Institute of Chemistry
Changchun Institute of Applied Chemistry, Chinese Academy Of SciencesNot a member yet
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Reduction of Eu3+ due to a change of the topological structure of the BO3 unit in borate glass
No full textAdjusting and controlling an ion's chemical state has always been a focus of researchers' attention. Herein, an intense long-lasting phosphorescence of Eu2+ is obtained without any sacrificial reductant. The remarkable self-reducing process and the unique luminescence properties stem from a variation of the topological structure of the BO3 triangle
Investigation of ZnCo2O4-Pt hybrids with different morphologies towards catalytic CO oxidation
No full textIn this work, three kinds of ZnCo2O4 morphologies, that is, rod, plate and sphere, have been successfully prepared and further used to support Pt nanoparticles (NPs) via in situ deposition. The as-prepared ZnCo2O4-Pt hybrid nanomaterials were then carefully characterized by SEM, TEM, XRD, XPS, ICP EDX, and N-2 adsorption measurement in great detail. Besides, the three catalysts were also evaluated by the model reaction of catalytic CO oxidation. After comparing the difference in the three kinds of morphologies, we have tried to clarify the reason for their different catalytic performances. As a result, the ZnCo2O4-Pt sphere was found to be the most active, attaining 100% CO conversion at a relatively low temperature of 140 degrees C, because more Pt NPs are prone to distribution on the surface of ZnCo2O4 spheres than the other ones. The following cycling tests confirm the excellent stability of the as-prepared ZnCo2O4-Pt samples
Label-free fluorescence detection of mercury ions based on the regulation of the Ag autocatalytic reaction
No full textIn this work, a novel facile nanoparticle autocatalytic sensor based on the inhibition of the Ag autocatalytic reaction for the determination of Hg2+ was developed. o-Phenylenediamine (OPD) tended to be oxidized into 2,3-diaminophenazine (OPDox) by silver ions (Ag+) followed by the formation of silver nanoparticles (AgNPs). Employed as a catalyst, the thus-formed AgNPs would further promote the reaction between OPD and Ag+. When Hg2+ was introduced, Hg2+ adsorbed on the surface of the AgNPs, thus inhibiting the oxidation process mentioned above and achieving weakened fluorescence intensity. A linear relationship between fluorescence intensity and Hg2+ concentration (within the range from 10 nM to 2500 nM) was obtained and the detection limit reached as low as 8.2 nM. The proposed method was also applied for the determination of Hg2+ in real water samples with satisfactory results. The protocol showed excellent advantages of sensitivity and selectivity for Hg2+ over various metal ions and anions. Meanwhile, this method was simpler and more cost-effective compared with many reported nanomaterial- and DNA-based approaches. Furthermore, an "INHIBIT" logic gate based on the Ag+-Hg2+-OPD system has also been designed
Ultrasensitive electrochemiluminescent determination of perphenazine at tris(1,10-phenanthroline) ruthenium(II)/Nafion bulk modified carbon nanotube ceramic electrode via solid-phase microextraction
No full textThe applications of carbon nanotube (CNT) as solid-phase extraction matrix and bulk modification material in electrochemiluminescence (ECL) have been demonstrated for the first time. The bulk modification of Ru(phen) (2+)(3) has been achieved through the preparation of Ru(phen) (2+)(3)/Nafion modified CNT ceramic electrode. The bulk modification method has the advantages of easy electrode surface renewal and facile electrode preparation over surface immobilization approaches. Moreover, Ru(phen)(3)(2+)/Nafion modified CNT ceramic electrode can serve as an excellent solid- phase microextraction matrix because of the presence of CNT in the electrode. The combination of the Ru(phen)(3)(2+)/Nafion modified CNT ceramic electrode with solid-phase extraction enables ultrasensitive detection of perphenazine. The log-log calibration plot for perphenazine is linear from 1 x 10(-6) to 1 x 10(-11) M with a detection limit of 5.8 x 10(-12) M. The Ru(phen)(3)(2+)/Nafion modified CNT ceramic electrode shows better detection limit than Ru(phen)(3)(2+)/Nafion modified graphite ceramic electrode by about two orders of magnitude because of strong adsorption capacity and large adsorbing area of multi-walled CNT as well as low ECL background. It is one of the most sensitive methods for the Ru(phen)(3)(2+) ECL determination of coreactants so far. The detection takes less than 3 min, which makes this method promising for on-site detection. This method was also successfully applied for the determination of perphenazine in human urine samples spiked with perphenazine. The Ru(phen)(3)(2+)/Nafion modified CNT ceramic electrode exhibits outstanding long-term stability and reproducibility. The remarkable extraction capability and outstanding long-term stability of Ru(phen)(3)(2+)/Nafion modified CNT ceramic electrode as well as the advantages of bulk modification method make the present detection strategy promising for ultrasensitive detection of organic compounds. (C) 2014 Elsevier B.V. All rights reserved
Preparation and characterization of porous polyelectrolyte complex membranes for nanofiltration
No full textPolyelectrolyte complex membranes were prepared from poly(acrylic acid-co-acrylonitrile)s and imidazolium-based polycations via a combination of blend film casting and ammonia solution immersion procedures. The membranes were free-standing and tough, showing excellent mechanical properties (with tensile strength of 6.71-23.7 MPa and elongation at break of 15-59%). Hierarchically structured nanopores were formed in the membranes during the ammonia soaking step, due to NH3-triggered -COOH deprotonation and in situ ionic crosslinking with polycations. Zeta potential measurements indicated that the membranes were negatively charged under neutral conditions. The membranes exhibited moderate rejection to salts in the order of Na2SO4 > NaCl > MgCl2, but high rejection to methyl orange (>99.9%)
Effects of interfacial tension on formation of poly(ethylene oxide)-block-polystyrene micelles from emulsions
No full textIn this report, we show that the structure of an amphiphilic block copolymer assembled through the emulsion and solvent evaporation method can be regulated by tuning the interfacial tension with a third solvent. Microspheres were obtained when a poly(ethylene oxide)-block-polystyrene copolymer was self-assembled by emulsification of its chloroform solution in water. Addition of water-miscible tetrahydrofuran or N, N-dimethylformamide into the aqueous phase by 20 vol% was shown to reduce the interfacial tension between chloroform and water significantly, and strings of vesicles became the dominant structure. Addition of ethanol by 15, 50 and 100 vol% was found to produce strings of vesicles, cylinders and microspheres, respectively. Introduction of cyclohexane, a hydrocarbon solvent, into the organic phase of 1,2-dichloroethane increased the interfacial tension with the aqueous phase, and vesicles were observed instead of the strings of spheres obtained previously. The different assembled structures are discussed in terms of interfacial curvature driven by variation in the interfacial tension
NiCo2O4 3 dimensional nanosheet as effective and robust catalyst for oxygen evolution reaction
No full textWater electrolysis plays a fundamental role in the development of a sustainable energy system. In practice the efficiency of water electrolysis is severely limited by the sluggish kinetics of the oxygen evolution reaction. We reported a kind of integrated 3 dimensional oxygen evolution reactions (OER) catalyst by growing NiCo2O4 nanosheet arrays directly on conductive substrates. Such self-supported NiCo2O4 nanosheet electrodes exhibit high catalytic activity, good durability and nearly 100% faradic efficiency (FE) in alkaline electrolyte due to the enlarged electrochemical surface area and reduced electron transference resistance
Emerging antitumor applications of extracellularly reengineered polymeric nanocarriers
No full textRecently, polymeric nanocarriers with shielding surfaces, e.g., poly(ethylene glycol) and small molecules, have been widely applied in antitumor drug delivery mainly because of their stealth during blood circulation. However, the shielding shell greatly hinders the tumor penetration, drug release, and cell internalization of the nanocarriers, which leads to unsatisfactory therapeutic efficacy. To integrate the extended blood circulation time and the enhanced drug transmission in one platform, some extracellularly stimuli-mediated shell-sheddable polymeric nanocarriers have been exploited. The systems are stealthy and stable during blood circulation, and as soon as they reach tumor tissue, the shielding matrices are removed, which is triggered by extracellular endogenous stimuli (e.g., pH or enzymes) or exogenous excitations (e.g., light or voltage). This review mainly focuses on recent advances in the designs and emerging antitumor applications of extracellularly reengineered polymeric nanocarriers for directional drug delivery, as well as perspectives for future developments
Control over fibril width via different solubility additives for diketopyrrolopyrrole-based photovoltaic devices
Get PDFControl over polymeric bulk heterojunction (BHJ) morphology is one of the key factors in obtaining high-efficiency devices. The domain size influence on device performance is widely considered critical. In this paper, the fibril width of 3,6-bis-(thiophen-2-yl)-N,N'-bis(2-octyl-1-dodecyl)-1,4-dioxopyrrolo[3,4-c]pyrrole and thieno[3,2-b]thiophene (PDBT-TT):[6,6]-phenyl-C-71-butyric acid methyl ester (PC71BM) blend thin film was adjusted by different processing additives. By decreasing the solubility of PDBT-TT in different additives, the fibril width can be decreased from 65.7 nm to 14.8 nm. It is possible that the PDBT-TT seed-crystallite nuclei concentration is higher in the relatively low solubility solvents than that in the relatively high solubility solvents, thus leading to the formation of narrower fibrils. The PDBT-TT/ PC71BM narrow fibrillar interpenetrating network structure was beneficial to exciton separation and charge transport processes. As a result, the solar cell with the narrowest fibril width has a higher short circuit current (J(sc)) and fill factor (FF), thus achieving optimized device performance from less than 1% to 4.75%. (C) 2015 Elsevier B. V. All rights reserved
The fluorescence detection of glutathione by center dot OH radicals' elimination with catalyst of MoS2/rGO under full spectrum visible light irradiation
No full textIn this study, a new method for the detection of glutathione (GSH) was designed based on the center dot OH radicals' elimination system due to the reducing ability of GSH for the first time. Fluorescence method with terephthalic acid (TA) as the probe was employed for the quantification of center dot OH radicals' production and elimination. Experimental conditions of center dot OH radicals' production were optimized in detail, and center dot OH radicals were found to be efficiently produced by the excellent catalysis performance of MoS2/rGO under full spectrum visible light irradiation. The introduction of GSH make fluorescent intensity decrease due to the elimination of center dot OH radicals. For the present fluorescence based GSH sensor, a wide detection range of 60.0-700.0 mu M and excellent selectivity have been achieved. Furthermore, it has been successfully employed for the determination of GSH in commercial drug tablets and human serum. (C) 2015 Elsevier B.V. All rights reserved