新型复合环氧光学树脂的制备与性能研究

通过2,2-二巯基乙硫醚(MES)与环氧氯丙烷反应合成了2,2-二巯基二乙硫醚二缩水甘油醚型环氧树脂(DGEMES),通过FTIR和MS对其进行表征;用乙二胺作为固化剂,将DGEMES与双酚A型环氧树脂(DGEBA)复合固化,得到了新型高折射率和低色散的光学树脂.DGEMES是一种较好的共聚单体,可以同时提高共聚树脂的折射率和阿贝数;DGEBA/DGEMES/乙二胺共固化树脂的nd=1.59～1.62,νd=35～39;当DGEMES的质量分数为40%时,固化树脂的折射率达到1.60以上,冲击强度22.5kJ/m₂,且其它性能较均衡.此外,以甲基六氢苯酐(B-650)为固化剂,还合成了具有中等折射率的DGEBA/DGEMES/B-650共固化树脂(nd=1.54～1.56,νd=38～40),并对其光学和机械性能进行了研究.     

Effect of pH on the Flocculation of SDS Micelles by Al3+

SDS micelles flocculate in the presence of Al³⁺, creating an aggregate with pollutant-removing properties. The fraction of SDS micelles flocculating depends on the concentrations of SDS and Al³⁺. This paper describes how this fraction also changes with pH. There are two reasons for this dependence: a change in pH has a strong effect in the solution chemistry of Al³⁺, converting it into the compound [Al₁₃O₄(OH)₂₄]⁷⁺, a strong flocculant, or precipitating it as Al(OH)₃; and at low pH protons may compete with Al³⁺ as binding counter-ions for micelles. An increase in pH allows flocculation of SDS at high concentrations of Al³⁺, which under unmodified pH does not occur. Micelle flocculates are reported in this work to exist between pH 5 and pH 8, suggesting the potential use of Adsorptive Micellar Flocculation for the removal of anionic pollutants from waste waters not necessarily limited to acidic solutions. Received: 18 August 2000 Accepted: 5 October 2000     

Aluminium ions at polyelectrolyte interfaces. I. Mechanism of polyacrylic acid/aluminium oxide and humic acid/kaolinite complex formation

Understanding adsorption phenomena involving humic acids and clays is a difficult challenge owing to their complex nature. Thus, to progress in the study of such systems, attempts were made to replace natural systems by polyacids and oxides of simpler chemical and morphological structure. Since the present investigation was dedicated to determine some characteristics of acidic soils which contain traces of aluminium ions, these ions were added to the adsorbent/polyacid systems as trace constituents. Phenomena related to the interactions of humic or polyacrylic acid with aluminium oxide and kaolinite clay have been investigated and the well-differentiated interfacial behaviour of the oxide and kaolinite was determined and discussed. The results of electrophoretic mobility measurements demonstrated the huge time-dependent effect of polymeric layers adsorbed on oxides and modified clays. Received: 24 July 2000 Accepted: 20 December 2000     

ADSORPTION OF DINITROPHENOLS ONTO POLYMERIC ADSORBENTS AND ITS MECHANISM

1 INTRODUCTIONPhenol and many substitUted phenols, such as nitrophenols, chlorophenols and aminophenolset al, are the common organic pollutantS existing in wane water of many chemical plants.Treatment of the wastewater containing phenols is an important project for environmentprotection and has been studied by various methods, such as dialysis ['l, microbial degradation ['1,oxidation l'l, extracting with solvents I4] and adsorption with polymeric adsorbents IS]. Theadsorption method is v…     

REMOVAL OF THIOL BY ACTIVATED CARBON FIBER

Sulfideisoneofthemainpollutionsources.Ifthereweremorethiolsingasoline,thiolswouldmakegasolinegivingoffafoulsmellandcausingcorrosionofmetal.Therefore,manycountriessetstrictdemandstothiolscontentingasoline.Ingeneral,thecontentofthiol-sulfuringasolineisrequestedtobelow10ppm.ActivatedCarbonFiber(ACF)isanewkindofecomaterial[1].Itssuperadsorptioncapacitymakesithavewiderandwiderapplicationprospectsinenvironmentalprotection.ThefurtherstudiesonACFareboththeoreticallyandpracticallyimportant.Therear…     

含硫氮螯合树脂对金、银及某些贱金属氰化物吸附性能的研究

用ＩＣＰ－ＡＥＳ研究了含硫氮螯合树脂对碱性氰化溶液中金、银、铜、铁、锌等金属离子的吸附行为。结果表明,该树脂除定量吸附金、银的氰化物外,也吸附铜、锌、铁的氰化物;吸附在树脂上的银及其它贱金属离子可以用２％ＮａＣＮ定量解吸,用硫脲－硫酸溶液可顺利地将金从树脂上洗脱下来,由此可实现金与银等元素的分离。树脂重复使用性能良好。对该树脂吸附金属氰化物的机理进行了初步探讨。     

Thermogravimetric Study of Carbonization Processes for Industrial Porous Co-polymers of Spherical Granules

The industrial porous co-polymers and resins in the form of spherical granules include three main matrices which serve as the basis of the large-scale production of ion-exchange materials: styrene/divinylbenzene, vinylpyridine/divinylbenzene and acrylonitrile/divinylbenzene. Complex thermal methods (TG, DTG and DTA) were used to study the carbonization processes of various industrial products utilized as starting materials for the preparation of synthetic active carbons. The DTG results, the thermal effects observed during the programmed heating of samples, and the mass-spectrometric and IR-spectroscopic data up to 800°C provided a picture of a multi-stage carbonization process. This includes the removal of moisture from the polymer matrices, the primary cross-linking of the chains, their aromatization and condensation due to the cross-linking of polynuclear structures, and the removal of ‘excess carbon’ as simple molecules and free radicals of hydrocarbon type. The results promoted the choice of the optimal regimes in which to carryout the isothermal pyrolysis of various polymer matrices and preliminary chemical modifications to increase the yields on carbon and to prepare synthetic active carbons such as those of SCN, SCAN and SCS types. General schemes were proposed for the chemical reactions accompanying the carbonization process for these polymer matrices. This revised version was published online in August 2006 with corrections to the Cover Date.     

Changes in density and surface tension of water in silica pores

 The density and surface tension of water in small pores of silicas have been investigated. These physical properties of water in the pores were calculated from a comparison of pore volumes and pore radii which were estimated from adsorption and desorption isotherms of nitrogen and water. Below a pore radius of about 5 nm both the density and the surface tension of water in the pores were smaller than those of the bulk liquid and decreased with a decrease in pore size. The density of water in the pores decreased with an increase in the concentration of surface hydroxyl groups. Similarly the surface tension of water in the pores is influenced by the surface hydroxyl groups. Anomalous changes in the density and surface tension of the water in the pores are attributed to the interaction of water molecules with surface hydroxyl groups and hydrogen-bond formation among water molecules. Received: 20 April 1999 Accepted in revised form: 17 November 1999     

球形壳聚糖树脂制备方法及吸附性能研究

本文采用滴加成球法制备球形壳聚糖树脂,对影响壳聚糖树脂粒径分布的多种因素进行了研究。研究了用戊二醛,环氧氯丙烷及乙二醇环氧丙基醚作交联剂时,不同交联剂对树脂吸附Ｎｉ＾２＋、Ｃｕ＾２＋、Ｚｎ＾２＋的吸附动力学曲线及吸附等温线的影响。研究了ｐＨ值,颗粒粒径、离子强度对吸附容量的影响。     

含偕胺肟基纤维对铬离子吸附性能的初步研究

本文制备了一种含胺肟基鳌合纤维,研究了纤维对六价铬吸附性能的影响因素,结果表明,纤维能将六价铬还原为三价铬,吸附量与温度、时间、溶液ｐＨ值有关,在ｐＨ值为２时,纤维对铬的吸附量最大．