悬浮聚合制备大粒径磁性聚甲基丙烯酸甲酯微珠: 反应参数对微珠粒径的影响

采用低速搅拌悬浮聚合制得了一系列磁性聚甲基丙烯酸甲酯(PMMA)微珠. 分别以聚乙烯醇(PVA 1788)和碱式碳酸镁作为稳定剂和助分散剂, Fe3O4磁流体为磁性物质, 双甲基丙烯酸甲酯为交联剂. 所有粒子的直径在1～3 mm 范围内, 微球的粒径及其分布可以通过改变聚合反应介质来进行调节. 着重研究了反应体系中电解质的用量、聚合反应温度、水油比、碱式碳酸镁及交联剂的用量等反应参数对微球粒径的影响. 利用振动探针式磁强计(VSM)和原子吸收光谱(AAS)分别对磁性PMMA微珠的超顺磁性和Fe3O4含量进行了表征.     

磁性复合材料在分离分析中的应用研究进展

磁性复合材料主要包括磁性碳复合材料、磁性聚合物复合材料和磁性金属复合材料等,它们在食品、环境和生物分析等领域具有广泛的应用。作为磁性复合材料的核心部分,磁性纳米粒子(MNPs)具有超顺磁性、高比表面积、化学稳定性和重复利用性等特点,被大量运用于各类磁性复合材料的制备。由于磁性复合材料的多孔性、高吸附能力以及快速分离等特点,MNPs已被广泛应用于生物大分子、小分子和金属离子等的分离分析。本文重点介绍了一些典型的磁性复合材料,并综述了其在包括蛋白质、核酸、染料、农药、多环芳烃、金属离子以及其他污染物等分离分析中的最新研究,为磁性复合材料在分离分析领域的发展提供了理论依据和技术支撑。     

磁性纳米材料在样品前处理中的应用进展

磁性纳米材料作为一种新型功能复合材料,因其具有吸附能力强、表面可修饰、易分离和良好的生物相容性等特点,已广泛应用于生物传感器、药物传导和医学成像方面。由于磁性纳米材料分离速度快且吸附性能好,因此在分析化学样品前处理中的应用也日益受到人们的关注。本文简略介绍了磁性纳米材料的特性、分类及制备方法,综述了磁性纳米材料在分离和富集生物大分子、有机物和无机物中的应用,并展望了磁性纳米材料的应用前景。     

磁性微球的制备及研究进展

磁性微球作为一种新型功能材料,在磁性材料、生物工程等领域有着广泛的应用前景。文章对磁性高分子微球的制备方法、性质作了较详细的综述,着重介绍了磁性微球在细胞分离、蛋白质的提纯、固定化酶、靶向给药及核酸的分离等领域的应用。     

磁性粒子在蛋白质分离纯化中的应用

磁性粒子与磁性分离技术结合用于生物分子和生物微粒的分离近年来受到了广泛关注。磁性粒子经过适当的表面修饰,可高度选择性地结合目标蛋白,在解决蛋白质的快速分离及高特异性的选择性分离方面具有优势。随着蛋白质组学研究的发展,磁性粒子用于蛋白质分离纯化的研究日渐增多。本文介绍了磁性粒子和磁性分离的基本特点,综述了近5年国内外有关磁性粒子在蛋白质分离纯化中的应用和发展现状。     

磁性蛋白印迹复合微球的研究进展

磁性蛋白印迹复合微球因其特异性识别、高效分离目标蛋白的优点在蛋白分离和检测中具有重要的应用价值。由于蛋白分子自身的结构性质,磁性蛋白印迹材料在制备及进一步提升性能方面还面临着诸多的挑战。本文综述了磁性蛋白印迹复合微球的制备方法及提高其印迹效率的设计策略方面的研究进展,并介绍了磁性蛋白印迹复合微球在蛋白分离、免疫分析、生物传感等方面的应用研究新进展。     

磁性荧光多功能纳米探针的研制及分析应用

磁性荧光多功能纳米探针由于具有磁性分离、靶向识别、荧光成像及磁共振成像等优势,受到化学、生物及医学等领域研究者的高度关注。本文就近年来磁性荧光多功能纳米探针的研究进展作简要评述。引用文献38篇。     

羧甲基壳聚糖修饰的磁性纳米粒应用于分离生物碱

制备羧甲基壳聚糖磁性纳米粒,并用于分离生物碱以研究其吸附分离能力。共沉淀法合成Fe_3O_4磁性纳米粒;壳聚糖先经羧甲基化,再通过碳二亚胺活化共价结合到Fe_3O_4纳米表面上。采用傅立叶变换红外光谱、透射电子显微镜和振动样品磁强计对磁性纳米材料进行结构表征,表明磁性纳米具有单一分散性,平均粒径14.4 nm。同时将制得的磁性纳米粒应用于分离生物碱,并对分离提取条件包括萃取液pH、萃取时间、洗脱液种类和浓度等进行了优化。在298~328 K间焓变化(ΔH)为-5.80 k J/mol,吸附过程自发进行,显示其具有较好的吸附分离能力。     

磁性纳米复合材料的制备及在萃取富集中的应用

本文介绍了磁性纳米复合材料的制备、分类以及特性,综述了磁性纳米复合材料在分离富集无机物、有机物和生物大分子等中的应用,并对磁性纳米复合材料在分析领域中的应用前景进行了展望。引用文献85篇。     

新型免疫磁性微球的制备及其在α-2b干扰素分离纯化中的应用

采用琼脂糖、纤维素和聚乙烯醇3种材料制备表面带有活性羟基的新型磁性微球,对其性能进行了表征并探讨其致敏条件。通过性能的比较,选择纤维素磁性微球作为分离纯化载体,并建立α-2b干扰素的免疫磁性分离方法。通过对α-2b干扰素发酵菌体裂解液的预处理、上样量和稀释倍数以及洗脱条件进行考察,确立免疫磁性分离条件,用于α-2b干扰素的一步分离纯化,其活性回收率达到88%,平均比活性为1.5×108IU/mg,纯度大于99%。实验结果表明,纤维素磁性微球作为性能优良的新型磁性载体,更适于目的蛋白的免疫磁性分离。     

Global and local relative convexity and oriented relative convexity; application to molecular shapes in external fields

The concepts of global and local relative convexity and oriented relative convexity are described and proposed as tools for the characterization of molecular shapes. The usual concept of convexity is a special case of the generalization described. Oriented relative convexity is suitable for the characterization of molecular shapes in external fields, such as magnetic fields or fields representing cavity regions of various enzymes or zeolite catalysts. Potential applications include new approaches to computer-based drug design and molecular engineering.     

质量、热量传递过程中的Marangoni效应*

由质量、热量传递引发,表面张力梯度驱动的Marangoni效应不但对化学工程、材料工程和热能工程等领域里的一系列过程具有重要的影响,而且具有非线性耗散系统理论研究的一个具有实际意义的课题。对Marangoni效应的实验及理论研究有助于增进对微观传热、传质机理的理解,它的合理利用也可以提高某些过程的效率。迄今为止,对Marangoni效应的认识还不能满足理论研究和工程应用的要求。按期在各相关领域内对Marangoni的研究十分活跃,本文回顾了这些研究成果。     

壳聚糖及其衍生物在生物医药中的研究进展

壳聚糖是一种用途很广的天然高分子化合物,具有无毒、生物相容性、吸附功能、生物可降解性及多种生物学活性等优异性能。本文综述了壳聚糖及其衍生物作为药物载体材料、组织工程材料、医用敷料和抗菌材料的应用,并且其在抗肿瘤方面也有一定的疗效。     

磁性微球及其在免疫学中应用的研究进展

磁性微球作为一种新型功能高分子材料,在生物医学领域有着广泛的应用前景。特别是在免疫学方面,常用于细胞分离、疾病诊断、食品检测等,并取得了显著的科研成果。本文介绍了磁性微球常见的制备和表面改性方法,并着重综述了其在免疫学中应用的研究进展。     

Molecular and Crystal Magnetic Engineering of Polymetallic Coupling System: From Magnetic Molecules to Molecular Magnets

One of the main challenges in the field of molecular materials is the design of molecular ferromagnets. General design strategy includes two steps, that is molecular magnetic engineering and crystal magnetic engineering. The first step is the synthesis of ferromagnetically coupled polymetallic systems. The second step is the assembly of polymetallic systems with muti‐dimensional structure and exhibiting a ferromagnetic transition. This paper summarized the strategies of molecular design and crystal engineering allowed to obtain such systems and our efforts in the fields of molecular magnetism and molecular‐based magnets.     

Multifaceted polymeric materials in three‐dimensional processing (3DP) technologies: Current progress and prospects

Three‐dimensional printing (3DP) technologies, which are sets of powerful deposition methods employed to fabricate 3D objects with materials in the fields of material sciences and engineering, biomedical and biocompatible structural components, automotive, aviation, and polymers, among others, are currently rapidly developing manufacturing technologies. The methods have significant advantages, which include designing flexibility, enhanced geometrical freedom, low cost, and net shape manufacture, among others, over the traditional “subtractive” method. This review highlights the major 3D printing techniques, especially in the fields of advanced polymeric material fabrication and engineering, as well as the synergy in the incorporation of different types of polymeric materials and composites in a process that will lead to an enhancement of dimensional accuracy for 3D technologies. Furthermore, composite ink systems especially polymer‐based and hydrogel‐based in tissue engineering applications are also discussed.     

Prediction of adsorption of small molecules in porous materials based on ab initio force field method

Computational prediction of adsorption of small molecules in porous materials has great impact on the basic and applied research in chemical engineering and material sciences. In this work,we report an approach based on grand canonical ensemble Monte Carlo(GCMC) simulations and ab initio force fields. We calculated the adsorption curves of ammonia in ZSM-5 zeolite and hydrogen in MOF-5(a metal-organic-framework material). The predictions agree well with experimental data. Because the predictions are based on the first principle force fields,this approach can be used for the adsorption prediction of new molecules or materials without experimental data as guidance.     

Type H superconductors and the vortex lattice.

Superconducting material is used, for example, in magnetic resonance imaging for medical examinations and particle accelerators in physics. Knowledge about superfluid liquids can give us deeper insight into the ways in which matter behaves in its lowest and most ordered state. Work by the author on superconduction in liquid helium established the existence of type II superconductors and proved that vortex lattices exist in superfluid helium, in the presence of magnetic fields. He showed that the Ginzburg-Landau theory could be extended to include this "new" type of superconductors, which today are in common use. His work on phase transitions of these superconductors under the influence of magnetic fields was groundbreaking, although he has worked in many other areas since then. He was awarded the Nobel prize in 2003 "for pioneering contributions to the theory of superconductors and superfluids" with V L. Ginzburg and A. J. Leggett.     

SnS2纳米片的制备及其器件应用进展

二维半导体是一种新兴的具有石墨烯类似结构的电子材料,拥有优异的电学、光学、磁学、力学等性能,可应用于不同的技术领域,因而成为当今材料科学研究领域的热点之一。在众多的二维半导体材料之中,二硫化锡(SnS₂)是一种对环境友好的电子材料,由自然界含量丰富的硫元素和锡元素组成。它在微电子学、太阳能电池、光催化等诸多方面均展现出巨大的应用潜力,受到了广泛的关注。本文主要介绍了近期气相沉积法制备SnS₂纳米片及其在电子学与光电子学领域中的应用进展。