液膜法脱除废水中的氰化物

本文用聚胺E644作乳化剂,研究了用内相包裹NaOH 水溶液的W/O 型乳状液脱除废水中氰化物的方法。讨论了影响液膜稳定性、液膜传质速率等的因素.表面活性剂浓度、油内比、乳水比、温度及搅拌速度对液膜的稳定性及液膜传质速率均有不同程度的影响。确认本系统中氰化物的迁移属Ⅰ型促进传递机理。本文还导出了同时考虑外相边界层及膜相传质阻力的固定液滴——渐进前沿模型。采用摄动法求得了该模型的零级近似解。模型计算值与实验值能很好地符合。     

液膜法提取废水中Cr（VI）的动力学传质模型’

基于液膜法提取Cr(Vr)的传质机理,对改进的渐进前沿模型进行简化,建立了简单、实用的Cr(VI)动力学传质模型.试验结果表明,膜外相边界层扩散阻力、界面化学反应阻力和膜相扩散层阻力是控制Cr(VI)迁移速率的主要传质阻力,外水相酸度、载体浓度是直接影响Cr(VI)迁移速率的重要因子.     

液膜法提取钼的研究——传质模型的改进

本文提出了一种改进的关于液膜传质的数学模型.该模型不仅考虑了非稳态下膜相扩散阻力,而且还考虑了外相边界层的扩散阻力及膜破裂.采用扰动法求得了非线性方程组的近似解,并用间歇式液膜法提取钼实验进行验证,结果表明,外水相浓度较大者,膜相扩散阻力占主导地位,此时可不考虑外相边界层的扩散阻力,反之则应考虑.而膜破裂因素,特别是在反应后期影响较大.模型计算与实验结果取得了较好的一致性.     

改进的Ⅱ型促进迁移液膜传质渐进前沿模型

提出了改进的Ⅱ型促进迁移液膜传质渐进前沿模型,该模型不仅考虑了滴内外扩散阻力、外界面反应,还同时引进了乳液渗透溶胀和液膜破损效应。用间歇式液膜提取苯丙氨酸进行了定量验证。模型计算值和实验值吻合良好。     

乳状液膜扩散－反应双控制过程传递机理数学模型研究

本文建立了乳状液膜扩散－反应双控制过程传递机理的数学模型,该模型综合考虑了膜外相边界层,金属离子与载体的界面化学反应以及膜相阻力等因素对传质的影响。实验验证了该模型具有较好的适应性,并模拟计算了各因素对传质的影响程度     

乳状液膜扩散—反应双控制过程传递机理数学模型研究

本文建立了乳状液膜扩散－反应双控制过程传递机理的数学模型，该模型综合考虑了膜外相边界层，金属离子与载体的界面化学反应以及膜相阻力等因素对传质的影响。实验验证了该模型具有较好的适应性，并模拟计算了各因素对传质的影响程度。     

液膜分离技术脱除废水中的醋酸——外相边界层及膜相扩散控制模型

本文导出了无再分散、无内循环、乳液滴直径均匀的液膜系统中的扩散控制模型。此模型同时考虑了外相边界层及膜相传质阻力。采用摄动法求得了非线性方程组的近似解。解中所含参数M,代表外相边界层中的传质阻力与乳液滴内最大传质阻力之比。当M等于零时,此解与渐进前沿模型的解相同。实验数据与模型计算值能很好吻合。通常,零级解(即拟稳态解)即可描述液膜传质。乳液溶胀可分为渗透溶胀与夹带溶胀。渗透溶胀速率随表面活性剂及内相试剂浓度的增加而增加。多次聚结再分散及增加搅拌强度加速了夹带溶胀。当内相试剂浓度较高时,渗透对溶胀的影响较大。本文提出了夹带溶胀机理。     

乳化液膜Ⅰ型促进传递的扩散-反应模型

本文同时考虑乳液滴内、外的传质以及传递组分与内相试剂在滴内的反应,建立了乳化液膜Ⅰ型促进传递的扩散-反应模型,并求得了其摄动解。模型计算结果表明:所得解均是收敛的,萃取速率分别随E(当量比的3倍)、Bi(Biot数)及Da(Damkhler数)的增加而增加。由此模型可以预测液膜萃取过程中的反应控制区与扩散控制区。模型计算值与萃取醋酸的实验值能很好地吻合。通常,零级解即可描述液膜萃取过程。     

垂直管降膜蒸发传热系数的数学模型

本文在前人工作基础上,利用边界层动量、热量和质量方程,对降膜流动综合考虑相间剪力和由于表面张力所引起的涡流扩散阻尼因素,建立了流动和传热的数学模型,并用计算机求得液膜的速度分布、温度分布、液膜乎和传热系数。模型计算值与本文实验值及前人曲实验值间能较好地吻合。作者还编制了计算机程序,希望为工业设计起参考作用。     

亚油酸乳状液体系氧化模型与求解

研究了恒表面氧压静置式无限氧补偿条件下乳状液中亚油酸的氧化,通过综合考虑气液边界传质阻力、水相扩散、油水边界乳化剂膜边界层阻力、多不饱和脂肪酸(PUFA)自催化氧化反应动力学,建立了扩散-氧化数学模型。采用非对称正交配置法处理特殊边界,求解偏微分方程组,计算了氧化过程中乳状液中氧和亚油酸在垂直于液膜方向的浓度分布,计算方法快捷、有效;结合数学模拟试验和实验值,确定了气液界面氧的液膜传质系数和水相中氧的扩散系数。实验验证该模型能较好地拟合静置式无限氧补偿条件下乳状液中氧的扩散和亚油酸的氧化过程。     

界面Rayleigh对流现象模拟的格子Boltzmann方法

采用格子Boltzmann方法中带有双分布函数的LBGK模型,在介观尺度上实现了对气液传质过程中界面对流现象的模拟,比较了不同Sc数、Ra数以及有局部浓度扰动的界面溶质扩散,对发生界面Rayleigh对流的临界条件进行了研究,发现临界Ra数在1.0×104—2.0×104之间。模拟结果和已有实验现象一致,证明双分布的LBGK模型适用于界面对流及扩散现象的模拟。     

界面聚合制备复合膜过程的数学模型

基于高分子物理化学、质量传递和相分离成膜理论,研究在复合膜制备过程中采用界面聚合反应成膜的机理,建立了非稳态条件下反应．扩散联合控制的数学模型;通过有针对性地简化,该模型可适用于反应控制和扩散控制。模型中无量纲参数有明确的物理意义,较好地反映了界面聚合反应成膜过程的机理。无量纲化处理使模型解析解形式更为简单、实用,模型与实验数据吻合良好,且优于现有模型。通过模拟计算,可得出单体(A组分)浓度、膜的厚度、膜厚增长率随时间的变化关系,并可考察聚合反应速率常数、单体(A组分)在复合层中的扩散系数、单体初始浓度等参数对成膜过程的影响．理论结果可用于指导界面聚合反应成膜实践。     

受限界面处流体分子行为的调控及相关分子热力学模型初探：基于高比表面氧化钛的研究进展

纳米受限界面处的流体由于受到界面性质的影响显著,且存在复杂的传递和反应机制耦合问题,其流体分子行为难以调控,成为了现代化工新技术（如膜过程、多相催化）突破的瓶颈。结合了近几年本课题组的相关工作进展,以化学性质稳定的高比表面氧化钛作为研究平台,对界面处流体分子受限行为进行分析,研究了传递和反应机制分别对界面处流体行为的影响,并探索其调控机制;同时对建立的相应分子热力学模型进行了初步探索,通过原子力显微镜技术将界面摩擦性质和分子间相互作用关联,为分子热力学模型提供分子参数。     

THE KINETICS OF COBALT(II) EXTRACTION WITH EHEHPA IN HEPTANE FROM ACETATE SYSTEM USING AN IMPROVED LEWIS CELL TECHNIQUE†

ABSTRACT

The cobalt(II) extraction kinetics and mechanism with EHEHPA (2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester) were investigated by an improved constant interfacial area stirred cell. The effects of the buffer species, stirring rate, temperature, specific interfacial area and surfactants on the extraction rate showed that the extraction regime was dependent on the extraction conditions and the most probable reaction zone was at the liquid-liquid interface. This extraction process was reaction controlled at lower concentration of the reactants, while it was mixed chemical reaction-diffusion or diffusion controlled only for higher concentration of the reactants. An interfacial extraction reaction model with diffusion was derived. The kinetics of the extraction process was simulated with this model.     

Effects of the boundary layer and interfacial reaction on the time lag in supported liquid membranes

A mathematical model is proposed to describe the effects of boundary layer resistance and interfacial reaction on the time lag in supported liquid membranes for metal ion separation. The model shows that the presence of boundary layer resistance and interfacial reaction delays the time-lag, compared with the limiting case that rapid equilibrium at the interfaces and negligible boundary layer resistance are assumed. Calculated result describes the expected trend and the model equation allows one to predict the lumped parameters which represent the ratios of the diffusion time in the membrane to the characteristic time for boundary layer transfer and interfacial reactions.     

Ternary fluid lattice Boltzmann simulation of dynamic interfacial tension induced by mixing inside microdroplets

A ternary fluid color-gradient lattice Boltzmann model is proposed to investigate the effect of mixing-induced dynamic interfacial tension on the diffusive mixing of two fluids inside microdroplets moving in a third continuous phase through a baffled channel. The diffusion coefficient of binary mixtures and dynamic interfacial tension in this model can be directly defined and independently adjusted. The simulation results show that the dynamic interfacial tension between miscible binary fluids at interfaces with ambient phase would lead to the motion of the interface and redistribution of solutes inside the droplet during mixing. The larger initial interfacial tension gradient would improve mixing efficiency at early stages by promoting faster solute flow. The present model can be easily applied to quantitatively characterize the mixing behavior inside droplets in the practical processes involving the dynamic interfacial tension phenomenon and inspire new designs for mixing intensification.     

CO2-乙醇体系中界面对流的混合格子Boltzmann方法三维模拟及实验验证（英文）

By using a hybrid lattice-Boltzmann–finite-difference method (hybrid LBM–FDM method), three-dimensional simulations of solutal interfacial convection were conducted for the process of CO2 absorption into ethanol. A self-renewal interface model is adopted as an interfacial perturbation model. The simulation results revealed some three-dimensional features of the induced interfacial convection, such as the development of diverging cellular flow and Rayleigh plume-like convection in liquid phase. The concentration distribution of the simulation result is validated and found to be in wel agreement with the Schlieren visualization results qualitatively. Addi-tionally, the mass transfer enhancements by interfacial convection were investigated via both simulation and experiment for the absorption process, and the mass transfer is shown to be enhanced by the interfacial convec-tion by about two-fold comparing with that by diffusion.     

Probing Surface Chemistry Effects on Effective Diffusion Coefficients in Hierarchically Porous Media Through Multiscale Simulations

Multiscale diffusion simulations in a realistic macro-mesoporosity model of a silica-based chromatographic bed are performed to study the effect of relevant surface chemistry parameters, namely length and ligand density of surface-tethered alkyl chains, on effective mesopore and bed diffusion coefficients. Efficient linker schemes enable integration of interfacial dynamics information obtained from molecular dynamics simulations at the single-mesopore level into the hierarchical porosity and multiscale transport model.     

熔融沉积3D打印材料粘接强度及模量预测研究

主要介绍了一种用于预测熔融沉积模型(FDM)层间粘接强度的扩散修复模型。根据流变数据确定温度相关扩散模型,基于一维瞬态热分析预测FDM部件层间的扩散。将温度历史上的扩散系数对时间积分得到界面分子总扩散,进而得到层间粘接强度预测模型。结果表明：不同打印条件下预测结果与测得的粘合强度结果的吻合度较好,且该模型经修正后也适用于FDM部件弹性模量的预测。通过三点弯曲实验与数值模拟的结果对比,验证了粘接强度及模量预测模型的可用性。因此,可以作为FDM打印件承载性能预测的有效模型。     

十六烷基三甲基溴化铵/氯化钠复合体系界面扩张粘弹性质研究

研究了十六烷基三甲基溴化铵和十六烷基三甲基溴化铵/氯化钠复合体系气-液界面的扩张粘弹性质。研究结果表明,十六烷基三甲基溴化铵表面膜的微观弛豫过程主要受扩散弛豫过程控制,十六烷基三甲基溴化铵/氯化钠复合体系的界面扩张粘弹性质参数随氯化钠浓度增加呈一定变化趋势,相角基本上不受氯化钠浓度影响。