Lub sij hawm surfactant los ntawm lus Askiv 'surfactant'. Nws yog ib lo lus condensed ntawm kab lus 'surface active agent'. Nws kuj muaj lub npe hu ua Tensor. Txhua yam khoom uas tuaj yeem txo qhov nro ntawm cov kua los ntawm kev ntxiv me me yog sib sau ua ke hu ua surfactant. Lawv txoj haujlwm saum npoo yog tshwj xeeb rau cov kua dej, feem ntau yog hais txog dej. Ib qho kawg ntawm cov surfactant yog cov saw hlau uas tsis yog-polar hydrocarbon (alkyl pawg) uas tsis tshua muaj affinity rau dej, feem ntau hu ua ib pawg hydrophobic; Ntawm qhov kawg, muaj pawg polar (xws li - OH, - COOH, - NH ₂, - SO3H, thiab lwm yam) uas muaj kev sib raug zoo rau cov dej, yog li lawv hu ua hydrophilic pawg thiab sib sau ua ke hu ua "amphiphilic molecules. "( lipophilic hydrophilic molecules ). Txhawm rau kom muaj kev ruaj ntseg, surfactants tuaj yeem yaj hauv dej hauv ob txoj kev:
1. Ua ib lub monolayer ntawm cov kua dej.
Tso cov pab pawg hydrophilic hauv dej thiab txuas ntxiv cov pab pawg hydrophobic rau saum huab cua kom txo tau cov pa phem. Lub zog quab yuam ntawm pawg hydrophobic thiab dej molecules yog sib npaug rau kev tawm dag zog sab nraud ntawm cov dej hauv dej molecules, offsetting sab hauv rub quab yuam uas cov dej hauv dej molecules tau txais thaum xub thawj, thiab txawm tias qhov nro ntawm cov dej txo qis. Qhov no yog lub hauv paus ntsiab lus ntawm foaming, emulsification, thiab wetting los ntawm surfactants. Nyob rau hauv cov roj-dej systems, surfactant molecules yog adsorbed ntawm qhov sib txuas ntawm cov roj thiab dej theem, thaum pawg polar tau muab tso rau hauv dej, thiab cov tsis-polar feem nkag mus rau hauv cov roj thiab yog taw qhia ntawm lub interface. Qhov no ua rau muaj kev sib txhuam ntawm cov roj-dej theem, txo qhov kev sib tshuam ntawm cov roj thiab dej. Cov cuab yeej no muaj kev cuam tshuam loj rau kev siv dav dav ntawm surfactants.
2. Daim ntawv 'micelles'.
micelles tuaj yeem yog kheej kheej lossis txheej txheej, ob qho tib si uas sim zais cov pab pawg hydrophobic hauv micelles thiab nthuav tawm cov pab pawg hydrophilic kom ntau li ntau tau. Yog tias pawg polar sawv cev los ntawm spheres thiab hydrophobic non-polar pawg yog sawv cev los ntawm txhua kab, ces monolayers thiab micelles tuaj yeem tau. Yog hais tias muaj cov roj insoluble (ib lo lus dav dav rau cov kua organic uas tsis muaj dej tsis sib haum hauv cov dej) hauv cov tshuaj, lawv tuaj yeem nkag mus rau hauv nruab nrab ntawm cov micelles kheej kheej thiab yaj nyob rau hauv lub interlayer ntawm txheej micelles. Qhov no yog hu ua cov nyhuv solubilization ntawm surfactants.
Surfactants tuaj yeem muaj ntau yam haujlwm xws li ntxuav, emulsification, foaming, wetting, soaking, thiab dispersion, thiab tus nqi ntawm surfactant siv me me (feem ntau yog ob peb feem pua rau ob peb txhiab feem pua). Lawv yooj yim rau kev khiav lag luam, tsis muaj tshuaj lom, thiab tsis muaj corrosive, ua rau lawv cov khoom siv tshuaj zoo tagnrho. Yog li ntawd, lawv muaj cov ntawv thov tseem ceeb hauv kev tsim khoom thiab kev tshawb fawb txog kev tshawb fawb. Thaum cov concentration zoo ib yam, cov khoom tsis-polar hauv cov surfactant loj dua thiab muaj kev ua haujlwm zoo dua. Ntawm homologues, cov neeg uas muaj cov pa roj carbon ntau dua muaj cov dej num ntau dua. Tab sis thaum cov saw hlau carbon ntev dhau lawm, nws tsis muaj txiaj ntsig zoo vim nws tsis tshua muaj dej solubility hauv dej.