Structure of a Lamellar Phase Formed by Non-ionic Surfactant and Water: Effects of shear flow

We have investigated effects of shear flow on the structure of lamellar phase in hepta(oxyethylene glycol)—n—hexadecylether—water system using small-angle neutron scattering (SANS) under shear flow at the shear rates (

二甲基亚砜防冻机理的拉曼光谱分析

采用拉曼光谱对不同体积比的二甲基亚砜(DMSO)水溶液进行测量, 并利用Origin 7.5对水的光谱带进行分峰, 求得拉曼光谱峰面积比值. 应用混合模型对实验结果进行了分析, 分析结果表明, 防冻剂二甲基亚砜与水混合时, 其SO基团与水分子的OH基团形成氢键(SO…H—O), 有效地阻止了四面体结构冰的生成, 并证实了二甲基亚砜与水的体积比为1∶1时, 防冻效果最佳.     

Solvent Effect of Dimethyl Sulfoxide on the Chemical Shifts of Phenyl Vinyl Ketones

In our study on the 1D and 2D NMR spectra of synthetic chalcones in DMSO‐d₆, we found that, contrary to our expectation, the signals of α‐carbon correlated to the olefinic protons resonating at lower field whereas the signals of β‐carbon correlated to the olefinic protons resonating at higher field in the spectra of chalcones. To further investigate such solvent effect, four α,β‐unsaturated ketones were prepared and studied separately in CDCl₃ and DMSO‐d₆. The result indicated that the α,β‐unsaturated ketones that possess benzoyl moiety experienced solvent effect in DMSO‐d₆ to result in an anomalous chemical shift. The shift arose from the complexation of solute molecule with DMSO that fixed the steric conformation of solute molecule so that H_β was kept apart from its benzene ring whereas its H_α became more accessible by its benzene ring. Thus, these two olefinic protons would experience a different extent of anisotropic effect exerted by the neighboring benzene ring.     

温度对二甲基亚砜水溶液的结构和热力学性质的影响

应用参考作用格位模型理论计算了二甲基亚砜(DMSO)摩尔分数为0.002时不同温度下溶液的微观结构和热力学性质. 计算结果表明, DMSO加入到水中能够增强溶液的分子网络结构. 温度升高, 配位数减小, 溶液中分子排布趋向无序. 平均力势的波动增大表明分子间的诱导力表现为斥力. 计算得到的各种热力学性质显示: 温度升高, 溶液的熵和溶剂化自由能增加, 相互作用能和过剩化学位也增加, 即高温下溶液越来越偏离理想溶液; 空位形成能降低表明溶液分子结构在高温下更容易重组.     

新型热塑性淀粉的制备和性能

以二甲基亚砜(DMSO)为增塑剂, 通过熔融共混法制备了一种新型热塑性淀粉(TPS), 研究不同增塑剂含量对材料结构和性能的影响, 并与甘油及甘油/水复合增塑淀粉体系进行了比较. FTIR结果显示, DMSO能够与淀粉产生强烈而稳定的氢键相互作用. WAXD和SEM的研究结果表明, DMSO的加入破坏了淀粉的有序结构, 实现了淀粉的塑化, 形成均一的非晶连续相. 同甘油及甘油/水增塑体系相比, DMSO与淀粉的羟基形成更为稳定的氢键, 能够有效抑制淀粉的重结晶. 动态力学和拉伸力学性能测试结果表明, 经过DMSO的增塑, 有效降低了淀粉的玻璃化转变温度, 改善了材料的韧性, 增塑效率要好于甘油及甘油/水复合增塑体系.     

Measurement and Prediction on the Surface Properties of Dimethyl Sulfoxide/Water Mixtures

Pendent drop method was adopted to measure the surface tension of dimethyl sulfoxide(DMSO)/water mixtures. A new pendent drop apparatus was built up and checked with water, and a good agreement of our data with literature could be found. With the new apparatus, the surface tensions of nine DMSO/water mixtures with mass fractions of water from 0.1 to 0.9 were investigated in a temperature range of 298-338 K. The expanded uncertainty for surface tension measurement was estimated to be 0.5% at a confidence level of 95%(k=2) in the whole temperature range. A thermodynamic-based relation was used to predict the surface properties of DMSO/water mixtures. Based on the relation and Gibbs adsorption theory, a prediction model was proposed for the calculation of surface relative excess and the thickness of the surface molecule layer.     

二甲基亚砜和四氢呋喃对胃蛋白酶催化动力学和分子光谱的影响

为了研究二甲基亚砜(DMSO)和四氢呋喃(THF)对胃蛋白酶(Pepsin, PP)催化活性的影响及其作用本质, 测定了在这两种有机溶剂的作用下胃蛋白酶的催化活性、 动力学参数、 紫外吸收光谱、 紫外差示光谱和荧光发射光谱的变化. 结果表明, 体积分数为9%的DMSO使PP活性提高83.4%; 而体积分数为1%的THF只能使PP活性提高3.59%. 在盐酸溶液中, PP的动力学参数K_m=2.22 mg/mL, v_max=1.1×10⁶ U/mg Pro; 在9%DMSO中, 其K_m=1.50 mg/mL, v_max=0.5×10⁶ U/mg Pro; 在1%THF中的K_m=1.91 mg/mL, v_max=0.51×10⁶ U/mg Pro. 9%DMSO强烈抑制PP分子肽键的紫外吸收, 而对芳香族氨基酸无影响; 1%THF则对PP的紫外吸收光谱影响不大. 9%DMSO和1%THF都使PP的紫外差示光谱出现明显的负吸收峰和正吸收峰. 9%DMSO使酶分子的荧光发射峰向短波方向移动1 nm; 而1%THF则对其无影响. 实验结果表明, 在9%DMSO和1%THF中, PP分子的立体构象发生了变化, 使酶分子的K_m下降, 酶分子对底物的亲和力有所升高, 从而导致酶分子的催化活性有不同程度的提高.     

表面活性剂体系中电荷诱导的层状相向囊泡相的转化

向一种非离子表面活性剂LA070(英文名AlcoholC12-C16Poly(1-6)Ethoxylate)复配体系LA070/C8H17OH/H2O形成的层状相中加入离子型表面活性剂使其电荷化,在电荷诱导下,双分子层的曲率发生变化,闭合形成具有黏弹性的囊泡相.离子型表面活性剂的加入量增大到一定程度时,由于反离子的屏蔽作用,囊泡结构被破坏,溶液的黏弹性消失,澄清的溶液逐渐变混浊,然后分为两相.     

二甲基亚砜对乙酸气相色谱保留时间的影响及其机理

通过气相色谱、红外光谱分析和量子化学计算,探究溶于二甲基亚砜（DMSO）中乙酸保留时间发生波动的原因。 结果显示,乙酸保留时间变化与DMSO体积等量递增呈线性关系,R²=0.99301;根据红外光谱分析得出,DMSO和乙酸之间生成了氢键,以DMSO-乙酸分子的形式通过色谱柱;根据Gaussian09程序计算结果,DMSO电子密度大的部分给予电子,与乙酸之间形成了氢键,而DMSO电子密度小的部分容易获得电子与具有强偶极矩的色谱柱固定液聚乙二醇产生作用力,吸附在固定液上。因此,在上述一系列复杂的分子间作用力的共同影响下,乙酸保留时间发生了波动,且随着溶剂DMSO体积比增加,乙酸保留时间不断延长。     

稀土异硫氰酸盐与二甲基亚砜配合物的合成,性质及热分析研究

合成了15种稀土异硫氰酸盐与二甲基亚砜(DMSO)的配合物,经化学分析和元素分析确定其组成为RE(NCS)_s·mDMSO(RE=La,Ce,Pr,Nd,Sm,Eu,Gd;m=5.RE=Tb,Dy,Ho,Er,Tm,Yb,Lu,Y;m=4).用红外光谱及X射线衍射技术进行了表征.运用TG-DTA-DTG联用技术研究了该系列配合物的热分解过程,求算热重动力学参数发现,第一步热分解阶段的活化能随着中心高子——镧系元素原子序数的依次递增呈现“双峰现象”.     

Molecular Dynamics Simulations of Sulfobetaine-Type Zwitterionic Surfactant at the Decane/Water Interface

Automated Topology Builder (ATB) and GAMESS (US) were used to build the model of a new sulfobetaine-type zwitterionic surfactant. And a serious of molecular dynamics simulations of the new sulfobetaine-type zwitterionic surfactant were performed at the decane/water interface by GROMACS, the influence of surfactant structure to the interfacial properties was investigated. The results show that the surfactant molecules can adsorb at the decane/water interface closely and reduce the interfacial tension significantly between decane and water. In another word, the model of the sulfobetaine-type zwitterionic surfactant is correct. The minimum interfacial tension could reach up to 1.6 mN · m^?1 when the number of surfactants was up to 134, which corresponds to the critical micelle concentration and consistent with the experimental values of the system.     

钨钼杂多酸及其盐与二甲基亚砜加合物的制备和性质研究

在乙腈和水的混合溶剂中制备了9种钨钼杂多酸和杂多酸盐的二甲基亚砜加合物。研究结果表明,加合物中杂阴离子的Keggin结构基本不变。配体DMSO以S=O键上的氧作为配位原子,它不直接与杂阴离子骨架结构发生配位作用,而是与杂多酸中的质子氢或杂多酸盐中的金属阳离子以氢键或配位键相配位,生成的质子(钅羊)离子和金属配离子再通过离子缔合键与杂阴离子相结合,形成杂多酸或杂多酸盐加合物。     

二甲基亚砜对钒磷氧催化剂性能的影响

在制备钒磷氧催化剂前驱体的过程中,加入高沸点溶剂二甲基亚砜（DMSO）,改善了钒磷氧催化剂对正丁烷氧化制顺丁烯二酸酐的催化性能．催化性能评价实验表明,当DMSO／V（摩尔比）=0．1时,用催化剂（D0.1-VPO）制备顺酐的收率达到最大（49．4％）,与没有加入DMSO的催化剂（VPO）相比其选择性由57％提高到76％,转化率达到65％．采用BET,XRD,SEM,FT-IR等方法分析,发现添加DMSO能增大催化剂的比表面积,改变催化剂前驱体择优取向和催化剂的微观形貌,形成了一些具有纳米尺度的催化剂颗粒．     

Thermodynamic Investigation of Dimethyl Sulfoxide Binary Mixtures at 293.15 and 313.15 K

Densities (ρ), speeds of sound (u), and isentropic compressibilities (k _S) of binary mixtures of dimethyl sulfoxide (DMSO) with water, methanol, ethanol, 1-propanol, 2-propanol, acetone and cyclohexanone have been measured over the entire composition range at 293.15 and 313.15 K. The excess molar volumes (V ^E), the deviations in speed of sound (u ^E) and the deviations in isentropic compressibility (k _S ^E) have been determined. The V ^E, u ^E and k _S ^E values were fitted by the Redlich-Kister polynomial equation and the A _k coefficients as well as the standard deviations (d) between the calculated and experimental values have been derived. The results obtained are discussed from the viewpoint of the existence of interactions between the components of the binary mixtures.     

Affinity of Tripodal and Linear Tetraamines for Silver(I) in Dimethyl Sulfoxide

The thermodynamic functions of the complexation of Ag(I) by the tripodal ligands, tris(2-(methylamino)ethyl)amine (Me₃tren) and tris(2-(dimethylamino)ethyl)amine (Me₆tren) (L), are determined in dimethyl sulfoxide (DMSO) by potentiometric and calorimetric techniques at 298.0 K and 0.1 mol⋅dm⁻³ ionic strength (Et₄NClO₄). A comparison is made between previous data concerning Ag(I) complex formation with the non-alkylated tripodal 2,2′,2″-triaminotriethylamine (tren), in order to analyze the influence of N-methylation on this type of branched donor, and with those relative to the linear triethylenetetramine (trien) and 1,1,4,7,10,10-hexamethyltriethylenetetramine (Me₆trien). The results are discussed taking into account different σ-donating properties, geometric arrangement of the ligands, steric repulsions and solvation effects.     

二甲基亚砜在锂二次电池中的应用

采用二甲基亚砜(DMSO)作为锂二次电池的电解液, 研究了锂在DMSO中的沉积形貌和循环效率. 比较了六氟磷酸锂(LiPF₆)在DMSO、 碳酸丙烯酯(PC)和1,3-二氧环戊烷(DOL)3种溶剂中的沉积形貌和循环效率, 并研究了LiPF₆、 四氟硼酸锂(LiBF₄)、 高氯酸锂(LiClO₄)和二(三氟甲基磺酰)亚胺锂(LiTFSI)4种锂盐在DMSO中的沉积形貌和循环效率. 结果表明, 锂在DMSO中沉积得到的表面光滑平整且致密均匀, 循环效率在前10周要高于在PC中的, 溶剂DMSO有望用于金属锂二次电池中.     

十二烷基硫酸钠对两性咪唑类离子液体表面活性剂1-磺丙基-3-十二烷基咪唑内盐界面聚集行为的影响

利用界面扩张流变技术,研究了两性咪唑类离子液体表面活性剂1-磺丙基-3-十二烷基咪唑内盐(C₁₂imSP)的界面聚集行为,探讨传统表面活性剂十二烷基硫酸钠(SDS)对C₁₂imSP界面聚集行为的影响机制。 结果表明,少量SDS的加入可以填补界面上疏松的C₁₂imSP分子间的空位,界面上形成表面活性剂混合吸附膜,界面张力显著降低;提高SDS的浓度,其分子从体相向界面层的扩散交换占优势,界面层分子逐渐达到饱和吸附,此后体系中有混合胶束形成。 体相胶束中富集的SDS分子对C₁₂imSP分子的“收纳”作用及进一步的“挽留”作用,加之C₁₂imSP分子本身相对较大的空间位阻效应导致界面上的C₁₂imSP分子一旦通过扩散作用被交换至体相,其很难再回复到表面层,即界面膜以SDS分子为主。 通过调节体系中SDS的含量,可以实现对混合体系SDS/C₁₂imSP/NaCl(0.1 mol/L)界面聚集行为的调控,进而实现对界面膜性质的调控。     

Inorganic Polymerization in a Non-Ionic Lyotropic Lamellar Phase

Silicon tetramethoxide was polymerized within a nonionic lyotropic lamellar phase. After gelation, the birefringence of the sample is preserved and polarized light optical microscope observations reveal no segregation. High Resolution Small Angle X-ray Scattering patterns of the gel shows Bragg peaks characteristic of a layered structure. Freeze fracture experiments on the lamellar gel show stacks of parallel bilayers. The experimental observations indicate that the silica is located in the lamellar structure.     

某些稀土硝酸盐与N,N-二亚水杨基乙二胺-二甲基亚砜三元配合物的合成和晶体结构

合成了Tb(Ⅲ)、Y(Ⅲ)、Nd(Ⅲ)硝酸盐与N,N-二亚水杨基乙二胺、二甲基亚观的配合物[RE(C₆H₄OHCHNC₂H₄NCHC₆H₄OH)(NO₃)₃(CH₃SOCH₃)］.Tb(Ⅲ)配合物晶体为单斜晶系,空间群P2₁/n,a=0.9628(3)nm,b=1.6439(4)nm,C=1.6256(2)nm,β=102.78(2)°,V=2.509(2)nm₃,D_x=1.830g/cm³,Z=4,μ=2.996mm^-1,F(000)=1368,R=0.043,R_w=0.046.Tb(Ⅲ)的配位数是9,配位几何为单帽四方反核柱.所有的配位原子都是氧原子.两个中心离子被双Schiff碱桥联,形成一维无限长链.     

Liquid-to-Solid Phase Transitions of Imidazolium-Based Zwitterionic Polymers Induced by Hofmeister Anions

In this study, we compared the responses of two different types of zwitterionic polymers (ZPs), polyvinylimidzole sulfobetaine (poly(SBVI)) and polymethacrylate sulfobetaine (poly(SBMA)) to Hofmeister anions. Although the anions of the two ZPs were the same as the sulfonate anions and only the types of their cations were different from each other, the aggregation behavior of each in the salt aqueous solution was remarkably different. Consequently, poly(SBVI) exhibited both salting-in and salting-out effects depending on the type and concentration of salt, while poly(SBMA) only exhibited the anti-polyelectrolyte effect. The results of this study provide a deeper understanding of the behavior of zwitterionic polymers in salt solutions and will greatly expand their applications.