Bipolar surfactants yog cov surfactants uas muaj ob qho tib si anionic thiab cationic hydrophilic pawg.

Feem ntau hais lus, amphoteric surfactants yog cov tshuaj uas muaj ob pawg hydrophilic hauv tib lub molecule, suav nrog anionic, cationic, thiab nonionic hydrophilic pawg. Cov amphoteric surfactants uas siv ntau yog feem ntau yog cov pab pawg hydrophilic nrog ammonium lossis quaternary ammonium ntsev hauv qhov cationic thiab carboxylate, sulfonate, thiab phosphate hom hauv qhov anionic. Piv txwv li, amino acid amphoteric surfactants nrog amino thiab segment pawg hauv tib lub molecule yog betaine amphoteric surfactants ua los ntawm cov ntsev sab hauv uas muaj ob qho tib si quaternary ammonium thiab carboxyl pawg, nrog ntau hom.

Qhov kev tso saib ntawm amphiphilic surfactants sib txawv nrog tus nqi pH ntawm lawv cov tshuaj.

Qhia txog cov yam ntxwv ntawm cationic surfactants hauv cov kua qaub; Qhia txog cov yam ntxwv ntawm anionic surfactants hauv cov alkaline; Qhia txog cov yam ntxwv ntawm non-ionic surfactants hauv cov kua nruab nrab. Lub ntsiab lus uas cov yam ntxwv cationic thiab anionic sib npaug zoo hu ua isoelectric point.

Ntawm qhov isoelectric point, cov amino acid hom amphoteric surfactants qee zaum precipitate, thaum betaine hom surfactants tsis yooj yim precipitate txawm tias ntawm qhov isoelectric point.

Hom BetaineCov surfactants tau raug cais ua cov ntsev ammonium quaternary, tab sis tsis zoo li cov ntsev ammonium quaternary, lawv tsis muaj anions.
Betaine tswj nws cov nqi molecular zoo thiab cov khoom cationic hauv cov kua qaub thiab alkaline. Hom surfactant no tsis tuaj yeem tau txais cov nqi zoo lossis tsis zoo. Raws li tus nqi pH ntawm cov kua dej ntawm hom tshuaj no, nws yog qhov tsim nyog los faib nws ua amphoteric surfactant tsis raug.

Raws li qhov kev sib cav no, cov tshuaj betaine yuav tsum tau muab faib ua cov cationic surfactants. Txawm hais tias muaj cov kev sib cav no, feem ntau cov neeg siv betaine compound tseem txuas ntxiv faib lawv ua cov tshuaj amphoteric. Hauv qhov ntau ntawm heteroelectricity, muaj cov qauv biphasic hauv kev ua haujlwm ntawm qhov chaw: R-N + (CH3) 2-CH2-COO -.

Piv txwv li feem ntau ntawm betaine hom surfactants yog alkylbetaine, thiab nws cov khoom sawv cev yog N-dodecyl-N, N-dimethyl-N-carboxyl betaine [BS-12, Cl2H25-N+(CH3)2-CH2COO-]. Betaine nrog amide pawg [Cl2H25 hauv cov qauv hloov los ntawm R-CONH - (CH2)3-] muaj kev ua tau zoo dua.

Qhov hardness ntawm dej tsis cuam tshuam rau qhov zoo ntawm cov dejbetainesurfactant. Nws tsim cov ua npuas dej zoo thiab ruaj khov zoo hauv ob qho dej mos thiab dej tawv. Ntxiv nrog rau kev sib xyaw nrog cov tshuaj anionic ntawm cov pH qis, nws kuj tseem siv tau ua ke nrog cov tshuaj anionic thiab cationic surfactants. Los ntawm kev sib xyaw betaine nrog anionic surfactants, qhov viscosity zoo tagnrho tuaj yeem ua tiav.