用于扁平样品的 ParaCell 套件

Overview

The ParaCell operates with 300 mL of electrolyte. In addition to the two end plates for mounting the working and counter electrodes, there are four other ports. In a conventional electrochemical cell configuration, the setup is as follows:

• End plate with blue/green socket: Flat sample (working electrode)
• End plate with red/orange socket: 2° flat sample or auxiliary electrode (graphite plate)
• Top #7 Ace thread on working electrode end plate for use with Luggin capillaries/bridge tubes for use with Gamry's SCE, Ag/AgCl, and Hg/Hg2SO4 reference electrodes (electrodes ordered separately)
• The remaining three #7 Ace threads can be used for reagent addition, foaming/protection/exhaust, etc.

The cell body is chemically resistant polycarbonate and all metal is 304 stainless steel. The two end brackets are separated from each other by plastic sleeves so that contact with the sample will not short-circuit the electrodes installed in the ParaCell. Be careful not to place the ParaCell in spilled electrolyte, for example, to avoid shorting the two ends.

The center hole in each end plate exposes a nominal area of ​​2.6 cm2, exposing the working electrode and counter or second working electrode. The Paracell uses Teflon-sealed silicone O-rings to define the sample area. To prevent crevice corrosion, a potential problem with all flat samples, the 1 cm2 Portholes™ electrochemical sample mask can be used with the ParaCell.

The hole at the top also has a small vent to the top of the electrochemical cell, which can be used to relieve pressure when the bubbler is almost full.

The reference electrode bridge tube is a vertical tube. This eliminates trapped air bubbles in the thin horizontal tube, a problem that often affects other flat cell designs. A low impedance Vycor frit is used to make electrical contact with the electrolyte.

The electrode connectors are color coded to match the color scheme of the cell cables for Gamry's potentiostats.

Recommended Uses

Galvanic corrosion

When performing a galvanic corrosion experiment with the ParaCell, two dissimilar metals are clamped in between. One sample becomes the working electrode by connecting the working (green) and working sense (blue) wires, and the other sample becomes the counter electrode by connecting the counter (red) and counter sense (orange) wires. It doesn't matter which material is the working electrode and which is the counter electrode, the direction of the current will let you know which one is more active and which one is more inert (positive current = active working, negative current = inert working).

The reference electrode is optional in this setup, but can be inserted on either side if desired. Generally speaking, it will be placed on the working electrode side.

Electrochemical noise

Electrochemical noise is very similar to galvanic corrosion in setup, only the same materials are used for the working and counter electrodes. Electrochemical noise is a more powerful and complex technique. Corrosion scientists who are not familiar with noise should research it.

Corrosion of flat samples

ParaCell 非常适合扁平样品的腐蚀试验（DC 和 AC-EIS/EFM-实验）。 与以上情况相比，设置有几处不同。 首先，辅助电极应该是惰性材料（标准石墨板是一种不错的材料），并且不需要附加辅助传感，尽管留下它也不会产生问题。 第二，必须将 Reference 夹入，优选地是夹入工作电极侧的参比桥管中的参比电极。 应使用工作电极中心的维克玻璃熔块将桥管定位。

屏蔽工作电极表面来减少缝隙腐蚀是一个好方法，特别是对容易点蚀的样品而言。 请注意，腐蚀速率非常低的材料的电流将非常低；因为 ParaCell 仅露出多 2.6 cm2，更优选的方式是使用允许更多露出面积的配置。

涂层样品

涂层样品涉及多种领域： 腐蚀、物理电化学、材料科学。 任何导电或半导电样品均适用。 随着厚度增加，样品绝缘成为一个问题。 具有非常低电容的屏蔽涂层（即厚样品）产生非常小的信号；并且，与腐蚀速率低的材料类似，较大的暴露面积更为可取。

对于有涂层的样品，该设置将非常类似测量腐蚀的设置，除非涂层位于绝缘衬垫之上（如玻璃）。 ParaCell 的端板连接要求样品对该板导电。 如果样品涂覆在玻璃或其他绝缘基板上，则需要以另一种方式来制作电触头。 有两种可能的解决方案：一是留出足够的样品，让它能够夹到样品上；二是固定一条可以四处导引的线。

• 用于扁平样品的 ParaCell™ 套件 User's Manual
• 用于扁平样品的 ParaCell™ 套件 Data Sheet