Reischl Martin, Köstler Stefan, Kellner Gerhard, Stana-Kleinschek Karin, Ribitsch Volker
Department of Physical Chemistry, Institut fur Chemie, Karl-Franzens University Graz, Graz, Austria.
Rev Sci Instrum. 2008 Nov;79(11):113902. doi: 10.1063/1.3020699.
A method and instrumentation is described capable of streaming potential measurements of various macroscopic surfaces. It differs from other approaches due to the creation of an oscillatory flow of electrolyte solutions through or alongside the sample. This technique offers a wide range of applied flow frequency and amplitude resulting in a fast and highly accurate measurement. This enables the streaming potential detection at rather high ionic strength and in a short time regime, which allows the monitoring of adsorption processes. Streaming potential and applied pressure are measured simultaneously, together with the specific conductivity of the bulk solution, pH value, and temperature. Combining these data, the zeta potential (zeta) for many different material types (fibers, films, foils, granules, and particles) can be calculated. The apparatus comprises reliable and robust measurements, simple handling, a high degree of automation, and advanced software control. With this setup, automated pH and concentration dependent zeta-potential measurements are possible for a variety of analytes and adsorbing species (e.g., ionic strength, surfactants, polyelectrolytes, and proteins); time-resolved measurements are facilitated down to the seconds time scale. The device allows the necessary sample preparation and equilibration outside the instrument using exchangeable sample holders. This offers the opportunity of high sample throughput.
本文描述了一种能够对各种宏观表面进行流动电位测量的方法和仪器。它与其他方法不同之处在于，通过样品或在样品旁边产生电解质溶液的振荡流。该技术提供了广泛的应用流动频率和幅度，从而实现快速且高度准确的测量。这使得能够在相当高的离子强度下并在短时间内检测流动电位，进而可以监测吸附过程。同时测量流动电位和施加压力，以及本体溶液的电导率、pH值和温度。结合这些数据，可以计算许多不同材料类型（纤维、薄膜、箔片、颗粒和粒子）的zeta电位（ζ）。该仪器具有可靠且稳健的测量、操作简单、高度自动化以及先进的软件控制。通过这种设置，可以对各种分析物和吸附物质（例如离子强度、表面活性剂、聚电解质和蛋白质）进行自动化的pH和浓度依赖性zeta电位测量；便于进行时间分辨测量，时间尺度可达秒级。该设备允许使用可更换的样品架在仪器外部进行必要的样品制备和平衡。这提供了高通量样品处理的机会。
