Okuvelele
● I-Rheology yezingxube ze-surfactant ezingenayo i-sulfate ezimbili ichazwa ngokuhlola.
● Imiphumela ye-pH, ukwakheka kanye nokuhlushwa kwe-ionic kuhlolisiswa ngendlela ehlelekile.
● Isilinganiso sesisindo se-surfactant se-CAPB:SMCT esingu-1:0.5 sakha i-viscosity ephezulu kakhulu ye-shear.
● Kudingeka ukuhlushwa okukhulu kukasawoti ukuze kufezwe ukujiya okuphezulu.
● Ubude be-contour ye-micellar obuthathwe ku-DWS buhlobene kakhulu ne-shear viscosity.
Isifinyezo
Ekufuneni amapulatifomu esizukulwane esilandelayo e-surfactant angenayo i-sulfate, umsebenzi wamanje unikeza olunye lwezinhlolovo zokuqala ezihlelekile ze-rheological zezingxube zamanzi ze-Cocamidopropyl Betaine (CAPB)-Sodium Methyl Cocoyl Taurate (SMCT) kuzo zonke izinhlobo, i-pH, kanye namandla e-ionic. Izixazululo zamanzi ze-CAPB-SMCT (inani eliphelele le-surfactant elisebenzayo elingu-8–12 wt. %) zalungiswa ngezilinganiso eziningana zesisindo se-surfactant, zalungiswa ku-pHs 4.5 no-5.5, futhi zafakwa i-tit nge-NaCl. Ukulinganiswa kwe-shear okuzinzile nokuguquguqukayo kwalinganisa i-macroscopic shear viscosity, kuyilapho i-diffusing wave spectroscopy (DWS) microrheology inikeze i-viscoelastic moduli exazululiwe kaningi kanye nezikali zobude be-micellar ezihlukile. Ngaphansi kwezimo ezingenasawoti, ukwakheka kwabonisa i-Newtonian rheology ene-maximal shear viscosities ku-CAPB:SMCT weight ratio engu-1:0.5, okubonisa ukuqiniswa kwe-cationic-anionic headgroup bridging ethuthukisiwe. Ukwehlisa i-pH kusuka ku-5.5 kuya ku-4.5 kunikeze i-net positive charge enkulu ku-CAPB, ngaleyo ndlela kwandisa i-electrostatic complexation nge-anionic SMCT ephelele futhi kwakha amanethiwekhi e-micellar aqinile. Ukwengezwa kwe-systematic salt kushintshe ukuxoshwa kwe-headgroup-headgroup, okuqhuba ukuvela kwe-morphological kusuka kuma-micelles ahlukene kuya kuma-aggregates amade, afana nezikelemu. Ukuqina kwe-Zero-shear kubonise i-maxima ehlukile kuma-critical salt-to-surfactant ratios (R), kugqamisa ibhalansi eyinkimbinkimbi phakathi kokuhlolwa kwe-electrostatic double-layer kanye ne-micellar elongation. I-DWS microrheology iqinisekisile lokhu kubonwa kwe-macroscopic, kwembula ama-spectra ahlukile e-Maxwellian ku-R ≥ 1, okuhambisana nezindlela zokuphinda zihlukaniswe ngokuphindaphindwa. Okuphawulekayo ukuthi ubude bokunamathelana kanye nokuphikelela buhlale bungaguquguquki ngamandla e-ionic, kuyilapho ubude be-contour bubonise ubudlelwano obuqinile ne-zero-shear viscosity. Lokhu okutholakele kugcizelela indima ebalulekile yokwandiswa kwe-micellar kanye nokusebenzisana kwe-thermodynamic ekulawuleni i-viscoelasticity yoketshezi, okuhlinzeka ngohlaka lobunjiniyela be-surfactants ezingenayo i-sulfate esebenza kahle ngokulawula okunembile kobuningi beshaja, ukwakheka, kanye nezimo ze-ionic.
Isifinyezo Sezithombe
Isingeniso
Izinhlelo ze-surfactant ezinamanzi eziqukethe izinhlobo ezishaja ngokuphambene zisetshenziswa kakhulu emikhakheni eminingi yezimboni, kufaka phakathi izimonyo, imithi, amakhemikhali ezolimo, kanye nezimboni zokucubungula ukudla. Ukwamukelwa kabanzi kwalezi zinhlelo kubangelwa kakhulu ukusebenza kwazo okuphezulu kwe-interfacial kanye ne-rheological, okuvumela ukusebenza okuthuthukisiwe ekwakhiweni okuhlukahlukene. Ukuhlangana kwe-synergistic kwama-surfactants anjalo abe ama-aggregates afana nezibungu, ahlanganisiwe kunikeza izakhiwo ze-macroscopic eziguquguqukayo kakhulu, kufaka phakathi ukwanda kwe-viscoelasticity kanye nokuncipha kokucindezeleka kwe-interfacial. Ikakhulukazi, inhlanganisela yama-surfactants e-anionic kanye ne-zwitterionic ibonisa ukuthuthukiswa kwe-synergistic emsebenzini wobuso, i-viscosity, kanye nokuguquguquka kokucindezeleka kwe-interfacial. Lokhu kuziphatha kuvela ekusebenzisaneni okuqinile kwe-electrostatic kanye ne-steric phakathi kwamaqembu ekhanda le-polar kanye nemisila ye-hydrophobic yama-surfactants, okungafani nezinhlelo ze-single-surfactant, lapho amandla e-electrostatic axoshayo evame ukukhawulela ukusebenza kahle.
I-Cocamidopropyl betaine (CAPB; SMILES: I-CCCCCCCCCC(=O)NCCCN+ (C)CC([O−])=O) iyi-surfactant esetshenziswa kakhulu ekwenziweni kwezimonyo ngenxa yokusebenza kwayo okuthambile kokuhlanza kanye nezakhiwo zokulungisa izinwele. Imvelo ye-zwitterionic ye-CAPB ivumela ukusebenzisana kwe-electrostatic nama-surfactants e-anionic, okuthuthukisa ukuqina kwe-foam nokukhuthaza ukusebenza okuphezulu kokwakheka. Eminyakeni engamashumi amahlanu edlule, izingxube ze-CAPB nama-surfactants asekelwe ku-sulfate, njenge-CAPB–sodium lauryl ether sulfate (SLES), ziye zaba yisisekelo emikhiqizweni yokunakekelwa komuntu siqu. Kodwa-ke, naphezu kokusebenza kahle kwama-surfactants asekelwe ku-sulfate, ukukhathazeka mayelana nekhono lawo lokucasuka kwesikhumba kanye nokuba khona kwe-1,4-dioxane, umkhiqizo wenqubo ye-ethoxylation, kuye kwabangela intshisekelo kwezinye izindlela ezingenayo i-sulfate. Izinketho ezithembisayo zifaka ama-surfactants asekelwe ku-amino-acid, njenge-taurates, ama-sarcosinates, nama-glutamate, abonisa ukuhambisana okuthuthukisiwe kwe-bio kanye nezakhiwo ezithambile [9]. Noma kunjalo, amaqembu amakhulu ekhanda le-polar alezi zindlela avame ukuvimbela ukwakheka kwezakhiwo ze-micellar ezibambeke kakhulu, okudinga ukusetshenziswa kwe-rheological modifiers.
I-Sodium methyl cocoyl taurate (SMCT; UKUMOMOTHEKA:
I-CCCCCCCCCCCC(=O)N(C)CCS(=O)(=O)O[Na]) iyi-anionic surfactant eyenziwe njengosawoti we-sodium ngokusebenzisa i-amide coupling ye-N-methyltaurine (2-methylaminoethanesulfonic acid) ene-coconut-derived fatty acid chain. I-SMCT ineqembu le-taurine elixhunywe yi-amide eceleni kweqembu le-sulfonate elinamandla kakhulu, okwenza libole futhi lihambisane ne-pH yesikhumba, eliyibeka njengomuntu othembisayo we-formulations ezingenayo i-sulfate. Ama-surfactant e-Taurate abonakala ngokuhlanzeka kwawo okunamandla, ukuqina kwamanzi aqinile, ubumnene, kanye nokuqina kwe-pH ebanzi.
Amapharamitha e-rheological, kufaka phakathi i-shear viscosity, i-viscoelastic moduli, kanye nokucindezeleka kwe-yield, abalulekile ekunqumeni ukuzinza, ukuthungwa, kanye nokusebenza kwemikhiqizo esekelwe ku-surfactant. Isibonelo, i-shear viscosity ephezulu ingathuthukisa ukugcinwa kwe-substrate, kuyilapho i-yield stress ilawula ukunamathela kwefomula esikhumbeni noma ezinweleni ngemuva kokusetshenziswa. Lezi zimfanelo ze-rheological ze-macroscopic ziguqulwa yizici eziningi, kufaka phakathi ukuhlushwa kwe-surfactant, i-pH, izinga lokushisa, kanye nokuba khona kwe-co-solvents noma izithasiselo. Ama-surfactants ashajelwe ngokuphambene angadlula ezinguqukweni ezahlukahlukene ze-microstructural, kusukela kuma-micelles ayindilinga nama-vesicles kuya ezigabeni ze-crystalline eziwuketshezi, ezithinta kakhulu i-bulk rheology. Izingxube zama-surfactants e-amphoteric kanye ne-anionic zivame ukwakha ama-micelles amade afana ne-worm (WLMs), athuthukisa kakhulu izakhiwo ze-viscoelastic. Ngakho-ke, ukuqonda ubudlelwano be-microstructure-property kubalulekile ekwenzeni ngcono ukusebenza komkhiqizo.
Izifundo eziningi zokuhlola zihlole izinhlelo ezifanayo ze-binary, njenge-CAPB-SLES, ukuze kucaciswe isisekelo sesakhiwo sezakhiwo zazo. Isibonelo, uMitrinova nabanye [13] bahlobanise usayizi we-micelle (i-hydrodynamic radius) ne-viscosity yesisombululo ku-CAPB-SLES-medium-chain co-surfactant mixes esebenzisa i-rheometry kanye ne-dynamic light scattering (DLS). I-rheometry yemishini inikeza ukuqonda ngokuvela kwesakhiwo sezakhiwo zalezi zingxube futhi ingandiswa yi-optical microrheology isebenzisa i-diffusing wave spectroscopy (DWS) eyandisa isizinda semvamisa esifinyelelekayo, ibamba i-dynamics yesikhathi esifushane ehlobene kakhulu nezinqubo zokuphumula ze-WLM. Ku-DWS microrheology, ukufuduka kwesikwele okumaphakathi kwama-probe e-colloidal ahlanganisiwe kulandelwa ngokuhamba kwesikhathi, okuvumela ukukhishwa kwe-moduli ye-viscoelastic eqondile ye-medium ezungezile ngokusebenzisa ubudlelwano obujwayelekile be-Stokes-Einstein. Le ndlela idinga amavolumu amancane kuphela esampula futhi ngaleyo ndlela inenzuzo yokufunda uketshezi oluyinkimbinkimbi olunokutholakala okulinganiselwe kwezinto, isib. ukwakheka okusekelwe kumaprotheni. Ukuhlaziywa kwedatha ye-< Δr²(t)> kuwo wonke ama-spectra e-wide frequency kwenza kube lula ukuqagela amapharamitha e-micellar njengosayizi we-mesh, ubude bokuxinana, ubude bokuphikelela, kanye nobude be-contour. U-Amin nabanye babonise ukuthi izingxube ze-CAPB-SLES zivumelana nezibikezelo ezivela kumbono kaCates, okubonisa ukwanda okukhulu kwe-viscosity ngokufakwa kosawoti kuze kube yilapho ukuhlushwa kukasawoti okubalulekile, okungaphezu kwalokho i-viscosity yehla ngokushesha—impendulo evamile ezinhlelweni ze-WLM u-Xu no-Amin basebenzise i-mechanical rheometry kanye ne-DWS ukuhlola izingxube ze-SLES-CAPB-CCB, okwembula impendulo ye-Maxwellian rheological ekhombisa ukwakheka kwe-WLM ehlanganisiwe, okwaqinisekiswa ngokwengeziwe ngamapharamitha e-microstructural atholwe ezilinganisweni ze-DWS. Ngokwakhela phezu kwalezi zindlela, ucwaningo lwamanje luhlanganisa i-mechanical rheometry kanye ne-DWS microrheology ukuze kucaciswe ukuthi ukuhlelwa kabusha kwe-microstructural kuqhuba kanjani ukuziphatha kwe-shear kwezingxube ze-CAPB-SMCT.
Ngenxa yokwanda kwesidingo sama-agent okuhlanza athambile futhi ahlala isikhathi eside, ukuhlolwa kwama-surfactants anionic angenayo i-sulfate kuye kwanda naphezu kwezinselele zokwakheka. Ukwakheka kwama-molecule ahlukene kwezinhlelo ezingenayo i-sulfate kuvame ukuveza amaphrofayili e-rheological ahlukene, okwenza kube nzima amasu avamile okuthuthukisa i-viscosity njengosawoti noma ukuqina kwe-polymeric. Isibonelo, uYorke et al. bahlole ezinye izindlela ezingezona i-sulfate ngokuphenya ngokuhlelekile izakhiwo ze-foam kanye ne-rheological zezingxube ze-surfactant ezimbili nezintathu ezine-alkyl olefin sulfonate (AOS), i-alkyl polyglucoside (APG), kanye ne-lauryl hydroxysultaine. Isilinganiso esingu-1:1 se-AOS-sultaine sibonise izici ze-shear-thinning kanye ne-foam ezifana ne-CAPB-SLES, okubonisa ukwakheka kwe-WLM. URajput et al. [26] bahlole enye i-surfactant anionic engenayo i-sulfate, i-sodium cocoyl glycinate (SCGLY), kanye ne-nonionic co-surfactants (i-cocamide diethanolamine kanye ne-lauryl glucoside) nge-DLS, i-SANS, kanye ne-rheometry. Nakuba i-SCGLY yodwa yakha ama-micelles ayindilinga kakhulu, ukwengeza ama-co-surfactant kwenze kwaba nokwakhiwa kwe-mofology ye-micellar eyinkimbinkimbi kakhulu, evumelana nokuguquguquka okuqhutshwa yi-pH.
Naphezu kwalezi ntuthuko, ucwaningo oluncane kakhulu luye lwagxila ezicini ze-rheological zezinhlelo ezingenayo i-sulfate ezizinzile ezihilela i-CAPB kanye ne-taurates. Lolu cwaningo luhlose ukugcwalisa lesi sikhala ngokunikeza esinye sezimpawu zokuqala ze-rheological ezihlelekile zesistimu ye-CAPB-SMCT binary. Ngokushintshashintsha okuhlelekile ukwakheka kwe-surfactant, i-pH, kanye namandla e-ionic, sichaza izici ezilawula i-shear viscosity kanye ne-viscoelasticity. Sisebenzisa i-mechanical rheometry kanye ne-DWS microrheology, silinganisa ukuhlelwa kabusha kwesakhiwo esingaphansi kokuziphatha kwe-shear kwezingxube ze-CAPB-SMCT. Lokhu okutholakele kuchaza ukusebenzisana phakathi kwe-pH, isilinganiso se-CAPB-SMCT, kanye namazinga e-ionic ekukhuthazeni noma ekuvimbeleni ukwakheka kwe-WLM, ngaleyo ndlela sinikeza ukuqonda okusebenzayo kokulungisa amaphrofayili e-rheological emikhiqizo esuselwe ku-surfactant eqhubekayo ukuze kusetshenziswe izimboni ezahlukahlukene.
Isikhathi sokuthunyelwe: Agasti-05-2025