激光诱导三维网状石墨烯的一步法制备及应用

三维多孔石墨烯作为一种优异的石墨烯碳材料, 其独特的多孔结构使得材料在具有较大比表面积的同时还保持着足够高的电子迁移率和机械稳定性, 在电子器件中得到了广泛的应用. 本文介绍的激光诱导石墨烯是一种以一步法直接制备得到的三维网状石墨烯材料, 该技术将三维石墨烯的制备和图案化相结合, 无需进行湿化学反应处理, 制作方法更简便, 材料性能更优异. 目前研究主要集中在通过掺杂提高性能和利用转移法实现不同基底器件的制备. 激光诱导石墨烯自身特有的属性如多孔微纳米结构和大的比表面积等使其在超级电容器和传感器等领域拥有较高的应用价值.     

Pt-Ni/γ-Al2O3 双金属催化剂上1,3-环己二烯的低温加氢和脱氢反应

 采用等体积浸渍法制备了 γ-Al2O3 负载的 Pt 和/或 Ni 双金属催化剂或单金属催化剂, 测定了它们的 CO 化学吸附量, 并在原位红外间歇反应装置上评价了其催化 1,3-环己二烯 (1,3-CHD) 的低温 (308 K) 加氢和脱氢性能. 结果表明, Pt-Ni/γ-Al2O3 催化剂性能优于 Pt/γ-Al2O3 或 Ni/γ-Al2O3. 结合密度泛函理论计算的不同催化剂上 1,3-CHD 的表面吸附能, 验证了具有较弱环烯烃吸附能的双金属催化剂加氢活性较高.     

Quantitative characterization of membrane formation process of alginate–chitosan microcapsules by GPC

The semi-permeable membrane of alginate–chitosan (AC) microcapsules has been proven important to control the microcapsule stability and selective substance diffusion rate. Therefore, a novel and operable methodology based on gel permeation chromatography (GPC) was established for quantitative characterization of the membrane formation process, so as to provide guidance on performance improvement of AC microcapsules in biomedical applications. Not only the molecular weight (M_w) and its distribution of chitosan can be obtained by GPC, but also the area integral of molecular weight peaks can be linearly correlated to chitosan concentration in certain range. The dynamic membrane formation process was then obtained by quantitatively analyzing reaction amount of chitosan with time, which showed that for chitosan molecules with wide M_w distribution, only parts of molecules bind with alginate to form microcapsule membrane. Moreover, the contribution of chitosan molecules participating in the membrane formation process was also different. These new findings, therefore, are helpful for adjusting and controlling the membrane formation process and properties of microcapsule membrane.     

Monitoring of Cell Viability and Proliferation in Hydrogel-Encapsulated System by Resazurin Assay

Cell microencapsulation is a promising approach for cell implantation, cell-based gene therapy and large-scale cell culture. For better quality control, it is important to accurately measure the microencapsulated cell viability and proliferation in the culture. A number of assays have been used for this purpose, but limitations arise. In this study, we investigated the feasibility and reliability of resazurin as a cell growth indicator in microencapsulated culture system. According to the experiment data, there was a reversible, time- and dose-dependent growth inhibition as observed for resazurin application in encapsulated cells. A positive relationship was observed between reduction of resazurin and CHO cell number in microcapsule. Moreover, the resazurin assay provided an equivalent result to the commonly used MTT method in determining CHO cell proliferation in APA microcapsule with no notable influence on cell distribution and organization pattern. In conclusion, resazurin assay is offered as a simple, rapid and non-invasive method for in vitro microencapsulated cell viability and proliferation measurement.     

An Antibacterial Nonenzymatic Glucose Sensor Composed of Carbon Nanotubes Decorated with Silver Nanoparticles

A glucose sensor composed of silver nanoparticles decorated carbon nanotubes (Ag‐NPs/CNTs) prepared by ion implantation is described. Ag‐NPs with size of 2–4 nm are uniformly distributed in the CNTs after ion implantation. This process provides a strong combination between Ag‐NPs and CNTs and can effectively prevent the Ag‐NPs from aggregation. A linear range of 125 µM to 10 mM towards glucose determination was obtained. The Ag‐NPs/CNTs electrode shows minimal interferences from co‐existence species such as uric acid and ascorbic acid and an antibacterial rate of 94 % towards E. coli.     

A Nanoscale Multiresponsive Luminescent Sensor Based on a Terbium(III) Metal–Organic Framework

A nanoscale terbium‐containing metal–organic framework ( nTbL ), with a layer‐like structure and [H₂NMe₂]⁺ cations located in the framework channels, was synthesized under hydrothermal conditions. The structure of the as‐prepared sample was systematically confirmed by powder XRD and elemental analysis; the morphology was characterized by field‐emission SEM and TEM. The photoluminescence studies revealed that rod‐like nTbL exhibited bright‐green emission, corresponding to ⁵D₄→⁷F_J (J=6–3) transitions of the Tb³⁺ ion under excitation. Further sensing measurements revealed that as‐prepared nTbL could be utilized as a multiresponsive luminescent sensor, which showed significant and exclusive detection ability for Fe³⁺ ions and phenylmethanol. These results highlight the practical applications of lanthanide‐containing metal–organic frameworks as fluorescent probes.     

非共价键交联海藻酸钠水凝胶的制备与性能

天然多糖海藻酸钠制备的水凝胶具有优越的生物相容性和生物组织相似性,作为生物医用材料在药物控制释放、组织工程支架、抗菌材料及创伤敷料等领域发挥着越来越大的作用。本文在介绍海藻酸钠物化性质的基础上,重点综述了非共价键交联(静电作用、氢键、范德华力、亲疏水作用等)海藻酸钠水凝胶的制备方法以及性能表征方法,最后讨论了制备方法及性能表征研究中的一些需要解决的问题。     

Heterometallic zinc uranium oxyfluorides incorporating imidazole ligands

Two heterometallic uranium oxyfluorides with hybrid networks were hydrothermally synthesized by incorporating two imidazoles, 1-(biphenyl-4-yl)-1H-imidazole(bpi) and 1,4-di(1H-imidazol-1-yl)benzene(dib), formulated as Zn(bpi)2(UO2)2(H2O)F6(1) and Zn(dib)(UO2)F4 0.5H2O(2). Compound 1consists of chains of edge-sharing UO2F5 and UO2F4(H2O) pentagonal bipyramids, which are linked by Zn(bpi)2moieties to form the sheet structure with decorated bpi. While in compound 2, sheets of edgesharing dimers of UO2F5 pentagonal bipyramids and Zn F3N2 polyhedra are linked by dib, creating a pillared three-dimensional framework. The two compounds represent the few examples of heterometallic uranium oxyfluorides incorporating organic ligands. The syntheses, structure as well as the IR spectra, UV–vis spectra and luminescent properties of the bimetallic uranium oxyfluorides are studied.     

Self‐Assembled Colloidal Particle Clusters from In Situ Pickering‐Like Emulsion Polymerization via Single Electron Transfer Mechanism

A simple route is reported to synthesize colloidal particle clusters (CPCs) from self‐assembly of in situ poly(vinylidene fluoride)/poly(styrene‐co‐tert‐butyl acrylate) [PVDF/P(St‐co‐tBA)] Janus particles through one‐pot seeded emulsion single electron transfer radical polymerization. In the in situ Pickering‐like emulsion polymerization, the tBA/St/PVDF feed ratio and polymerization temperature are important for the formation of well‐defined CPCs. When the tBA/St/PVDF feed ratio is 0.75 g/2.5 g/0.5 g and the reaction temperature is 35 °C, relatively uniform raspberry‐like CPCs are obtained. The hydrophobicity of the P(St‐co‐tBA) domains and the affinity of PVDF to the aqueous environment are considered to be the driving force for the self‐assembly of the in situ formed PVDF/P(St‐co‐tBA) Janus particles. The resultant raspberry‐like CPCs with PVDF particles protruding outward may be promising for superhydrophobic smart coatings.

     

(NH4)6[Mn3B6P9O36(OH)3]·4H2O: a new open-framework manganese borophosphate synthesized by using boric acid flux method

A new three-dimensional (3-D) open-framework manganese borophosphate, (NH(4))(6)[Mn(3)B(6)P(9)O(36)(OH)(3)]·4H(2)O (denoted as MnBPO-CJ31), has been synthesized by using boric acid flux method. Its anionic framework structure is constructed by the connection of MnO(6) octahedra and BO(4), PO(4) and PO(3)(OH) tetrahedra. It contains 12-ring channels along the [001] direction with a pore diameter of 7.1 ?. It is the first borophosphate featuring a 3-D anionic partial structure with a B/P ratio of 2/3 and an unprecedented fifteen mer tetrahedral fundamental building unit (FBU) [B(6)P(9)O(36)(OH)(3)] exists in this compound. NH(4)(+) ions locate in the void space to balance the negative charge of the inorganic framework. The compound is further characterized by powder XRD, ICP, CHN, TGA and IR analyses. Magnetic study reveals that MnBPO-CJ31 shows interesting canted antiferromagnetic behaviour at low temperature.