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1、The Experts in Dynamic Surface Tension表面张力测试仪 SURFACE TENSIOMETERS上海立拓实业有限公司代理美国S e n s a D y n e 表面张力测试仪 联系人：段思齐1 3 5 0 1 9 4 4 5 1 6 Q Q ：1 2 8 5 6 7 5 9 0 8 电话：0 2 1 - 6 1 5 3 6 3 6 1 传真：0 2 1 - 5 0 3 5 2 1 0 9Surface Tension Simplified液体表面张力有着一种互相吸引的倾向，当液体与 水气面（气体）互相接触时，而两者之间产生的 面，便是所知道的“界面”。一个非
2、常贴切的例子是：一滴水自空气中落下所形 成的球形状态，是因为表面张力使它表面最小化而 成的体积。分子在液体表面挥发出很强的吸引力，互相吸引在 邻近的分子，这种合力在每一单位长度的表面任 何交点成垂直线，便是所述的表面张力，它是以 Dynes/cm为测量单位。最大气泡压力法，气泡在压力下出自不同直径的两 支玻璃管口，在液体里最大压力差产生的气泡直 接与表面张力是成正比例的。在处理液体表面张 力的变化，传统测试表面张力的Du Nouy ring法和 Wilhelmy Plate法是不足够的（得不出具体数据）。 表面活性剂内含的活性分子的表面张力变化便需要 用最大气泡压力法去测量。气泡形成时，根据速
3、度 的改变所得到的数据，便可作为研究表面活性剂的 活跃分子扩散时间，即是动态表面张力测量方法。The surface tension of a fluid is the tendency of the fluid to “stick“ to itself when there is a surface between the liquid and the vapor phase (known as an interface). A good example is a drop of water falling in air. The drop assumes a spherical shape
4、 due to surface tension forces, that minimize its surface given the volume.Molecules at the surface of a liquid exert strong attractive forces on other molecules within their vicinity. The resultant force acting perpendicular to a line of unit length in the surface is known as surface tension, usual
5、ly measured in Dynes/ Centimeter.In the maximum bubble pressure method, bubbles are formed at the ends of two immersed tubes of difierent orifice diameters. The diffrence in the maximum pressures required to generate bubbles in the fluid is directly proportional to the fluid surface tension.In proce
6、sses where new liquid surfaces are created or terminated. the classical methods used to measure surface tension. such as the Du Noy ring or the Wilhelmy Plate are inadequate. The Maximum Bubble Pressure method is required to detect changes in “active“ surfactant containing systems. Varying the rate
7、of bubble formation allows the study of active surfactants at various surfactant molecule diffusion times resulting in “Dynamic“ Surface Tension Measurement.Dynamic Measurement表面活性剂的活跃分子，动态是它的特征，表面张 力高，界面扩展时间便减少，限制了表面活性剂分 子移往界面，因此便发现液体的测量尺度可以是动 态表面张力或表面扩散时间。而表面活性剂亦显示 了它的3个特征，即表面张力测量的同时可研究表面 活性剂浓度功能，
8、动态表面张力和界面扩散时间。2SensaDyne表面张力测试仪，设计了（有）间歇的和 连续的测量方法，它可以从表面活性剂的动态曲线的 任何点做开始间歇或连续测量，而连续测量的功能是 基于表面张力的控制参数。 在慢速度的气泡下，表 面张力扩散时间大约等于气泡速度，当气泡速度增加 时，表面扩散时间与气泡速度即成反比例的减少。如 果气泡速度很快增加，气泡便会鏈接一起，形成振荡 射流式（测量动态表面张力），示波器的相关软件程 序可以准确检验（核实）气泡分离和准确读出快速气 泡的扩散时间。Active surfactants are known to have dynamic characteristi
9、cs. Higher surface tension results as the interface development time (Surface Age) is reduced, limiting the time that surfactant molecules migrate to the interface. This allows characterization of fluids in two dimensions; Dynamic Surface Tension versus Surface Age (diffusion time).The characteristi
10、cs of a surfactant can also be shown in three dimensions, when the surface tension is also measured as a function of Surfactant Concentration, as well as Dynamic Surface Tension and Surface Age.The SensaDyne tensiometer allows both intermittent and continuous measurements at any point on the dynamic
11、 curve of an active surfactant containing formulation. Continuous measurement capability also facilitates process control applications where surface tension is the controlling parameter.At slow bubble rates the surface age Is approximately equal to the bubble rate. As the bubble rate increases the s
12、urface age becomes a decreasing percentage of the bubble rate. If the bubble rate is increased too much, then bubbles begin to link together in an oscillating jet mode. An oscilloscope software program is available to verify bubble separation and to very accurately read bubble rate as well as surfac
13、e age at very fast bubble rates.3The SensaDyne Surface TensiometerSensaDyne的表面张力测试仪是先进的全电脑软件控 制操作的仪器，可测试液体的静态与动态表面张力， 一般传统的测试方法如：Du Nouy Ring, Capillary Height,和Wilhelmy Plate法在有表面污染的液体或充 满泡沫的状态下都不能测量，只有SensaDyne表面张 力测试仪在液体表面污染环境下及充满泡沫的状态下 可连续监控测试液体表面张力。SensaDyne的最大气 泡法的专利技术最早是由Simon于1851年提出，后于 1917
14、年Jaeger发展出来。第一台可应用的商业仪器便 是由SensaDyne于1982年正式开发，并配合电脑应用 软件操作。最大气泡压力测量法避开了任何可能导致 测量的错误因素，它是在液体内测量，最简单，最直 接，但是最准确的测量表面张力法。有关最大气泡压 力法的数学分析，可在美国专利注册号4，416，148 内认证（此认证包含了SensaDyne的技术）。两支不同直径的玻璃管，在最大气体压力下，在液体 中产生的气泡，它的压力差数据便相等于液体表面张 力。与其它的最大气泡压力法不同的是SensaDyne的 专利双探测器完全沉浸在液体深度内，获得准确及不 断的数据。SensaDyne的稳定空压法，使
15、得可调流速 的管径口，获得供应独立稳定的气体流量。因此界面 形成的时间（气泡速度）可选择由每秒40个气泡或再 多些气泡；也可以选择每30秒或至120秒一个气泡。有 关的气泡速度，液体温度，液体表面张力数据全部显 示在电脑屏幕。SensaDyne表面张力测试仪是唯一商业测试仪器符 合美国“动态表面张力测试气泡技术方法ASTM Test Method D3825-90的标准”。SensaDyne Tensiometers are the most advanced, computerized, instruments now available for measuring both static
16、and dynamic fluid surface tension. Classical methods such as the Du Noy ring, Capillary Height, and others, require a clear surface without contaminants in order to obtain accurate measurements. These methods cannot be used where surface foaming occurs, or surface debris is present.SensaDyne instruments can continuously monitor surface tension within fluid sample streams, using a flow-through cell arrangement. The meas
