表面印迹聚合物的制备及其在药物分离分析中的应用

表面分子印迹技术是在载体表面上发生聚合反应,将分子识别位点建立在载体的外层或者表面。从而使表面分子印迹聚合物具有结合速度快、识别选择性强、结合容量高、提高印迹材料的效率等优点。近年来表面分子印迹技术在药物分离分析中的应用引起人们的关注。简要介绍了表面分子印迹聚合物的原理及4种制备方法(溶胶-凝胶法、接枝共聚法、牺牲载体法、聚合加膜法、活性可控自由基聚合法),并对其在药物分离分析的4个方面(中药提取分离中;药物传感器方面;手性药物拆分中;药物释放中)的应用进行了综述。     

中空型分子印迹聚合物的制备及其对4-甲基二苯并噻吩的吸附性能研究

以SiO2为载体,4-乙烯基吡啶为功能单体,结合牺牲载体法合成了一种具有特异性识别4-甲基二苯并噻吩的中空型分子印迹聚合物。利用傅立叶变换红外光谱、氮气吸附实验、扫描电镜对形态结构进行了表征。通过在模拟油中的静态吸附试验,对印迹聚合物的吸附性能进行了研究。结果表明,在SiO2表面成功地合成了具有多孔结构的分子印迹层,经过牺牲载体法处理后得到的中空分子印迹聚合物具有更好的表面特性,提高了吸附性能。中空型分子印迹聚合物对4-甲基二苯并噻吩表现出良好的特异性识别性能,吸附动力学满足Langergren准二级动力学方程,等温线符合Freundlich等温线模型,吸附热力学研究表明吸附是自发的吸热过程,在328K下的吸附容量为18.31498mg/g,吸附平衡时间为3h。     

分子印迹聚合物微球制备方法研究进展

分子印迹聚合物微球具有制备简单、使用方便、分子识别效率高且便于控制粒径大小和功能设计等优点，近年来成为分子印迹技术领域研究的热点之一。对分子印迹聚合物微球的制备方法：溶胀悬浮聚合法、沉淀聚合法、悬浮聚合法和表面聚合法及其最新研究进展作了较为详细的综述。     

茶碱表面分子印迹聚合物微球的制备及性能

以Poly(GMA-DVB)微球为载体,将4,4′-偶氮双(4-氰基戊酸)(ACPA)连接到微球表面,然后以茶碱为模板分子,α-甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸酯(EGDMA)为交联剂,通过4,4′-偶氮双(4-氰基戊酸)(ACPA)引发聚合,在Poly(GMA-DVB)微球表面上均匀地接枝分子印迹聚合物,制备茶碱表面分子印迹聚合物微球。借助红外、电镜、粒度等表征方法对微球的制备进行了评价和探讨,采用静态法研究微球对茶碱的结合性能与分子识别特性。研究表明,分子印迹微球的接枝率随着载体微球表面环氧基含量的增加以及溶剂用量的减少而增大;分子印迹微球对茶碱具有特异的识别选择性与优良的结合亲和性,相对于咖啡碱识别选择性系数为2.81~3.62,室温吸附3 h内可以达到吸附平衡。     

分子印迹聚合物微球合成方法研究进展

对近年来发展起来的分子印迹聚合物微球(MIPMs)合成方法的研究进展进行了综述。重点介绍了表面分子印迹聚合物合成法、核-壳型分子印迹聚合物合成法、基于β-环糊精分子印迹聚合物的合成法3种新型MIPMs制备方法。阐述了常用的沉淀聚合法、种子溶胀聚合法、悬浮聚合法合成MIPMs的发展现状。最后对MIPMs的发展趋势提出了展望。     

不同载体的表面离子印迹聚合物的特性及其应用

表面离子印迹聚合物近年来在固相萃取、膜分离、化学生物传感器等领域展现出良好的应用前景.表面离子印迹技术是将离子识别位点设计在载体表面或接近表面的地方,制得的表面离子印迹聚合物与传统的离子印迹聚合物相比,具有目标离子更易接近识别位点、吸附更快、吸附容量更高等优点.简述了表面离子印迹的最新研究进展,根据载体种类分别介绍了以...     

盐酸二甲双胍磁性分子印迹聚合微球的合成

以盐酸二甲双胍为模板分子、Fe_3O_4为磁核、α-甲基丙烯酸为功能单体、乙二醇二甲基丙烯酸酯为交联剂、偶氮二异丁腈为引发剂,采用表面印迹聚合法成功制备了对盐酸二甲双胍具有特异性识别功能的磁性分子印迹聚合微球。合成的磁性聚合物具有良好的磁响应,在外加磁场下可实现快速磁分离。红外光谱、X射线光电子能谱和扫描电镜结果证实聚合物为核壳结构,磁性粒子由硅烷偶联剂完全包覆,并在其表面形成了一层分子印记聚合物。静态吸附实验结果表明,制备的磁性分子印迹聚合物对模板分子盐酸二甲双胍具有良好的吸附能力,其饱和吸附量为83mmol/kg。以双胍类降糖成分盐酸丁二胍和盐酸苯乙双胍为竞争分子,磁性印迹聚合物对模板分子表现出良好的特异选择性。     

2,4,6-三硝基甲苯磁性分子印迹聚合物的合成

以2,4,6-三硝基甲苯(TNT)为模板分子、氨丙基三乙氧基硅烷为功能单体、正硅酸乙酯为交联剂,采用溶胶凝胶法成功制备了对TNT具有特异选择识别功能的磁性分子印迹聚合物。合成制备的磁性分子印迹聚合物具有良好的磁响应性,在外加磁场下可实现快速分离。红外光谱(FT-IR)、X射线光电子能谱和扫描电镜结果证实聚合物为核壳结构,磁性粒子由硅烷偶联剂完全包覆,并在其表面形成了一层分子印记聚合物;静态吸附实验结果表明,制备的磁性分子印迹聚合物对模板分子TNT具有良好的吸附能力,其饱和吸附量为77mmol/kg;通过以3,4-二硝基甲苯(DNT),为结构相似物的吸附选择性实验,磁性印迹聚合物对模板分子表现出良好的特异选择性。     

分子印迹纳米材料研究进展

概括分子印迹技术、纳米材料、分子印迹纳米材料研究状况;概述沉淀聚合法、表面分子印迹法、溶胶-凝胶聚合法、原位聚合法、磁性纳米粒子聚合法等分子印迹纳米材料合成方法;总结分子印迹纳米材料在样品前处理及色谱检测和纳米分子印迹传感器方面的应用。认为纳米技术和分子印迹技术相结合,可打破传统分子印迹聚合物的缺陷和不足,赋予分子印迹纳米材料良好的选择特异性、更高的结合能力、高的灵敏度和更快的结合动力学特性,在蛋白质、血液、传感器等方面会有广泛的应用。提出对纳米结构分子印迹材料进行研究须解决的问题。     

活性自由基聚合的白藜芦醇分子印迹聚合物的合成及在葡萄皮白藜芦醇分析中的应用

RAFT试剂介入制备白藜芦醇分子印迹聚合物并用于实际样品中白藜芦醇的分离富集。以二苄基三硫代碳酸酯(DBTTC)为RAFT试剂,以白藜芦醇为印迹化合物,以丙烯酰胺作为功能单体,利用可逆加成-断裂链转移自由基聚合法(RAFT)制备了白藜芦醇分子印迹聚合物。利用扫描电镜、红外光谱和色谱法考察了单体与交联剂比例、引发剂用量、溶剂用量、反应时间和反应温度对印迹聚合物形态结构、印迹聚合物的识别能力及分离效率的影响。结果显示,利用RAFT聚合法制备的白藜芦醇分子印迹聚合物对模板分子的结合量Q达到1 283μg/g,并具有特异性识别作用。通过活性自由基聚合法合成的分子印迹聚合物具有更好的形态结构,对目标分子具有较高的吸附效率。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Synthesis of Alumina-Zirconia Nanocomposites by Solgel Process

Al₂O₃-ZrO₂ nanocomposites were developed starting with the solgel process. Composite alumina-zirconia nanopowders were synthesized from metallorganic precursors (Aluminium secondary butoxide and zirconium Iso propoxide) using the solgel process. The parameters affecting the synthesis—solvent, concentration of precursor, R/H ratio (i.e., dilution of water in solvent)—were varied as also the temperature and pH. BET and TEM were used to measure nanosize. Diffuse reflectance spectroscopy and also qualitative optical absorption led to identical particle size estimate. The variation of process parameters was used to study the effect and interdependence of process parameters. Artificial Neural Networks was used to rigorously analyze the process. Although this led to confirmation of interdependence of parameters, the presence of a single overwhelming solvent variable was also established. Then the optimal process was used to synthesize more nanopowder. To produce bulk nanocomposite the nanopowders were sintered by varying the temperature and time period. The sintered lithoids were probed with a vickers hardness tester to measure elastic modulus, hardness, and fracture toughness. The results showed high elastic modulus, modest hardness, and very high fracture toughness.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.