囊泡研究进展

回顾了囊泡研究的发展历史 ,以目前最为热门的自发形成囊泡为重点 ,从囊泡的形成、表征、稳定性、理论模型和在囊泡中的反应方面作了阐述 ,并对囊泡的研究前景作了展望。     

金属离子诱导形成囊泡研究进展

金属离子诱导表面活性剂分子在水溶液中形成囊泡相,以其特有的作用方式以及潜在的应用价值而引起了广泛的关注。本文对金属离子诱导形成囊泡相的主要研究工作进行了综述,着重介绍了常见金属离子Cu2+,Ca2+,Fe3+与表面活性剂进行配位作用诱导形成囊泡相的研究进展及其作用机理,最后对金属离子诱导形成囊泡相的发展方向作出了展望。     

阴阳离子表面活性剂复配制备囊泡的研究

采用阴离子表面活性剂十二烷基苯磺酸钠与阳离子表面活性剂十二烷基三甲基氯化铵复配,在合适的比例自发形成囊泡。考察了形成囊泡的复配比例,发现温度升高和滴加有机溶剂都会使囊泡稳定时间更长,通过粒度分析仪检测囊泡的平均粒径在140nm左右,并且囊泡大小均匀。     

H—420软泡匀泡剂

合成了软泡用匀泡剂Ｈ－４２０。讨论了匀泡剂的聚硅氧烷链段聚合度、聚硅氧烷与聚醚链段数之比等因素对其发泡过程中性能的影响,发泡试验结果表明,Ｈ－４２０对辛酸亚锡用量适应范围较宽,该匀泡剂已在软泡生产中应用,生成的泡沫,其主要性能与采用进口的相当。     

管内Taylor泡初始位置的可视化实验研究

使用高速动态分析仪对低温倾斜上升并且底部封闭的管内Taylor泡的初始形成位置进行了可视化实验研究。通过对获得的汽泡图像的综合分析,给出了Taylor泡的初始形成的具体条件。并对获得的观测结果进行统计分析,研究了Taylor泡初始形成位置的变化规律。结果表明:随着管路倾斜角度的减小,Taylor泡平均初始形成位置先上升后降低。对于低温液氮管内沸腾工况,Taylor泡初始形成位置的分布服从对数正态分布。     

聚合物构筑的囊泡及应用

综述了形成囊泡的两亲聚合物的结构,如双链两亲聚合物、单链两亲聚合物、正／负离子复合聚合物、聚合物与小分子化合物及可聚合化两亲聚合物;介绍了这些聚合物形成囊泡的特点和形成条件;概括了囊泡在反应微环境、药物释放、基因载体和生物矿化等方面的潜在应用;并提出了聚合物构筑囊泡的发展前景。     

囊泡的制备与应用研究进展

囊泡是表面活性剂溶液中的一种特异聚集形态,它可以通过表面活性剂的复配形成,也可以在生物体内自发的形成.囊泡的微小尺寸和多层结构为纳米材料开发以及生物膜研究提供一种途径,因此受到科研人员的广泛关注.文章综述了囊泡的形成及其在医药和纳米粒子制备方面的应用.     

泡界线的偏斜及调整

本文通过配合料在窑内的传热及熔化理论分析阐明了泡界线的形成。对实际生产中经常出现的几种泡界线的偏斜进行了理论分析并且提出了解决办法。     

油用消泡剂的消泡抑泡性能评价

在自制的消泡剂性能评价装置上,研究了消泡剂在稠油模拟油中的使用量与消泡抑泡性能的关系。考察了硅油类、氟硅油类与硅醚类三种油用消泡剂的消泡抑泡性能与界面张力之间的关系。结果表明,硅油类、氟硅油类与硅醚类三种油用消泡剂合适的用量为35⁴5μg/g。在相同剂量下,硅醚型消泡剂的消泡抑泡性能最好。将消泡剂消泡性能与稠油模拟油界面张力进行关联发现,加入相同剂量的消泡剂后,硅醚消泡剂使稠油模拟油界面张力下降更显著。能大幅度降低稠油模拟油界面张力的消泡剂有更好的消泡抑泡性能。因此可以用降低界面张力能力的大小来衡量油用消泡剂的消泡抑泡性能。     

油用消泡剂的消泡抑泡性能评价

在自制的消泡剂性能评价装置上,研究了消泡剂在稠油模拟油中的使用量与消泡抑泡性能的关系。考察了硅油类、氟硅油类与硅醚类三种油用消泡剂的消泡抑泡性能与界面张力之间的关系。结果表明,硅油类、氟硅油类与硅醚类三种油用消泡剂合适的用量为35~45μg/g。在相同剂量下,硅醚型消泡剂的消泡抑泡性能最好。将消泡剂消泡性能与稠油模拟油界面张力进行关联发现,加入相同剂量的消泡剂后,硅醚消泡剂使稠油模拟油界面张力下降更显著。能大幅度降低稠油模拟油界面张力的消泡剂有更好的消泡抑泡性能。因此可以用降低界面张力能力的大小来衡量油用消泡剂的消泡抑泡性能。     

Bubble formation in cocurrently upward flowing liquid

The effects of liquid velocity, nozzle diameter, gas chamber volume and gas flow rate on volumes, shapes and growth curves of bubbles formed at a nozzle submerged in a cocurrently upward flowing liquid in a bubble column were experimentally investigated. The bubble volume decreases with increasing liquid flow velocity. The effect of liquid flow velocity on the volume of bubble increases with an increase in the gas flow rate. To simulate bubble formation at a nozzle submerged in cocurrently upward flowing liquid, a revised non-spherical bubble formation model was proposed. Bubble volumes, bubble growth curves and shapes experimentally obtained in this study, as well as in previous experimental studies, are well predicted by the present model.     

分布器对鼓泡塔中气泡直径分布的影响

采用电导探针测定了冷态鼓泡塔中不同气速下的气泡直径及气含率的轴向分布,考察了分布板对鼓泡塔操作性能的影响.结果表明:随着开孔率的减小,从均匀鼓泡区到过渡区的转变提前;在均匀鼓泡区,开孔率对气泡直径影响较小;在过渡区,开孔率大的分布器形成的稳定气泡直径较小、气含率较大;分布板开孔直径越大,形成的初始气泡直径越大,但对轴向气泡直径分布的影响仅限于分布器区.包含分布器影响的气泡直径经验关联式为d/D=140.2Bo-0.5Ga-0.12Fr0.099(h/D)-0.15T-0.34(0.5 cm/s＜ug＜7 cm/s).     

Bubble detonation conditions

Initiation of bubble detonation in the system “inert liquid-explosive gas bubbles” by a detonation wave in a gas was studied experimentally. Compression-wave pressure profiles were determined as functions of the length of the initiation section and the initial pressure of the explosive gas mixture in it. It was shown that because of the effect of the explosive-gas volume between the diaphragm and the upper boundary of the bubble medium, the pressure in front of the initiating wave increased much more slowly than the initial pressure. The optimal length of the initiation section was found, and the critical (minimum) initiation pressure in it and at the shock-wave front were determined. It was found that for a fixed gas volume concentration in the bubble medium, the pressure in the initiation section increased insignificantly as the length of the section decreased. __________ Translated from Fizika Goreniya i Vzryva, Vol. 43, No. 2, pp. 84–90, March–April, 2007.     

Bubble size distribution in bubble columns

The bubble size distributions are measured for the air-water system as a function of air velocity at room temperature in two bubble columns. High speed cinephotography and fiber optic probe techniques are used to measure the bubble size. Our limited measurements suggest that the bubble size may be independent of gas velocity in the range 3.6 to 9.2 cm/s and may be dependent on column diameter with smaller bubbles for narrower columns. The bubble size appears to be smaller at the column wall than at distances away from the wall.     

Discrete Bubble Model for Prediction of Bubble Behavior in 3D Fluidized Beds

A discrete bubble model has been developed taking into account multiple bubble‐bubble interactions and a delayed coalescence method. The obtained simulation results were compared with experimental data reported in literature. The simulation results predicted by the developed model indicate clearly that the multiple interactions of bubbles lead to more reasonable results than those predicted by a binary interaction model. In addition, two types of interaction models were applied and predicted results were compared. The frequency of gas bubbles passing through the bed cross section versus bed height follows the same trend as the experimental data.     

微细气泡技术标准体系探究

微细气泡技术是面向未来、绿色可持续的技术.气泡尺寸小到微纳米级的微细气泡技术快速发展,其应用也越来越广泛,在矿物浮选分离、超声造影剂、污水处理、工业清洗和精细剥离、日用清洗和护肤、农业种植以及水产养殖、盐碱地改良和土壤修复等诸多领域,微细气泡技术均颇有建树.但是,就像其他新兴技术发展初期一样,伴随着微细气泡的研究和应用...     

Local Bubble Dynamics and Macroscopic Flow Structure in Bubble Columns with Different Scales

Local bubble behaviours were investigated in three bubble columns with different diameters of 200, 400 and 800 mm. By means of a novel single‐tip optical fibre probe employing laser Doppler technique, the local gas holdup, bubble frequency, bubble size and velocity were measured simultaneously at different locations of the columns. Measurements were performed in air‐water system at superficial gas velocities up to 90 mm/s. The averaged profiles and instantaneous measurements were analyzed and compared for different columns. The presence of a coherent gross circulation structure spanning the entire column diameter in the larger column rather than a pair of symmetrical circulation cells observed in the smaller columns has been confirmed.     

A Simplified Correlation for Bubble Volume Estimation

In order to propose a simplified correlation to predict the detached bubble volume without considering the gas velocity, an experimental work has been performed to measure the detached bubble volume through a micro‐hole submerged in liquid. Several micro‐holes with diameters of 60, 90, 126, 220, 580, and 1200 µm are respectively used for bubble formation, while liquid in a test chamber is continuously drained at a constant rate of 0.006 ml/s. The predicted results by the present simplified correlation agree well with the measured values. Predictions of the detached bubble volume from previously published correlations using a model to compute the gas velocity are also compared with experimental data.     

Bubble detonation as a self-sustained solitary wave with energy release

Previous experiments have shown that a bubble detonation wave is a resonant or self-sustained solitary wave in a bubble medium. Bubble detonation is modeled by a solitary wave with energy release in bubbles. The equation describing a solitary wave of small amplitude is shown to be an analog of nonlinear Boussinesq equation of the fourth order. A comparison of the solution obtained with averaged experimental pressure profiles shows that the analytical solution is suitable for describing bubble detonation waves with a finite pressure amplitude. In the model proposed, the time of action of solitary-wave compression on a separate bubble is several times the bubble oscillation period. This result agrees with experimental data and confirms the presence of a collective resonant effect in a bubble medium. Satisfactory agreement is obtained between experimental and theoretical data on the pressure profile and extent and velocity of bubble detonation waves. __________ Translated from Fizika Goreniya i Vzryva, Vol. 43, No. 6, pp. 104–111, November–December, 2007.