Amphoteric surfactants yog surfactants uas muaj ob qho tib si anionic hydrophilic pawg thiab cationic hydrophilic pawg hauv tib lub molecule. Lawv qhov tseem ceeb tshaj plaws yog tias lawv tuaj yeem pub thiab txais protons. Lawv muaj cov yam ntxwv hauv qab no thaum siv: Amphoteric surfactants feem ntau muaj kev ua tau zoo hauv kev ntxuav, dispersing, emulsifying, sterilizing, softening fibers, thiab antistatic, thiab tuaj yeem siv ua cov khoom siv tiav ntaub, dyeing auxiliaries, calcium xab npum dispersants, qhuav-cleaning surfactants, thiab hlau corrosion inhibitors, thiab lwm yam. Lawv muaj cov khoom mos mos, du, thiab antistatic rau cov ntaub; qee yam khoom bactericidal thiab pwm-inhibiting; thiab zoo emulsifying thiab dispersing zog. Txawm li cas los xij, hom surfactant no kim heev, thiab nws qhov kev siv tiag tiag yog me dua li lwm hom surfactants. Nws yog ib qho surfactant mos mos. Tsis zoo li ib qho anionic lossis cationic surfactants, amphoteric surfactant molecules muaj ob qho tib si acidic thiab basic pawg ntawm ib kawg ntawm lub molecule. Cov pawg acidic feem ntau yog carboxyl, sulfonic acid, lossis phosphate pawg, thaum cov pawg yooj yim yog cov pawg amino lossis quaternary ammonium. Lawv tuaj yeem sib xyaw nrog anionic thiab nonionic surfactants thiab tiv taus cov kua qaub, alkalis, ntsev, thiab alkaline earth metal ntsev.
Tam sim no, cov tshuaj amphoteric surfactants uas siv ntau feem ntau muaj cov pawg carboxylate ua lawv cov anionic moieties, nrog rau ob peb muaj cov pawg sulfonate; lawv cov cationic moieties feem ntau yog cov ntsev amine lossis cov ntsev ammonium quaternary. Cov uas muaj cov ntsev amine ua cov cationic moiety hu ua amino acid type; cov uas muaj cov ntsev ammonium quaternary ua cov cationic moiety hu ua betaine type.
- Hom amino acid
Cov kua dej ntawm cov amino acid-hom amphoteric surfactants yog alkaline. Thaum hydrochloric acid maj mam ntxiv nrog kev do, tsis muaj kev hloov pauv thaum cov kua dhau los ua nruab nrab. Ib qho precipitate tsim thaum cov kua dhau los ua me ntsis acidic. Yog tias ntxiv ntau hydrochloric acid kom ua rau cov kua muaj zog acidic, cov precipitate yaj dua. Qhov no qhia tau hais tias nws ua haujlwm ua anionic surfactant hauv ib puag ncig alkaline thiab ua cationic surfactant hauv ib puag ncig acidic. Txawm li cas los xij, thaum cov khoom cationic thiab anionic sib npaug ntawm qhov isoelectric point, hydrophilicity txo qis, ua rau muaj precipitate. Lub anion hauv molecule yog ib pawg carboxyl, thiab lub cation yog ntsev ammonium. Hom surfactant no qhia txog cov haujlwm ntawm qhov chaw sib txawv nrog kev hloov pauv hauv pH ntawm qhov nruab nrab. Piv txwv li, dodecylaminopropionic acid (C12H25N+H2CH2CH2COO-) tuaj yeem hloov mus ua sodium dodecylaminopropionate (C12H25NHCH2CH2COO-Na+) hauv cov sodium hydroxide medium, ua haujlwm zoo li cov tshuaj anionic surfactant uas yaj tau hauv dej. Hauv cov hydrochloric acid medium, nws tuaj yeem hloov mus ua cov ntsev hydrochloride ntawm dodecylaminopropionic acid [(C12H25N+H2CH2CH2COOH)Cl-], ua haujlwm zoo li cov tshuaj cationic surfactant uas yaj tau hauv dej. Yog tias pH ntawm cov medium raug kho kom cov nqi zoo thiab tsis zoo sib npaug, nws raug hloov mus ua cov ntsev sab hauv (C12H25N+H2CH2CH2COO-), uas yaj tsis zoo hauv dej thiab tawm mus. pH ntawm qhov no hu ua isoelectric point. Txhawm rau kom muaj txiaj ntsig zoo ntawm cov amino acid-type amphoteric surfactants, lawv yuav tsum tau siv hauv cov kua dej nrog pH deviating ntawm isoelectric point. Cov khoom siv raw uas siv rau hauv kev npaj cov amino acid-type amphoteric surfactants suav nrog cov aliphatic primary amines siab dua, methyl acrylate (saib acrylate esters), acrylonitrile, thiab chloroacetic acid.
- Bhom etaine
Cov tshuaj betaine-type amphoteric surfactants muaj qhov zoo tshaj plaws ntawm kev yaj hauv cov kua dej txawm tias lawv yog acidic, neutral lossis alkaline. Lawv tsis precipitate txawm tias ntawm qhov isoelectric point. Tsis tas li ntawd, lawv kuj muaj cov khoom zoo xws li permeability, detergency thiab antistatic kev ua tau zoo. Yog li ntawd, lawv yog cov emulsifiers zoo thiab softeners.
Carboxybetaine
Cov anion hauv lub molecule yog ib pawg carboxyl, thiab cov cation yog ib pawg quaternary ammonium. Piv txwv li, alkyl dimethyl betaine [RN+(CH3)2CH2COO-], qhov twg pawg alkyl R muaj 12 txog 18 carbon atoms. Piv nrog rau cov amino acid hom, betaine hom tuaj yeem yaj hauv dej hauv acidic, neutral, lossis alkaline media, thiab tsis precipitate txawm tias ntawm isoelectric point, yog li lawv tuaj yeem siv rau hauv cov kua dej nrog txhua pH. Hauv acidic media, thaum pH ntawm isoelectric point qis dua, nws ua haujlwm zoo li cov dej-soluble cationic surfactant [[RN+(CH3)2CH2COOH]Cl-]; hauv neutral lossis alkaline media, piv txwv li, thaum pH sib npaug lossis siab dua qhov isoelectric point, nws ua haujlwm zoo li cov dej-soluble amphoteric surfactant thiab tsis ua haujlwm zoo li anionic surfactant. Amphoteric surfactants feem ntau tsim cov precipitates nrog anionic surfactants tsuas yog hauv acidic media. Lawv siv tau ua ke nrog txhua hom surfactant hauv cov xov xwm nrog ntau yam pH. Cov ntaub ntawv raw siv rau kev npaj betaine-hom amphoteric surfactants suav nrog alkyl dimethyl tertiary amines thiab sodium chloroacetate, thiab lwm yam.
Sulfobetaine
Pawg anionic hauv lub molecule yog pawg sulfo (SO3-), thiab pawg cationic yog pawg quaternary ammonium. Cov uas siv ntau yog alkyl dimethyl sulfonethyl betaines [RN+(CH3)2CH2CH2SO3-] thiab alkyl dimethyl sulfopropyl betaines [RN+(CH3)2CH2CH2SO3-]. Tus lej ntawm cov pa roj carbon hauv pawg alkyl R hauv cov qauv yog txij li 12 txog 18. Sulfobetaines muaj cov khoom siv dav dav; lawv tsis tsuas yog muaj txhua qhov zoo ntawm cov betaines ib txwm tab sis kuj muaj cov txiaj ntsig tshwj xeeb xws li kev tiv taus cov kua qaub, alkalis, thiab ntsev ntau. Tam sim no, hydroxy sulfopropyl [RN+(CH3)2CH2CH(OH)CH2SO3-] yog siv los hloov sulfopropyl betaines, uas tsim cov tshuaj lom neeg rau lub cev thaum lub sijhawm tsim khoom. Vim muaj ob qho tib si anionic thiab cationic pawg nrog hydroxyl pawg hauv lawv cov qauv, lawv tsis tsuas yog muaj tag nrho cov txiaj ntsig ntawm amphoteric surfactants tab sis kuj qhia txog kev tiv thaiv rau cov concentration siab ntawm cov kua qaub, alkalis, thiab ntsev, zoo emulsifying, dispersing, thiab antistatic zog, nrog rau bactericidal, antifungal, thiab viscoelastic zog. Lawv yog surfactants nrog kev ua tau zoo heev thiab tau siv dav hauv ntau qhov chaw xws li tshuaj txhua hnub, roj av roj hloov chaw, fracturing, thiab acidizing.
Phospholipid betaine
Pawg anionic hauv lub molecule yog pawg phosphate (HPO4-), thiab pawg cationic yog pawg quaternary ammonium. Piv txwv li, alkyl dimethyl hydroxypropyl phosphate betaine [RN+(CH3)2CH2CH(OH)CH2HPO4-], qhov twg pawg alkyl R muaj 12 txog 18 carbon atoms. Cov qauv no txiav txim siab tias nws tsis tsuas yog muaj cov khoom zoo heev ntawm amphoteric surfactants xws li wettability, detergency, solubilization, emulsifying thiab dispersing zog, antistatic zog, thermal stability, nrog rau kev sib raug zoo zoo, tsis khaus, thiab qhov zoo dua li cov anionic surfactants dav dav xws li zoo dua alkali tsis kam, electrolyte tsis kam, thiab antistatic zog, tab sis kuj muaj zog calcium xab npum dispersibility, qis nto nro, thiab zoo heev foaming kev ua tau zoo.
Lub sijhawm tshaj tawm: Lub Ob Hlis-04-2026