Electrochemical Oscillations Induced by Surfactants

HeZhanbopointedout[1] thatsurfactantscanbeusedtomakenewchemicaloscillatorsinaqueoussolution ,suchasbromateoscillator[2 ] andpermanganateoscillator[3] .Untilnow ,however,thereisnotanyelectrochemicaloscillatorre latedwithsurfactant.　　Anelectrochemicaloscillatorisoneofthefirstdisco veriesofchemicaloscillators .Todayhundredsofarticleshavebeenpublished[4— 6 ] aboutelectrochemicaloscillators.Theyprovidematerialstoenrichmaturetheoriesandmecha nisms[7— 8] .InourexperimentsweusedaDaniellcellasele…     

Effect of temperature on the hydration process and strength development in blends of Portland cement and activated coal gangue or fly ash

This paper describes the results of an investigation into the effect of the variation of curing temperatures between 0 and 60 °C on the hydration process, pore structure variation, and compressive strength development of activated coal gangue-cement blend (ACGC). Hardened ACGC pastes cured for hydration periods from 1 to 360 d were examined using the non-evaporable water method, thermal analysis, mercury intrusion porosimetry, and mechanical testing. To evaluate the specific effect of activated coal gangue (ACG) as a supplementary cementing material (SCM), a fly ash-cement blend (FAC) was used as a control. Results show that raising the curing temperature accelerates pozzolanic reactions involving the SCMs, increasing the degree of hydration of the cement blends, and hence increasing the rate of improvement in strength. The effect of curing temperature on FAC is greater than that on ACGC. The pore structure of the hardened cement paste is improved by increasing the curing temperature up to 40 °C, but when the curing temperature reaches 60 °C, the changing nature of the pore structure leads to a decrease in strength. The correlation between compressive strength and the degree of hydration and porosity is linear in nature.     

Interaction of nonionic surfactant AEO9 with ionic surfactants

INTRODUCTION Long chain nonionic surfactants such as poly-oxyethylenated alcohols C12H25O(CH2CH2O)9H (AEO9), are widely used in the chemical industry in fabric detergency and tertiary oil recovery due to their excellent surface-active properties. In many practical applications, surfactants are used in formulations containing mixtures of different compounds, and synergism can often be observed. Synergism is de-fined here as the condition in which the properties of a mixture are better…     

用于提取锆的高吸附活性硅胶的制备

以水玻璃和盐酸为原料 ,通过添加表面活性剂制备出高比表面、对高放射性废液中的锆具有高吸附容量的硅胶 .表面活性剂对初级溶胶粒子产生修饰作用 ,限制溶胶粒子的生长 ,但却促使溶胶粒子的连接 .因此 ,表面活性剂起到了无机结构导向剂的作用 ,并且促使溶胶粒子连接成网络结构 .该硅胶的比表面积可达 998m2 /g ,对锆的静态吸附量可达32 .6mg/g ,吸附分配系数为 5 6 .1mL/g .     

Photocatalytic Degradation of Diethyl Phthalate with Surfactant Addition

This paper studies the adsorption of diethyl phthalate (DEP,an environmental hormone) on the surface of nanoscale TiO_2, effects of pH value of solutions, initial concentrations of DEP and additive surfactant on photocatalytic degradation and dynamics of DEP. Under ultra violet illumination, the interaction between DEP and surfactants including DBS (sodium dodecylbenzenesulfon-ate), CTAB (cetyltrimethylammonium bromide), and OP-10 (nonylphenol polyoxyethylene ether) was exploited from the perspective of degradation speed calculated by the data of high pressure liquid chromatography (HPLC) and UV-Vis spectra, respectively. Photocatalytic degradation of DEP followed pseudo first-order reaction kinetics. DEP as substrate degraded fast when its initial concentration was 130 mg/L. TiO_2 had certain adsorption ability of DEP. TiO_2 could adsorb the most DEP at the approximately neutral pH of 6.91. Degradation of DEP was not affected obviously by additives OP-10 and DBS. Degradation rate of DEP was not enhanced greatly in the presence of surfactants, but degradation of DBS was sped up. Degradation rate of DEP was depressed in the presence of additive CTAB. The more CTAB was added, the less DEP was degraded. Degradation rate of CTAB became slow with the increase of initial CTAB concentration. The possible adsorption models among TiO_2, DEP and surfactants were given.     

不同类型表面活性剂与蛋白质作用研究进展

表面活性剂和蛋白质作用的方式与表面活性剂的种类、结构、浓度和其理化性质有关。本文系统地总结了多种类型表面活性剂(阴离子型、阳离子型、两性离子型、非离子型、氟表面活性剂及Gemini表面活性剂)的结构特点,以蛋白质-表面活性剂相互作用的物理化学特征为出发点,综述了该体系相互作用的最新研究成果及进展,包括二者作用时所形成的复合物的结构理论,复合物的吸附机理及其作用过程中蛋白质结构的变化;结合本课题组的工作总结分析了蛋白质分别与各类表面活性剂相互作用过程中作用力特征、相行为、作用机理及应用。     

Enhanced degradation of carbon tetrachloride by surfactant-modified zero-valent iron

Sorption of carbon tetrachloride （CT） by zero-valent iron （ZVI） is the rate-limiting step in the degradation of CT, so the sorption capacity of ZVl is of great importance. This experiment was aimed at enhancing the sorption of CT by ZVI and the degradation rate of CT by modification of surfactants. This study showed that ZVI modified by cationic surfactants has favorable synergistic effect on the degradation of CT. The CT degradation rate of ZVI modified by cetyl pyridinium bromide （CPB） was higher than that of the unmodified ZVI by 130%, and the CT degradation rate of ZVI modified by cetyl trimethyl ammonium bromide （CTAB） was higher than that of the unmodified ZVI by 81%. This study also showed that the best degradation effect is obtained at the near critical micelle concentrations （CMC） and that high loaded cationic surfactant does not have good synergistic effect on the degradation due to its hydrophilicity and the block in surface reduction sites. Furthermore degradation of CT by ZVI modified by nonionic surfactant has not positive effect on the degradation as the ionic surfactant and the ZVI modified by anionic surfactant has hardly any obvious effects on the degradation.     

液相化学法制备超细MoO_3研究

以仲钼酸铵和硝酸为原料,采用液相化学法制备超细MoO3.研究了表面活性剂类型及浓度对产物形貌的影响.结果表明,阴离子型表面活性剂的分散性能优于阳离子和非离子表面活性剂.在添加浓度为1.8mmol/L十二烷基苯磺酸钠(DBS)时,能够制备出分散性较好、粒径为100nm左右的球形超细MoO3粉末.     

表面活性剂在固——液界面上吸附过程的疏水效应研究

用表面张力法测定了烷基三甲溴化胺在活性炭表面的吸附数据。讨论了疏水效应在阳离子表面活性剂从水溶液中吸附到活性炭表面这一过程中所起的作用。结果表明：室温下表面活性剂的烃链尾巴自水中移出时总伴随着大的熵增和接近于零的焓变,吉布斯自由能变化也为一负值,由处理结果得到了分别来自水分子建构和开辟空穴贡献的热力学函数变化。     

用吸收光谱法研究甲苯胺蓝水溶液的聚合状态及其影响因素

本文通过光谱法研究了生物染料试剂甲苯胺蓝（ＴＢ）在水溶液中的聚集状态,及其表面活性剂十二烷基硫酸钠（ＳＬＳ）、无机盐ＮａＣｌ对其聚集状态的影响。通过对在不同条件下甲苯胺蓝吸光度的分析,得出如下结论：ＮａＣｌ可使甲苯胺蓝（ＴＢ）的双聚体解聚;表面活性剂对甲苯胺蓝的聚集状态有很大的影响     

Gemini (dimeric) surfactants

A gemini surfactant (GS) consists of two conventional surfactant molecules chemically bonded together by a spacer. The two terminal hydrocarbon tails can be short or long; the two polar head groups can be cationic, anionic or nonionic; the spacer can be short or long, flexible or rigid. The GS need not be symmetrically disposed about the center of the spacer. GS can self-assemble at much lower concentrations and are superior in surface activity as compared to conventional surfactants. GS are very attractive for catalysis and adsorption applications, new synthetic vectors for gene transfection, analytical separations, solubilization processes, nanoscale technology, biotechnology, enhanced oil recovery and as paint additives.     

活性炭/二氧化锰复合材料的制备及性能研究

采用水热法,以果壳活性炭为载体,制备活性炭（AC）/二氧化锰（MnO2）纳米线复合材料。采用X射线衍射仪（XRD）、场发射扫描电子显微镜（SEM）、比表面及孔径分析仪、同步热分析仪（TG）以及紫外可见吸收光谱（UV/Vis）对所得材料的组成、形貌和结构进行表征,并对其光催化性能进行研究。结果表明:采用水热法可实现活性炭与MnO2的有效复合。在复合材料中,MnO2纳米线多以无定形态的形式存在且尺寸均一,将活性炭有效胶结在一起,从而使得活性炭比表面积和孔隙率降低,但其孔径大小保持不变。光催化实验结果表明,AC/MnO2复合材料对于有机染料具有明显、高效的降解效果,对亚甲基蓝的降解主要是吸附和光催化两者协同效应的结果。该结果拓展了活性炭在光催化领域的应用。     

Preparation and characterization of metakaolin-phosphate cement

We prepared cold-setting cement with metakaolin from kaolin dehydrated at 800 ℃ and phosphate, and studied the phase composition, microstructure and setting reaction mechanism of the cementing material by means of infrared spectroscopy, thermogravimetry, X-ray diffraction, and scanning electron microscopy. The metakaolin-phosphate cement is predominantly amorphous, where the phases responsible for chemical setting are mainly amorphous aluminophosphate hydrates. The reactivity of metakaolin depends on the particle size. Metakaolin particles of 1.75 μm in D50 have an acid dissolution index up to 18.45%, and the reaction with phosphate at room temperature to form metakaolin-phosphate cement takes only 6 h. The so obtained cement shows a compressive strength of 92.5 MPa after 7 d and keeps its amorphous phase at 1 000 ℃, demonstrating better bonding and mechanical properties and higher stability at a medium or high temperature.     

Photocatalytic Reduction of 6-Chloro-3-Nitrotoluene-4-Sulfonic Acid in Presence of Surfactants

Photocatalytic reduction of 6-chloro-3-nitrotoluene-4-sulfonic acid （CNSA） was studied in UV-irradiated TiO2 suspensions in the presence of methanol and surfactants. A mixture of CNSA, TiO2, water, additives and surfac- tants was put into a quartz glass reactor with a jacket, which was irradiated with a high pressure Hg lamp in the purg- ing of nitrogen gas. With methanol, the conversion of CNSA increased from 7.7% to 34.6%. Three surfactants signifi- cantly promoted the photocatalytic reduction conversion in reduced order of sodium dodecylbenzenesulfonate （DBS）, cetyltrimethylammonium bromide （CTAB） and sodium dodecylsulfate （SDS）. In suspensions involving DBS and CTAB respectively, CNSA conversion increased in consistence with the adsorption ratio with methanol, but varied inversely with the adsorption ratio without methanol. But no obvious influence on the adsorption ratio was observed with or without methanol added when the SDS concentration was critical micelle concentration （cmc）. The photocata- lytic reduction of CNSA was enhanced in UV-irradiated TiO2 suspensions in the presence of methanol and surfactants. Methanol inhibited the recombination of photogenerated holes and electrons efficiently. Surfactants around 1 cmc led to the highest reduction conversion.     

Experimental investigation of the factors affecting accuracy and resolution of the pore structure of cement-based materials by thermoporometry

Thermoporometry （TPM） is a calorimetric-based technique for characterizing pore structure according to the freezing and melting point depression of liquid confined in pores which attributes to a varying phase-transition free energy by interface curvature. TPM has demonstrated an emerging success in applications for determining the mesopores of cement-based materials in recent decades. To improve its resolution and accuracy, this paper discussed these factors which show a great influence on the baseline heat flow and the derived pore structure using two molecular sieves with discontinuous size for calibration, referring to the sample handling, the mass of sample and the varying temperature. The pore size distributions of ordinary and high-strength concrete by TPM were favorably compared to the results taken by nitrogen adsorption/desorption （NAD） and mercury intrusion porosimetry （MIP）. The results illustrated that both the accuracy and resolution improve with the decreasing cooling/heating rate until 1 ℃/rain; however, if the rate is too slow, it can lead to an unstable result. The mass of the sample tested has much less an effect on the accuracy when it increases to more than 30 mg. TPM is demonstrated to be more accurate to characterize the mesopores with the size bigger than 4 nm as compared to NAD and MIP.     

Molecular simulation of the adsorption of linear alkane mixtures in pillared layered materials

The adsorption isotherms of mixtures of linear alkanes, involving n-pentane, n-hexane, and n-heptane in pillared layered materials （PLMs） with three different porosities ψ-0.98, 0.94 and 0.87, and three pore widths H=1.02, 1.70 and 2.38 nm at temperature T=300 K were simulated by using configurational-bias Monte Carlo （CBMC） techniques in grand canonical ensemble. A grid model was employed to calculate the interaction between a fluid molecule and two layered boards here. For alkane mixtures, the n-heptane, the longest chain component in alkane mixtures, is preferentially adsorbed at low pressures, with its adsorption increasing and then decreasing as the pressure increases continuously while the n-pentane, the shortest chain component in alkane mixtures, is still adsorbed at high pressures; the adsorption of the longest chain component of alkane mixtures increases as the pore width and the porosity of PLMs increase.     

三次采油用表面活性剂的合成和应用

三次采油(EOR)成为一种在一、二次采油之后有效提高采油率的重要技术，而表面活性剂在三次采油中的重要性越来越明显，其中表面活性剂驱和三元复合驱(ASP，即碱—表面活性剂—聚合物复合驱)则是具有发展潜力的三次采油技术。本主要介绍和概述了三次采油用表面活性剂的制备、性能、应用特点及其发展前景。     

应用于承载骨的梯度多孔支架力学性能研究

基于三周期极小曲面(TPMS)设计5种不同孔隙率梯度分布的梯度多孔支架,利用选区激光熔化(SLM)技术制造Ti6Al4V梯度多孔支架。该支架具有类似于人骨梯度多孔结构的梯度孔隙率。压缩测试结果表明,5种梯度多孔支架的弹性模量为8.75~13.88 GPa,抗压强度为219.48~ 528.21 MPa,符合承载骨的弹性模量和抗压强度要求。弹性模量和抗压强度都随着平均孔隙率P- (或边缘孔隙率PB )的增大而减小,P-对弹性模量和抗压强度的影响大于PB。采用Gibson-Ashby的拟合结果可以为承载骨的设计提供参考。     

酸增殖剂的合成及其应用原理

综述了酸增殖剂研究新进展 ,重点介绍了几种有应用前景的酸增殖剂及其反应机理 .讨论了酸增殖剂在化学增幅型抗蚀剂体系、UV紫外光固化材料、CTP制版中的应用 .     

Digital speckle pattern interferometric measurement of diffusion coefficients in hydrogels

The technique of real-time digital speckle pattern interferometry is proposed to study diffusion of surfactants in hydrogel. The diffusion coefficient is simply and directly determined from the interferograms. An example of diffusion coefficient measurement of surfactant in agarose gel demonstrates the usefulness of the method. The results obtained are compared with the theoretical simulating values. Project Supported by National Natural Science Foundation of China (No. 29904007), Zhejiang Provincial Natural Science Foundation of China (No. 699031), and SRF for ROCS, SEM, China