Preparation and Surface Properties of Fluorinated Acrylates Copolymers

Copolymerization of acrylates and styrene (St) with perfluorooctylacyloxyethyl methacrylate (FA) monomer, prepared from the reaction of perfluorooctanoic acid and hydroxymethyl methacrylate, was carried out by solution polymerization. The fluorinated acrylate and St copolymers (PFA) were examined by GPC, FT-IR, and ¹H NMR. The surface tension of the PFA solution in N-methyl pyrrolidone was tested by the drop volume method. The results showed that the surface tension of the PFA solution decreased in exponential decay with increase of the PFA concentration, and the surface tension of the solution also decreased with increased addition of the FA monomer in the copolymer at the same concentration. Meanwhile, the adsorption of the PFA macromolecules in the air–solution interface increased and enrichment of the fluorinated segments on the solution surface occurred. The studies of the surface free energy, polarity, fluorine content, and morphology of the PFA films illustrated that the surface free energy and polarity of the PFA films were decreased with the augment of the FA monomer in the copolymers, and that the fluorine content and the surface roughness were increased. The surface free energy of the PFA film was as small as 16.6 mN·m^?1. The surface properties of the PFA copolymers obtained by one shot feed during polymerization were superior to those obtained by continuing feed procedure. More fluorine segregation occurred and induced the formation of a fluorine-enriched surface if the PFA copolymer was postheated. The posttreatment was thus beneficial to the improvement of the surface properties of the PFA film.     

微波法合成2,2′-二苯-1,4-苯并噁嗪-3(4H)-酮及其结构表征

苯并噁嗪酮化合物广泛存在于禾本科植物中,这类化合物在前药合成和生物活性研究方面具有广泛的应用前景[1～4].目前已知的合成方法中,大多都是采用邻氨基酚与ClC(R1R2)COCl(氯酰氯)在碱性条件下长时间回流制得的,反应时间较长;除反应原料外,还需要加入其它碱性物质和溶剂[5～7]     

草酰胺配体的微波合成

在微波辐照下, 分别由苯胺、取代苯胺和草酸通过无溶剂法反应, 合成出N,N′-二(苯基)草酸二酰胺和N,N′-二(取代苯基)草酸二酰胺, 利用¹H NMR, MS和元素分析对其结构进行了表征. 研究表明, 增加辐照功率选择合适的辐照时间有利于产物收率的提高, 甲基或氯单取代的苯胺得率高于苯胺, 增加固液两相的接触面积可大大提高产物的收率.     

有机生色团/SiO_2-TiO_2二阶非线性光学杂化材料的研究

以分散橙－3（DO－3）与γ－缩水甘油氧与基三甲氧基硅烷（KH－560）反应 得到的功能性生色团ASD为前体，采用溶胶－凝胶（sol-gel）法使ASD与钛酸四正 丁酯在酸性条件下共水解缩合，合成了新型稳定的有机生色团/SiO_2-TiO_2杂化溶 胶，并对该溶胶体系的相图进行了研究。利用傅立叶红外（FTIR）、透射电镜（ TEM）和X射线能量色散谱仪（EDS）研究了杂化溶胶形成过程中的络合机理及溶胶 形态。由一维刚性取向气体模型计算杂化材料膜的二阶非线性光学（NLO）系数X~ (2) is 1.43 * 10~(-7) esu。差示扫描量热法（DSC）测得杂化材料的玻璃化温度 可达196 ℃；用紫外－可见光谱对杂化膜在极化前后的取向及取向稳定性进行了研 究。     

大型广义特征值问题的部分特征值和特征向量的块迭代求解

将求解标准特征值问题的Davidson方法推广到求解大型广义特征值问题, 并给出了相应的块迭代算法. 经过理论分析和数值计算发现, 如果迭代过程不发散, 则块迭代算法经过有限次迭代一定收敛. 设矩阵的维数为n, 要求的特征值和相应特征向量的个数为k, 初始的子空间大小为r(r≥k),迭代次数为m,则它们之间满足关系n=r+km. 通过调节子空间大小, 就得到迭代次数m的正整数解.     

水杨醛亚胺镍配合物催化的乙烯水相聚合

在含表面活性剂的水相体系中, 用一系列水杨醛亚胺镍配合物催化乙烯聚合, 得到了高分子量低支化度聚乙烯. 研究表明水杨醛亚胺镍配合物中苯环上取代基的电子效应和空间位阻对乙烯聚合活性和聚合物的分子量有所影响. 提高配合物酚氧环上取代基的吸电子性, 聚合活性相应增加, 但聚乙烯的分子量降低; 而增加苯胺环上取代基的空间位阻, 聚合活性和聚乙烯的分子量均增加. 粘度法测得由水相聚合得到的聚乙烯的分子量在10⁴～10⁵范围内. DSC测得该聚乙烯的结晶度在50%～70%之间, 熔点在115～137 ℃范围内. GPC分析表明用环辛二烯合镍[Ni(COD)₂]助催化乙烯, 聚乙烯的分子量分布随酚氧环上取代基电负性增加而从双峰到单峰变化, 动态流变学研究进一步说明了聚乙烯分子量及其分布的变化.     

Structural characterization,DFT studied,luminescent properties of cationic/neutral three-coordinated copper (I) complexes and application in warm-white light-emitting diode

A series of cationic/neutral copper (I) complexes, [Cu₂(Hbmb)(PPh₃)₄] (BF₄)₂ ( 1a ), [Cu₂(Hbmb)(DPEPhos)₂](BF₄)₂ ( 2a ), [Cu₂(Hbmb)(Xantphos)₂](BF₄)₂ ( 3a ), [Cu₂(bmb)(PPh₃)₄] ( 1b ), [Cu₂(bmb)(DPEPhos)₂] ( 2b ), [Cu₂(bmb)(Xantphos)₂] ( 3b ) (Hbmb = 1,4-bis (1H-benzimidazol −2-yl)benzene, PPh₃ = triphenylphosphine, DPEPhos = bis[2-(diphenylphosphino)-phenyl]ether, Xantphos =4,5-bis (diphenylphosphino)-9,9′-dimethyl-xanthene), have been synthesized and characterized by IR, TGA, XRD and X-ray crystal structure analysis. The structural analysis reveals that each Cu⁺ in all complexes adopts an almost ideal trigonal planar geometry, with three coordinate NP₂, and the C-H···π and π···π interactions are observed in the packing structures. DFT studied indicate the ingredients of the HOMOs and LUMOs for neutral copper (I) complexes 1b , 2b and 3b are different from cationic copper (I) complexes 1a , 2a and 3a , in accordance with the distribution of Mülliken atomic charges. Meanwhile, neutral copper (I) complexes 1b , 2b and 3b have fascinating broad blue-green emission bands at room temperature, while cationic copper (I) complexes 1a , 2a and 3a exhibit the existence of multiple emission peaks. Furthermore, the maximum phosphorescent lifetime and quantum yield at room temperature, for all copper (I) complexes, are 1143 μs and 8.82%, respectively. In addition, in order to measure the practical application of these complexes, the selection of complex 1b is used to fabricate the LED, which emits a bright warm-white light.     

二阶非线性光学聚氨酯对电光效应的共振增强

二阶非线性光学聚合物是最有希望实现在电光器件方面应用的材料之一.该类材料的非线性光学系数很高,响应速度快,与半导体材料的相容性较好,且比有机和无机晶体的制备更方便.目前所用的电光调制器多为光传输型,高光学活性的极化聚合物一般光学损耗较大,尤其是其吸收波段更大,使得调制器只能在其透明波段内使用,否则,传输型波导器件由于这种损耗将无法使用.     

新型非线性光学杂化材料结构与性能的研究

由硅烷染料ASD与钛酸四正丁酯在酸性条件下共水解、缩合得到杂化材料,利用透射电镜(TEM)和X射线能量色散谱仪(EDS)进行分析,结果表明,杂化溶胶粒子是由硅和钛的化合物组成的球形纳米粒子.由一维刚性取向气体模型计算杂化材料膜再极化后的二阶非线性光学系数χ⁽²⁾为1.43×10^-7esu.差示扫描量热法(DSC)测得杂化材料的玻璃化温度可达469K;用紫外-可见光谱对杂化膜在极化前后的取向及取向稳定性进行了研究.用原子力显微镜(AFM)和X射线衍射(XRD)研究了材料在极化过程中的结晶行为和微观结构对生色团取向稳定性的影响,初次在这种极化后的膜中观察到了介观结构.