Institute of Chemistry
Changchun Institute of Applied Chemistry, Chinese Academy Of SciencesNot a member yet
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受限高分子薄膜界面动力学与缠结的关系
No full text通过Monte Carlo模拟结合原始路径分析(PPA)的方法,阐述了缠结高分子薄膜的界面动力学与缠结程度的关系.研究发现,以吸附势能的临界值εwc≈-0.6 kBT附近为界,当墙壁-高分子作用势能从弱吸引到强排斥变化时,界面层中的链移动快于中心层,只有当墙壁的吸引作用增强到一定程度时,界面层中的链移动才会慢于中心层.界面动力学受到促进或阻碍可能与界面层和中心层的缠结程度直接相关:界面层的缠结程度保持在本体水平上基本不变;中心层的缠结程度在强吸引表面上低于界面层,而在弱吸引和排斥表面上高于界面层.此外,中心层和界面层中高分子链受限程度的变化对薄膜界面动力学行为的转变产生一定影响.对于薄膜中链密度分布情况随墙壁-高分子作用势能变化的分析为相关的物理化学机制提供了理论依据. 更多还
长春应化所染料敏化太阳电池研究获进展
No full text近日,致力于实时报道全球最新化学与化工研究成果、研究动态及发展趋势的美国《化学与工程新闻》(Chemical&Engineering News)以A Better Perylene Suncatcher为题,报道了中国科学院长春应用化学研究所研究员王鹏课题组发表在《美国化学会志》(J.Am.Chem.Soc.2015,137,3799)上的研究成果。同时,《美国化学会志》还以Metal-free molecule rivals high-performance metal-organic dyes为题对该成果进行了亮点评
主链含N-烷基咔唑环结构聚芳醚酮的性能表征
No full text对含N-烷基咔唑环结构的聚芳醚酮(PPCz E、PPCz B和PPCz H)进行基本物理性能方面的表征,并与商业化酚酞基聚芳醚酮(PEK-C)进行比较。咔唑环结构的引入使聚合物在345 nm附近有强紫外光吸收并表现出发蓝光能力。由于疏水性烷基侧链的存在,聚合物薄膜的水接触角(87°~103°)大于PEK-C(76°),但同时烷基侧链所引起的聚合物链间距的增大导致聚合物的吸水率(0.65%~0.86%)高于PEK-C(0.56%)。此外,聚合物表现出较好的尺寸稳定性(平均线膨胀系数6.4×10-5℃-1)和电绝缘性能(体积电阻率1016Ω·cm)。聚合物的拉伸模量在1.9~2.0 GPa之间,拉伸强度在72.5~75.0 MPa之间以及断裂伸长率在6.5%~7.2%之间。高温条件下(≤225℃),PPCz E仍具有良好的拉伸性能
PVC/α-MSAN/ABS共混物的力学性能与形态结构
No full text采用熔融共混的方法将聚氯乙烯(PVC)树脂、α-甲基苯乙烯-丙烯腈共聚物(α-MSAN)和丙烯腈-丁二烯-苯乙烯接枝共聚物(ABS)共混,通过改变共混物的组成,制备了一系列不同橡胶含量和基体组成的PVC/α-MSAN/ABS共混物,研究了共混物的力学性能及形变机理。结果发现,随着基体树脂中PVC含量的增加,共混物的冲击韧性显著提高,而拉伸强度逐渐降低,同时促使共混物发生脆韧转变所需的橡胶含量逐渐减少。形态结构研究表明,由于基体树脂链缠结密度的增加,共混物的形变机理逐渐由银纹向剪切屈服转变,进而导致体系韧性的增加
新型伊立替康衍生物ZBH-1208的体外抗肿瘤活性及机制研究
No full text目的研究新型伊立替康衍生物ZBH-1208体外对肿瘤细胞的生长抑制作用并初步探讨其作用机制。方法采用四甲基偶氮唑盐比色(MTT)法检测分析ZBH-1208对人宫颈癌HeLa细胞、人非小细胞肺癌A549细胞、人小细胞肺癌NCI-H446细胞、人乳腺癌MCF-7细胞、人结肠癌SW1116细胞、人胃腺癌SGC-7901细胞、人肝癌SMMC-7721细胞及人胚肾293细胞的生长抑制作用,计算IC50值;流式细胞术检测ZBH-1208对肿瘤细胞周期及活化Caspase-3表达的影响。结果 ZBH-1208对肿瘤细胞的生长具有抑制作用,呈剂量-时间依赖关系。ZBH-1208作用各肿瘤细胞后IC50值在0.002μmol/L-0.265μmol/L之间,而对照组伊立替康(CPT-11)的IC50值在0.464μmol/L-52.111μmol/L之间,两者相比较差异均有统计学意义(P<0.05)
基于MATLAB图像处理的金刚石微粉颗粒参数测量
No full text目的探讨不同炮制温度对人参酸性多糖抗氧化活性的影响。方法 ip四氧嘧啶200 mg/kg建立糖尿病小鼠模型,按血糖值随机分为5组,即模型组、阳性组、生晒参酸性多糖组、100℃红参酸性多糖组、120℃红参酸性多糖组,每组12只,同时取健康小鼠做对照组,分别ig 100 mg/kg的人参酸性多糖,每天定时给药1次,给药体积为10 m L/kg体质量,阳性组ig 100 mg/kg格列美脲,模型组和对照组ig等体积的0.9%生理盐水。28 d后分别测定小鼠血清和肝组织中超氧化物歧化酶(SOD)、丙二醛(MDA)、谷胱甘肽过氧化物酶(GSH-Px)、维生素C(VC)和维生素E(VE)的量。结果 3种人参酸性多糖均可提高SOD、GSH-Px活性,降低MDA水平,且作用效果120℃红参酸性多糖>100℃红参酸性多糖>生晒参酸性多糖,并且能提高肝组织和血清中VC和VE的量,且120℃红参酸性多糖效果最明显。结论不同炮制温度的人参酸性多糖均有抗氧化作用,在一定范围内,抗氧化性随炮制温度的升高而增强
弱外延生长红荧烯薄膜
No full text有机半导体材料由于具有分子结构多样性，丰富的物理、化学性质，并且容易实现功能的多样化，与生物亲和性好，可实现柔性器件的制备，易于大面积加工，成本低廉等优势特性，使其成为制备下一代电子器件的有力竞争体系。近几十年来，随着研究的不断深入，有机半导体材料发展迅速，以其为有源材料制备的器件性能得到了大幅度提高。尤其是在晶体管器件方面，已经超越了非晶硅的水平，具有广阔的应用前景。在有机半导体材料中，红荧烯是具有较高晶体管器件性能的一种小分子材料，单晶晶体管迁移率最优可达到40 cm2/Vs，但其薄膜晶体管器件性能却与之存在很大的差距，原因在于其在结晶薄膜的制备上存在困难，红荧烯容易在基底上形成非晶薄膜，进而限制了其薄膜晶体管器件的发展。因此如何制备出高有序的红荧烯结晶薄膜成为了研究热点，但是对于红荧烯结晶薄膜的成核机理还尚不清楚。因此，开展对于高有序红荧烯结晶薄膜成核规律以及特性的研究具有重要的意义...Organic semiconductor materials have become a powerful competitive material system for the preparation of next generation electronic devices duo to their special advantages such as diversity in molecular structures, rich in physical and chemical properties, easy to realize the device with multiple functions, good biological compatibility, realization of flexible device, easy for large-area processing and low cost. In recent decades, with the deepening of the research, organic semiconductor materials developed rapidly and their device performances were improved to a great extent. Especially in the field of transistor devices, the device performance has transcended the amorphous silicon level with a broad application prospect. In organic semiconductor materials, rubrene is a kind of small mo..
An efficient green-emitting alpha-Ca1.65Sr0.35SiO4: Eu2+ phosphor for UV/n-UV w-LEDs: synthesis, luminescence and thermal properties
No full textA series of Eu2+ singly doped alpha-Ca1.65Sr0.35SiO4: Eu2+ phosphors have been synthesized via the high-temperature solid-state reaction method. X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), diffuse reflectance spectroscopy and photoluminescence (PL) including temperature-dependent PL were used to characterize the as-prepared samples. The XRD patterns and Rietveld refinement of the presented sample show the pure phase of the as-prepared samples. All of the phosphors exhibit intense and broad absorption bands in the ultraviolet and near ultraviolet (n-UV) range, and produce bright green emission upon 365 nm UV radiation. The critical concentration of Eu2+ for the maximum intensity was determined to be about 1 mol% in alpha-Ca1.65Sr0.35SiO4: Eu2+ after optimizing the composition. The energy transfer mechanism between Eu2+ was demonstrated to be dipole-dipole interaction. Besides, the fluorescence decay curves, the temperature dependent PL and CIE value of alpha-Ca1.65Sr0.35SiO4: Eu2+ phosphors were investigated. It is reasonable that the decay times of samples decrease with increasing Eu2+ content. The CIE chromaticity coordinates shift from green (0.197, 0.395) to the border between the green and yellow (0.242, 0.547) region, which agree with the corresponding emission spectra. The maximum quantum yield is 69% for alpha-Ca1.65Sr0.345SiO4:0.005Eu(2+). The thermal stability of luminescence of selected alpha-Ca1.65Sr0.34SiO4:0.01Eu(2+) was also investigated and compared with that of the commercial green phosphor, which shows its good performance. The above results suggest that it is a good candidate for green-emitting phosphors applied in UV/n-UV pumped w-LEDs
Recent Advances in the Synthesis and Electrocatalytic Applications of Platinum-Based Bimetallic Alloy Nanostructures
No full textPt-based bimetallic alloy nanomaterials with a low Pt loading can exhibit promising catalytic properties with exciting electrochemical applications. An effective structure control of Pt-based bimetallic alloy nanomaterials is critical to achieve enhanced catalytic properties. This review article focuses on recent advances in the controllable synthesis and electrocatalytic applications of Pt-based bimetallic alloy nanostructures. Recent contributions on the controllable synthesis of a rich variety of Pt-based bimetallic alloy nanostructures, for example, PtPd, PtCu, PtNi, PtCo, and PtFe, and hybrid nanostructures based on Pt-based bimetallic alloy nanomaterials are summarized. Different Pt-based bimetallic alloy nano-electrocatalysts with enhanced activity and durability for different electrocatalytic reactions, such as the fuel cell reaction and the hydrogen evolution reaction, are outlined. Finally, an outlook on future trends and developments is provided
Mussel-inspired biopolymer modified 3D graphene foam for enzyme immobilization and high performance biosensor
No full textA simple and versatile method is described to construct high performance three-dimensional (3D) graphene-based enzyme biosensor. Monolithic and macroporous 3D graphene foam grown by chemical vapor deposition (CVD) was used as a freestanding electrode for co-immobilization of horseradish peroxidase (HRP) and a commonly used redox mediator, methylene blue (MB). Carbon nanotubes (CNTs) were employed as carriers of MB molecules to immobilize them on 3D graphene surface through strong pi-pi stacking force. Mussel-inspired biopolymer polydopamine (PDA) was formed by in-situ polymerization and served as a green linker, which could covalently graft HRP on the surface of 3D graphene/MB-CNTs electrode. In addition, PDA layer could also effectively prevent the leakage of inner electron mediators. Owing to the 3D macroporous architecture, exceptional properties of graphene and surface-bound mediators, the biosensor demonstrated outstanding performance for reagentless detection of H2O2 in terms of wide linear range (0.2 mu M to 1.1 mM), high sensitivity (227.8 mu A mM(-1) cm(-2)), low detection limit (58.0 nM), and fast response (reaching 95% of the steady current within 3 s). The biosensor exhibited high reproducibility and stability. (C) 2015 Elsevier Ltd. All rights reserved