Kumvetsetsa Amphoteric Surfactants mu Nkhani Imodzi—— Mtundu wa Amino Acid ndi Mtundu wa Betaine

Ma surfactants a Amphoteric ndi ma surfactants omwe ali ndi magulu a anionic hydrophilic ndi magulu a cationic hydrophilic mu molekyulu imodzi. Khalidwe lawo lofunika kwambiri ndilakuti amatha kupereka ndikulandira ma proton. Ali ndi makhalidwe awa akagwiritsidwa ntchito: Ma surfactants a Amphoteric nthawi zambiri amakhala ndi magwiridwe antchito abwino pakutsuka, kufalitsa, kusakaniza, kuyeretsa, kufewetsa ulusi, komanso antistatic, ndipo angagwiritsidwe ntchito ngati othandizira kumaliza nsalu, othandizira utoto, osakaniza sopo wa calcium, ma surfactants owuma, ndi zoletsa dzimbiri zachitsulo, ndi zina zotero. Ali ndi zofewa zabwino, zosalala, komanso antistatic pa nsalu; zinthu zina zophera mabakiteriya ndi zoletsa nkhungu; komanso zinthu zabwino zophatikiza ndi kufalitsa. Komabe, mtundu uwu wa surfactant ndi wokwera mtengo, ndipo ntchito yake yeniyeni ndi yocheperako kuposa mitundu ina ya ma surfactants. Ndi surfactant yofatsa. Mosiyana ndi ma surfactants amodzi a anionic kapena cationic, mamolekyu a amphoteric surfactant ali ndi magulu a acidic komanso oyambira kumapeto kwa molekyulu. Magulu a acidic ambiri ndi a carboxyl, sulfonic acid, kapena phosphate groups, pomwe magulu oyambira ndi amino kapena quaternary ammonium groups. Amatha kusakanizidwa ndi anionic ndi nonionic surfactants ndipo amalimbana ndi ma acid, alkalis, mchere, ndi alkaline earth metal salts.

Pakadali pano, ma amphoteric surfactants omwe amagwiritsidwa ntchito kwambiri nthawi zambiri amakhala ndi magulu a carboxylate ngati ma anionic moieties awo, ndipo ochepa ali ndi magulu a sulfonate; ma cationic moieties awo nthawi zambiri amakhala amine salts kapena quaternary ammonium salts. Omwe ali ndi amine salts ngati ma cationic moiety amatchedwa amino acid type; omwe ali ndi quaternary ammonium salts ngati ma cationic moiety amatchedwa betaine type.

1. Mtundu wa amino acid

Madzi a amino acid amphoteric surfactants ndi a alkaline. Hydrochloric acid ikawonjezedwa pang'onopang'ono ndi kusakaniza, palibe kusintha komwe kumachitika pamene yankholo limakhala lopanda mbali. Precipitate imapangidwa pamene yankholo limakhala ndi asidi pang'ono. Ngati hydrochloric acid yochulukirapo yowonjezeredwa kuti yankholo likhale ndi asidi wambiri, precipitate imasungunukanso. Izi zikusonyeza kuti imagwira ntchito ngati anionic surfactant m'malo okhala ndi alkaline komanso ngati cationic surfactant m'malo okhala ndi acidic. Komabe, pamene cationic ndi anionic zili bwino pamalo a isoelectric, hydrophilicity imachepa, zomwe zimapangitsa kuti precipitate ipangidwe. Anion mu molekyulu ndi gulu la carboxyl, ndipo cation ndi mchere wa ammonium. Mtundu uwu wa surfactant umasonyeza zochitika zosiyanasiyana pamwamba ndi kusintha kwa pH ya medium. Mwachitsanzo, dodecylaminopropionic acid (C12H25N+H2CH2CH2COO-) ikhoza kusinthidwa kukhala sodium dodecylaminopropionate (C12H25NHCH2CH2COO-Na+) mu sodium hydroxide medium, imagwira ntchito ngati anionic surfactant yosungunuka m'madzi. Mu hydrochloric acid medium, imatha kusinthidwa kukhala hydrochloride salt ya dodecylaminopropionic acid [(C12H25N+H2CH2CH2COOH)Cl-], imagwira ntchito ngati cationic surfactant yosungunuka m'madzi. Ngati pH ya medium yasinthidwa kuti ma positive ndi negative charges akhale ofanana, imasinthidwa kukhala mchere wamkati (C12H25N+H2CH2CH2COO-), womwe sungasungunuke bwino m'madzi ndipo umatuluka. pH pamalopo imatchedwa isoelectric point. Kuti igwiritse ntchito mokwanira mphamvu ya amino acid-type amphoteric surfactants, iyenera kugwiritsidwa ntchito m'madzi okhala ndi pH yopatuka pa isoelectric point. Zipangizo zodziwika bwino zomwe zimagwiritsidwa ntchito pokonza ma amino acid-type amphoteric surfactants ndi monga ma aliphatic primary amines apamwamba, methyl acrylate (onani ma acrylate esters), acrylonitrile, ndi chloroacetic acid.

1. Bmtundu wa etaine

Ma surfactants a mtundu wa Betaine amphoteric ali ndi khalidwe lalikulu losungunuka m'madzi amadzi kaya ndi acidic, neutral kapena alkaline. Sagwa ngakhale pamalo a isoelectric. Kuphatikiza apo, ali ndi makhalidwe abwino monga kulowererapo, detergent komanso antistatic performance. Chifukwa chake, ndi ma emulsifier abwino komanso ofewetsa.

Carboxybetaine

Anion mu molekyulu ndi gulu la carboxyl, ndipo cation ndi gulu la ammonium la quaternary. Mwachitsanzo, alkyl dimethyl betaine [RN+(CH3)2CH2COO-], komwe gulu la alkyl R lili ndi maatomu 12 mpaka 18 a kaboni. Poyerekeza ndi mitundu ya amino acid, mitundu ya betaine imatha kusungunuka m'madzi mu acidic, neutral, kapena alkaline media, ndipo siigwa ngakhale pamalo a isoelectric, kotero ingagwiritsidwe ntchito mumadzi okhala ndi pH iliyonse. Mu acidic media, pamene pH ya malo a isoelectric ili yotsika, imagwira ntchito ngati surfactant yosungunuka m'madzi [[RN+(CH3)2CH2COOH]Cl-]; mu malo a neutral kapena alkaline media, mwachitsanzo, pamene pH ili yofanana kapena yokwera kuposa malo a isoelectric, imagwira ntchito ngati surfactant yosungunuka m'madzi ndipo sichita ngati surfactant ya anionic. Amphoteric surfactants nthawi zambiri amapanga ma precipitates ndi anionic surfactants okha mu malo a acidic media. Zingagwiritsidwe ntchito pamodzi ndi mtundu uliwonse wa surfactant mu media yokhala ndi pH zosiyanasiyana. Zipangizo zodziwika bwino zomwe zimagwiritsidwa ntchito popanga ma betaine-type amphoteric surfactants ndi monga alkyl dimethyl tertiary amines ndi sodium chloroacetate, ndi zina zotero.

Sulfobetaine

Gulu la anionic mu molekyulu ndi gulu la sulfo (SO3-), ndipo gulu la cationic ndi gulu la ammonium la quaternary. Omwe amagwiritsidwa ntchito kwambiri ndi alkyl dimethyl sulfonethyl betaines [RN+(CH3)2CH2CH2SO3-] ndi alkyl dimethyl sulfopropyl betaines [RN+(CH3)2CH2CH2CH2SO3-]. Chiwerengero cha maatomu a kaboni mu gulu la alkyl R mu ma formula chimayambira pa 12 mpaka 18. Sulfobetaines ali ndi makhalidwe ambiri; sikuti ali ndi ubwino wonse wa betaines wamba komanso ali ndi ubwino wapadera monga kukana kuchuluka kwa ma acid, alkalis, ndi mchere. Pakadali pano, hydroxy sulfopropyl [RN+(CH3)2CH2CH(OH)CH2SO3-] imagwiritsidwa ntchito m'malo mwa sulfopropyl betaines, zomwe zimapanga zinthu zovulaza thupi la munthu popanga. Chifukwa cha kukhalapo kwa magulu a anionic ndi cationic okhala ndi magulu a hydroxyl m'mapangidwe awo, sikuti ali ndi ubwino wonse wa amphoteric surfactants komanso amalimbana ndi kuchuluka kwa ma acid, alkali, ndi mchere, amateteza bwino ku zinthu zosagwirizana ndi chilengedwe, amabalalitsa, amabalalitsa, komanso amaletsa kusinthasintha kwa kutentha, komanso amapha mabakiteriya, amapha mabakiteriya, amapha mavairasi, komanso amapha mabakiteriya. Ndi ma surfactants omwe amagwira ntchito bwino kwambiri ndipo akhala akugwiritsidwa ntchito kwambiri m'magawo osiyanasiyana monga mankhwala a tsiku ndi tsiku, kusuntha kwa mafuta a m'munda wamafuta, kusweka, ndi kupangitsa kuti asidi alowe m'thupi.

Phospholipid betaine

Gulu la anionic mu molekyulu ndi gulu la phosphate (HPO4-), ndipo gulu la cationic ndi gulu la quaternary ammonium. Mwachitsanzo, alkyl dimethyl hydroxypropyl phosphate betaine [RN+(CH3)2CH2CH(OH)CH2HPO4-], komwe gulu la alkyl R lili ndi maatomu a kaboni 12 mpaka 18. Kapangidwe kameneka kamatsimikizira kuti sikuti kokha kali ndi makhalidwe abwino kwambiri a amphoteric surfactants monga kunyowa, detergent, solvent, emulsifying and dispersing properties, antistatic properties, thermal stability, komanso kugwirizana bwino, kuchepa kwa kuyabwa, komanso ubwino kuposa anionic surfactants monga alkali resistance yabwino, electrolyte resistance, ndi antistatic properties, komanso lili ndi calcium sopo dispersibility yamphamvu, kuchepa kwa mphamvu ya pamwamba, komanso kuchita bwino kwambiri kwa thovu.