荧光探针法研究新型Gemini表面活性剂在水溶液中的聚集行为

以芘为荧光探针、二苯酮为猝灭剂,用稳态荧光探针法测定了新型Gemini表面活性剂的临界胶团浓度(CMC)、胶团聚集数(N_agg)及胶团微极性.研究了Gemini表面活性剂结构和氯化钠浓度对CMC、N_agg、胶团微极性的影响.结果表明,新型Gemini表面活性剂的CMC比常规表面活性剂的CMC低1—2个数量级.当疏水基碳原子数增加时,CMC依次降低,N_agg增大,胶团微极性减小.当氯化钠浓度增大时,N_agg增大,胶团微极性减小.     

荧光探针法研究双子型阳离子表面活性剂与明胶的相互作用

利用荧光探针法研究了双子型阳离子表面活性剂与明胶的相互作用,考察了此类表面活性剂的分子结构和明胶对临界胶团浓度(cmc)、胶团聚集数(N_agg)和胶团微极性的影响.结果表明,当双子型阳离子表面活性剂的疏水基增长时,cmc减少,N_agg增加,胶团的微极性降低;加入明胶后,双子型阳离子表面活性剂的N_agg减少,cmc和胶团微极性增加.     

Bola型阴离子表面活性剂与溴化十二烷基三乙铵混合体系的表面性质与聚集行为

研究了具有简单结构的bola型阴离子表面活性剂二十酸二钠（C_(20)Na_2)与 阳离子型普通表面活性剂溴化十二烷基三乙铵（C_(12)Et_3）混合体系的表面性质 ，发现混合体系的cmc和γ_(cmc)比C_(12)Et_3单一体系未有显著降低。以负染色 ，FF-TEM，动态光散射（DLS）及粘度方法研究了混合体系的聚集行为，发现混合 体系中同时形成球形囊泡和管状聚集体，提出了产生这种聚集行为的机制。     

烷基氯化铵体系中分子有序组合体的转化

采用动态光散射、吸收光谱、粘度及电镜透射等方法研究了烷基氯化铵在弱碱性条件下溶液浓度变化对分子有序组合体结构的影响.当表面活性剂浓度大于cmc时,分子有序组合体的形态随表面活性剂浓度的增加出现胶团-囊泡-球状胶团的转化过程,这与水解产生的极性有机物烷基胺量的变化密切相关.     

碳氢与碳氟表面活性剂混合水溶液的胶团与囊泡形成

碳氢与碳氟表面活性剂混合水溶液的胶团与囊泡形成丁慧君，戴群英，张兰辉，赵国玺（北京大学物理化学研究所，北京，１００８７１）关键词囊泡，表面活性剂，胶团形成，负离子结合度，表面活性利用结构简单的表面活性剂代替生物膦脂形成人工囊泡的研究正受到普遍关注［１...     

稳态荧光探针法研究对-烷基-苄基聚氧乙烯醚羧酸甜菜碱的聚集行为

利用荧光探针法和表面张力法测定了一类疏水基中含有苯基的新型甜菜碱两性离子表面活性剂对-烷基-苄基聚氧乙烯醚羧酸甜菜碱(ABECB)的临界胶团浓度(cmc)、胶团微极性和表面张力(γ_cmc).研究结果表明,荧光探针(芘)法可用来测定这类表面活性剂的临界胶团浓度(cmc),且测定结果与表面张力法(吊片法)接近;ABECB具有较低的cmc和γ_cmc值,表明此类表面活性剂具有优良的表面活性; 胶团的微极性随着疏水链长的增大而略微减小,氧乙烯(EO)单元数的增大对ABECB胶团核内的微极性影响不明显.     

10-十一烯酸衍生物混合体系的表面化学

自表面张力测定对１０－十一烯酸胆碱衍生物（三甲基－［２－（１０－十一烯酰氧乙基）］碘化铵）与１０－十一烯酸钠混合体系的表面吸附和胶团形成作了研究；对该体系中的囊泡形成进行了电镜观察。结果表明，疏水链端基为不饱和烯基的正、负离子表面活性剂混合体系和有饱和疏水链的混合体系一样，也有很高的表面活性，易于表面吸附和形成胶团，并且容易在水及乙醇－水溶液中形成相当稳定的囊泡。这些结果的原因可归之于正、负表面活     

荧光探针法和电子自旋共振技术研究干扰基团对烷基苯磺酸钠聚集行为的影响

利用稳态荧光探针法和电子自旋共振技术测定多烷基苯磺酸钠的临界胶团浓度(cmc)、胶团聚集数(N_agg)、胶团的微极性和微粘度.当干扰基团增加时,烷基苯磺酸钠的临界胶团浓度减少,胶团聚集数减少,胶团微粘度降低,胶团的微极性增强.     

辛基甲基亚砜与离子型表面活性剂在水溶液中的相互作用

本文用测定表面张力的方法研究了非离子表面活性剂辛基甲基亚砜(OMS)分别与离子型表面活性剂C_(10)H_(21)SO_4N_a(SDeS)、C_7F_(15)COONa(SPFO), C_(10)H_(21)N(CH_3)_3B_r(DeTAB)等在水溶液中的相互作用。发现上述混合体系的胶团形成及表面吸附都有不同程度的增效作用; 表面活性分子在吸附层中的相互作用参数β~s以及在胶团中的相互作用参数β~m均为负值并有一定变化规律; OMS与DeTAB的相互作用较OMS与SDeS或SPFO的相互作用弱得多; 此现象自OMS分子在水溶液中的质子化作用得到解释。     

荧光探针法研究连接基团对双子型阳离子表面活性剂聚集行为的影响

利用荧光探针法和表面张力法测定了新型双子型阳离子表面活性剂的临界胶团浓度(cmc)、最低表面张力(γ_cmc)、胶团微极性和胶团聚集数(N_agg),探讨了连接基团对此类表面活性剂在水溶液中聚集行为的影响.结果表明,当连接基团增长时,cmc和胶团微极性增加,γ_cmc增大,N_agg减少,表面活性降低,在溶液中自发形成胶团的能力减弱.     

HEPT类化合物的QSAR研究

为定量结构／活性相关性研究提取了量子化学参数,拓扑指数Am,分子连接性指数^mxt及疏水性常数,同时应用正交变换和最佳变量子集算法（Leaps-and-Bonds)进行了变量压缩和选择,进而实施了多元回归分析,并由此结果进行了HEPT类化合物（1－[(2-hydroxyethoxy)methyl]-6-(phenylthio)-thymine derivatives)的结构／活性关系的理论解释,进行了人工神经网络法对于该类化合物的活性预测,其结构明显好于多元回归法。     

From the Micro- to the Macro-: Managing the Conservation of the Warship,Vasa

Sweden's famous warship, Vasa, sank on her maiden voyage in August 1628, and remained on the bottom of Stockholm harbour for 333 years. Raised in 1961, she became the first large-scale wooden object to be treated with polyethylene glycol (PEG). In the summer of 2000 a number of acidic salt precipitations were noticed on the surface of the ship and on wooden artefacts in the storerooms. An international research project has been established to look into the causes of this problem and suggest possible re-treatments. Meanwhile projects are underway to monitor movements in the ship, to build a better support system, and to replace the thousands of iron bolts holding the structure together, while a sophisticated new climate system has recently been installed in the museum.     

液滴荧光传感与计算机联用技术在微量分析中的应用

通过在LS55型荧光-磷光-发光分光光度计上加装液滴产生及调节附件,采用计算机采集与分析处理数据,成功地研制了双通道液滴光化学传感装置.利用葡聚糖凝胶对复合维生素B中不同组分的选择性吸附来达到分离与同时检测的目的,并将其用于复合维生素B药片的分析,取得了满意的结果.     

On the scaling of the interface energy of the liquid clusters in the disordered nanoporous medium

Similarity of the extrusion curves of non-wetting liquid in a nanoporous medium with different initial fill volume fractions is observed experimentally. The similarity can be explained by the scaling of the interface energy and the self-similarity of the infinite percolation cluster of fluid-filled pores. Understanding the physical processes leading to the observed phenomena is a foundation for the development of high-performance devices for damping and energy storage on the basis of such heterogeneous systems.     

Using of the Agglomeration-in-liquid for the Technology of the Fine Materials

The content of the fine and ultrafine particles in the raw material results in difficulty of the separation, the loss of the valuable components and ecological contamination. Secondary using of the fine particles is impossible without their granulation. This problem has been solved by the agglomeration-in-liquid method.An agglomeration-in-liquid method is a process to produce agglomerates in a liquid phase from solid particles suspended in the liquid. The surface of solid particles and the binding liquid must be of identical polarity, but the continuous phase must be of the opposite polarity. The water solutions of the surfactant are the binding liquids or the organic liquids.     

Copper-containing dendromesogens: the influence of the metal on the mesomorphism

The synthesis and liquid crystalline behaviour of the first and second generations of a dendrimeric structure based on poly(propyleneimine)(DAB-dendr(NH₂)_x) are reported. 4-(4-n-Alkoxybenzoyloxy)salicylaldehydes are used as mesogenic moieties attached at the peripheral amino groups of the dendrimers giving rise to dendromesogens with four and eight mesogenic branches. From these dendromesogens, considered as organic ligands, were prepared six metal-containing dendrimers which incorporate two or four copper atoms in their structures. All the dendrimeric ligands and three of the metal-containing dendrimers exhibit liquid crystalline properties which were studied by optical microscopy, DSC, X-ray diffraction and EPR spectroscopy.     

On the quality of the hardness kernel and the Fukui function to evaluate the global hardness

An approximated hardness kernel, which includes the second derivative with respect to the density of the kinetic energy, the electron-electron coulomb repulsion, and the exchange density functionals, has been tested for the calculation of the global hardness. The results obtained for a series of 40 cations and neutral systems and 16 anions represent in most cases an improvement of the results obtained using the HOMO-LUMO gap approach and indicate the viability of this approach to evaluate global hardness. In addition, the relevance of the Fukui function approximation and the role of the three components of the hardness kernel in the evaluation of the global hardness have been analyzed.     

Influence of the Position of the Connecting Spacer of the Chromophore on the Nonlinear Optical Response

A new chromophore, C1 , based on a similar DπA‐structure as in the FTC ‐chromophore but with a hydroxyalkyl spacer perpendicular to the direction of the dipole moment was synthesized. Both chromophores and the CLD ‐chromophore were used to prepare high T_g nonlinear optical vinyl polymers. The influence of the position of the spacer on the DπA‐system on the NLO response of the resulting polymers was investigated.

     

光亮剂对银电沉积行为的影响

用电势阶跃法和旋转圆盘电极法 (RDE)以及SEM和XRD测试手段 ,初步研究了光亮剂对氰化体系中银电沉积行为的影响 .研究表明 ,光亮剂的加入并未导致银电沉积成核机理的改变 ,但显著增强了镀液的微观平整效应 ,并且所得镀层的表观光滑程度明显改善 .XRD测试亦同时表明光亮剂的加入并未改变镀层的择优取向