Bipolar surfactants yog surfactants uas muaj ob pawg anionic thiab cationic hydrophilic.

Hais dav dav, amphoteric surfactants yog cov tebchaw uas muaj ob pawg hydrophilic nyob rau hauv tib lub molecule, suav nrog anionic, cationic, thiab nonionic hydrophilic pawg. Cov feem ntau siv amphoteric surfactants yog feem ntau hydrophilic pawg nrog ammonium los yog quaternary ammonium ntsev nyob rau hauv cationic ib feem thiab carboxylate, sulfonate, thiab phosphate hom nyob rau hauv lub anionic ib feem. Piv txwv li, amino acid amphoteric surfactants nrog cov amino thiab ntu pawg hauv tib lub molecule yog betaine amphoteric surfactants ua los ntawm cov ntsev sab hauv uas muaj ob pawg quaternary ammonium thiab carboxyl, nrog ntau hom.

Cov zaub ntawm amphiphilic surfactants txawv nrog pH tus nqi ntawm lawv cov tshuaj.

Qhia cov khoom ntawm cationic surfactants hauv acidic media; Qhia cov khoom ntawm anionic surfactants hauv alkaline xov xwm; Tso cov khoom ntawm non-ionic surfactants hauv nruab nrab xov xwm. Lub ntsiab lus uas cationic thiab anionic zog zoo kawg nkaus sib npaug yog hu ua isoelectric point.

Ntawm qhov taw tes isoelectric, amino acid hom amphoteric surfactants qee zaum los nag, thaum betaine hom surfactants tsis yooj yim precipitated txawm nyob rau ntawm isoelectric point.

Betaine homsurfactants tau xub muab faib ua quaternary ammonium ntsev tebchaw, tab sis tsis zoo li quaternary ammonium ntsev, lawv tsis muaj anions.
Betaine tuav nws cov nqi zoo molecular thiab cationic zog hauv acidic thiab alkaline xov xwm. Hom surfactant no tsis tuaj yeem tau txais cov nqi zoo lossis tsis zoo. Raws li tus nqi pH ntawm cov tshuaj aqueous ntawm hom kev sib xyaw no, nws tsim nyog los faib nws ua amphoteric surfactant tsis raug.

Raws li qhov kev sib cav no, betaine hom compounds yuav tsum tau muab cais ua cationic surfactants. Txawm hais tias cov lus sib cav no, feem ntau cov neeg siv betaine compound txuas ntxiv muab faib ua cov tshuaj amphoteric. Nyob rau hauv qhov ntau ntawm heteroelectricity, muaj ib tug biphasic qauv nyob rau hauv cov dej num: R-N + (CH3) 2-CH2-COO -.

Feem ntau piv txwv ntawm betaine hom surfactants yog alkylbetaine ua, 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 yog hloov los ntawm R-CONH - (CH2) 3-] muaj kev ua tau zoo dua.

Cov dej hardness tsis cuam tshuam raubetaine uasurfactant. Nws ua tau zoo ua npuas ncauj thiab zoo stability nyob rau hauv ob qho tib si mos thiab tawv dej. Ntxiv nrog rau kev sib xyaw nrog anionic tebchaw ntawm pH qis, nws tuaj yeem siv ua ke nrog anionic thiab cationic surfactants. Los ntawm kev sib xyaw betaine nrog anionic surfactants, qhov zoo tshaj plaws viscosity tuaj yeem ua tiav.