基于物性推算法的膜分离材料设计

针对渗透汽化或蒸汽渗透法进行有机溶剂混合物分离,首次提出基于物性推算法的膜分离材料设计方法。基于溶解－扩散机理模型,使用统计热力学和状态方程式为基础的GCLF－EOS模型进行溶解度计算,自由体积模型推算扩散系数,同时考虑填充型复合膜的基膜影响,建立膜渗透通量计算模型。溶解性、扩散性的物性推算结果,较好地再现芳香族有机溶剂在高分子材料中的溶解和扩散行为,复合膜的渗透通量计算值与实验测定结果基本一致。由于计算模型中不包含任何从实验直接回归参数,本设计法具有可预测性和普遍适用性。     

聚碳酸亚丙酯与丙烯酸甲酯-丙烯酸共聚物复合作用研究

研究了聚碳酸亚丙酯与丙烯酸甲酯－丙烯酸共聚物的混合稀溶液性质,发现在一定条件下两种高分子可以生成氢键复合物。其氢键强度,复合物的稳定性受溶剂类型和分子量的影响。     

有机溶剂分离膜结构和膜材料设计理论研究

综述现存有机溶剂分离膜的不同结构特点，分析膜结构对溶剂渗透性能的影响．围绕溶剂渗透过程的溶解-扩散机理模型，重点阐述预测溶解性的溶液热力学理论和计算扩散系数的自由体积理论，强调化工热力学理论对新型溶剂分离膜开发的指导作用．在此基础上，提出膜材料和膜结构相互协调，利用物性推算法进行有机溶剂分离膜材料设计的思想．     

聚丙烯酸甲酯齐聚物的合成及乙氧基化

以四氩呋喃为溶剂,正十二硫醇为链转移剂,采用自由基溶液聚合的方法合成了聚丙烯酸甲酯齐聚物.考察了单体滴加时闻对黏均分子量的影响,确定滴加时间为40 min可以得到较低黏均分子量的聚丙烯酸甲酯齐聚物.在自制的插入式酯基乙氧基化催化荆MCT-09催化下成功地对聚丙烯酸甲酯齐聚物进行了乙氧基化反应.反应结果显示,随着反应进行...     

PAA-PSF交联复合膜对低分子量有机物水溶液反渗透分离性能研究

研究了聚丙烯酸－聚砜（ＰＡＡ－ＰＳＦ）交联复合膜对低分子量有机酸、胺、醛、酮、酯等水溶液的反渗透分离性能．实验结果表明，ＰＡＡ－ＰＳＦ交联复合膜对低分子量有机酸类的分离效果欠佳，对正丁酸的截留率仅为４５．６％．对低分子量有机胺和醛类水溶液有好的反渗透分离性能，对乙胺和乙醛水溶液，截留率分别为５１％和８４％，且随分子量的增大截留率不断上升，对正丁胺和正丁醛的截留率可达７７％和９６％．ＰＡＡ－ＰＳＦ交联复合膜对其他低分子量有机酮、酯、酚、多元醇等水溶液均具有很好的反渗透分离性能．对不同结构有机胺类的分离性能研究表明，截留率存在有ｔｅｒｔ－＞ｓｅｃ－＞ｉｓｏ－＞ｎ－的规律．     

聚丙烯酸酯与聚碳酸酯共混体系相容性及酯交换反应研究

利用示差扫描量热计和傅立叶变换红外光谱仪，研究了双酚Ａ型聚碳酸酯与一系列聚丙烯酸烷基酯的相容性及热处理过程中的酯交换反应，实验证明了ＰＣ与聚丙烯酸酯是不相容的。在高温状态下，共混体系中存在酯交换反应，可以导致该共混体系均相比。     

双轴旋转超滤膜组件过滤厌氧泥水混合液

设计开发了一套中试规模的双轴旋转超滤膜组件系统.系统容器容积120 L,内装填的有效膜面积为4 m2.试验选用两种不同截留分子量(5万和10万)的PVDF超滤膜,采用该系统处理厌氧生物反应器内泥水混合液,研究了膜截留分子量、膜渗透通量、过膜压差、膜旋转速度之间的相互关系.结果表明,一定膜旋转速度下,随着过膜压差的提高,存在一个膜极限渗透通量;随着膜旋转速度的降低,膜极限渗透通量明显下降,且膜极限渗透通量出现时对应的过膜压差往低压方向迁移;截留分子量大小对膜过滤行为的影响在高压、高转速区有减弱趋势.     

石墨烯/星形聚丙烯酸酯纳米复合涂料的制备及性能

采用电子转移活化再生催化剂原子转移自由基聚合(ARGET-ATRP)方法,设计和制备了适合涂料用的线型、三臂和六臂星形聚丙烯酸酯。凝胶渗透色谱和差示扫描量热分析结果表明合成的聚丙烯酸酯相对分子质量与理论值相近,分布较窄,玻璃化转变温度适中。以这些树脂为基体,制得石墨烯/星形聚丙烯酸酯纳米复合涂料。相对于石墨烯/线型聚丙烯酸酯纳米复合涂料漆膜,石墨烯/星形聚丙烯酸酯纳米复合涂料漆膜具有低至0.8%的导电逾渗阈值。流变测试表明,星形聚丙烯酸酯溶液的黏度明显低于线型聚丙烯酸酯溶液的黏度,石墨烯的加入引起星形聚丙烯酸酯溶液的黏度增加程度远小于线型聚丙烯酸酯溶液黏度的增加程度。透射电镜和激光粒度分析结果证实石墨烯在星形聚丙烯酸酯中的分散性好于线型聚丙烯酸酯。石墨烯可以提高漆膜的模量、玻璃化转变温度及其它的基本物理性能。     

石墨烯/星形聚丙烯酸酯纳米复合涂料的制备及性能EI北大核心CSCD

采用电子转移活化再生催化剂原子转移自由基聚合(ARGET-ATRP)方法,设计和制备了适合涂料用的线型、三臂和六臂星形聚丙烯酸酯。凝胶渗透色谱和差示扫描量热分析结果表明合成的聚丙烯酸酯相对分子质量与理论值相近,分布较窄,玻璃化转变温度适中。以这些树脂为基体,制得石墨烯/星形聚丙烯酸酯纳米复合涂料。相对于石墨烯/线型聚丙烯酸酯纳米复合涂料漆膜,石墨烯/星形聚丙烯酸酯纳米复合涂料漆膜具有低至0.8%的导电逾渗阈值。流变测试表明,星形聚丙烯酸酯溶液的黏度明显低于线型聚丙烯酸酯溶液的黏度,石墨烯的加入引起星形聚丙烯酸酯溶液的黏度增加程度远小于线型聚丙烯酸酯溶液黏度的增加程度。透射电镜和激光粒度分析结果证实石墨烯在星形聚丙烯酸酯中的分散性好于线型聚丙烯酸酯。石墨烯可以提高漆膜的模量、玻璃化转变温度及其它的基本物理性能。     

UV固化含氟聚丙烯酸酯的制备

以甲基丙烯酸十二氟庚酯、丙烯酸-2-乙基己酯、甲基丙烯酸羟乙酯、苯乙烯为聚合单体,偶氮二异丁腈为引发剂,通过溶液聚合制得了含氟羟基聚丙烯酸酯共聚物(PGHES),以含异氰酸酯的不饱和单体HIp与共聚物PGHES侧链上的羟基反应制得光敏性含氟聚丙烯酸酯(U-PGHES)。用傅立叶红外光谱(FT-IR)、核磁共振氢谱(1 H-NMR)表征聚合物结构;用凝胶渗透色谱(GPC)及差示扫描量热仪(DSC)表征聚合物分子量及玻璃化转变温度;用光学接触角测量仪测量了聚合物固化膜接触角并计算得到表面能。结果表明,固化膜表面能随U-PGHES中含氟量的增加而降低,当含氟量达到9%时,表面能降低趋缓。     

Cr对Cu-V氢分离合金组织与氢传输性能的影响

氢分离金属膜是目前备受关注的一种用于氢气提纯的功能材料.为了获得综合性能优异且价格低廉的氢分离金属膜,本文借鉴"多相构成、功能分担"的设计理念,通过非自耗电弧熔炼炉制备合金,采用XRD、扫描电子显微镜等手段研究合金相组成及微观组织,采用课题组自主设计的仪器设备在不同温度和压力下进行氢溶解和氢渗透实验,开发了具有双相结构的新型Cu-V-Cr氢分离合金.结果发现:该合金微观组织中的bcc-(V)固溶体相起渗氢作用,是氢的主要扩散通道;而组织中的fcc-(Cu)固溶体相起提高塑性作用.合金化元素Cr主要固溶在bcc-(V)中,显著降低合金的氢溶解能力,大幅度提高抗氢脆性能,但同时也降低合金的氢扩散系数和渗氢性能.实验表明,具有双相结构的Cu-V-Cr氢分离合金有望达到氢溶解、扩散和渗透性能的良好匹配,从而同时实现优异的氢渗透性能与抗氢脆性能.     

Structure-properties relationships for densely cross-linked epoxide-amine systems based on epoxide or amine mixtures

The solubility and diffusivity of water at 100° C, 95% relative humidity were studied for 14 stoichiometric epoxide-amine networks based on epoxide or amine mixtures. Neither the packing density nor the glass transition temperature nor the crosslink density seemed to play a significant role. The water absorption is essentially linked to the concentration of polar structures, but also decreases with the extent of intramolecular hydrogen bonding. This can be accurately predicted using a simple additive relationship. The diffusivity decreases with the hydrophilicity and packing density, but in a complex way probably involving the nature of hydrogen bonds between the water and the substrate.     

Effect of trapping on the solubility and diffusivity of hydrogen in palladium (α-phase)

The solubility and diffusivity data of hydrogen in palladium with different concentrations of defects are discussed within the framework of the two-level model with local equilibrium (Oriani's model). Analytical expression of the solubility isotherm and of the variation of the apparent diffusion coefficient depending on the total bulk concentration are derived. A good agreement is found between the experimental results on the solubility and diffusivity of hydrogen and the calculated values using the theoretical expressions.     

Influence of alloying on hydrogen-assisted cracking and diffusible hydrogen content in Cr-Mo steel welds

Study of hydrogen-assisted cracking and measurement of diffusible hydrogen content in different Cr-Mo steel welds shows that under identical conditions, susceptibility to cracking increased and diffusible hydrogen content decrease with increase in alloy content. Hydrogen permeation studies show that hydrogen diffusivity decreases and solubility increases with increase in alloy content. Thus decrease in diffusible hydrogen content with increase in alloying is attributed to increase in apparent solubility and decrease in apparent diffusivity of hydrogen. Analysis of the results indicates that variation of diffusible hydrogen content and apparent diffusivity of hydrogen with alloy content can be represented as a function of carbon equivalent CE₁ originally proposed to predict the hardness in the heat-affected zone of alloy steel welds.     

单体溶剂对液相沉降聚合聚3,4-乙撑二氧噻吩分子结构及性能的影响

将吸附有FeCl_3的聚酰亚胺(PI)膜悬于不同溶剂的3,4-乙撑二氧噻吩(EDOT)溶液中,在PI膜表面原位合成了导电聚3,4-乙撑二氧噻吩(PEDOT)涂层。以UV-vis分析溶剂的溶剂化效应,以红外光谱和X射线光电子能谱分析PEDOT的分子结构和氧化态,研究溶剂对液相沉降聚合PEDOT的共轭链长度和掺杂度及导电性的影响。在研究的正庚烷、环己烷、甲苯和氯仿中,溶剂的溶剂化作用依次增强,在其EDOT溶液中沉降聚合产物PEDOT的共轭链长度和掺杂度也依次增大,PEDOT涂层的电导率分别为33.7 S/cm,43.8 S/cm,163.2 S/cm和77.2 S/cm,对PI膜的附着力由0级上升到5B级。溶剂的溶解能力和溶剂化效应增强,液相沉降聚合PEDOT分子的共轭链长度和掺杂度上升,涂层的电导率和附着力增加;溶剂化效应的影响尤为突出。     

Electrochemical methods for studying hydrogen diffusivity,permeability, and solubility in AISI 420 and AISI 430 stainless steels

Abstract

Hydrogen permeation and diffusivity were studied electrochemically at temperatures between 283 and 343 K at constant current for annealed and hardened AISI 420 and annealed AISI 430 stainless steel. Permeation rate, effective diffusivity, and solubility were calculated from these data. Annealed AISI 420 shows higher permeation rate and lower diffusivity than annealed AISI 430 stainless steel. Hardened AISI 420 has the highest permeation rate and lowest effective diffusivity. The calculation of solubility values from permeation data is in good agreement with the values obtained using a newly developed electrochemical hydrogen solubility measurement technique.

MST/1026     

Hydrogen behaviour in aged low activation martensitic steel F82H for fusion reactor applications

Abstract

A time dependent permeation method is used to measure the permeability, diffusivity, and solubility of hydrogen in the low activation martensitic steel F82H, based on 7–10%Cr steel agedfor 2000 h under vacuum at 773 K. The measurements cover the temperature range 373–723 K which includes the onset of hydrogen trapping effects on diffusivity and solubility. The results are interpreted using a trapping model. The number of trap sites and their average energies for hydrogen in the aged F82H steel are determined. These data are compared with those obtainedfor deuterium in F82H steel.     

Study of water behaviour of chemically treated flax fibres-based composites: A way to approach the hydric interface

Silane (Si) and styrene (S) treatments were applied on flax fibres in order to improve their adhesion with a polyester resin and to increase their moisture resistance. The water sorption and permeation kinetics of the composites were correlated with the water sorption behaviour of untreated and treated fibres. An increase of the water barrier effect was observed in treated fibres-based composites in comparison with untreated ones. This was related to the shift-down of water solubility and to a decrease of the water diffusivity in treated fibre-based composites. In the case of (S) treatment, the presence of styrene increased the moisture resistance of the treated fibres and made compatible the fibres and the matrix. In the case of (Si) treatment, a good hydric fibre/matrix interface was obtained due to crosslinking reactions and hydrogen bonding between water molecules and free hydroxyl groups of (Si) treated fibres. In order to interpret water permeation behaviour of composite films, a simple illustrated model is suggested and represented by a schematic view.