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Chen J.,Nanjing University of Technology | Zhu L.,Nanjing University of Technology | Xie H.,Nanjing University of Technology | Zhang J.,Nanjing University of Technology | And 5 more authors.
Polymer International | Year: 2014

We report a facile strategy for fabricating fluorescent quantum dot (QD)-loaded microbeads by means of microfluidic technology. First, a functional fluorine-containingmicroemulsionwas synthesizedwith poly[(2-(N-ethylperfluorobutanesulfonamido)ethyl acrylate)-co-(methyl methacrylate)-co-(butyl acrylate)] (poly(FBMA-co-MMA-co-BA)) as the core and glycidyl methacrylate (GMA) as the shell via differential microemulsion polymerization. Then, CdTe QDs capped with N-acetyl-L-cysteine (NAC) were assembled into the poly(FBMA-co-MMA-co-BA-co-GMA) microemulsion particles through the reaction of the epoxy group on the shell of the microemulsion and the carboxyl group of the NAC ligand capped on the QDs. Finally, fluorescent microbeads were fabricated using the CdTe QD-loaded fluorine-containing microemulsion as the discontinuous phase and methylsilicone oil as the continuous phase by means of a simple microfluidic device. By changing flow rate of methylsilicone oil and hybrid microemulsion system, fluorescentmicrobeads with adjustable sizes ranging from 290 to 420 μm were achieved. Themorphology and fluorescent properties of the microbeads were thoroughly investigated using optical microscopy and fluorescence microscopy. Results showed that the fluorescent microbeads exhibited uniform size distribution and excellent fluorescence performance. © 2014 Society of Chemical Industry.

Tang W.-Q.,Nanjing University of Technology | Mao L.-H.,Nanjing University of Technology | Zhou Z.-F.,Nanjing University of Technology | Wang C.-F.,Nanjing University of Technology | And 3 more authors.
Colloid and Polymer Science | Year: 2014

We report herein the fabrication of poly(AAM-co-4VP) hydrogels (AAM = acrylamide, 4VP = 4-vinylpyridine) by using laser-ignited frontal polymerization (LIFP) in an easy and rapid way. The appropriate amounts of AAM, 4VP, γ-methacryloxypropyltrimethoxysilane-modified nanosilica, and couple redox initiator of ammonium persulfate/N,N,N′,N′-tetramethylethylenediamine were mixed together in the presence of dimethylsulfoxide as solvent. LIFP was initiated by heating the upper side of the mixture with the laser. Once initiated, no further energy or treatment was required for the following polymerization to occur. A variety of features for the preparation of hydrogels, such as the initiator concentration and the ratio of different monomers, were thoroughly investigated. The morphology and swelling behavior of hydrogels were investigated. For comparison, the hydrogels prepared via traditional thermal frontal polymerization were also presented and discussed. Furthermore, the hydrogels possess absorption capacity towards copper ions, which can be applied to remove heavy metals. © 2014, Springer-Verlag Berlin Heidelberg.

Mao L.-H.,Nanjing University of Technology | Zhang Q.-H.,Nanjing University of Technology | Zhang Y.,Nanjing University of Technology | Wang C.-F.,Nanjing University of Technology | And 3 more authors.
Industrial and Engineering Chemistry Research | Year: 2014

Highly red-luminescent N-acetyl-l-cysteine-stabilized CdTe/CdS@ZnS-SiO2 quantum dots (QDs) were successfully synthesized in the aqueous phase via a promising microwave strategy for the first time; they were prepared by coating SiO2 layers doped with ZnS-like clusters on CdTe/CdS core/shell QDs. Owing to the effective passivation of the coating CdS shell and ZnS-SiO2 layer, the as-prepared QDs show high photoluminescence, good optical stability, and low biotoxicity. Moreover, the outermost SiO2 layer endows the QDs with excellent silicone compatibility. The structures and photoluminescence properties of the CdTe/CdS@ZnS-SiO2 QDs were well studied by various characterizations. For their practical applications, we explored the promising red-luminescent QDs as novel red phosphors to fabricate two types of white-light-emitting diodes (WLEDs), a low-power surface-mounted device and a high-power device. Both of the devices produce bright white light with remarkable color rendering. Especially, the color-rendering index (CRI) of the high-power device even reaches up to 91.9, suggesting the great potential of the highly red-luminescent QDs for solid-state lighting systems with high CRI. © 2014 American Chemical Society.

Wang W.,Nanjing University of Technology | Deng Z.,Nanjing University of Technology | Zhang Y.,Nanjing University of Technology | Wang C.-F.,Nanjing University of Technology | And 3 more authors.
Industrial and Engineering Chemistry Research | Year: 2014

In this work, we present the self-replication fabrication of oil-soluble and ligand-free CdSe quantum dots (QDs) via a "solid-liquid interface" method using electrospun nanofibrous mats as the microreactor. The electrospun sodium alginate-based nanofibers with the cadmium source act as the solid phase, while octadecene containing selenium in trioctylphosphine as the Se source serves as the liquid phase. After reacting on the nanofibrous microreactor, the as-prepared CdSe QDs without using any ligands are released from the microreactor, presenting a monodispersion with a mean diameter of ∼3 nm along with good fluorescent properties (λem = 620 nm). ZnSe QDs could also be prepared in the same manner, indicating this self-replication method to have wide suitability for the construction of QDs via this solid-liquid interface microreactor. For practice, we further applied the CdSe QDs as fluorescent inks for versatile printing of luminescent patterns toward anticounterfeit and optoelectronic applications. © 2014 American Chemical Society.

Liu S.-S.,Nanjing University of Technology | Wang C.-F.,Nanjing University of Technology | Wang C.-F.,Jiangsu Key Laboratory of Fine Chemicals and Functional Polymer Materials | Li C.-X.,Nanjing University of Technology | And 4 more authors.
Journal of Materials Chemistry C | Year: 2014

We report a simple and green route to the fabrication of fluorescent carbon dots (CDs), and demonstrate their versatile applications. Hair, a kind of natural and nontoxic raw material, was chosen as the precursor to prepare CDs via a one-step pyrolysis process. The structure and fluorescence properties of the CDs were thoroughly investigated. The obtained CDs can emit bright blue light under UV light with the quantum yield of ca. 17%, and exhibit excitation-, pH- and solvent-dependent fluorescence. The functional groups on the surface of CDs confer these nanomaterials with excellent dispersibility in water and most polar organic solvents, as well as good compatibility with polymer matrices such as poly(methyl methacrylate) and polyvinylpyrrolidone. Then multidimensional CD-polymer hybrid materials, including one-dimensional (1D) microfibers, 2D patterned films and 3D microbeads were constructed with excellent overall performance, which are useful in fluorescent patterns, flat panel displays and anti-counterfeiting labeling fields. This journal is © the Partner Organisations 2014.

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