Bipolar surfactants jẹ surfactants ti o ni mejeeji anionic ati awọn ẹgbẹ hydrophilic cationic.

Ni sisọ ni gbooro, awọn ohun elo amphoteric jẹ awọn agbo ogun ti o ni eyikeyi awọn ẹgbẹ hydrophilic meji laarin moleku kanna, pẹlu anionic, cationic, ati awọn ẹgbẹ hydrophilic nonionic. Awọn surfactants amphoteric ti o wọpọ julọ jẹ awọn ẹgbẹ hydrophilic pẹlu ammonium tabi awọn iyọ ammonium quaternary ni apakan cationic ati carboxylate, sulfonate, ati awọn oriṣi fosifeti ni apakan anionic. Fun apẹẹrẹ, amino acid amphoteric surfactants pẹlu amino ati awọn ẹgbẹ apakan ninu moleku kanna jẹ betaine amphoteric surfactants ti a ṣe lati inu iyọ inu ti o ni awọn ammonium quaternary mejeeji ati awọn ẹgbẹ carboxyl, pẹlu ọpọlọpọ awọn oriṣi.

Ifihan awọn surfactants amphiphilic yatọ pẹlu iye pH ti ojutu wọn.

Ifihan awọn ohun-ini ti awọn surfactants cationic ni media ekikan; Ifihan awọn ohun-ini ti awọn surfactants anionic ni media ipilẹ; Ṣe afihan awọn ohun-ini ti awọn surfactants ti kii-ionic ni media didoju. Ojuami nibiti awọn ohun-ini cationic ati anionic ti ni iwọntunwọnsi pipe ni a pe ni aaye isoelectric.

Ni aaye isoelectric, amino acid iru amphoteric surfactants nigbamiran ṣafẹri, lakoko ti iru betaine surfactants ko ni irọrun ni irọrun paapaa ni aaye isoelectric.

Iru BetaineSurfactants won lakoko classified bi quaternary ammonium iyọ agbo, sugbon ko quaternary ammonium iyọ, won ko ni anions.
Betaine n ṣetọju idiyele rere molikula rẹ ati awọn ohun-ini cationic ni ekikan ati media ipilẹ. Iru surfactant yii ko le gba awọn idiyele rere tabi odi. Da lori iye pH ti ojutu olomi ti iru agbo-ara yii, o jẹ ohun ti o bọgbọnwa lati ṣe lẹtọ rẹ bi ohun amphoteric surfactant ti ko tọ.

Ni ibamu si ariyanjiyan yii, iru awọn agbo ogun betain yẹ ki o jẹ ipin bi awọn surfactants cationic. Pelu awọn ariyanjiyan wọnyi, pupọ julọ awọn olumulo agbopọ betaine tẹsiwaju lati ṣe lẹtọ wọn bi awọn agbo ogun amphoteric. Ni ibiti o ti heteroelectricity, o wa biphasic be ni dada aṣayan iṣẹ-ṣiṣe: R-N + (CH3) 2-CH2-COO -.

Apeere ti o wọpọ julọ ti iru betain surfactants jẹ alkylbetain, ati ọja aṣoju rẹ jẹ N-dodecyl-N, N-dimethyl-N-carboxyl betaine [BS-12, Cl2H25-N + (CH3) 2-CH2COO -]. Betaine pẹlu awọn ẹgbẹ amide [Cl2H25 ninu eto ti rọpo nipasẹ R-CONH - (CH2) 3-] ni iṣẹ to dara julọ.

Lile omi ko ni ipa loribetainsurfactant. O ṣe agbejade foomu ti o dara ati iduroṣinṣin to dara ni mejeeji asọ ati omi lile. Ni afikun si sisọpọ pẹlu awọn agbo ogun anionic ni awọn iye pH kekere, o tun le ṣee lo ni apapo pẹlu anionic ati cationic surfactants. Nipa apapọ betaine pẹlu anionic surfactants, iki pipe le ṣee ṣaṣeyọri.