Institute of Chemistry
Changchun Institute of Applied Chemistry, Chinese Academy Of SciencesNot a member yet
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基于紫外光引发表面接枝聚合的聚合物刷研究
No full text聚合物刷以其化学成分可调、结构可控等特点，已成为材料表面/界面功能化与性质调控的重要手段，并在诊断、抗吸附、抗腐蚀以及生物医药领域显示出潜在的应用。本论文主要利用紫外光引发表面接枝聚合和稀土金属催化的表面引发基团转移聚合方法在系列无机与聚合物材料表面（二氧化钛薄膜、硅片、氧化锆粒子、聚合物微球、交联聚合物薄膜）接枝聚合物，并对其结构与性质进行了系统研究，进而将所合成的聚合物刷应用于制备非均相催化剂和化学响应型开关，主要研究成果如下： （一）基于无定形二氧化钛平面基底，建立了一种操作简便、快速制备聚合物刷的新方法。利用紫外光引发表面接枝聚合方法在二氧化钛表面制备了聚甲基丙烯酸甲酯刷、聚苯乙烯刷、聚4-乙烯基吡啶刷和聚N-乙烯基咪唑刷。通过傅里叶红外光谱、X光电子能谱、水接触角、原子力显微镜等对制备聚合物刷的结构与表面形貌进行了系统表征，证实了紫外光引发表面接枝聚合反应的成功进行。通过聚合物刷...Polymer brushes are emerging as key elements in the context of regulating the surface characteristics of materials due to their structural controllability and adjustable functionalities. Therefore, they play a vital role in a wide range of potential applications, such as diagnosis, antifouling, corrosion resistance and biomedical area. This thesis describes how to prepare polymer brushes on some versatile materials, such as planar titanium dioxide, silicon wafers, zirconia particles, polymer microspheres and untrathin cross-linked polymer network ?lm via UV light initiated photografting and photopolymerization and the surface-initiated group transfer polymerization (SIGTP) mediated by rare earth metals. The as-prepared polymer brushes can be further employed to form hybrid catalyst system ..
Electronic vs Steric Effects on the Stability of Anionic Species: A Case Study on the Ortho and Para Regioisomers of Organofullerenes
No full textThe stability of the anionic species of the ortho and para regioisomers of (MeO)BnC(2)n (Me = methyl, Bn = benzyl, n = 30 or 35) has been examined. The results show that the ortho adducts (electronically favored regioisomers) are stable upon receiving one or two electrons, while the para ones (sterically favored adducts) decompose by removing the methoxy group under similar conditions. Computational calculations indicate that the stability of the anionic species is significantly affected by the electronic structure, where the [5,6]-double bond is responsible for the instability of the reduced species of the para adducts. Further study with 1,15-(MeO)(2)-2,4-Bn2C60, an adduct with both the ortho and para positioned methoxy, shows that the reduced species is stable, indicating that the 1,2,4,15-configuration is an electronically preferential structure even though it has a [5,6]-double bond
Employment of triketones to construct a dysprosium(III) single-molecule magnet
No full textThe initial employment of a triketone ligand in 4f coordination chemistry afforded a series of dinuclear complexes. Magnetic studies revealed that an antiferromagnetic interaction exists in a digadolinium(III) compound, while a dysprosium(III) constructed complex exhibits single-molecule magnet (SMM) behaviour at low temperatures with an energy barrier of 86.8 K
Well-defined phosphino-phenolate neutral nickel(II) catalysts for efficient (co)polymerization of norbornene and ethylene
No full textPhosphino-phenolate neutral nickel catalysts 1-3/B(C6F5)(3), without the help of any organoaluminum compound, were found to be efficient catalytic systems for norbornene polymerization and its copolymerization with norbornene derivatives. The amount of B(C6F5)(3) required for achieving a high efficiency (3 equiv.) was markedly lower compared to previous reports, and high molecular weight polymers were obtained (>10(6) g mol(-1)). Efficient incorporation of polar monomers NBC, NBA, and NBM was also achieved in a controllable fashion, yielding high molecular weight copolymers. Catalysts 1-3 were highly active for ethylene polymerization as single component catalysts, with an activity of up to 10(7) g mol(Ni)(-1) h(-1), and catalyst 3 was more readily initiated at lower temperature. Catalysts 1-3 were also efficient in incorporating norbornene (up to 30%) into the polyethylene backbone. Bisligated phosphino-phenolate nickel complex 4 and salicylaldimine complex 5 were also studied for comparison, which further verified the unique performance of catalysts 1-3. Preliminary NMR analyses were conducted to explore the norbornene polymerization mechanism
Thiadiazole molecules and poly(ethylene glycol)-block-polylactide self-assembled nanoparticles as effective photothermal agents
No full textA new photothermal nano-agent was obtained by the coprecipitation of 2,5-Bis(2,5-bis(2-thienyl)-N-dodecyl pyrrole) thieno[3,4-b][1,2,5] thiadiazole (TPT-TT) and a biodegradable amphiphilic block copolymer, methoxypoly(ethylene glycol)(2K)-block-poly(D,L-lactide)(2K) (mPEG(2K)-PDLLA(2K)). TPT-TT, a donor-acceptor-donor (D-A-D) type small molecule, with bis(2-thienyl)-N-alkylpyrrole (TPT) as the donor and thieno[3,4-b]thiadiazole (TT) as the acceptor was a strong near infrared (NIR) absorber, which could convert the absorbed light energy into heat. The formation of TPT-TT nanoparticles (TPT-NPs), which possessed high stability in water, was confirmed by dynamic light scattering (DLS) and transmission electron microscopy (TEM). TPT-NPs showed high photothermal conversion efficiency (32%) and excellent photostability and heating reproducibility. The photostability of TPT-TT NPs was much better than that of indocyanine green (ICG), a federal drug administration (FDA) approved NIR dye. Besides, TPT-TT NPs exhibited significant photothermal therapeutic effect toward human cervical carcinoma (HeLa) and human liver hepatocellular carcinoma (HepG2) cells, while no appreciable dark cytotoxicity was observed. These results highlight the potential of TPT-TT NPs as an effective photothermal agent for cancer therapy. (C) 2015 Elsevier B.V. All rights reserved
Constructing calixarene-supported high nuclearity Co-27, Co-28 and Ni18Na6 clusters with triazoles as co-bridges
No full textThree nanosized flying saucer-like cobalt compounds, [Co-28(TC(4)A)(6)(3-SH-trz)(8)(di-S-trz)(4)(SO4)Cl-10(OH)(4)(CH3OH)(4)(H2O)(6)] (CIAC-210), [Co-27(TC(4)A)(6)(3-SH-trz)(8)(di-S-trz)(4)(CO3)(0.25)(SO3)(0.75)Cl-10(OH)(2)(CH3OH)(2)(H2O)(4)] (CIAC-1211) and [Co-28(TC(4)A)(6)(trz)(16)(CO3)Cl-11(OH)(3)(CH3OH)(2)(H2O)(6)] (CIAC-212), and one ring-like mixed NiNa compound, [Ni18Na6(TC(4)A)(6)(3-S-trz)(6)Cl-6(H2O)(6)] (CIAC-213), were obtained by solvothermal reactions of the metal salts, p-tert-butyltetrathiacalix[4]arene (H(4)TC(4)A) and 1H-1,2,4-triazole-3-thiol (1H-3-SH-trz)/1H-1,2,4-triazole-3-carboxylic acid (1H-3-COOH-trz). All these four compounds are feathered with some shuttlecock-like secondary building units (SBUs) which are constructed by four metal atoms capped by a calixarene molecule. In CIAC-210, -211 and -213, the M4-TC4A SBUs are bridged together by 3-SH-trz and its dimer, forming high nuclearity clusters, while in CIAC-212, the SBUs are bridged by 1H-1,2,4-triazole (trz). It is found that not only the kind of metal and the molar ratio of the reactants play important roles in the formation of the clusters, but also the mixed solvents and their ratio affect the final structures. Magnetic measurements suggested that the metal centers exhibit antiferromagnetic interactions for all these four compounds
Mesoscale morphology evolution of a GdAl3(BO3)(4) single crystal in a flux system: a case study of thermodynamic control of the anisotropic mass transfer during crystal growth
No full textIn the flux system of GdAl3(BO3)(4), the compromise in competition between thermodynamic and kinetic control on the mass transfer has been studied from the viewpoint of chemical engineering. Different control mechanisms on the mass transfer in the melt growth system result in various mesoscale morphologies of a single crystal. Both the calculated and experimental results demonstrate thermodynamic control of the anisotropic mass transfer during crystal growth, leading to the mesoscale morphology evolution of the GdAl3(BO3)(4) single crystal similar to the matryoshka. The present work can deepen our understanding of mesoscale morphology evolution of the GdAl3(BO3)(4) single crystal in the flux growth system
A microfluidic-based controllable synthesis of rolled or rigid ultrathin gold nanoplates
No full textA continuous, microfluidic-based, seed-mediated synthesis of high-purity gold nanoplates with different thicknesses was developed. The thickness of the nanoplates can be fairly tuned from less than 1 nm to a few nm by varying the flow rate. Depending on the thickness, the obtained nanoplates could be rigid and flat-surfaced with thicknesses larger than 2 nm or flexible with crumpled or rolled shapes when the thickness is around 1 nm. These nanoplates are poly-crystalline with different crystal faces and show high electrochemical activity towards glucose oxidation
A facile hard-templating synthesis of mesoporous spinel CoFe2O4 nanostructures as promising electrocatalysts for the H2O2 reduction reaction (vol 4, pg 1754, 2014)
No full textPalladacycles derived from arylphosphinamides for mild Suzuki-Miyaura cross-couplings
No full textWe present a type of palladacyclic complexes derived from arylphosphinamides which can be used as efficient and versatile precatalysts for mild Suzuki-Miyaura cross-coupling. With the presence of 1.0 mol% of palladacycles, a wide variety of aryl bromides and boronic acids could be coupled very efficiently at ambient temperature and under air atmosphere without the need of external supporting ligands. Moreover, the mild conditions also allow for smooth coupling of electron-deficient, i.e., the less stable aryl triflates. In addition to the highly catalytic activity, the palladacyclic complexes can be very easily prepared through a two-step procedure from the readily affordable diphenyl-phosphinic chloride and exhibit excellent stability toward air and moisture. Due to these prominent properties, the new palladacycles would find practical use in Suzuki-Miyaura couplings