Synchronously synthesizing and immobilizing porphyrins on crosslinked polystyrene microspheres and preliminary study on catalytic activity of supported metalloporphyrins

A novel method for immobilizing porphyrins as well as metalloporphyrins (MPs) on polymeric supports was found, and it is the way to synchronously synthesize and immobilize porphyrins on polymeric microspheres. By using 4‐hydroxybenzaldehyde (HBA)‐bound crosslinked polystyrene (CPS) microspheres, pyrrole, and benzaldehyde in a solution as co‐reactants and through the Adler's reaction between solid–liquid phases, it was successfully realized to simultaneously synthesize and immobilize phenyl porphyrin (PP) on CPS microspheres, resulting in PP‐supported microspheres PP–CPS. With the same method, substituted PPs, 4‐chlorophenyl porphyrin (CPP) and 4‐nitrophenyl porphyrin (NPP), were also successfully immobilized on CPS microspheres by using substituted benzaldehydes, 4‐chlorobenzaldehyde and 4‐nitrobenzaldehyde, as one reactant in the solution, respectively, and other two porphyrin‐supported microspheres, CPP–CPS and NPP–CPS, were obtained. The effects of various factors on the process of synchronously synthesizing and immobilizing porphyrins on CPS microspheres were mainly studied. Further, the coordination reaction of cobalt salt with PP–CPS as well as CPP–CPS and NPP–CPS was conducted, forming three solid catalysts, CoPP–CPS, CoCPP–CPS, and CoNPP–CPS. The catalytic properties of these catalysts in the catalytic oxidation of ethylbenzene to acetophenone by dioxygen were preliminarily examined. The experimental results indicate that the Adler's reaction between solid–liquid phases, namely the reaction between HBA‐bound CPS microspheres and pyrrole as well as free benzaldehyde or analogs in the solution can favorably be carried out. For this process, the fitting protonic acid catalyst is p‐nitrobenzoic acid and appropriate solvent is dimethyl sulfoxide (DMSO). By comparison, the process of preparing CPP–CPS microspheres is easier to be carried out. The obtained three solid catalysts can effectively catalyze the oxidation of ethylbenzene to acetophenone by dioxygen. In comparison, the catalytic activity of CoNPP–CPS is the highest. Copyright © 2009 John Wiley & Sons, Ltd.     

溶剂热法制备钴微球及其表征

<正>0引言过渡金属钴以及它的一些氧化物,以其特殊的电、磁和光学性能被广泛应用到信息存储[1]、催化剂[2]、磁光材料[3]、铁磁流体[4]以及生物医学[5]等诸多领域。前人曾经用羰酰钴热解法[6-7]、γ射线照射法[8]、光刻气相沉积法[9]、电化学沉积法[10]和金属盐溶液的     

磁性壳聚糖去除水中腐殖酸的研究

采用高温水热法合成了磁性壳聚糖,并研究了其对水中腐殖酸(HA)的吸附、脱附行为。表征结果表明,磁性壳聚糖粒径大小为200～300nm,氨基含量1.29mmol·g-1,BET比表面积36.00m2·g-1,饱和磁化强度为38.78emu·g-1,易于磁性分离。HA在磁性壳聚糖上的吸附等温线可用Freundlich方程模拟,吸附动力学符合拟二级动力学方程。HA的吸附量随溶液pH值的升高而降低,随不同阳离子浓度增加而增加,不同类型的阳离子对HA吸附效果影响的大小顺序为:Ca2+Mg2+Na+K+。经5个脱附再生循环,磁性壳聚糖仍能保持79.8%的吸附量,表明该吸附剂再生性好,可循环使用。     

Dissolution of sintered thorium dioxide in phosphoric acid using autoclave and microwave methods with detection by gamma spectrometry

A quantitative and fast method of dissolution of refractory thoria (ThO₂) was developed for the determination of thorium (Th) in a given sample. The dissolution of sintered ThO₂ powder, microspheres and pellets using 88% phosphoric acid was investigated. The conditions of quantitative dissolution of ThO₂ microspheres were optimized by conventional heating in autoclave and also by microwave heating. 100 mg of sintered ThO₂ microspheres were dissolved in 8 g of phosphoric acid in an autoclave, and heating at 170 °C for 3 h, in comparison to 5 g of phosphoric acid by microwave heating (375 W) at 220 °C for 1 h. Dissolution studies on the powder form of sintered ThO₂ were also performed. 1 g of sintered ThO₂ powder could be dissolved in 6.5 g of phosphoric acid in autoclave heating at 170 °C for 1 h. Strong complexing of (PO₄)³⁻ with Th⁴⁺ may be the influencing factor for quantitative dissolution of ThO₂.     

PS-PBA粒子分散系的介电弛豫谱解析——同、反离子对弛豫的影响及表界面电参数的计算

制备了近纳米级的聚苯乙烯-丙烯酸丁酯(PS-PBA)复合微球粒子,并在40Hz～110×106Hz的宽频范围测量了该粒子分散在9种电解质中时的介电弛豫谱,发现了与PS微球粒子分散系不同的特异介电弛豫:低频弛豫对反离子种类具有敏感性而高频弛豫则与电解质种类几乎无关;根据Shilov-Dukhin模型和M-W-O模型分别分析了高、低频率的弛豫机制,并通过对介电谱的Cole-Cole拟合获得了各体系的介电参数.进一步利用Hanai方法由介电参数计算获得了所有体系的相参数;详细分析了体系的内部参数受PS-PBA微球自身结构以及电解质种类影响的原因;讨论了离子扩散系数对介电参数的影响,从而得出了低、高频的弛豫特征时间分别由同离子的扩散系数和反离子的扩散系数所决定之结论.最后,结合Grosse宽频介电理论计算了粒子表面的以及双电层的主要电参数,并分析了电解质种类差异对这些电参数的影响.     

苯乙烯-甲基丙烯酸羟基乙酯共聚物微球固载金属卟啉催化剂的制备及其催化性能

 将酰氯化的羧基金属卟啉 (MP) 与表面含羟基的苯乙烯-甲基丙烯酸羟基乙酯共聚物微球 (P(St-co-HEMA)) 进行酯化反应, 制备了共聚物微球固载的金属卟啉催化剂 (P(St-co-HEMA)MP). 采用扫描电镜、紫外-可见光谱、红外光谱和热重等手段对微球进行了表征, 并考察了它在“金属卟啉?抗坏血酸?分子氧”体系中催化环己烷羟化反应性能. 结果表明, 共聚物微球固载的金属卟啉比非固载的金属卟啉具有更高的催化活性, 催化剂重复使用 4 次, 仍保持较高催化活性. 各共聚物微球固载的金属卟啉催化活性顺序为 P(St-co-HEMA)FeP > P(St-co-HEMA)MnP > P(St-co-HEMA)CoP.     

Preparation of magnetic polylactic acid microspheres and investigation of its releasing property for loading curcumin

In order to obtain a targeting drug carrier system, magnetic polylactic acid (PLA) microspheres loading curcumin were synthesized by the classical oil-in-water emulsion solvent-evaporation method. In the Fourier transform infrared spectra of microspheres, the present functional groups of PLA were all kept invariably. The morphology and size distribution of magnetic microspheres were observed with scanning electron microscopy and dynamic light scattering, respectively. The results showed that the microspheres were regularly spherical and the surface was smooth with a diameter of 0.55-0.75 μm. Magnetic Fe₃O₄ was loaded in PLA microspheres and the content of magnetic particles was 12 wt% through thermogravimetric analysis. The magnetic property of prepared microspheres was measured by vibrating sample magnetometer. The results showed that the magnetic microspheres exhibited typical superparamagnetic behavior and the saturated magnetization was 14.38 emu/g. Through analysis of differential scanning calorimetry, the curcumin was in an amorphous state in the magnetic microspheres. The drug loading, encapsulation efficiency and releasing properties of curcumin in vitro were also investigated by ultraviolet-visible spectrum analysis. The results showed that the drug loading and encapsulation efficiency were 8.0% and 24.2%, respectively. And curcumin was obviously slowly released because the cumulative release percentage of magnetic microspheres in the phosphate buffer (pH=7.4) solution was only 49.01% in 72 h, and the basic release of curcumin finished in 120 h.     

Model filled polymers. IX. Synthesis of uniformly crosslinked polystyrene microbeads

Monodisperse sized crosslinked polystyrene (PS) beads prepared by reaction of styrene (S) and divinylbenzene (DVB), in batch emulsion copolymerization in the absence of emulsifiers, are not uniformly crosslinked, because DVB is more reactive than S. For copolymerization of 1 to 10 mol % DVB and S, within each crosslinked PS microbead, the crosslink density varies by a factor exceeding two and decreases with increased conversion. A semicontinuous copolymerization, involving incremental additions of DVB, produces uniformly crosslinked PS beads. For both copolymerization techniques, T_g correlates well with crosslink density and PS beads are spherical and monodisperse in size. © 1992 John Wiley & Sons, Inc.     

Model filled polymers. XI. Synthesis of monodisperse crosslinked polymethacrylonitrile beads

Monodisperse polymethacrylonitrile beads of varied size and crosslink density are prepared by emulsion copolymerization of methacrylonitrile and allylmethacrylate in the absence of emulsifier. The particle size is very sensitive to polymerization temperature and initiator concentration. Because of a nitrile group effect, the maximum conversion varies with reaction conditions. The highest conversion obtained was 82%. © 1992 John Wiley & Sons, Inc.     

染料分子印迹聚硅氧烷的制备及性能研究（I）

分别以分散蓝和分散红两种染料为模板分子，3种硅烷偶联剂为功能单体，二氧化硅微球为载体，应用自组织法，制备了两种染料分子印迹的微球形聚硅氧烷。采用分光光度法，研究了分子印迹聚硅氧烷对各自模板分子的吸附性能及选择性识别性能。结果表明，与非印迹聚硅氧烷相比，染料分子印迹的聚硅氧烷对其模板分子具有较高的吸附能力，分子印迹聚硅氧烷的吸附速率也被讨论。