纳米材料掺杂聚合物整体柱的构筑及在前处理领域的应用

聚合物整体柱是由单体、交联剂、引发剂和致孔剂在模具中通过原位聚合而成的棒状整体.与传统的填充式固相萃取柱相比,聚合物整体柱吸附剂凭借制备简单、柱压低、传质快及pH使用范围宽泛等优点已广泛应用于食品分析、生物医药和环境卫生等领域的前处理中.然而,通常由于聚合方式难以控制,聚合物整体柱在制备过程中容易产生颗粒堆积、孔道不均...     

手性有机聚合物毛细管电色谱整体柱研究进展

毛细管电色谱具有高分离效率、多种保留机制和高选择性的优点。近年来,利用毛细管电色谱进行对映异构体的手性拆分受到了广泛关注。相对于传统的填充柱和开管柱,整体柱在手性拆分方面具有显著优势。与手性硅基整体柱相似,手性有机聚合物整体柱由于具有大孔,可产生较高的流速而压降较小。该文综述了近十年手性有机聚合物整体柱制备方法的研究进展,将手性有机聚合物整体柱的制备方法分为"原位聚合法"和"手性修饰法"两种,虽然前者制备简单并广泛应用于早期研究,但聚合混合液成分的微小改变即可引起最终聚合物的形态变化,并且大部分带丙烯基的手性选择剂较难从市场购买。因此,手性修饰法因作为手性选择剂基质的整体柱制备且优化只需进行一次的优势而受到普遍关注。亲核取代、杂环开环和点击化学是常用的修饰手段。该文总结了这两种制备方法的应用,同时对未来的研究方向提出参考性意见。     

高效液相色谱整体柱在药物分离分析中的应用进展

本文对高效液相整体柱在药物分离分析方面的应用进行了综述.主要介绍了以烷氧基硅烷为主要原料,采用溶胶-凝胶法制备的硅胶整体柱,由于其具有微米级通孔结构和大的比表面积,他们在高效、快速分离小分子物质方面得到广泛地应用.对于聚合物整体柱,主要介绍了包括分子印迹聚合物在内的有机聚合物整体柱在药物分离、生物样品的处理等方面的应用.     

乙烯基酯树脂整体柱用于溶菌酶的分离

以甲基丙烯酸间苯二酚二缩甘油酯树脂兼作单体和交联剂,偶氮二异丁腈(AIBN)为引发剂,十六醇为致孔剂,在不锈钢柱管中制成聚合物整体柱,通过电镜分析考察了该聚合物的微观孔结构.以此聚合物整体柱为基质,将该柱修饰为具有二醇基的聚合物整体柱,考察了此修饰柱的通透性,并将其作为高效液相色谱固定相考察了该柱对溶菌酶(Lys)的最大吸附量、α-淀粉酶(α-Amy)和溶菌酶在该柱上的分离,并对蛋清中的溶菌酶进行了分离.结果表明,分离效果良好,为蛋白分离提供了一种简单、快捷、有效的方法.     

混合模式毛细管聚合物整体柱的制备及应用

混合模式毛细管整体色谱柱由于保留机理多样,具有很好的应用前景。本文以[2-（甲基丙烯酰基氧基）乙基]二甲基-（3-磺酸丙基）氢氧化铵（SPE）为单体,乙二醇二甲基丙烯酸酯（EDMA）为交联剂,偶氮二异丁腈（AIBN）为引发剂,正丙醇/1,4-丁二醇/水三元体系为致孔剂,制备了聚合物基质SPE-co-EDMA毛细管液相色谱整体柱。通过系统优化致孔剂和反应物种类和配比、引发剂的用量、反应时间和反应温度等因素,提高了整体柱的柱效、机械强度、渗透性和重复性。结果表明该毛细管整体柱在10 MPa内具有良好的机械强度,渗透性为2.17×10^-14 m²,而且批次内和批次间峰面积的重现性（RSD）分别为1.0%和4.6%。以极性和非极性的多种化合物评价了该毛细管整体柱的色谱性能,结果表明该柱在高有机相中具有亲水相互作用机理,在低有机相中具有反相作用机理,显示出混合模式分离特性。     

智能型色谱整体固定相的研究进展

整体柱作为新一代色谱固定相,具有原位制备、快速传质和高通透性的特点,近年来引起人们的极大关注。智能型聚合物作为一类功能性材料,能在温度、pH和盐等环境因素的刺激下产生特异性响应变化,通常被修饰到固相载体表面用来构造环境敏感性材料,使得该智能材料在药物控释、化学传感和细胞生长等领域有着广泛的应用。因此,在整体柱上构造智能型表面更为其在色谱领域的发展提供了新的契机。本文主要综述了近年来智能型整体柱在色谱领域的研究进展。     

高效液相色谱整体柱技术研究进展

高效液相色谱整体柱作为一种新型的分离介质,由于其制备工艺简单、易于修饰改性和分离性能优异,近年来引起了人们的广泛关注。聚合物整体柱具有生物相容性好、柱效高、寿命长、选材范围广、重现性好及使用不受p H限制等优势,广泛应用于食品、化工、农业、环境及生物医学领域小分子化合物及蛋白质的分离和检测,显示出较好的应用前景。本文就近10年液相色谱整体柱的制备、改性方法及应用的研究成果进行综述,并对其在不同应用领域的发展前景作了展望。     

有机-硅胶杂化整体柱的制备及应用研究进展

有机-硅胶杂化整体柱结合了有机聚合物整体柱和硅胶整体柱的优势, 具有制备简单、机械强度高和通透性好等优点, 近年来备受关注. 有机-硅胶杂化整体柱的制备方法主要有常规溶胶-凝胶法、“一锅法”和其它聚合方法. 目前, 杂化整体柱已被广泛应用于微纳尺度分离分析、样品预处理和固定化酶反应器基质中. 本文综述了有机-硅胶杂化整体柱的制备方法及应用研究进展, 并展望了其今后的发展前景.     

整体柱离子色谱的研究进展

该文介绍了离子色谱的分类,整体柱的分类、制备及特点,并以此为依据归纳总结了常规整体柱在离子色谱中的应用和毛细管整体柱在毛细管离子色谱中的应用,其中包括硅胶基质整体柱和聚合物基质整体柱,评述并展望了整体柱离子色谱的发展前景.     

有机聚合物整体柱及其在生物样品分离分析前处理中的应用

整体柱由于具有制备简单、内部结构均匀、重现性好、柱效较高和可进行快速分离等优点,在分离、催化等众多领域具有良好的应用前景。 本文综述了近年来有机聚合物整体柱在生物样品分离分析中的应用,并对其存在的问题和发展趋势进行了讨论。     

Annealing-free high-mobility diketopyrrolopyrrole-quaterthiophene copolymer for solution-processed organic thin film transistors

A donor-acceptor polymer semiconductor, PDQT, comprising diketopyrrolopyrrole (DPP) and β-unsubstituted quaterthiophene (QT) for organic thin film transistors (OTFTs) is reported. This polymer forms ordered layer-by-layer lamellar packing with an edge-on orientation in thin films even without thermal annealing. The strong intermolecular interactions arising from the fused aromatic DPP moiety and the DPP-QT donor-acceptor interaction facilitate the spontaneous self-assembly of the polymer chains into close proximity and form a large π-π overlap, which are favorable for intermolecular charge hopping. The well-interconnected crystalline grains form efficient intergranular charge transport pathways. The desirable chemical, electronic, and morphological structures of PDQT bring about high hole mobility of up to 0.97 cm(2)/(V·s) in OTFTs with polymer thin films annealed at a mild temperature of 100 °C and similarly high mobility of 0.89 cm(2)/(V·s) for polymer thin films even without thermal annealing.     

Study of PDMS conformation in PDMS-based hybrid materials prepared by gamma irradiation

Polydimethylsiloxane-silicate based hybrid materials have recognized properties (high flexibility, low elastic modulus or high mechanical strength) for which there are a large number of applications in development, such as for the bioapplications field. The hybrids addressed in the present study were prepared by gamma irradiation of a mixture of polydimethylsiloxane (PDMS) with tetraethylorthosilicate (TEOS) and zirconium propoxide (PrZr) without addition of any solvent or other product. The materials are homogeneous, transparent, monolithic and flexible. The structure dependence on the PrZr content is addressed. A combination of X-ray diffraction (XRD) and Infrared Spectroscopy (IR) was used. The results reveal that the polymer in the hybrids prepared with PrZr, in a content≤5 wt%, shows a structure similar to that in the irradiated pure polymer sample. In these samples the presence of ordered polymer regions is clearly found. For samples prepared with higher content of Zr almost no ordered polymer regions are observed. The addition of PrZr plays an important role on polymer conformation in these hybrid materials.     

聚合物在高压下的结构、形态和性能（下）

聚合物在高压下的结构、形态和性能（下）张雄伟，黄锐（成都科技大学塑料工程系，成都，６１００６５）在上篇中我们介绍了结晶性聚合物在高压下结晶的结构和形态。本篇将介绍聚合物在高压下的结晶动力学和热力学以及聚合物在高压下的退火等方面内容。２高压结晶动力学研...     

Topological factors governing the HOMO-LUMO band gap of the density of states of periodic hydrocarbon polymer networks

The band structures and density of states of 77 infintely large conjugated hydrocarbon polymer networks are calculated with HMO. A general rule for predicting whether the HOMO-LUMO band gap is zero or non-zero is proposed for an arbitrary hydrocarbon polymer network with periodic structure. The effects of bond alternation and of conjugate branching are discussed. Molecular design of high spin polymer networks is proposed.     

Review on Comparative Study of Solid Polymer Electrolyte Polyethylene Oxide (PEO) Doped with Ionic Liquid

Future demands for energy shortages have prompted a lot of effort to be put into finding alternatives. The use of renewable energies as a revolutionary energy source has gained acceptance. Due to their high flexibility and the interaction between the electrode and the electrolyte, solid polymer electrolytes are employed as a favorable electrolyte for application of electrochemical devices to storage renewable energy. As these are easy in synthesis, have much lower mass density, shows high mechanical stability, also have low binding energy with salts, and high mobility of charge carriers, polyethylene Oxide (PEO) based electrolyte has attracted a lot of interest. Configuration rectification combining PEO with ionic liquids has been introduced to enhance the low ionic conductivity and poor thermodynamic stability of the PEO materials in high-voltage devices at ambient temperature. This configuration modification can successfully validate the applications of PEO polymer electrolyte with large electro-stable voltage ranges. Solution casting method has been used for the synthesis of polymer electrolyte. The essential physical characteristics of PEO in polymer matrices work as a polymer host in SPEs has been described in this review paper, along with several modifications to overcome these limitations. It has been seen that the addition of ionic liquid increases the all over conductivity of the solid polymer electrolyte in most cases also improves the electrical stability of the electrolyte.     

Optimal extent of fluorination enabling strong temperature-dependent aggregation,favorable blend morphology and high-efficiency polymer solar cells

Temperature-dependent aggregation is a key property for some donor polymers to realize favorable bulk-heterojunction(BHJ)morphologies and high-efficiency(10%) polymer solar cells.Previous studies find that an important structural feature that enables such temperature-dependent aggregation property is the 2nd position branched alkyl chains sitting between two thiophene units.In this report,we demonstrate that an optimal extent of fluorination on the polymer backbone is a second essential structural feature that enables the strong temperature-dependent aggregation property.We compare the properties of three structurally similar polymers with 0,2 or 4 fluorine substitutions in each repeating unit through an in-depth morphological study.We show that the non-fluorinated polymer does not aggregate in solution(0.02 mg mL~(-1) in chlorobenzene) at room temperature,which results in poor polymer crystallinity and extremely large polymer domains.On the other hand,the polymer with four fluorine atoms in each repeating unit exhibits an excessively strong tendency to aggregate,which makes it difficult to process and causes a large domain.Only the polymer with two fluorine atoms in each repeating unit exhibits a suitable extent of temperature-dependent aggregation property.As a result,its blend film achieves a favorable morphology and high power conversion efficiency.This provides another key design rationale for developing donor polymers with suitable temperature-dependent aggregation properties and thus high performance.     

喷墨打印聚合物薄膜均匀性调控研究进展

聚合物发光显示材料具有发光颜色在全可见光区可调、可溶液简单加工及适用于柔性大面积基底的特点,成为目前研究的热点。 在聚合物发光薄膜图案化技术中,喷墨打印因为具有加工过程简单高效、适用于溶液方式加工、柔性的加工过程等特点而被认为是最具有应用潜力的技术。 高质量聚合物薄膜的制备是高精度发光显示器件制作的关键,但喷墨打印液滴在干燥过程中通常伴随着“咖啡环”现象,造成薄膜不均匀沉积。 因此,消除“咖啡环”现象,实现聚合物薄膜的均匀沉积,是喷墨打印高性能器件的重要研究方向。 本文主要论述了“咖啡环”效应的产生机理,如何抑制喷墨打印聚合物薄膜加工过程中的“咖啡环”效应,最终实现聚合物薄膜均匀性调控。     

Fast and efficient size-based separations of polymers using ultra-high-pressure liquid chromatography

Ultra-high-pressure liquid chromatography (UHPLC) has great potential for the separations of both small molecules and polymers. However, the implementation of UHPLC for the analysis of macromolecules invokes several problems. First, to provide information on the molecular-weight distribution of a polymer, size-exclusion (SEC) columns with specific pore sizes are needed. Development of packing materials with large pore diameters and pore volumes which are mechanically stable at ultra-high-pressures is a technological challenge. Additionally, narrow-bore columns are typically used in UHPLC to minimize the problem of heat dissipation. Such columns pose stringent requirements on the extra-column dispersion, especially for large (slowly diffusing) molecules. Finally, UHPLC conditions generate high shear rates, which may affect polymer chains. The possibilities and limitations of UHPLC for size-based separations of polymers are addressed in the present study. We demonstrate the feasibility of conducting efficient and very fast size-based separations of polymers using conventional and wide-bore (4.6 mm I.D.) UHPLC columns. The wider columns allow minimization of the extra-column contribution to the observed peak widths down to an insignificant level. Reliable SEC separations of polymers with molecular weights up to ca. 50 kDa are achieved within less than 1 min at pressures of about 66 MPa. Due to the small particles used in UHPLC it is possible to separate high-molecular-weight polymers (50 kDa ≤ M(r) ≤ 1-3 MDa, upper limit depends on the flow rate) in the hydrodynamic-chromatography (HDC) mode. Very fast and efficient HDC separations are presented. For very large polymer molecules (typically larger than several MDa, depending on the flow rate) two chromatographic peaks are observed. This is attributed to the onset of molecular deformation at high shear rates and the simultaneous actions of hydrodynamic and slalom chromatography.     

Shear-thickening flow of nanoparticle suspensions flocculated by polymer bridging

The steady-shear viscosity, dynamic viscoelasticity, and stress relaxation behavior were measured for suspensions of silica nanoparticles dispersed in aqueous solutions of poly(ethylene oxide) (PEO). The suspensions of silica with diameters of 8-25 nm show striking shear-thickening profiles in steady shear and highly elastic responses under large strains in oscillatory shear. Since the silica particles are much smaller than the polymer coils, one molecule can extend through several particles by intrachain bridging. Each polymer coil may remain isolated as a floc unit and the silica particles hardly connect two flocs. Therefore, the flow of suspensions is Newtonian with low viscosity at low shear rates. When the polymer coils containing several nanoparticles are subjected to high shear fields, three-dimensional network is developed over the system. The shear-thickening flow may arise from the elastic forces of extended bridges. But, the polymer chain is easily detached from particle surface by thermal energy because of large curvature of particles. As a result, the network structures are reversibly broken down in a quiescent state and the suspensions behaves as viscoelastic fluids with the zero-shear viscosity.     

Formation of a mesoscopic skin barrier in mesoglobules of thermoresponsive polymers

With the combination of molecular scale information from electron paramagnetic resonance (EPR) spectroscopy and meso-/macroscopic information from various other characterization techniques, the formation of mesoglobules of thermoresponsive dendronized polymers is explained. Apparent differences in the EPR spectra in dependence of the heating rate, the chemical nature of the dendritic substructure of the polymer, and the concentration are interpreted to be caused by the formation of a dense polymeric layer at the periphery of the mesoglobule. This skin barrier is formed in a narrow temperature range of ~4 K above T(C) and prohibits the release of molecules that are incorporated in the polymer aggregate. In large mesoglobules, formed at low heating rates and at high polymer concentrations, a considerable amount of water is entrapped that microphase-separates from the collapsed polymer chains at high temperatures. This results in the aggregates possessing an aqueous core and a corona consisting of collapsed polymer chains. A fast heating rate, a low polymer concentration, and hydrophobic subunits in the dendritic polymer side chains make the entrapment of water less favorable and lead to a higher degree of vitrification. This may bear consequences for the design and use of thermoresponsive polymeric systems in the fast growing field of drug delivery.