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《色谱》2020,(4)
通过十八烷基胺的氨基与二醛微晶纤维素的醛基共价键合,制备了基于二醛微晶纤维素(DMCC)官能化C_(18)的新型反相/亲水色谱固定相(C_(18)-DMCC/SiO_2),该色谱固定相被用于反相色谱(RPLC)和亲水相互作用色谱(HILIC)模式。C_(18)-DMCC/SiO_2色谱柱展现了良好的疏水选择性和芳香选择性,在反相色谱模式下可分离烷基苯和多环芳烃(PAHs)。苯胺类、酚类和糖苷类等极性化合物被用于评估该色谱柱在反相色谱模式下的极性选择性,商品C_(18)柱作对照柱,色谱评价结果令人满意。核酸碱基被用于评估C_(18)-DMCC/SiO_2色谱柱的亲水色谱性能。通过考察有机溶剂含量对分析物保留的影响,发现该新型色谱固定相具有反相/亲水色谱的典型特征。 相似文献
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新型高分子多孔小球的研究 总被引:7,自引:0,他引:7
本文研究出一种用双甲基丙烯酸乙二醇酯作交联剂, 通过二次聚合反应得出新型高分子多孔小球(NKG), 可作为气相色谱法的固定相. 它比通用的商品高分子多孔小球具有较高的分离效能和较广的应用范围, 并且克服了后者由于使用难以纯化的二乙烯苯作交联剂所导致的缺点. 提出以五种有机化合物的保留指数表征高分子多孔小球的极性. NKG有较高的柱效, 表明二次聚合反应大大地增加了它的溶剂效应, 从而使色谱过程中气液色谱占主导地位。通过测定NKG的吸附焓,证明二次聚合加强了组份固定相之间的相互作用. 此外, 本文还对双甲基丙烯酸乙二醇酯的合成方法进行研究, 用一种新的催化剂使酯交换反应时间从一般方法需要8h缩短到2h, 并且收率和纯度分别可达95和98%以上。 相似文献
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高分子多孔小球是一类已被广泛应用的色谱固定相。它耐腐蚀,无流失,对极性化合物峰形对称,适用于气体和小分子极性化合物的分离。但是,长期来这类固定相存在的主要问题是柱效不高,原因是,为了要保持刚性骨架气相色谱固定相的多孔微球通常都采用高交联网络结构,这就增大了溶质的传质阻力,使 相似文献
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将醋酸乙烯酯与三烯丙基异氰尿酸酯共聚物进行皂化制得含有羟基和羧基盐的共聚物以增强共聚物的亲水性,用作气相色谱固定相,考察了不同交联度对皂化反应的影响,测定了皂化后共聚物的孔结构参数及溶胀性能,并对该固定相的色谱性能进行评价。 相似文献
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将醋酸乙烯酯与三烯丙基异氰尿酸酯共聚物进行皂化制得含有羟基和羧基盐的共聚物以增强共聚物的亲水性,用作气相色谱固定相。考察了不同交联度对皂化反应的影响,测定了皂化后共聚物的结构参数及溶胀性能,并对该固定相的色谱性能进行评价。 相似文献
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合成了PM和PA两个系列甲基丙烯酸甲酯或丙烯酸甲酯与二乙烯苯的多孔聚合物,测定了它们的物理、化学性能和气相色谱性能,并评价其极性。通过实例说明它们对各种混合物的分离情况;保留时间较短,柱温较低,选择性较高,性能优于PorapakT或其它极性相近的商品聚合物固定相。 相似文献
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本文提出一种新型高分子多孔小球固定相,它具有比商品的尤其是苯乙烯系高分子多孔小球更加优越的色谱性能,特别适合于各种有机物和无机气体中微量至常量水的分析,同时还是测定大量水中微量有机物的一种较为理想的固定相。 相似文献
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Jinhua Lei Dongliang Li Honghua Wang Zhuqian Wang Guangyuan Zhou 《Journal of polymer science. Part A, Polymer chemistry》2011,49(6):1503-1507
Monodisperse cyano‐functionalized porous polymeric beads were synthesized by seeded polymerization; these microparticles were further used as support for zirconocene catalyst, which performed as a solid homogeneous catalyst in ethylene polymerization. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献
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大孔交联聚苯乙烯吸附树脂的合成及其对叶绿素铜的吸附性能 总被引:4,自引:0,他引:4
通过改变苯乙烯-二乙烯苯共聚物的交联度和使用不同结构的二乙烯苯,合成了树脂Ⅰ-Ⅵ,在工业二乙烯苯共聚体系中加入少量丙烯酸甲酯合成了树脂Ⅶ;交联聚苯乙烯经Friedel-Grafts酰化反应在其苯环上引入乙酰基制备了树脂Ⅷ。用物理技术和化学方法表征了树脂的结构。树脂对叶绿素铜的吸附量不仅与其二乙烯苯含量有关,还与二乙烯基的位置(间-,对-)异构有关,树脂骨架极性的增加,不利于树脂对叶绿素铜的吸附。 相似文献
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Y. Hu M. Nareen A. Humphries P. Christian 《Journal of Sol-Gel Science and Technology》2010,53(2):300-306
We report a new method for preparing porous silica beads using a high internal phase emulsion (HIPE) sol–gel templating method.
The method uses a silica sol based HIPE and does not rely on a polymeric support to produce the final structure. As a result
beads may be formed readily in large numbers. The beads have an open porous structure commensurate with the formation of a
HIPE precursor phase. We also describe how the rheology of the HIPE reflects the formation of an open porous structure and
how the viscosity of the HIPE can affect the shape of the beads and how HIPE destabilization may be used to vary the pore
size. 相似文献
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Steffen Fischer Katrin Thümmler Bert Volkert Kay Hettrich Ingeborg Schmidt Klaus Fischer 《Macromolecular Symposia》2008,262(1):89-96
Cellulose acetate is one of the most important esters of cellulose. Depending on the way it has been processed cellulose acetate can be used for great varies of applications (e.g. for films, membranes or fibers). The properties of the applied cellulose acetates are very important for these applications. A special field for using cellulose acetate is the synthesis of porous, spherical particles, so called cellulose beads. Different types of technical cellulose acetates were used and their ability to form such cellulose beads was characterized. First the different types of cellulose acetates were characterized by means of solubility; turbidity and degree of substitution. In addition the molar mass and the distribution of substituents along the polymeric chain were analyzed. Next, the cellulose beads were synthesized within an emulsion process using these different cellulose acetates. Then the properties (particle size, porosity, morphology) of the cellulose beads were determined. Finally, the relationship between the characteristic of cellulose acetates and properties of cellulose beads was investigated. 相似文献
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The conventional method for the synthesis of porous cross-linked copolymer beads is by suspension polymerisation. Suspension
polymerisation reactions are generally performed in a stirred tank, which generally results in a large size distribution.
By careful control of the polymerisation conditions, polymer beads can be produced using a tubular poly(tetrafluoroethylene)
continuous reactor. Such beads are produced with the same average pore size, but with a lower degree of polydispersity than
analogous systems produced in a batch reactor (stirred tank). This is achieved by density-matching the droplet and continuous
phases (by the use of a brominated monomer or a porogenic diluent) and increasing the viscosity of the monomer phase (with
the addition of small amounts of polystyrene).
Received: 26 June 1999/Accepted in revised form: 7 October 1999 相似文献
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Baggiani C Baravalle P Giovannoli C Anfossi L Passini C Giraudi G 《Journal of chromatography. A》2011,1218(14):1828-1834
One of the most interesting methods for preparing molecularly imprinted polymers with controlled morphology consists in filling the pores of silica beads with an imprinting mixture, polymerizing it and dissolving the support, leaving porous imprinted beads that are the "negative image" of the silica beads. The main advantage of such an approach consists in the easy preparation of spherical imprinted polymeric particles with narrow diameter and pore size distribution, particularly indicated for chromatographic applications. In this approach it has been shown that the resulting morphology of polymeric beads depends essentially on the porosity and surface properties of the silica beads that act as microreactors for the thermopolymerization process. Anyway, it is not yet clear if the porosity of the silica beads influences the binding properties of the resulting imprinted beads. In this paper, we report the effect of different porosities of the starting mesoporous silica beads on the resulting binding properties of imprinted polymers with molecular recognition properties towards the fungicide carbendazim. The morphological properties of the imprinted beads prepared through this hierarchical approach were measured by nitrogen adsorption porosimetry and compared with a reference imprinted material prepared by bulk polymerization. The chromatographic behaviour of HPLC columns packed with the imprinted materials were examined by eluting increasing amounts of carbendazim and extracting the binding parameters through a peak profiling approach. The experimental results obtained show that the resulting binding properties of the imprinted beads are strongly affected by the polymerization approach used but not by the initial porosity of the silica beads, with the sole exception of the binding site density, which appears to be inversely proportional to them. 相似文献