金属的溶剂萃取热力学研究 2:In~2(SO~4)~3+Na~2SO~4+D~2EHMTPA+n-C~8H~18+H~2O体系

在温度278.15-303.15K和离子强度=为0.1-2.0mol/kg范围内,在萃取体系In~2(SO~4)~3+Na~2SO~4+D~2EHMTPA+n-C~8H~18+H~2O体系中,本文测定了萃取平衡的In^3+的平衡浓度和水相pH值,其中Na~2SO~4为支持电解质.根据Pitzer电解质溶液理论,估算了平衡水相中的真实离子强度值,并用直线外推法和多项式拟合法确定了萃取过程的热力学平衡常数K^ ,进而计算了这个萃取过程的各个热力学量.     

不同稀释剂中HDEHP的界面性质研究

用滴体积法研究了HDEHP在不同稀释剂-0.05mol.dm^-^3(N2, Na2)SO4(pH=2.40)体系中的界面性质, 认为吸附于液-液界面的是单体HDEHP分子, 得到了各体系中HDEHP的Cmin, Tmax, Ai以及△Gad等界面吸附参数。HDEHP在不同稀释剂体系中的界面活性顺序为: 脂肪烃>芳香烃>氯仿>甲基异丁基酮, 这种变化主要是在体相中和界面上稀释剂与萃取剂、界面上的萃取剂及稀释剂与界面层水之间分子间相互作用的结果。同时讨论了HDEHP在不同稀释剂中的萃取动力学机理。     

Using self-assembled monolayer technology to probe the mechanical response of the fiber interphase-matrix interphase interface

In this paper, a brief review of the fiber-matrix interphase/interface region is given for carbon- and glass-fiber composites. The substructure of the interphase/interface region is discussed in terms of three interphases: (a) the fiber interphase (FI), (b) the sizing interphase (SI), and (c) the matrix interphase (MI), and two interface regions: (a) the FI-SI interface and (b) the SI-MI interface. These substructures are a synthesis of the ideas advanced by Ishida and Koenig and Drzal. The schematic model of interphase deformation behavior originally given by Bascom is reconstructed to include research results from the above researchers. To systematically probe adhesion at the SI-MI interface, functionalized self-assembled monolayers (SAMs) using bonding and non-bonding C₁₁- type trichlorosilanes are prepared using the research of Menzel and Heise, and that of Cave and Kinloch as a guide. Results from this research are compared with short chain bonding and nonbonding silanes prepared by aqueous and non-aqueous deposition processes. The data were interpreted using the mechanisms proposed by Sharpe, Ishida and Koenig, and Drzal and the mathematical equation proposed by Nardin and Ward. For the non-bonding short-chain silane deposited by aqueous deposition, 90% of the adhesion was found to be due to mechanical interlocking, with the remaining adhesion due to physicochemical interactions. For the bonding short-chain silane deposited by aqueous deposition, the interface strength relative to the non-bonding short-chain silane increased by 31%. However the interfacial shear strength (IFSS) of this system was approximately 40% lower than the comparable bonding SAM interface. This difference was interpreted in terms of the propensity of the C₃-alkylamine to form cyclic ring structures in the MI region as described by Ishida, Koenig, et al. The SAM data also indicates that 70-85% of the maximum IFSS is obtained with 25-50% of the surface covered with functional groups. This suggests that steric hindrance, due to the size of the DGEBA molecules, restricts access to the functional groups on the surface. Therefore, only 35% of the surface functional groups are accessible for bonding in the DGEBA/m-PDA epoxy resin system.     

生物功能电极I: GOD修饰电极的电化学活性

以二环己基碳化二亚胺为活化剂将葡萄糖氧化酶(GOD)共价键接在玻碳电极上, 伏安实验观察到酶与电极基体的直接电子传递, 有观电子传递速度常数约为1s^-^1, 过程归因于全酶中辅基FAD的氧化还原转变。Ag^+离子的存在强烈地阻碍酶辅基的还原, 这与该离子抑制酶活性的机理可能有联系。Ag^+的抑制作用可由EDTA处理或电化学处理而解除, GOD电极对氧和苯醌的电还原有催化作用。测定了苯醌同还原态GOD的化学反应速度常数, 并讨论用苯醌代替氧作为生物电催化中的电子传递体的优点。     

Effect of a Novel Polymeric Coupling Agent on the Water Uptake Property and Warp Stability of Poly(vinyl chloride)/Bamboo Flour Composite

Water uptake property and warp stability of poly(vinyl chloride) (PVC)/bamboo flour composite were investigated employing a novel polymeric coupling agent, poly(styrene-co-maleic anhydride)-block-poly(styrene-co-acrylonitrile) {P[(SMA)-b-(SAN)]}. P[(SMA)-b-(SAN)] was synthesized through controlled/'living' radical polymerization (CRP) technique in an one-pot reaction and incorporated into the composite to improve the interfacial adhesion between PVC and bamboo flour. The structure of P[(SMA)-b-(SAN)] was confirmed by ¹H-NMR, FT-IR and GPC. PVC/bamboo flour composite sheets were then prepared from a single screw extruder and two-roll mill in the presence of P[(SMA)-b-(SAN)] coupling agent. As the content of the coupling agent increased, improved interfacial bonding between PVC and bamboo flour filler was observed. Water uptake property and warp stability were also improved in the presence of the coupling agent. These results suggest that the block copolymer successfully acted as a coupling agent in PVC/bamboo flour composites.     

Hydrolytically Stable Interphase on Alumina and Glass Fibers via Hydrosilylation

The poor hydrolytic stability of silane interphase greatly limits the use of fiber reinforced composites (FRC) in demanding applications in which the FRC part is permanently exposed to a moist environment such as in prosthetic dentistry and orthodontics. To improve hydrolytic stability of the interphase between the matrix composed of a blend of triethyleneglycol dimethacrylate (TEGMA) and bisphenol A glycidylmethacrylate (Bis–GMA) monomers and glass or alumina oxide fibers, a two-step hydrosilylation procedure was employed. The process consisted of creating hydride intermediate on the fiber surface followed by hydrosilylation reaction attaching the unsaturated organic monomer (Bis–GMA) forming stable –Si–C bonds. Infrared spectroscopy (FTIR) confirmed formation of the hydride intermediate on the surface and then, attachment of the appropriate organic compound in the second step. The amount of deposited interphase and its stability was significantly enhanced compared to standard silanization treatment. Fracture surfaces were observed by scanning electron microscopy (SEM) before and after environmental exposure proving that the most stable interfacial bond was obtained with the two-step treated fibers. It was concluded that hydrosilylation provides a viable alternative to silanization for both glass and ceramic fibers in composites intended for applications requiring enhanced hydrolytic stability of the composite parts.     

7-取代-8-羟基喹啉的合成

由2-氯辛烷与8-羟基喹啉钠反应制得7-(1′-甲基庚基)-8-羟基喹啉.用长碳链脂肪醛在碱性介质中与8-羟基喹啉反应,合成了一系列7-烯基-8-羟基喹啉(1);对不同结构长碳链脂肪醛合成作了研究.     

溶剂萃取动力学的研究 II: 三辛基氧化膦从盐酸体系中萃取铀(IV)的速率

The kinetics of the oxtraction of U(IV) chloride in the TOPO-HCl system has been studied using the single drop technique, The effects of the concentrations of U(IV, TOPO and HCl on the extraction rate for U(IV) have been examined. The extraction rate measured were found to be of first order with respect to (U(IV)) and (TOPO) (0). Moreover, the rate varied with (HCl)^3^/^2 between 2-7M hydrochloric acid. The extraction rate equation can be written as R=K(U(IV))(TOPO)(0) The rate constant K was evaluated to be 3.7X10^-^5 at 3M HCl and 15`C. The extraction rate was increased with increasing temperature. The apparent activation energy was found to be 10.8 kcal/mol between 15 to 45`C. It is suggested that the rate-controlling step may be the chemical reaction of UCl4 with TOPO at the interface and the formation of the interfacial complex UCL4.TOPO.