optical amplification. The X-ray single crystal structure confirms that this is an excellent binuclear complex model with a short metal-to-metal distance (about 4 A) to facilitate the intramolecular (not intermolecular) Yb–Er energy transfer process. ESI-MS confirmed the molecules Er2(Ba)6(Phen)2, Yb2(Ba)6(Phen)2 and ErYb(Ba)6(Phen)2 exist in solution.

Fabrication of continuous highly ordered mesoporous silica nanofibre with core/sheath structure and its application as catalyst carrier

A core/sheath structured mesoporous silica nanofibre was prepared by coaxial electrospinning combined with the solvent evaporation induced surfactant assembly process. The characterization has given convincing evidence for the continuous highly ordered mesoporous structures, and its catalyst application was tested.

Single-molecule behavior of dendritic poly(ethylene glycol) structures towards lithium ions.

Poly(ethylene glycol) (PEG)-ylated functional structures are attracting increasing interest due to their applications ranging from materials to biological science. For example, PEG-based polyplex micelles have been developed as nonviral gene vectors, PEG-ylated nanographene oxide can deliver water-insoluble cancer drugs, and raft-mimetic PEG-ylated polyvalent liposomes are attractive for designing inhibitors and efficient targeted drug-delivery systems. PEG-coated materials have been extensively studied in various bio-applications, such as blood-compatible materials, implants, and stealth carriers for either drug or gene delivery. Furthermore, as a receptor for lithium ions, oligoethylACHTUNGTRENNUNGeneACHTUNGTRENNUNGoxy-modified macromolecules constitute an important type of polymer electrolyte materials for high-performance lithium-ion batteries. 8] In this regard, there has been a challenge to develop detection methods to characterize their interactions with related guests in solution. As a popular, minimally fragmenting tool for investigating supramolecular noncovalent interactions, matrix-assisted laser desorption/ ionization (MALDI) time-of-flight (TOF) mass spectrometry and electrospray ionization (ESI) mass spectrometry have been at the forefront of these developments. MALDI-TOF-MS and ESI-MS are soft ionization techniques and can provide various information for possible supramolecular complexes present in solution. However, since commercially available linear PEG structures are not monocomponent, there is a difficulty to accurately analyse them by MALDI-TOF-MS and ESI-MS. Although recently the aim has been focused on synthesis of linear and dendritic PEG structures with higher molecular weght, the molecular weight for linear PEG moieties is still below 1000 (the ethylene oxide unit number is 16), and the dendritic PEG structures exhibit multicomponent isotopic patterns in MALDI-TOF-MS. From a viewpoint of synthesis methodologies for higher molecular weight PEG compounds, constructing dendritic structures may become a good strategy for this purpose. We present here that amphiphilic oligoethyleneoxy-modified poly(benzyl ether) dendron revealed excellent single-molecule behavior to lithium ions characterized by MALDI-TOF-MS and TOF-ESI-MS. The synthesis of amphiphilic oligoethyleneoxy-modified poly(benzyl ether) dendron (D) was achieved according to a