Studies on the phase properties of lyotropic liquid crystals of Brij35/sodium oleate/oleic acid/water system:By means of polarizing microscope,SAXS,~2H-NMR and rheological methods

The pseudo-quaternary phase diagram of Brij35/sodium oleate/oleic acid/water systems has been investigated, and the liquid crystal area has been identified, which covers about two thirds of the whole phase diagram. The liquid crystal structure and behavior have been also studied by using polarizing texture, small angle X-ray scattering, 2H-NMR and rheometer etc. The result shows that when the composition of the system changes along the line of AA′ in this large liquid crystal region, the structural change is cubic→cubic/lamellar→lamellar→lamellar/hexagonal→hexagonal. Meanwhile, we made the first attempt of systematic study of the rheological properties of the above system. The lattice constants of cubic and hexagonal liquid crystals are 10.53 and 5.68 nm, respectively.     

超高分子量PE凝胶膜的超拉伸性与旁式构象关系研究

通过ＩＲ方法，观测并讨论了在不同条件下制备的超高分子量ＰＥ（ＷＨＭＰＥ）凝胶膜中旁式（Ｇ构象）构象与超拉伸性的关系，提出了Ｇ构象浓度及分布对ＵＨＭＰＥ凝胶膜超拉伸性影响的新概念，同时也讨论了它与链缠结之间的联系，发现：反映Ｇ构象的相对浓度的比值σ＝Ｉ１３０３Ｉ１３５２随制膜浓度的增大而增加，在临界浓度Ｃ０（０．４～０．５ｇ＠１００ｍｌ）附近所形成的膜，具有超高拉伸性（λ＝２００），其Ｇ构象的变化与Ｍａｔｓｕｏ由比浓粘度提出的缠结链改变相对应；热处理温度比热处理时间对σ值的影响更显著，在一定温度下约４分钟后σ值基本不变；在σ值最低的温度范围拉伸，凝胶膜具有良好的超高拉伸性．     

水杨酸分子印迹分离介质的水相制备及色谱行为

以水杨酸为模板分子,2-乙烯基吡啶为功能单体,在甲醇/水体系中制备了水杨酸分子印迹聚合物,并将其作为高效液色谱分离介质研究了其对水杨酸及水杨酸的位置异物体———对羟基苯甲酸的色谱行为。结果表明,该聚合物固定相表现出良好的分离选择性,能够使水杨酸与对羟基苯甲酸快速基线分离。通过对流动相组成与色谱分离效果关系的探讨,证实溶质与印迹固定相的疏水相互作用是分子识别的主要作用力。     

Effect of sucrose on the structure of a cubic phase formed from a monoolein/water mixture

The effect of sucrose on the structure of molecular assemblies formed in an MO/H2O mixture has been studied using a small-angle X-ray scattering method. It was found that the phase transition Ia3d --> Pn3m --> H(II) occurs with increased sucrose concentration in the mixture with the composition 70 wt% MO at 20 degrees C. This structural change induced by sucrose addition would be ascribed to a cosmotropic property of sucrose, which leads to the dehydration of the MO head group and hence causes a decrease in the effective area occupied by the MO molecule at the polar/apolar interface, which facilitates the formation of molecular assemblies with a high curvature for the reversed liquid-crystal mesophase.     

密封罐微波消化法序列ICP-AES测定环境试样中多元素

本文采用密闭罐微波消化方法快速分解生物、土壤、沉积物等环境样品。按样品性质,分别采用HNO3/H_2O_2或HNO_3/H_2O_2/HF在聚四氟乙稀密闭罐中于500W微波功率分解0.1～0.2g样品2～3min,溶液(或在其中加入10ml硼酸饱和溶液)稀释至2.5～5.0ml后,直接用序列ICP-AES法测定。方法准确度经分析6个生物、土壤、沉积物标准参考物质验证,10个元素的均值均与定值吻合。     

提高大分子Fullerene含量的有效方法

通过用掺有异相物质的石墨电极进行电弧反应，所得的混合物中大分子Ｆｕｌｌｅｒｅｎｅ的含量在１０％以上，为进一步分离，提纯以及深入研究大分子Ｆｕｌｌｅｒｅｎｅ打下了基础。研究发现，阳极材料中完整石墨结构的存在是生成Ｆｕｌｌｅｒｅｎｅ的必要条件，异相物质的存在为Ｆｕｌｌｅｒｅｎｅ的生长提供了热的载体，从而使产物中大分子Ｆｕｌｌｅｒｅｎｅ的含量增加。     

A convenient catalytic approach to synthesize straight boron nitride nanotubes using synergic nitrogen source

Straight boron nitride nanotubes (BNNTs) with pure hexagonal phase were conveniently prepared by heating the mixture of Mg(BO₂)₂ · H₂O, NH₄Cl, NaN₃ and Mg powder in an autoclave at 600 °C for 20–60 h. These BNNTs had diameters mainly ranging 30–300 nm and lengths up to 5 μm, and a majority of them had at least one closed end. Besides the traditional end tips, additional cone-like tips were frequently found to be attached on the BNNTs. The effects of temperature, reactants and the possible mechanism of the catalytic formation of the BNNTs are discussed.     

地质样品中岩性自动分类X－射线荧光光谱分析研究

鉴于地质样品岩性变化大，容易引起对Ｘ－射线荧光分析准确度的影响，尤其是主、次量元素受影响更大，因此，作者提出了岩性自动分类，交互有效－基本参数法分析地质样品中主、次量元素，并与原有的经验系数和其它方法进行了比较．结果表明本方法的准确度更好些，对岩性的变化具有更好的适应能力     

Effects of simultaneously doped and deposited Ag on the photocatalytic activity and surface states of TiO2

Ag-TiO2 catalysts with different Ag contents were prepared via a sol-gel method in the absence of light. Based on the characterizations of XRD, photoluminescence (PL), surface photovoltage spectroscopy (SPS), field-induced surface photovoltage spectroscopy (FISPS), and XPS as well as the evaluation of the photocatalytic activity for degrading rhodamine B(RhB) solutions, it was found that the Ag dopant promoted the phase transformation as well as had an inhibition effect on the growth of anatase crystallite. The PL and SPS intensities were decreased with increasing Ag content, indicating that the Ag dopant could effectively inhibit the recombination of the photoinduced electrons and holes. However, the active sites capturing the photoinduced electrons reduced, while the Ag content exceeded 5 mol %. At rather low Ag dopant concentrations, the migration and diffusion of Ag+ ions were predominant, while at rather high Ag dopant concentrations, the migration, diffusion, and reduction of Ag ions simultaneously occurred. The Ag-TiO2 photocatalysts with appropriate content of Ag (Ag species concentration is from about 3 to 5 mol %) possessed abundant electron traps so as to be favorable for the separation of the photoinduced electron-hole pairs, which could greatly enhance the activity of the photocatalysts. From the results of FISPS measurements, it could be found that the impurity bands and abundant surface states were introduced into the interfacial layer of TiO2 because of Ag simultaneously doping and depositing, which could improve the absorption capability for visible light of the photocatalysts.     

Specific interaction between fluorine atoms and thiol groups accounting for higher domain purity and photostability in narrowband BHJ systems

In order to explore the role of fluorine atoms on photostability as well as morphology control of active layer in the presence of 1,4‐butanedithiol (BT), the four polymers with or without fluorine atoms in the backbones including polythieno[3,4‐b]thiophene/benzodithiophene, poly[(4,8‐bis‐(2‐ethylhexyloxy)‐benzo(1,2‐b:4,5‐b9)dithiophene)‐2,6‐diyl‐alt‐(4‐(2‐ethylhexanoyl)‐thieno[3,4‐b]thiophene‐)‐2‐6‐diyl)], poly[4,8‐bis(5‐(2‐ethylhexyl)thiophen‐2‐yl)benzo[1,2‐b;4,5‐b′]dithiophene‐2,6‐diyl‐alt‐(4‐(2‐ethylhexyl)‐3‐fluorothieno[3,4‐b]thiophene‐)‐2‐carboxylate‐2‐6‐diyl)], and poly[4,8‐bis‐(2‐ethyl‐hexyl‐thiophene‐5‐yl)‐benzo[1,2‐b:4,5‐b0]dithiophene‐2,6‐diyl]‐alt‐[2‐(20‐ethyl‐hexanoyl)‐thieno [3,4‐b]thiophen‐4,6‐diyl] were selected for comparison. It is found that the specimens containing fluorine atoms in polymer backbones showed of higher stability after illumination for 1 h in the presence of BT additive, contributing to the higher domain purity. The specific interaction between fluorine atoms and thiol groups was demonstrated by the appearance of novel absorption peak at 2663.1 cm^?1, in addition to the broadening of peak at 2556.2 cm^?1 ascribing to S? H stretching vibration as confirmed by Fourier transform infrared (FTIR) spectroscopy. The finding may guide the accurate use of thiols as effective solvent additive in morphology and stability optimization. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019 , 57, 941–951