清洗液中使用表面活性劑作(zuo)(zuo)清(qing)洗(xi)劑,降低清(qing)洗(xi)液(ye)及污(wu)(wu)物(wu)(wu)(wu)(wu)間界面張力,清(qing)洗(xi)液(ye)首先可潤濕污(wu)(wu)物(wu)(wu)(wu)(wu)表(biao)(biao)面,使(shi)污(wu)(wu)物(wu)(wu)(wu)(wu)膨潤,然后(hou)滲透到污(wu)(wu)物(wu)(wu)(wu)(wu)之間,使(shi)污(wu)(wu)物(wu)(wu)(wu)(wu)分散(san)。污(wu)(wu)物(wu)(wu)(wu)(wu)如屬(shu)油(you)類,則油(you)脂先形成(cheng)球狀聚集在(zai)金(jin)屬(shu)表(biao)(biao)面,表(biao)(biao)面活(huo)性(xing)劑擠(ji)入,使(shi)污(wu)(wu)物(wu)(wu)(wu)(wu)自金(jin)屬(shu)表(biao)(biao)面脫(tuo)離(li),移至清(qing)洗(xi)液(ye)中(zhong)。本來不(bu)溶(rong)解(jie)的油(you)污(wu)(wu)粒子,在(zai)表(biao)(biao)面活(huo)性(xing)劑膠束中(zhong)包圍(wei)而“增(zeng)溶(rong)”于(yu)清(qing)洗(xi)液(ye)中(zhong),不(bu)會再吸附到金(jin)屬(shu)表(biao)(biao)面上。在(zai)洗(xi)滌時,如有機械力作(zuo)(zuo)用(yong),就有助(zhu)于(yu)污(wu)(wu)物(wu)(wu)(wu)(wu)脫(tuo)離(li)金(jin)屬(shu)表(biao)(biao)面,提高清(qing)洗(xi)效果。由表(biao)(biao)面活(huo)性(xing)劑制備的乳狀液(ye)除(chu)了具(ju)有上述清(qing)洗(xi)劑的清(qing)洗(xi)作(zuo)(zuo)用(yong)外(wai),還根據溶(rong)劑相(xiang)似溶(rong)解(jie)原理(li),內相(xiang)油(you)相(xiang)的存在(zai)將使(shi)其對油(you)污(wu)(wu)的溶(rong)解(jie)清(qing)洗(xi)作(zuo)(zuo)用(yong)大(da)大(da)增(zeng)強。理(li)想(xiang)的清(qing)洗(xi)乳狀液(ye),一般(ban)具(ju)有以下四個特性(xing):
(1)乳狀液(ye)穩定(ding),油相對油污溶解能力強;
(2)油(you)相粘度低,終易于(yu)水(shui)洗干凈;
(3)油相好(hao)無揮發性、無毒、清洗過程不會產(chan)生(sheng)污(wu)染;
(4)容易破乳回收,再生(sheng)利(li)用。
堿性(xing)表面活性(xing)劑(ji)溶液雖具有(you)潤濕乳化分散與增溶等性(xing)能(neng)(neng),對去除輕油垢(gou)(gou)、重油垢(gou)(gou)有(you)較大能(neng)(neng)力(li),但去除含(han)積炭瀝青較多的(de)焦(jiao)(jiao)油垢(gou)(gou)的(de)能(neng)(neng)力(li)較差,這時應加入有(you)機溶劑(ji),一種是兩(liang)親的(de)醇(chun)類,如異丙醇(chun),會使膠束(shu)增大,有(you)利(li)于非極性(xing)有(you)機物插(cha)入膠束(shu)“柵欄”間,使清除焦(jiao)(jiao)油垢(gou)(gou)能(neng)(neng)力(li)大大增強。