流动注射壳聚糖在线微柱预富集电热原子吸收光谱法测定痕量Cr(Ⅵ)

以天然高分子材料壳聚糖作在线预富集柱填料,流动注射与电热原子光谱联用测定痕量Cr(Ⅵ).采样体积5.80mL,采样频率22样/h,富集倍数51倍,线性范围0.02μg/L～0.12μg/L,该方法的检出限(3s,n=11)0.69ng/L,相对标准偏差5.1%(CCr(Ⅵ)=0.10μg/L,n=11).将该方法用于环境水样、茶叶样品和头发样品中Cr(Ⅵ)的测定,结果满意.     

Preparation of a Star Network PEG-based Gel Polymer Electrolyte and Its Application to Electrochromic Devices

A star network polymer with a pentaerythritol core linking four PEG-block polymeric arms was synthesized, and its corresponding gel polymer electrolyte based on lithium perchlorate and plasticizers EC/PC with the character being colorless and highly transparent has been also prepared. The polymer host was characterized and confirmed to be of a star network and an amorphous structure by FTIR, ^1H NMR and XRD studies. The polymer host hold good mechanical properties for pentaerythritol cross-linking. Maximum ionic conductivity of the prepared polymer electrolyte has reached 8.83 × 10 ^-4 S·cm^-1 at room temperature. Thermogravimetry （TG） of the polymer electrolyte showed that the thermal stability was up to at least 150 ℃. The gel polymer electrolyte was further evaluated in electrochromic devices fabricated by transparent PET-ITO and electrochromically active viologen derivative films, and its excellent performance promised the usage of the gel polymer electrolyte as ionic conductor material in electrochrornic devices.     

STUDY ON THE NANOSECOND TRANSIENT ABSORPTION SPECTRA OF HYPOCRELLIN A

In this paper, the nanosecond transient absorption spectra and the fluorescence spectraof Hypocrellin A(HA) are examined in solvents of varying polarity. There are three absorp-tion bands in dilute HA solutions: Ⅰa, Ⅱa are defined as the triplet-triplet absorption ofHA, the band Ⅲa is supposed to be the absorption of the solvent--sepatated ion pair (SSIP).In more concentrated solutions, only the absorption of SSIP was observed. The effects ofsolvent polarity on transient absorption spectra and fluorescence spectra of HA and the effectof oxygen on the intensities of the fluorescence of HA are discussed. Then a reasonablemechanism for the photolysis of HA is proposed.     

关于超高分子量聚丙烯超拉伸膜的结构性能的研究——Ⅰ.拉伸取向过程的表征

 用超高分子量聚丙烯的对二甲苯溶液中冷却析出的结晶沉积压制成的结晶垫,经热拉伸制备了不同拉伸倍数的薄膜.与用低分子量聚丙烯制备的结晶垫或熔融结晶物不同,超高分子量聚丙烯的结晶垫显示出极高的拉伸变形性能,因而制得了高达69倍的拉伸样品.WAXD照片表明在未拉伸的结晶垫中,微晶的c轴沿结晶垫法线方向择优取向,但仅经2-4倍的拉伸,微晶即发生破裂,且产生的较小的折叠链微晶已转向沿拉伸轴方向取向;晶区取向因子在拉伸过程中迅速增加并在较低拉伸倍数下即接近于理想取向.但非晶区取向因子在整个拉伸领域中增加缓慢.随拉伸倍数的增大,晶粒尺寸D₁₁₀及D₀₄₀逐渐减小;而长周期L逐渐增加.这表明在高倍拉伸样品中存在着折叠链被从片晶中拉出并部分形成伸直链结晶的转变.     

2，4-二羟甲基四氢吡咯衍生物的合成及对烯烃环氧化反应的诱导

用手性的丙烯酸薄荷醇酯与原位生成的1，3-偶极试剂发生Diels-Alder反应， 得到一系列新的手性2，4-二酯基四氢吡咯衍生物，经氢化铝锂还原得到纯的手性 2，4-二羟甲基吡咯衍生物。并首次发现，在用Oxone氧化烯时，2，4-二羟甲基四 氢吡咯衍生物能有效地诱导烯烃发生环氧化反应，转化率达到定量。     

高灵敏分光光度法测定全血铁

为建立一种快速、简便、灵敏的分光光度法测定全血中微量铁,在非离子型表面活性剂聚氧乙烯月桂醚(Brij-3 5 )及聚氧乙烯异辛基苯基醚(TritonX -1 0 0 )存在下,用2 (5 硝基2 吡啶偶氮) 5 [N 正丙基 N (3 磺酸丙基)氨基]苯酚二钠(简称Nitro -PAPS)作显色剂直接光度法测定全血中微量铁。结果表明,该法在pH 4 0的乙酸乙酸钠缓冲液中,以5 90nm为测定波长,可直接测定全血中微量铁,本法线性范围为0～2 2 7μg/mL ,表观摩尔吸光系数为9 97×1 0 4L/(mol·cm) ,回收率为97 5 %～1 0 1 8%。结论:该法具有操作快速、简便、结果灵敏可靠等优点,适合临床医疗、预防保健等应用,值得推广。     

聚4-重氮基苯乙烯与聚苯乙烯磺酸钠的自组装

1991年Ｄｅｃｈｅｒ等将带相反电荷的聚电解质 ,于水溶液中交替沉积在片基上 ,制备了多层超薄膜[1] ,这种制膜方法现称为静电自组装 .它操作简单 ,无需专用设备 ;一般在水体系进行 ,对环境友好 ;静电力比范德华力强 ,使它比ＬＢ膜稳定 ,所以近年来有很大发展[2 ] .现在自组装成膜驱动力已从静电力扩展到氢键力、电荷转移相互作用、疏水相互作用等 ,用于组装的组分也从聚电解质扩展到多官能团小分子、胶体粒子、无机纳米颗粒 ,ＤＮＡ、蛋白质等生物大分子等[3～ 11] .虽然自组装膜比ＬＢ膜稳定 ,但它也不耐极性溶剂、电解质水溶液等侵蚀 .如…     

光敏型季铵盐类阳离子表面活性剂的合成及表面活性和泡沫性质

本文报道了一种光敏型的阳离子表面活性剂（AZO），其分子结构中含有偶氮苯基团，并研究了光照对表面活性和泡沫性能的影响。经紫外光照射后，表面活性剂的饱和吸附量（Г_max）减小，临界胶束浓度（cmc）、最低表面张力（γ_cmc）和分子极限占有面积（A_min）增大；气泡数目增多，直径变小，发泡能力和泡沫稳定性降低。实验结果证实，该表面活性剂的表面活性和泡沫稳定性可以用光照进行调控。     

聚甲基丙烯酸4［（4＇－硝基－1＇硫酰基苯）－1－羟烷氧基本基］酯的合成

new series of sulfur-contalning side chain liquid crystalline polymers were described. Mesomorphic side chains with methylene spacer in different length have been synthesized and their structures were identified by NMR, IR and MS.The liquid crystalline nature of the polymers was characterlzed by microscopy.The Polymers have liquid crystalline nature.     

用热分析技术测定碳化硅粉体对聚乙二醇的吸附量

用热分析技术TG-DTA(thermal gravimetric and differential thermal analysis)测定浆料中碳化硅粉体对分散剂聚乙二醇PEG(polyethylene glycol)的吸附量. 结果显示PEG在Ar气氛中411.5 ℃时完全分解; 碳化硅表面分散剂PEG的吸附量随着pH的增大而下降, 在较高pH下大多数分散剂仍存在于溶液中; 分散剂PEG的吸附量通过公式(1)进行计算. 该方法简单方便, 可以应用于测量氧化物或非氧化物吸附紫外-可见分光光度法不能测定的一些有机聚合物分子.