Institute of Chemistry
Changchun Institute of Applied Chemistry, Chinese Academy Of SciencesNot a member yet
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有机半导体薄膜中的载流子传输特性研究
No full text在有机发光二极管中，载流子的注入和传输特性直接影响器件的性能，由于有机半导体分子结构及其薄膜形态的多样性和掺杂体系中分子-分子之间相互作用的不同行为，使有机半导体的传输特性变得更为复杂。因此，深入系统地研究有机半导体中载流子的传输行为，对建立传输特性与器件性能的关系，改进器件性能具有非常重要的意义。本论文以掺杂和非掺杂的有机电子传输材料以及共混材料体系为研究对象，用阻抗和电流-电压特性方法系统地研究了它们薄膜中载流子的传输特性。论文的具体工作内容如下： 1. 研究了不同厚度Alq3薄膜的电子传输特性。稳态电流-电压特性研究表明，Alq3薄膜的电子传输符合陷阱呈幂指数分布的空间电荷限制电流模型，总的陷阱密度约为8.6×1017 cm-3。导纳法测定的Alq3薄膜的电子迁移率（10-7 ~ 10-5 cm2V-1s-1）与薄膜厚度、电场强度相关。当薄膜厚度小于150 nm时，电子迁移率随电场增...In organic light emitting diodes, the carriers injection and transport properties directly affect the performance of the devices. In organic semiconductors, the charge transport characteristics become more complex because of the variety of molecular structures and film morphologies and the different behaviors of the interactions between molecules. Therefore, the systematical investigation on the charge transport characteristics in organic semiconductors is very important for establishing the relationship between the transport properties and device performance, and improving the performance of the devices. In this thesis, we have systematically investigated the carrier transport properties in doped and undoped organic electron-transport materials and blends by admittance spectroscopy techni..
载药电纺纳米纤维膜用于局部化疗治疗癌症的研究
No full text在过去几十年里，以高分子聚合物为药物载体，提高癌症患者的恶性病灶处药物浓度的相关研究获得了广泛的发展。为了提高生存率和生存质量，人们致力于提高药物在病灶处的生物利用度、药物浓度和溶解度，以减少全身副反应。近年来基于高分子材料的局部控释给药系统成为研究热点, 其原理是将药物植入载体直接送至肿瘤，使抗肿瘤药以一定的浓度和时间在肿瘤组织内充分发挥作用, 相对传统系统化疗而言具有增强疗效和减少毒副作用的优势。 在各种局部控释给药系统中，由静电纺丝技术制得的纤维膜具有比表面积大、孔隙率高、载药量大、透气透湿性好等优点，被广泛应用于抗生素、抗肿瘤药物和生物大分子等药物的控制释放。但将载药静电纺丝纳米纤维膜应用于动物体内抗癌活性的研究较少，少数相关研究也局限于皮下肿瘤模型，难以模拟临床实际应用情况。因此，本论文以静电纺丝制得的纤维膜为药物载体，将其应用于不同的动物原位肿瘤模型上，评价其疗效和安全性。研究...In the last few decades, the studies on the Polymer-based drug delivery systems have been developed widely as a means of achieving high therapeutic concentrations of chemotherapy to the site of malignant disease in cancer patients. In order to improve overall survival and quality of life, researchers have been devoting to increase the bioavailability, concentration and solubility of drug to the site of disease, thereby minimizing systemic side effects. Recently, polymer-based, controlled release drug delivery depot systems have been brought into focus. By implantation of polymer delivery vehicles intra-tumorally or adjacent to the cancerous tissue, anti-cancer drug can interact with tumor tissue at a certain concentration within a predictable time, which is more successful in improving eff..
功能化石墨烯/聚氨酯纳米复合材料的结构与性能研究
No full text热塑性聚氨酯（TPU）是用多异氰酸酯和多元醇反应制得的一类聚合物。其强度和模量介于橡胶与塑料之间，具有优良的耐磨性能和承载性能、较大的撕裂强度以及优异的耐低温、耐油、耐臭氧等性能，因此TPU广泛应用于航空航天、医疗器械、制鞋、电器等行业。但传统TPU材料存在气体阻隔性不良、耐热性能不好、强度偏低等缺点，限制了其应用范围。因此，有必要在TPU体系中添加高阻隔性、稳定性好和强度高的填料，以期制备优良TPU复合材料，从而大幅度提高TPU的综合性能。 石墨烯是目前已知最薄的材料，仅由单个碳原子层组成，厚度为0.335nm，片层宽度可达几个微米甚至几百微米，这种独特的二维结构赋予了石墨烯优异的性能，如导电性优良，强度极高，结构稳定等。另外，无缺陷的石墨烯几乎能阻隔所有气体分子扩散渗透，当石墨烯均匀分散在聚合物基体中时，可以极大提高聚合物的气体阻隔性能。因此，石墨烯是理想的纳米填充阻隔材料。 本文紧紧...Thermoplastic polyurethane (TPU) is a kind of polymer prepared with multi-isocyanate and polyol, which modulus and strength between rubber and plastics. With the properties of excellent wear resistance, good bearing capacity, large tear strength, excellent low temperature resistance, oil resistance and ozone resistance, TPU is widely used in aerospace, medical, shoe, electrical appliances and so on. But the application of traditional TPU material is limited by its disadvantages such as bad gas barrier properties, low tensile strength and bad heat resistant capacity. Therefore, highly gas barrier, good stability and high strength filler is necessary to be added into the pure TPU system to improve the comprehensive properties of TPU. Graphene, the thinnest material, consists of only a single..
Colorimetric detection of iron ions (III) based on the highly sensitive plasmonic response of the N-acetyl-L-cysteine-stabilized silver nanoparticles
No full textWe report here a facile colorimetric sensor based on the N-acetyl-L-cysteine (NALC)-stabilized Ag nanoparticles (NALC-Ag NPs) for detection of Fe3+ ions in aqueous solution. The Ag NPs with an average diameter of 6.55 +/- 1.0 nm are successfully synthesized through a simple method using sodium borohydride as reducing agent and N-acetyl-L-cysteine as protecting ligand. The synthesized silver nanoparticles show a strong surface plasmon resonance (SPR) around 400 nm and the SPR intensity decreases with the increasing of Fe3+ concentration in aqueous solution. Based on the linear relationship between SPR intensity and concentration of Fe3+ ions, the as-synthesized water-soluble silver nanoparticles can be used for the sensitive and selective detection of Fe3+ ions in water with a linear range from 80 nM to 80 mu M and a detection limit of 80 nM. On the basis of the experimental results, a new detection mechanism of oxidation-reduction reaction between Ag NPs and Fe3+ ions is proposed, which is different from previously reported mechanisms. Moreover, the NALC-Ag NPs could be applied to the detection of Fe3+ ions in real environmental water samples. (C) 2015 Elsevier B.V. All rights reserved
Labeling of Enveloped Virus via Metabolic Incorporation of Azido
No full textModification of an enveloped measles virus was achieved by metabolic incorporation of azido sugars in host cells through the protein glycosylation process. Based on this, the resulting measles virus particles could be modified with azido groups on the surface glycoproteins, which could be further labeled with fluorescence dyes using a strain-promoted azide-alkyne cycloaddition reaction. We envision this metabolic labeling approach to be applicable to a wide variety of enveloped viruses, allowing the facile conjugation and surface modification
Cu/(Cu(OH)(2)-CuO) core/shell nanorods array: in-situ growth and application as an efficient 3D oxygen evolution anode
No full textIn this paper, we develop a novel strategy toward the in-situ growth of core/shell nanorods array consisting of Cu(OH)(2)-CuO nanosheets as the shell and Cu as the core on Cu foil [Cu/(Cu(OH)(2)-CuO) NA/CF]. As an integrated 3D non-noble-metal oxygen evolution anode, the Cu/(Cu(OH)(2)-CuO) NA/CF shows high catalytic activity with an onset overpotential of 350 mV and a Tafel slope of 76 mV/dec. It needs an overpotential of 417 mV to drive current density of 10 mA/cm(2) and maintains its catalytic activity for at least 22 h. The attractive performances make it promising candidate as a future high-performance catalyst for applications. (C) 2015 Elsevier Ltd. All rights reserved
Porous NiCo2O4 nanostructures as bi-functional electrocatalysts for CH3OH oxidation reaction and H2O2 reduction reaction (vol 113, pg 290, 2013)
No full textInvestigations on structures, thermal expansion and electrochemical properties of La0.75Sr0.25Cu0.5-xCoxMn0.5O3-delta (x=0, 0.25, and 0.5) as potential cathodes for intermediate temperature solid oxide fuel cells
No full textA series of perovskite oxides have been investigated as excellent potential cathodes for intermediate-temperature solid oxide fuel cells (IT-SOFCs). In this paper, we take the La0.75Sr0.25Cu0.5-xCoxMn0.5O3-delta (LSCCM, x = 0, 0.25 and 0.5) system as subject, with Cu/Mn and/or Co/Mn on B-site and 25% Sr-substituted La ions on A-site, to investigate their structures, thermal stability and electrochemical properties. Pure rhombohedral crystal with space group R (3) over barc (no. 167) is identified by Rietveld refinement of X-ray diffraction data (XRD). It is found that the thermal expansion coefficient (TEC) is manageable when Co ion is incorporated, and the low TEC value ranges from 12.7 x 10(-6) to 15.4 x 10(-6) K-1 that are well compatible with prototypical electrolytes Zr0.84Y0.16O1.92 (YSZ) and Ce0.8Sm0.2O2-delta (SDC). The dc-conductivity is significantly enhanced from 36.5, 90.5 to 173.7 S cm(-1) at 850 degrees C with the increasing Co percent, and accordingly, polarization resistance (R-p) is determined as 0.1291, 0.0835 and 0.0486 V cm(2) at 800 degrees C. The high electrical conductivities and low resistances can be attributed to the strong B-O bond hybridization and oxygen vacancy formation at elevated temperatures with the introduction of Co ion, which is consistent with the results of first-principles calculation and thermogravimetric analysis. All these results demonstrate that LSCCM series are promising cathodes with controllable TEC for IT-SOFCs. (C) 2015 Elsevier Ltd. All rights reserved
Simultaneous Control over both Molecular Order and Long-Range Alignment in Films of the Donor-Acceptor Copolymer
No full textControl over both molecular order and long-range alignment order in films of the donor-acceptor copolymer of 3,6-bis(thiophen-2-yl)-N,N'-bis(2-octyl-1-dodecyl)-1,4-dioxo-pyrrolo[3,4-c]pyrrole and thieno[3,2-b]thiophene (PDBT-TT) was demonstrated via off-center spin-coating (OCSC) from its blend solution with polystyrene (PS). It was found that the dichroic ratio (DR) of OCSC blend films was dependent on both the physical process of spin-coating and the effect of PS chains. The highest DR of 2.75 was obtained via OCSC from the blend solution in oDCB at 1500 rpm. Meanwhile, both the intrachain and interchain molecular order were improved in blend films compared with neat ones, which were indicated by the red-shift of the max absorption, enhanced J-aggregation absorption, and smaller pi-pi stacking distance (from 3.77 to 3.70 angstrom). According to the results of the investigation into the macro anisotropy, micro morphology, solution rheology properties, and photophysics features of films, an overall mechanism of simultaneous control over molecular and long-range order of D-A copolymer films was proposed. On the one hand, a larger viscosity and the pseudoplastic nature of the solution tuned by choosing good solvents with high boiling points and adding PS resulted in a better chain disentanglement, better shear transfer, and a slower contact line receding velocity to induce an enhanced alignment of chains and thus fibrillar aggregates. Also, the critical contact line receding velocity for alignment dominated by the solvent evaporation rate accounted for the variation of DR with OCSC rates. A vertical phase separation accompanying the formation of aligned fibrils during OCSC was also confirmed due to the friction shear between air and solution surface. On the other hand, the negligible dependence of the blend OCSC films photophysical and morphological features on the solvent suggested the critical role of PS in determining the better intrachain conjugation in blend films, which was attributed to multiple reasons, like limited phase separation room, a coil-toward conformation promotion, and a high surface energy. Furthermore, the enhanced pi-attraction and smaller steric hindrance induced by improved intrachain conjugation accounted for the smaller pi-pi stacking distance in the blend films than that in the neat ones
L-Lysine-assisted fabrication of PdxPt1-x/Ni(OH)(2) (0 <= x <= 1) hybrids with composition-dependent catalytic properties
No full textA fast and facile self-assembly method has been developed to deposit 3-5 nm sized PdxPt1-x (0 <= x <= 1) nanoparticles (NPs) on Ni(OH)(2) nanosheets. The biomolecule L-lysine has been used here as the linker to hybridize PdxPt1-x NPs and Ni(OH)(2) nanosheets together. The catalytic properties of the obtained PdxPt1-x/Ni(OH)(2) hybrids were evaluated by employing the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) by NaBH4 as a model reaction. The results reveal that the stability, activity and recyclability of PdxPt1-x NPs have been remarkably enhanced after being supported on Ni(OH)(2) nanosheets. Moreover, the influence of the composition of noble metals on the catalytic properties has been studied in depth and Pd0.5Pt0.5/Ni(OH)(2) hybrids show the optimal catalytic properties