DNA分子光开关钌配合物[Ru(phen)2(dppz)]2+的研究进展

综述了近20年来典型的DNA-分子光开关钌(Ⅱ)多吡啶类配合物[Ru(phen)2(dppz)]2+在实验和理论上的研究进展与应用.阐明了该配合物的结构特征及其与DNA的作用机理、作用模式以及在一些相关热点问题上的争议,同时还介绍了该配合物在DNA-结构识别及定量分析等方面的重要应用.基于此,还对DNA-分子光开关钌配合物的开发作了展望.     

芳香基团修饰的三联吡啶钌（Ⅱ）配合物光物理性质及其光损伤CT-DNA研究

钌（Ⅱ）多吡啶配合物具有丰富的光物理和光化学性质，在无机生物光化学的发展和应用中发挥了重大作用．例如，作为高效DNA光断裂试剂，钌（Ⅱ）多吡啶配合物已经得到广泛而深入的研究．DNA光断裂试剂在研究DNA复杂结构、探索蛋白质或其它生物活性分子同DNA的相互作用以及开辟癌症治疗新药物和新疗法方面均有重要应用．然而，目前作为DNA光断裂试剂的钌（Ⅱ）多吡啶配合物均为二齿配体配合物，三联吡啶钌（Ⅱ）配合物由于极短的激发态寿命和极低的单重态氧量子产率而难于应用在DNA光断裂或光损伤领域．本文通过改变三联吡啶钌（Ⅱ）配合物最低能量激发态的属性和利用三联吡啶钌（Ⅱ）配合物与TiO2纳米颗粒间的光诱导电子转移反应两种途径，显著提高了它们光损伤DNA的能力，为该类型配合物在DNA光断裂以及其它相关领域中的应用打下了基础．论文主要研究内容和所获重要结果如下。     

金属有机配合物在光解水制氢体系中的应用

实现可见光光解水制氢一直被认为是最终解决能源和环境问题的最佳途径,有效地实现可见光光解水制氢技术的关键在于光敏剂材料的制备及其改性。综述了贵金属钌Ru(Ⅱ)、铂Pt(Ⅱ)、铱Ir(Ⅲ)和铼Re(Ⅰ)的配合物、金属卟啉配合物作为光敏剂在光解水制氢体系中的应用。最后,对金属有机配合物光敏剂未来的发展趋势进行了展望。     

紫外可见光谱法研究芹菜素-铕配合物与ct-DNA的相互作用

以Tris-HCl缓冲溶液为介质,利用紫外可见光谱法研究了芹菜素(Apigenin,简写为Ap)与稀土铕离子配位的酸度及芹菜素-铕(Ⅲ)配合物与小牛胸腺DNA(ct-DNA)的相互作用。实验表明芹菜素与铕(Ⅲ)能形成稳定的配合物;在生理条件(pH=7.4),随ct-DNA浓度的增大,配合物最大吸收峰吸光度降低,吸收带变宽,有微弱的红移,说明芹菜素-铕配合物主要以插入方式与DNA相结合。     

一种新型钌配合物的合成及表征

以邻菲罗啉为起始原料,经过一系列氧化还原反应,合成出联吡啶配体。然后将联吡啶配体和三氯化钌反应生成钌配合物,最后将此钌配合物水解得到最终产物。各中间产物及最终产物的结构经~1H NMR表征。     

吡啶二亚胺钌配合物催化酮的氢转移氢化反应

以2,6-二[1-(苯基亚胺基)乙基]吡啶与三苯基膦氯化钌的配合物为催化剂,考察了苯乙酮的氢转移氢化反应.在苯乙酮、钌配合物和KOH的初始摩尔比为250∶1∶12、反应温度为82℃时,反应2 h后苯乙酮的转化率达到98.3%.研究了反应温度、底物浓度、碱强度等对氢转移催化反应的影响.结果表明,这种吡啶二亚胺钌配合物对苯乙酮等的氢转移反应具有良好的催化性能.     

一种席夫碱钴(Ⅱ)配合物的合成及其与DNA的相互作用

以邻苯二胺、水杨醛和乙酸钴为原料,合成了一种新型的席夫碱钴(Ⅱ)配合物(CoL,L=双水杨醛缩邻苯二胺),采用红外光谱和元素分析对配体及配合物结构进行了表征。在pH 7.0的Britton-Robinson(B-R)缓冲溶液中,采用紫外光谱法、粘度法和循环伏安法研究了该席夫碱钴(Ⅱ)配合物与DNA的相互作用。紫外光谱实验表明DNA的加入能引起配合物特征吸收峰的减色效应,表明了二者之间的相互作用,通过光谱滴定法测得二者的结合常数为1.1×104L/mol。粘度实验显示,随着配合物浓度的加大,DNA相对粘度先增大后减小,说明二者之间通过部分嵌插模式结合。电化学实验表明配合物在玻碳电极上有一对对应于中心Co(Ⅱ)离子的氧化还原峰,当加入一定量的DNA后,该对氧化还原峰电流显著降低,进一步表明席夫碱钴配合物与DNA发生了相互作用。     

不同软段类型聚氨酯的水解失重情况初探

分别选择以聚乳酸、聚ε?己内酯、聚碳酸亚丙酯、聚己二酸乙二酯和聚四氢呋喃二元醇为原料合成的聚氨酯弹性体材料为对象，探索其在常用有机溶剂中的溶解性以及在磷酸盐缓冲溶液（PBS）中的水解情况。结果表明，这5类聚氨酯在不同pH缓冲溶液中的水解表现不同，16周内的质量损失为6％～14％；同等条件下，聚氨酯在pH＝8?4的缓冲溶液中水解程度最高，在pH＝6?4缓冲溶液中次之，在pH＝7?4的缓冲溶液中最弱。     

生物基聚丁二酸丁二醇酯的生物降解性能研究

在模拟自然环境下,以磷酸氢二钠配制不同p H值(3~11)的磷酸盐缓冲溶液,并在缓冲溶液中加入脂肪酶,对比研究了生物基聚丁二酸丁二醇酯(PBS)在不同缓冲溶液中的降解性能。结果表明:酸和碱对PBS在缓冲溶液中的降解具有促进作用,碱的作用更明显;脂肪酶可加速PBS的降解,在p H值为9~11时,脂肪酶的活性最大;PBS在p H值为9~11、含脂肪酶的缓冲溶液中降解49 d,失重率达8%,黏均相对分子质量降低,熔点降低,结晶度略微减小,表面出现了裂纹和腐蚀点;生物基PBS具有良好的生物降解性能。     

铈(Ⅲ)-组氨酸-邻菲啰啉三元配合物的合成及其电化学活性

在乙醇水溶液介质中,60℃水浴加热的条件下,合成了标题化合物.经络合滴定、摩尔电导、元素分析、红外光谱、紫外光谱、热重-差热和循环伏安等测试对配合物进行了表征,确定配合物的化学组成为:[Ce(Ⅲ)(His)3phen]Cl3·3H2O.重点通过循环伏安测定了配合物在玻碳工作电极上的电化学行为,在HAc-NaAc缓冲溶液...     

PBS/PHB共混合金的制备及其性能

采用双螺杆挤出机将聚羟基丁酸酯(PHB)与聚丁二酸丁二酯(PBS)熔融共混,制备了PBS/PHB合金,并研究了其性能。结果表明:PBS与PHB组成了热力学互容体系;随着PHB用量的增加,PBS/PHB合金的晶体形态为尺寸逐渐减小的环带球晶,合金的拉伸强度与韧性显著增加;PBS/PHB合金在紫外光老化后的抗冲击性能下降,但PHB含量高的合金在老化后仍具有较高的冲击强度。     

Study on the properties of nano‐TiO2/polybutylene succinate composites prepared by vane extruder

Different proportions of nanoscale TiO₂ (nano‐TiO₂)‐filled polybutylene succinate (PBS) composites were prepared by vane extruder. The crystalline, thermal, dynamic viscoelastic, mechanical, and UV‐resistance properties of the composites were studied, and X‐ray diffraction, differential scanning calorimetry, and thermogravimetric analysis were conducted. Results show that the crystalline structure of the PBS composites did not change with TiO₂ addition. TiO₂ almost has no effect on the crystallization and melting behavior of PBS. Nevertheless, the introduction of TiO₂ has improved the thermal stability, tensile modulus, flexural modulus, and flexural strength of the PBS composites. The UV resistance of the composites has also been significantly enhanced with TiO₂ addition. POLYM. COMPOS., 35:53–59, 2014. © 2013 Society of Plastics Engineers     

Eco-friendly cellulose acetate butyrate/poly(butylene succinate) blends: crystallization,miscibility, thermostability,rheological and mechanical properties

In this work, the crystallization, miscibility, thermostability, rheological and mechanical properties of cellulose acetate butyrate (CAB)/poly(butylene succinate) (PBS) blends were investigated in detail. Differential scanning calorimetry analysis confirmed that PBS could form crystalline phase in the solution casted CAB/PBS blends with W_CAB?≤?60 wt.%. When the blends were crystallized from melt, the crystallization of PBS was found to be severely suppressed by the amorphous diluent of CAB. CAB and PBS were confirmed to be thermodynamic miscible in molten state by the negative value of Flory-Huggins interaction parameter (χ₁₂?=??0.89) between CAB and PBS. The rheological characterization results and thermogravimetric analysis revealed that the melt viscosity and thermostability of CAB were reduced and improved by blending CAB with PBS, respectively. Moreover, the rigid CAB became more flexible after incorporating with ductile PBS. The application of CAB is expected to be extended via blending the two species of eco-friendly polymers.     

Effects of polymer concentration and zone drawing on the structure and properties of biodegradable poly(butylene succinate) film

To produce various biodegradable poly(butylene succinate) (PBS) films for particular use, the effects of initial polymer concentration and zone drawing on the structure, physical properties, and hydrolytic degradation of PBS film were investigated. PBS films were prepared from chloroform solutions with different initial concentrations of 8, 11, 14, 17 and 20 g/dl. In order to investigate the drawing behavior of the PBS films with different solution concentrations, the films were drawn under various zone drawing conditions. Through a series of experiments, it turned out that the initial concentration of PBS solution in chloroform caused significant changes in the draw ratio of the PBS film. That is, the zone draw ratios of the film at initial concentration of 14 g/dl exhibited its maximum values and gradually decreased at higher or lower concentrations. Thus, it was concluded that the initial concentration of 14 g/dl is the optimum polymer concentration to produce maximum draw ratio in this work. In addition, the crystal and amorphous orientations and tensile properties of PBS film having similar draw ratio and similar crystallinity were highest at 14 g/dl and surface crystal morphologies of these films were absolutely different. The hydrolytic degradation rate of the film at 14 g/dl was lowest, but with similar draw ratio, film dimension, and crystallinity, indicating that the degradation behaviors were greatly affected by the initial polymer concentration, orientation, and crystal morphology.     

聚丁二酸丁二醇酯(PBS)在不同pH条件下的降解

对聚丁二酸丁二醇酯(PBS)薄膜在不同pH值水溶液中的降解进行对比研究.用失重率及薄膜表面形貌观察等时降解结果进行表征,结果表明:PBS薄膜在不同pH值水溶液中的降解速度为:碱性溶液>酸性溶液>中性溶液.降解过程中不同降解溶液的pH值均有一定程度的下降.     

Synthetic aliphatic biodegradable poly(butylene succinate)/clay nanocomposite foams with high blowing ratio and their physical characteristics

Poly(butylene succinate) (PBS)/organoclay nanocomposites were prepared by both solution blending and melt mixing methods. In addition, nanocomposites of PBS/organoclay were also prepared by a two‐step process where the solution blended mixture is subsequently compounded in the melt state using a torque rheometer (SOAM method). We then investigated thermal and mechanical properties of the PBS/organoclay nanocomposite at first and determined an optimum organoclay content for the preparation of nanocomposite foams. All PBS/organoclay nanocomposite foams are found to possess closed spherical‐shaped cells without any rupture when examined by an optical microscopy. The blowing ratio also increased with the increase in the blowing temperature and time, with the maximum blowing ratio of 19. Furthermore, the addition of a small amount of organoclay is found to allow the cell size to follow Gaussian distribution. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers     

聚丁二酸丁二醇酯泡沫材料的制备

采用模压化学发泡的方法制备了可生物降解的聚丁二酸丁二醇酯(PBS)泡沫材料,并研究了其性能.结果表明,采用过氧化二异丙苯(DCP)作交联剂辅以三羟基甲基丙烷三甲基丙烯酸酯(TMPTAM)作助交联剂能明显提高PBS的黏度,使其具有较高的熔体强度.当DCP用量为4～5份时,泡沫材料泡孔均匀且密度适中,同时,PBS泡沫材料在...     

Nanoparticle‐loaded UV‐blocking contact lenses

We have developed a novel approach of incorporating UV‐blocking features into contact lenses by dispersing nanoparticles into the lenses. The nanoparticles are prepared by controlling polymerization dynamics using chain terminating and chain transfer agents. A theoretical model is developed to predict the effect of various formulation parameters on the particle size. This approach can produce UV‐blocking nanoparticles of controlled size below 10 nm in diameter with close to 10% conversion. The model predictions for the mean size are in reasonable agreement with the experimental data. The nanoparticles are cleaned and loaded in silicone hydrogel contact lenses by soaking the lenses in a solution of particles in ethanol and acetone. Lenses loaded with about 6% particles w/w in the hydrated lens block sufficient UV light to be classified as Class 1 blockers. The nanoparticles are retained in the lens during soaking in phosphate buffered saline (PBS) and are stable to sterilization by autoclaving. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42495.     

Characterization and improved electrical conductivity of partially biodegradable polyaniline/poly(1,4‐butylene succinate) polymer composite films

Polyaniline/poly(1,4‐butylene succinate) (PANI/PBS) composites were prepared by the polymerization of aniline hydrochloride in the presence of different weight percentages of poly(1,4‐butylene succinate) biodegradable polymer by in situ deposition technique. The oxidative polymerization of aniline hydrochloride was performed by the drop wise addition of an aqueous ammonium persulfate solution. Fourier‐transform infrared spectroscopy, surface morphology, and thermogravimetric analyses indicated a strong interaction between PANI and PBS. The temperature‐dependent DC conductivity and biodegradable properties of PANI/PBS were also investigated. The results showed that both the conductivity and biodegradability of the composites was significantly increased by the addition of PBS. POLYM. COMPOS., 35:2010–2017, 2014. © 2014 Society of Plastics Engineers     

Crystallization,morphology, and mechanical properties of poly(butylene succinate)/poly(ethylene oxide)‐polyhedral oligomeric silsesquioxane nanocomposites

The biodegradable poly(butylene succinate) (PBS)/poly(ethylene oxide)‐polyhedral oligomeric silsesquioxane (PEO‐POSS) nanocomposites were prepared by the solution blending and melt‐injection methods. The effect of PEO‐POSS on the non‐isothermal and isothermal crystallization, morphology, as well as mechanical properties of PBS was carefully investigated. The PEO‐POSS nanoparticles dispersed well in the PBS matrix, with the diameters around 30 nm. From isothermal crystallization analysis, the incorporation of PEO‐POSS enhanced the crystallization of PBS due to the heterogeneous nucleation effect while the crystal structure of PBS remained. PBS/PEO‐POSS nanocomposites showed of higher glass transition temperatures than that of neat PBS, attributing to the existence of PEO‐POSS decreasing the flexibility of PBS chains. The elongation at break of the PBS/PEO‐POSS nanocomposites reached the maximum value with PEO‐POSS content of 5 wt%. However, the elastic modulus of PBS decreased after the incorporation of PEO‐POSS. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers