Institute of Chemistry
Changchun Institute of Applied Chemistry, Chinese Academy Of SciencesNot a member yet
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二氧化碳/环氧丙烷/马来酸酐三元共聚物对PPC/PHB共混物力学性能的影响
Get PDF采用稀土三元催化剂制备了二氧化碳-环氧丙烷-马来酸酐三元共聚物(PPCMA).用红外和核磁谱图确定了PPCMA的结构及马来酸酐单元的含量,3 wt%马来酸酐投料量的PPCMA(共聚物中马来酸酐单元含量4.1%)的玻璃化转变温度(Tg)和起始热分解温度(Td-5%)分别为13.4℃和217℃,拉伸强度为2.88 MPa,断裂伸长率为1669%,与二氧化碳-环氧丙烷共聚物(PPC)相比,引入少量马来酸酐的PPCMA有望成为一种韧性材料,并可对PPC和聚3-羟基丁酸酯(PHB)共混体系进行改性.当在PPC/PHB共混体系中添加10 wt%的PPCMA时,所得共混材料的拉伸强度为18.2 MPa,断裂伸长率则提高到85%,较没有添加PPCMA的样品提高了4.25倍,因此PPCMA的加入能有效提高PPC/PHB共混体系的韧性,改善PPC/PHB共混体系的力学性能.偏光显微镜的研究表明PPC/PHB共混体系加入PPCMA后,很快形成大量尺寸小的PHB球晶,且结晶速度大幅度提高,因此PPCMA在一定意义上可视为一种特殊的"成核剂"
一种连续长纤维增强热塑性树脂片材的装置
No full text本发明公开了一种连续长纤维增强热塑性树脂片材的装置,包括浸渍装置、剪切加热装置和给热压延输送装置。使用时,浸渍装置将熔体包裹纤维纱或纤维布,之后进入剪切加热装置,剪切加热装置剪切加热包裹在纤维纱或纤维布上的熔体,且将熔体压入纤维纱或纤维布中,接着,进入热压延输送装置中,给热压延输送装置将熔体包裹的纤维纱或纤维布加热且压延成预设的片材,并输送出来,最终得到连续长纤维增强热塑性树脂片材。本发明提供的连续长纤维增强热塑性树脂片材的装置通过剪切加热装置剪切并加热包裹在纤维纱或纤维布上的熔体,将熔体能够均匀的压入维纱中,使得造出的长纤维增强热塑性树脂片材强度均匀
Approach to High Open-Circuit Voltage in Organic Solar Cells Utilizing a Structural Change of the Oxazolino-C-70 Derivative
No full textReactions of 2,5-Bn2C70 (Bn = CH2Ph) with hydroxide and ArCN (Ar = Ph, m-ClPh) followed by quenching with I-2 and BnBr afforded dibenzylated and tetrabenzylated oxazolino[70]fullerenes, respectively. The latter has a novel structural configuration, in which the addends are positioned from the polar to the transequatorial region. A key structural feature of this compound is that the oxygen atom of the oxazoline ring is bound to the equatorial belt region of C-70, giving structural change in its reduced state. This enables stabilization of the reduced state, suppressing charge recombination dynamics in organic solar cells to give a high open-circuit voltage (0.85, 0.93, and 1.11 V in devices using P3HT, PTB7, and DPP(TBFu)(2), respectively)
Aptamer-Mediated Up-conversion Core/MOF Shell Nanocomposites for Targeted Drug Delivery and Cell Imaging
No full textMultifunctional nanocarriers for targeted bioimaging and drug delivery have attracted much attention in early diagnosis and therapy of cancer. In this work, we develop a novel aptamer-guided nanocarrier based on the mesoporous metal-organic framework (MOF) shell and up-conversion luminescent NaYF4:Yb3+/Er3+ nanoparticles (UCNPs) core for the first time to achieve these goals. These UCNPs, chosen as optical labels in biological assays and medical imaging, could emit strong green emission under 980 nm laser. The MOF structure based on iron (III) carboxylate materials [MIL-100 (Fe)] possesses high porosity and non-toxicity, which is of great value as nanocarriers for drug storage/delivery. As a unique nanoplatform, the hybrid inorganic-organic drug delivery vehicles show great promising for simultaneous targeted labeling and therapy of cancer cells
Competitive binding-accelerated insulin release from a polypeptide nanogel for potential therapy of diabetes
No full textA kind of glucose-sensitive polypeptide nanogel was prepared via a two-step procedure. First, methoxy poly(ethylene glycol)-block-poly(gamma-benzyl-L-glutamate-co-(gamma-propargyl-L-glutamate-graft-glucose) (mPEG-b-P(BLG-co-(PLG-g-Glu))) was synthesized by clicking 2'-azidoethyl-O-alpha-D-glucopyranoside to the PLG unit in mPEG-b-P(BLG-co-PLG), which was synthesized by the ring-opening polymerization (ROP) of gamma-benzyl-L-glutamate N-carboxyanhydride and gamma-propargyl-L-glutamate N-carboxyanhydride with mPEG-NH2 as the macroinitiator. The novel nanogel was subsequently prepared by cross-linking the glucose moieties through adipoylamidophenylboronic acid (AAPBA). The formation of the nanogel, i.e. the successful incorporation of phenylboronic acid (PBA) in the core, was systematically verified. The resultant nanogel showed a remarkable glucose-sensitivity in phosphate-buffered saline (PBS). Thus, insulin as a model drug was loaded into the glucose-sensitive polypeptide nanogel. The in vitro drug release profiles revealed that the release of insulin from the nanogel could be triggered by the presence of glucose through a competitive binding mechanism with the conjugated glucose. In detail, a faster release rate and a larger amount of released insulin were observed by the increased glucose concentration in PBS, which confirmed the potential application of the nanogel. Furthermore, the excellent cytocompatibility and hemocompatibility of the nanogel were demonstrated. Therefore, the biocompatible nanogel with an intelligent capacity for glucose-accelerated payload release should be promising for applications in diabetes treatment
Efficient synthesis and stabilization of poly-(propylene carbonate) from delicately designed bifunctional aluminum porphyrin complexes
No full textBifunctional aluminum porphyrin complexes were designed to synthesize poly(propylene carbonate) (PPC) by copolymerization of propylene oxide and carbon dioxide. The catalytic performance is adjustable via delicate control of the electronic environment of the central Al by the number of methoxy groups in the ligand framework as well as the length of the alkyl chain in the quaternary ammonium cation. The optimal catalyst having six methoxy groups in the ligand framework, two trihexylammonium cations linked to benzene via a six-methylene spacer, and NO3- as the axial ligand and quaternary ammonium anions exhibited a TOF of 1320 h(-1) at 80 degrees C and 3 MPa, and a PPC selectivity of 93%, and the TOF even reached 2824 h(-1) at 90 degrees C and 3 MPa, while the PPC selectivity remained at 89%, the highest recorded in aluminum porphyrin complexes to date. In another concern, even though the bifunctional aluminum porphyrin complex has a soil-compostable feature and can be left in PPC without separation, the depolymerization was very rapid even at 25 degrees C under an ambient atmosphere, and over a 50% decrease in number average molecular weight was observed in 8 days, which could be stabilized by treatment with aqueous HCl solution
Development of a donor polymer using a B <- N unit for suitable LUMO/HOMO energy levels and improved photovoltaic performance
Get PDFThe LUMO/HOMO energy levels of conjugated polymers are key parameters for their applications as polymer electron donors for polymer solar cells (PSCs). The widely-used strategy to tune the LUMO/HOMO levels of polymer donors is to develop D-A type polymers based on an alternating electron-donating unit (D) and an electron-accepting unit (A). In this paper, we report a novel approach to tune the LUMO/HOMO levels of polymer donors via replacing a C-C unit by a B <- N unit for enhanced PSC device performance. The control polymer PCPDT shows the LUMO/HOMO levels of -2.71 eV/-4.98 eV, which are both much higher than those required for an ideal polymer donor. By replacing a C-C unit with a B <- N unit, the resulting polymer PBNCPDT exhibits much lower LUMO/HOMO levels of -3.23 eV/-5.20 eV. PBNCPDT also shows a narrower optical bandgap (E-g = 1.73 eV) than that (E-g = 1.85 eV) of PCPDT, which is helpful for harvesting of sunlight. Moreover, PBNCPDT with the B <- N unit is not a typical D-A type conjugated polymer because its LUMO and HOMO are both delocalized over the whole conjugated framework. As the control PSC device based on PCPDT exhibits an open-circuit voltage (V-oc) of 0.45 V and power conversion efficiency (PCE) of 0.63%, the device of PBNCPDT shows much improved V-oc of 0.82 V and PCE of 3.74%. These results indicate that a B <- N unit can be used to develop polymer donors for high-performance PSC devices
新型钴-铈催化剂的设计合成及性能研究
No full text二氧化铈（CeO2）以其独特的储放氧性质成为催化剂领域的研究热点。对一系列的氧化还原反应，CeO2都表现出了优异的催化性能。更重要的是，大量研究表明，将CeO2与其他催化活性组分结合，设计合成新型杂化纳米催化剂，可以实现其催化性能的优化，这是由于CeO2与其他组分之间存在一定的协同作用。而且通过CeO2壳包覆纳米催化剂可以有效地改善催化剂的热稳定性。将CeO2与具有良好CO催化氧化性能的Co3O4结合可能有利于催化性能的进一步优化。本论文围绕Co3O4@CeO2核壳催化剂的设计合成开展了一系列系统性研究工作，主要包括以下几个部分： （1）我们报道了一种简单快速的自组装方法，第一次合成了高质量的Co3O4@CeO2核壳立方块。通过简单改变自组装过程中反应物的加入比例实现了对Co3O4@CeO2样品中CeO2壳层厚度的调控。对所合成的具有不同CeO2壳层厚度的Co3O4@CeO2系列样品进行了...CeO2, which possesses strong oxygen storage capacity, has become the research focus in the catalysis area. It is highly catalytic active in lots of reduction and oxidation reaction. More importantly, lots of previous literatures have shown that when combined CeO2 with other catalytic active components, the designed and fabricated novel hybrid structures show much enhanced catalytic performances. It can be attributed to the excellent synergistic effects between the two conponents. Moreover, the thermal stability of the catalysts can also be improved by encapsulating other catalytic active components in CeO2 shell. Since Co3O4 shows great performance for catalytic CO oxidation, it is reasonably considered that the catalytic performance of Co3O4 catalyst could be optimized through the combina..
环境友好催化剂下二氧化碳和环氧丙烷的共聚/偶联反应
No full text二氧化碳（CO2）是一种储量丰富、价格低廉、无毒的C1资源，以其为原料制备大宗化学品是一条高附加值利用二氧化碳的有效途径。其中，利用二氧化碳与环氧化物偶联反应制备环状碳酸酯和聚碳酸酯备受关注。环状碳酸酯可以被广泛地用作溶剂、电解液、燃料添加剂和合成聚合物的中间体；聚碳酸酯则可以用作制备食品和医用包装材料等。但是，二氧化碳热力学上高度稳定，合适的催化剂可以大大降低该反应的活化能，是活化二氧化碳、促进反应进行的有效方法。经过几十年的努力，科研工作者们已经制备出了一系列催化剂用于二氧化碳与环氧化物的共聚/偶联反应。其中的Salen钴催化剂不论是用于二氧化碳与环氧化物偶联还是共聚合，都体现了很高的活性和选择性，是该领域综合性能最好的催化体系。但是金属钴的毒性较大，尤其是作为生物降解塑料使用时，堆肥过程严格限制了钴的残留，因此大大限制了其应用。其它的催化体系如铁系、钛系和铝系催化剂，尽管单一某种性能...Carbon dioxide (CO2) is an abundant, cheap and non-toxic C1 resource. Employing CO2 as a raw material to prepare large scale chemicals may create a way to high value-added utilization of CO2. Among all the reported CO2 fixation routes, the copolymerization/coupling of CO2 and epoxide to prepare polycarbonates and cyclic carbonates has drawn much attention. Polycarbonates may find new applications in throw-away packages and biomedical materials, while cyclic carbonates are widely used as green solvents, electrolytes, fuel additives and intermediates for the production of polymers. However, CO2 has high thermodynamic stability, suitable catalyst is necessary to promote the above reaction. In recent decades, numerous catalyst systems have been reported to catalyze this transformation, among w..
利用液-液界面在离子液体萃取体系可控制备稀土纳米材料
No full text液-液界面法是近年来发展起来的一种合成纳米材料的方法。这是将一种前驱物溶于一相，另一种反应物溶于另一相，并在液-液界面处进行的反应。液-液界面合成法具有诸多优点，例如简单直接、成本低、不需要模板和载体等，因而在材料制备方面展示出了广阔的应用前景。近年来萃取体系在纳米材料制备方面的研究一直受到人们的广泛关注，原因在于该方法具有适用性强、便于放大、成本低廉、操作简便等优点。因为负载有机相中的萃取络合物可以作为纳米材料的前驱体来，因此萃取体系很适合用液-液界面法来合成纳米材料。另外，将离子液体应用于萃取体系，还可以利用离子液体便于调控的特性来控制纳米材料的制备。因此本文主要讨论结合离子液体和萃取体系的特点，利用液-液界面法可控合成稀土纳米材料的新方法。 在[A336][Cyanex272]萃取体系中，利用负载有机相和含有沉淀剂的水溶液形成的油-水界面，使用液-液界面法制备了不同形貌的CePO4纳...In recent years, the liquid-liquid interface synthesis is emerging as a facile, convenient, and inexpensive strategy for the preparation of nanomaterials owing to its unique structures and properties. This method involves dissolving an organic precursor of the relevant metal in one layer and the appropriate reagent in another layer, then the reaction proceeds at the interface. This method exhibits many advantages, including straightford, imexpensive, template-free and supporter-free. As an important system of wet strategy to prepare rare earth nanomaterials, the extraction system has some unique advantages, such as wide applicability, easy to scale-up, low cost and simple operation. As the extracted complex in the organic phase can be used as the precursor, the extraction system is suitabl..