Zeta電位的介紹

Zeta potential is an electrostatic potential that exists very near the surface of particles suspended in liquids1. Zeta potential (ζ) is responsible for particle-particle repulsion forces in colloidal suspensions ａnd thus can be used to predict colloid stability against particle aggregation. Figure 1 illustrates a particle suspended in a liquid along with various notional regions around it.  The“slipping plane” or “shear plane” is where Zeta potential is located versus the potential in the bulk solution. Within this slipping plane, the liquid is bound to the particle while it moves freely outside this boundary. The net potential far from the particle (in the bulk of the liquid) is zero.

Zeta電位是液體中懸浮的粒子很接近表面位置的靜電勢(shì)1.Zeta電位(ζ)是由膠體中粒子與粒子間的相互作用造成的，因此它可以用來(lái)預(yù)測(cè)膠體體系里粒子聚集的穩(wěn)定性。圖1顯示了懸浮在液體中的粒子及其周?chē)�的各種概念區(qū)域。Zeta電位指的是液體中滑動(dòng)面或者剪切面的電位。在這個(gè)滑動(dòng)平面內(nèi)，當(dāng)液體在這個(gè)邊界外自由運(yùn)動(dòng)時(shí)，它與粒子結(jié)合在一起。遠(yuǎn)離粒子的凈電勢(shì)(在液體中)為零。

Figure 1. A negatively charged particle suspended in a liquid. Notional boundaries are shown.

圖1懸浮在液體中的帶負(fù)電的粒子及其周?chē)�的各種概念區(qū)域

PS：這個(gè)是另外的一種說(shuō)法，但是要描述的內(nèi)容是一樣的；

由于分散粒子表面帶有電荷而吸引周?chē)�的反�?hào)離子，這些反號(hào)離子在兩相界面呈擴(kuò)散狀態(tài)分布而形成擴(kuò)散雙電層。根據(jù)Stern雙電層理論可將雙電層分為兩部分，即Stern層和擴(kuò)散層。Stern層定義為吸附在電極表面的一層離子（IHP or OHP）電荷中心組成的一個(gè)平面層，此平面層相對(duì)遠(yuǎn)離界面的流體中的某點(diǎn)的電位稱為Stern電位。穩(wěn)定層(Stationary layer) (包括Stern層和滑動(dòng)面slipping plane以內(nèi)的部分?jǐn)U散層) 與擴(kuò)散層內(nèi)分散介質(zhì)(dispersion medium)發(fā)生相對(duì)移動(dòng)時(shí)的界面是滑動(dòng)面(slipping plane)，該處對(duì)遠(yuǎn)離界面的流體中的某點(diǎn)的電位稱為Zeta電位或電動(dòng)電位（ζ-電位）。