Zofunika Kwambiri
● Kusanthula kwa zosakaniza za binary sulfate-free surfactant kumafotokozedwa mwachiyeso.
● Zotsatira za pH, kapangidwe kake ndi kuchuluka kwa ayoni zimafufuzidwa mwadongosolo.
● Chiŵerengero cha kulemera kwa CAPB:SMCT surfactant cha 1:0.5 chimamanga kukhuthala kwakukulu kwa shear.
● Kuchuluka kwa mchere kumafunika kuti pakhale kukhuthala kwakukulu.
● Kutalika kwa micellar contour komwe kwapezeka kuchokera ku DWS kumagwirizana kwambiri ndi kukhuthala kwa shear.
Chidule
Pofuna kupeza mapulatifomu atsopano a surfactant opanda sulfate, ntchito yomwe ilipo pano imapereka imodzi mwa kafukufuku woyamba wa rheological wa aqueous Cocamidopropyl Betaine (CAPB)-Sodium Methyl Cocoyl Taurate (SMCT) mixtures pamitundu yosiyanasiyana, pH, ndi mphamvu ya ionic. Ma CAPB-SMCT aqueous solutions (kuchuluka kwa surfactant komwe kumagwira ntchito kwa 8–12 wt. %) adakonzedwa pamitundu ingapo ya kulemera kwa surfactant, kusinthidwa kukhala pH 4.5 ndi 5.5, ndikuwonjezeredwa ndi NaCl. Kuyeza kwa shear kokhazikika komanso kosasunthika kunayesa macroscopic shear viscosity, pomwe diffusing wave spectroscopy (DWS) microrheology idapereka ma frequency resolved viscoelastic moduli ndi ma specific micellar length scales. Pansi pa mikhalidwe yopanda mchere, ma formulations adawonetsa Newtonian rheology yokhala ndi ma maximal shear viscosities pa CAPB:SMCT weight ratio ya 1:0.5, zomwe zikusonyeza kukulitsa kwa cationic-anionic headgroup bridging. Kuchepetsa pH kuchokera pa 5.5 mpaka 4.5 kunapereka mphamvu yayikulu pa CAPB, motero kunakulitsa electrostatic complexation ndi fully anionic SMCT ndikupanga ma network olimba a micellar. Kuwonjezeredwa kwa mchere mwadongosolo kunasintha ma headgroup-headgroup repulsions, zomwe zinapangitsa kusintha kwa morphological kuchokera ku discrete micelles kupita ku aggregates ataliatali, ofanana ndi nyongolotsi. Zero-shear viscosities zinawonetsa maxima osiyana pa critical salt-to-surfactant ratios (R), zomwe zikuwonetsa bwino kwambiri pakati pa electrostatic double-layer screening ndi micellar elongation. DWS microrheology inatsimikizira izi, ndikuwulula ma Maxwellian spectra osiyana pa R ≥ 1, mogwirizana ndi njira zosweka-recombination zomwe zimayendetsedwa ndi reptation. Chodziwika bwino ndi chakuti, kutalika kwa entanglement ndi resistance kunakhalabe kosasintha ndi mphamvu ya ionic, pomwe kutalika kwa contour kunawonetsa mgwirizano wamphamvu ndi zero-shear viscosity. Zomwe zapezekazi zikugogomezera ntchito yofunika kwambiri ya kutalika kwa micellar ndi mgwirizano wa thermodynamic pakulamulira viscoelasticity yamadzimadzi, kupereka njira yopangira ma surfactants opanda sulfate omwe amagwira ntchito bwino kwambiri kudzera mu kuwongolera molondola kuchuluka kwa mphamvu, kapangidwe kake, ndi momwe zinthu zilili.
Chidule cha Zithunzi
Chiyambi
Machitidwe amadzi a binary surfactant okhala ndi mitundu yosiyanasiyana yamafuta amagwiritsidwa ntchito kwambiri m'magawo ambiri amafakitale, kuphatikiza zodzoladzola, mankhwala, mankhwala a agrochemicals, ndi mafakitale opangira chakudya. Kugwiritsa ntchito kwambiri machitidwewa kumachitika makamaka chifukwa cha magwiridwe antchito awo apamwamba a interfacial ndi rheological, zomwe zimathandiza kuti magwiridwe antchito aziyenda bwino m'njira zosiyanasiyana. Kudzipangira kwa ma surfactants otere kukhala ma aggregates ofanana ndi nyongolotsi, kumapereka mphamvu zosinthika kwambiri, kuphatikiza kuwonjezeka kwa viscoelasticity ndi kuchepa kwa mphamvu ya interfacial. Makamaka, kuphatikiza kwa ma surfactants a anionic ndi zwitterionic kumawonetsa kukulitsa kwa synergistic mu ntchito ya pamwamba, kukhuthala, ndi kusintha kwa mphamvu ya interfacial. Makhalidwe amenewa amachokera ku kuyanjana kwakukulu kwa electrostatic ndi steric pakati pa magulu a polar head ndi hydrophobic tails ya ma surfactants, mosiyana ndi machitidwe a single-surfactant, komwe mphamvu zamagetsi zonyansa nthawi zambiri zimachepetsa kukonza magwiridwe antchito.
Cocamidopropyl betaine (CAPB; SMILES: CCCCCCCCCCCC(=O)NCCN+ (C)CC([O−])=O) ndi amphoteric surfactant yomwe imagwiritsidwa ntchito kwambiri mu zodzoladzola chifukwa cha kuyeretsa kwake pang'ono komanso mphamvu zake zowongolera tsitsi. Kapangidwe ka zwitterionic ka CAPB kamathandiza kuti electrostatic synergy ndi anionic surfactants igwirizane, kukulitsa kukhazikika kwa thovu ndikulimbikitsa magwiridwe antchito apamwamba a formula. Kwa zaka makumi asanu zapitazi, zosakaniza za CAPB ndi sulfate-based surfactants, monga CAPB–sodium lauryl ether sulfate (SLES), zakhala maziko azinthu zosamalira thupi. Komabe, ngakhale kuti ma surfactants okhala ndi sulfate amagwira ntchito bwino, nkhawa zokhudzana ndi kuthekera kwawo kuyabwa pakhungu ndi kupezeka kwa 1,4-dioxane, chinthu chochokera mu njira ya ethoxylation, zapangitsa chidwi cha njira zina zopanda sulfate. Zosankha zabwino zimaphatikizapo ma surfactants okhala ndi amino acid, monga taurates, sarcosinates, ndi glutamates, zomwe zimasonyeza kuyanjana bwino kwa biocompatibility komanso mphamvu zofatsa [9]. Komabe, magulu akuluakulu a mitu ya polar a njira zinazi nthawi zambiri amalepheretsa mapangidwe a micellar omangika kwambiri, zomwe zimapangitsa kuti pakhale kugwiritsa ntchito ma rheological modifier.
Sodium methyl cocoyl taurate (SMCT; KUMWEtulira:
CCCCCCCCCCCC(=O)N(C)CCS(=O)(=O)O[Na]) ndi anionic surfactant yopangidwa ngati sodium salt kudzera mu amide coupling ya N-methyltaurine (2-methylaminoethanesulfonic acid) yokhala ndi kokonati-derived fatty acid chain. SMCT ili ndi gulu la taurine lolumikizidwa ndi amide pamodzi ndi gulu la anionic sulfonate, zomwe zimapangitsa kuti liwonongeke komanso ligwirizane ndi pH ya khungu, zomwe zimaiyika ngati yabwino kwambiri pakupanga ma sulfate opanda sulfate. Taurate surfactants amadziwika ndi mphamvu zawo zoyeretsera, kulimba mtima kwa madzi olimba, kufatsa, komanso kukhazikika kwa pH yayikulu.
Ma rheological parameters, kuphatikizapo shear viscosity, viscoelastic moduli, ndi yield stress, ndizofunikira kwambiri pakutsimikiza kukhazikika, kapangidwe, ndi magwiridwe antchito a zinthu zopangidwa ndi surfactant. Mwachitsanzo, shear viscosity yapamwamba imatha kusintha kusungidwa kwa substrate, pomwe yield stress imalamulira kutsata kwa mankhwalawa pakhungu kapena tsitsi pambuyo pogwiritsidwa ntchito. Ma macroscopic rheological features awa amasinthidwa ndi zinthu zambiri, kuphatikiza kuchuluka kwa surfactant, pH, kutentha, ndi kupezeka kwa co-solvents kapena zowonjezera. Oppositely charged surfactants amatha kusintha ma microstructural transitions osiyanasiyana, kuyambira spherical micelles ndi vesicles mpaka liquid crystalline phases, zomwe, zimakhudza kwambiri bulk rheology. Zosakaniza za amphoteric ndi anionic surfactants nthawi zambiri zimapanga ma micelles ataliatali ngati nyongolotsi (WLMs), zomwe zimawonjezera kwambiri viscoelastic properties. Chifukwa chake, kumvetsetsa ubale wa microstructure ndi katundu ndikofunikira kwambiri pakukonza magwiridwe antchito azinthu.
Kafukufuku wochuluka wafufuza machitidwe ofanana a binary, monga CAPB-SLES, kuti afotokoze maziko a microstructural a makhalidwe awo. Mwachitsanzo, Mitrinova et al. [13] adagwirizanitsa kukula kwa micelle (hydrodynamic radius) ndi solution viscosity mu CAPB-SLES-medium-chain co-surfactant mixtures pogwiritsa ntchito rheometry ndi dynamic light scattering (DLS). Mechanical rheometry imapereka chidziwitso pa kusintha kwa microstructural kwa ma mixture awa ndipo ikhoza kuwonjezeredwa ndi optical microrheology pogwiritsa ntchito diffusing wave spectroscopy (DWS) yomwe imakulitsa accessible frequency domain, kutenga short-timescale dynamics makamaka yogwirizana ndi WLM relaxation processes. Mu DWS microrheology, mean square displacement ya embedded colloidal probes imatsatiridwa pakapita nthawi, zomwe zimathandiza kuchotsa linear viscoelastic moduli ya medium yozungulira kudzera mu generalized Stokes-Einstein relation. Njirayi imafuna zitsanzo zochepa zokha ndipo motero ndi yopindulitsa pophunzira madzi ovuta omwe ali ndi zinthu zochepa, mwachitsanzo mapuloteni opangidwa. Kusanthula deta ya < Δr²(t)> kudutsa ma spectra afupipafupi kumathandiza kuwerengera magawo a micellar monga kukula kwa maukonde, kutalika kwa kulowerera, kutalika kwa kupirira, ndi kutalika kwa contour. Amin ndi ena adawonetsa kuti zosakaniza za CAPB-SLES zimagwirizana ndi zomwe Cates adaneneratu, kuwonetsa kuwonjezeka kwakukulu kwa kukhuthala ndi kuwonjezera mchere mpaka kuchuluka kwa mchere kofunikira, komwe kupitirira apo kukhuthala kumatsika kwambiri - yankho lofala m'machitidwe a WLM Xu ndi Amin adagwiritsa ntchito makina ozungulira ndi DWS kuti ayang'ane zosakaniza za SLES-CAPB-CCB, kuwulula yankho la Maxwellian rheological lomwe likuwonetsa kupangika kwa WLM yolumikizidwa, komwe kunatsimikiziridwanso ndi magawo a microstructural omwe adaganiziridwa kuchokera ku muyeso wa DWS. Pogwiritsa ntchito njira izi, kafukufuku wapano akuphatikiza makina ozungulira ndi DWS microrheology kuti afotokoze momwe kukonzanso kwa microstructural kumayendetsera khalidwe la CAPB-SMCT mixtures.
Poganizira kufunikira kwakukulu kwa mankhwala oyeretsera ofatsa komanso okhazikika, kufufuza kwa ma surfactants anionic opanda sulfate kwakula ngakhale kuti pali zovuta pakupanga. Mapangidwe osiyanasiyana a mamolekyu a machitidwe opanda sulfate nthawi zambiri amapereka mawonekedwe osiyanasiyana a rheological, zomwe zimapangitsa kuti njira zachikhalidwe zowonjezera kukhuthala monga mchere kapena polymeric thickening. Mwachitsanzo, Yorke et al. adafufuza njira zina zopanda sulfate mwa kufufuza mwadongosolo momwe thovu ndi rheological zimagwirizanirana ndi binary ndi ternary surfactant zomwe zili ndi alkyl olefin sulfonate (AOS), alkyl polyglucoside (APG), ndi lauryl hydroxysultaine. Chiŵerengero cha 1:1 cha AOS-sultaine chinawonetsa kuchepeta kwa shear ndi thovu mofanana ndi CAPB-SLES, zomwe zikusonyeza kupangika kwa WLM. Rajput et al. [26] adawunikanso anionic surfactant ina yopanda sulfate, sodium cocoyl glycinate (SCGLY), pamodzi ndi nonionic co-surfactants (cocamide diethanolamine ndi lauryl glucoside) kudzera mu DLS, SANS, ndi rheometry. Ngakhale kuti SCGLY yokha imapanga ma micelles ambiri ozungulira, kuwonjezera kwa ma co-surfactant kunathandiza kupanga mawonekedwe ovuta kwambiri a micellar, omwe amagwirizana ndi kusintha kwa pH.
Ngakhale kuti zinthu zapita patsogolo chonchi, kafukufuku wochepa kwambiri ndi amene wayang'ana kwambiri makhalidwe a rheological a machitidwe okhazikika opanda sulfate omwe amagwiritsa ntchito CAPB ndi taurates. Kafukufukuyu cholinga chake ndi kudzaza kusiyana kumeneku popereka chimodzi mwa zizindikiro zoyambirira za rheological za CAPB-SMCT binary system. Mwa kusintha kapangidwe ka surfactant, pH, ndi mphamvu ya ionic, tikufotokoza zinthu zomwe zimalamulira shear viscosity ndi viscoelasticity. Pogwiritsa ntchito mechanical rheometry ndi DWS microrheology, timayesa kukonzanso kwa microstructural komwe kumayambitsa khalidwe la shear la CAPB-SMCT mixtures. Zomwe zapezekazi zikufotokoza momwe pH, CAPB-SMCT ratio, ndi milingo ya ionic ikugwirizanirana kapena kuletsa mapangidwe a WLM, motero kupereka chidziwitso chothandiza pakusintha mawonekedwe a rheological a zinthu zokhazikika zopangidwa ndi surfactant kuti zigwiritsidwe ntchito m'mafakitale osiyanasiyana.
Nthawi yotumizira: Ogasiti-05-2025