三酰甘油氧化聚合物的制备型快速柱层析-体积排阻色谱测定法

建立了一种简便、灵敏、无需内标的检测油脂中三酰甘油氧化聚合物(TGP)的分析方法。以制备型快速层析柱(PFC)(flash硅胶柱,20 g,40～60μm,6 nm)分离1 g油脂样品中极性组分(PC),经高效体积排阻色谱(HPSEC)(GPC柱,Ф7.8 mm×300 mm,粒径5μm,孔径10 nm)将PC细分为氧化三酰甘油寡聚物(TGO)、氧化三酰甘油二聚物(TGD)、氧化三酰甘油单体(ox-TGM)、二酰甘油(DG)、游离脂肪酸(FFA)。结合重量法测定油脂中PC、面积归一法测定PC中TGP,可准确定量油脂中的TGP含量。结果表明,TGO、TGD分别在28～1 800、11～2 800 mg/L范围内线性关系良好,相关系数(r2)分别为0.998 2、0.998 7,TGO及TGD的检出限(LOD)分别为28、11 mg/L,定量下限(LOQ)分别为113、44 mg/L;相当于油脂中TGP的LOD为0.01%。PFC-HPSEC法检测油脂TGP的相对标准偏差(RSD)均小于10%。PFC对3个PC加标水平(2.27%、8.47%、30.94%)的平均回收率为95%～98%,相对标准偏差(RSD)均低于4%。PFC-HPSEC方法与经典的硅胶柱-HPSEC方法定量油脂TGP的结果吻合度高,相对误差为0～8.9%。该方法能够在2 h内实现各种油脂中TGP含量的定量检测,包括使用过的废弃油脂与未使用的食用油脂,尤其适用于低含量TGP的初榨油和精炼油脂。     

Synthesis of fluorinated hyperbranched polymers capable as highly hydrophobic and oleophobic coating materials

A series of coating materials were prepared from two classes of hyperbranched polymers containing short fluorocarbon chains (HPEFs/HPUFs). The obtained hyperbranched polymers were characterized by FT-IR, ¹H NMR, ¹³C NMR, ¹⁹F NMR, GPC and TG analyses. HPEFs/HPUFs exhibited very low surface free energies (13.67-24.49 mJ/m²) which almost are independent of their internal backbone but dependent on the terminal fluorocarbon chains. Highly hydrophobic and/or oleophobic surfaces of cotton woven fabric can be achieved from these polymers by solution-immersion coating method. The static and dynamic wettabilities of the HPEFs/HPUFs treated fabrics have been investigated. The static contact angles reached to 146°, 122° and 102° for water, hexadecane and decane, respectively. The lowest contact angle hysteresis reached to 5.9°.     

高灵敏共轭聚合物化学传感器

金属离子和化学小分子的检测在人类健康、环境污染以及食品安全等领域具有重要意义,科学工作者们已经在设计、发展高灵敏化学传感器方面进行了大量研究。在过去的几十年里,共轭聚合物由于其卓越的光电性质,引起了人们极大的关注,并取得了众多革命性科技进展。最近,利用共轭聚合物的荧光信号放大机制,人们设计、发展了一系列新型的化学和生物传感体系。共轭聚合物的信号传感机制包括电子转移,荧光共振能量转移以及共轭聚合物聚集或构象改变。本文主要介绍我们实验室在利用共轭聚合物实现金属离子和化学小分子荧光检测方面取得的进展,并对未来发展方向与面临的挑战进行了讨论。     

分子印迹水相分离技术及其在分析化学中的应用

分子印迹分离技术通过模拟抗体-抗原相互作用原理,专一地与目标分子互补性结合,从而将目标分子与杂质分离,是一种非常具有发展前景的分离技术。传统的分子印迹技术通常是在有机相中制备对印迹分子具有选择性的印迹聚合物,然而分子印迹技术的实际应用环境大多是水相体系。近年来,分子印迹水相分离技术受到了科学工作者的广泛关注。本文分别从以下几个方面总结了分子印迹水相分离技术的最新研究进展:水相中分子印迹聚合物的设计原理与合成方法;印迹聚合物在水相中的作用机制;印迹水相分离技术在分析化学中的应用。最后讨论了该项技术现存的问题,并对其未来发展进行了展望。     

琥乙红霉素分子印迹聚合物微球的制备及表征

以琥乙红霉素为模板分子,甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,采用悬浮聚合法制备得到了平均粒径约为60μm的琥乙红霉素分子印迹聚合物微球(MIPs),并用扫描电镜对其表面形貌进行了表征。考察了琥乙红霉素分子印迹聚合物的印迹效果,研究了琥乙红霉素分子印迹聚合物的动力学吸附特性。比较了MIPs对琥乙红霉素及其它3种抗生素的吸附情况。结果表明,制备得到的琥乙红霉素分子印迹聚合物微球对琥乙红霉素具有最好的吸附能力,显示出MIPs具有高的选择性。     

Network dimensionality and ligand flexibility in lanthanide terephthalate hydrates

Various lanthanide open framework materials incorporating the terephthalate (TP) entity were prepared using hydrothermal synthesis methods at a moderate temperature of 170 °C. The compounds Nd₂(TP)₃(H₂O)₄(1), Er₂(TP)₃(H₂O)₄(2), Yb₂(TP)₃(H₂O)₂(3), Yb₂(TP)₃(H₂O)₆(4), and Yb₂(TP)₃(H₂O)₈·2H₂O (5), were characterized by single crystal structural analysis and FT-IR spectroscopy. While compounds 1 and 2 have been reported before on the basis of powder X-ray diffraction, the structural characterization of any ytterbium terephthalate species is unprecedented. Compounds 1-5 crystallize in triclinic settings with space group P-1. The compounds are compared with their previously reported Er and Tb-counterparts and the reduction of the dimensionality of the resulting networks from 3D over 2D to 1D with increasing level of hydration is discussed. Compounds 1, 2, and 3 with the lowest water content assemble in three-dimensional network lattices. Compounds 4 and 5, however, form 2D layered systems and 1D rod like chains, respectively, which are held together by hydrogen bonds originating from coordinating H₂O. The crystal lattices of the 3D networks experience higher levels of tension as can be seen by increasing out-of-plane torsion with regard to the terephthalate carboxylate groups. Moreover, there seems to be a correlation between the level of strain on the aromatic ligands and the reduction of the number of carboxylate oxygen atoms that are part of the coordination polyhedra.     

Synthesis, crystal structures and characterization of four coordination polymers based on 5-amino-2,4,6-triiodoisophthalic acid

One homochiral 1D coordination polymer [Cu(ATIBDC)(2,2′-bipy)]·3H₂O·CH₃OH (1) and three achiral 1D coordination polymers: [Cd(ATIBDC)(2,2′-bipy)(H₂O)]·3H₂O (2), [Cd(ATIBDC)(phen)(H₂O)]·4H₂O (3), and [Mn(ATIBDC)(phen)₂]·5H₂O (4) have been synthesized and characterized (H₂ATIBDC=5-amino-2,4,6-triiodoisophthalic acid, 2,2′-bipy=2,2′-bipyridine, and phen=1,10-phenanthroline). Extended high dimensional network architectures are further constructed with the help of weak secondary interactions, such as hydrogen bonding, aromatic stacking, and halogen bonding (C-I…π and C-I…N/O). Complex 1 crystallizes in the monoclinic system with chiral space group P2(1) and exhibits a right-handed 2₁ helical chain structure. The homochirality of 1 was confirmed by CD spectrum. Interestingly, two new configurations of decameric water cluster are found in 3 and 4. The acyclic tetrameric cluster (H₂O)₃(CH₃OH) in 1 and (H₂O)₄ in 2 array into highly ordered helical infinite chains. Thermal stabilities of all the complexes have been studied. Solid state fluorescent properties of the Cd(II) complexes have been explored.     

天然水中优势菌胞外聚合物及其中主要成分对铅的吸附

研究了吉林省长春市南湖天然水环境中生物膜胞外聚合物及由其分离得到的胞外多糖和胞外蛋白对铅的吸附特性,讨论了时间、pH值、其它共存金属离子等对其吸附的影响;初步探讨了胞外多糖和胞外蛋白吸附铅的反应机理. 结果表明,3种吸附剂对铅的吸附量在pH=6时最大,分别为23.64、15.8和3.48 mg/g ;吸附体系均在6h以后达到吸附平衡;共存金属离子镉对铅的吸附有影响.胞外聚合物及其中的胞外多糖和胞外蛋白对铅的吸附过程符合Langmuir和Freundlich热力学方程.胞外聚合物中胞外多糖对铅的吸附所作贡献大于胞外蛋白.胞外蛋白的胺基、酰胺基,胞外多糖的羟基、酰胺基等是胞外聚合物吸附铅离子过程中起关键作用的化学基团.     

聚酰亚胺研究新进展

聚酰亚胺（PI）是一类重要的高性能聚合物,广泛应用在航空航天、微电子、汽车、石油等高科技领域。由于其结构上的可设计性,世界上越来越多的研究者投入到这类高技术材料的研究开发中。本文分别从可溶性PI的分子设计与合成、功能性PI的合成与用途、PI绿色合成方法、PI纳米复合材料的制备4个方面综述了近年来PI的研究热点和新进展,为了解聚酰亚胺的研究提供了有价值的信息。     

Copper(II)–lanthanide(III) 15-metallacrown-5 complexes based on pyrazinohydroxamic acid as new multiple-binding pentagonal platforms with Lewis amphoteric nature

Reaction of copper(II) acetate, lanthanium(III) or gadolinium(III) nitrate (1/5 equiv.) with pyrazinohydroxamic acid (H₂Pyzha) in DMF led to a series of new heterobimetallic 15-metallacrown-5 complexes. In a MeOH/H₂O solution the complexes exist as molecular unassociated metallacrowns. In solid state their structures are more complicated as it has been confirmed by X-ray analysis: discrete molecular metallacrowns [Gd(NO₃)₂{Cu(pyzha)}₅(DMF)₄(NO₃)] · 0.5C₆H₆ · H₂O (1), [Gd(NO₃)₂{Cu(pyzha)}₅(DMF)₅](NO₃) · 1.5DMF · 0.5H₂O (2), [La(NO₃)₂{Cu(pyzha)}₅(DMF)₅]NO₃ · 1.5DMF · 2C₆H₆ (3) are solvates, whereas compound [{La(NO₃)₂{Cu(pyzha)}₅(DMF)₅}₂(μ²-NO₃)](NO₃) · 3DMF (4) is a dimer, where μ-bridged nitrate links two copper centres of the adjacent metallamacrocycles. Complex [Gd(NO₃)₂{Cu(pyzha)}₅(DMF)₂(H₂O)(NO₃)] · CH₂Cl₂ · DMF (5) self-associates into a polymer chain by means of one pyrazine moiety and the copper ring atom. Reaction of the molecular metallacrowns with excess of inorganic salts CdBr₂ or Cu(OAc)₂ proceeds as anion methathesis process affording heteroanionic metallacrowns: molecular [Gd(NO₃)₂{Cu(pyzha)}₅(DMF)₅] [Gd(NO₃)₂{Cu(pyzha)}₅(DMF)₄(H₂O)][CdBr₄] · 1.5DMF (6), and 3D hydrogen bonded polymer [La(μ²-OAc)(H₂O)₃{Cu(pyzha)}₅ (H₂O)₄(NO₃)](NO₃) · 4H₂O (7).