Feem ntau, ib theem ntawm emulsion yog dej los yog aqueous tov, uas yog hu ua aqueous theem; Lwm theem yog ib theem organic uas yog immiscible nrog dej, hu ua roj theem.

1 、 Kev faib tawm

Peb txoj kev faib tawm:

1. Muab faib los ntawm qhov chaw: cov khoom ntuj tsim thiab cov khoom siv hluavtaws;

2. Muab faib los ntawm qhov hnyav molecular: qis molecular hnyav emulsifiers (c10-c20) thiab siab molecular hnyav emulsifiers (c txhiab);

3. Raws li seb nws puas tuaj yeem ionize hauv cov tshuaj aqueous, nws tuaj yeem muab faib ua hom ionic (anions, cations, thiab anions thiab cations) thiab hom non-ionic.

Qhov no yog txoj kev faib ua feem ntau siv.

 

2, Kev ua haujlwm thiab lub hauv paus ntsiab lus ntawm emulsifiers

Lub luag haujlwm tseem ceeb ntawm emulsifiers yog los txo qhov nro ntawm ob lub kua ua emulsified. Yog li ntawd, thaum surfactants yog siv los ua emulsifiers, ib kawg ntawm lawv cov hydrophobic pawg adsorbs mus rau saum npoo ntawm insoluble kua hais (xws li roj), thaum lub hydrophilic pab pawg neeg txuas mus rau hauv dej. Surfactants yog directionally teem rau saum npoo ntawm cov kua dej los ua ib tug hydrophilic adsorption zaj duab xis (interfacial zaj duab xis), thiaj li yuav txo tau cov kev sib nrig sib attraction ntawm cov tee dej, txo cov nto nro ntawm ob theem, thiab txhawb kev sib nrig sib dispersion los tsim emulsions.

Qhov concentration ntawm surfactant muaj kev cuam tshuam ncaj qha rau lub zog ntawm lub ntsej muag ntsej muag interfacial. Nrog siab concentration, muaj ntau surfactant molecules adsorbed ntawm lub interface, tsim ib tug ntom thiab muaj zog interface lub ntsej muag daim npog qhov ncauj.

Cov emulsifiers sib txawv muaj cov teebmeem emulsification sib txawv, thiab tus nqi yuav tsum tau ua kom tiav cov txiaj ntsig zoo emulsification kuj txawv. Feem ntau hais lus, qhov ntau dua qhov molecular quab yuam ntawm emulsifier uas ua rau ciam teb daim npog ntsej muag, lub zog ntawm zaj duab xis ntau dua, thiab cov tshuaj pleev kom ruaj khov dua; Ntawm qhov tsis sib xws, lub zog me me, qhov qis ntawm zaj duab xis lub zog, thiab qhov tsis ruaj khov ntawm emulsion.

Thaum muaj cov polar organic molecules xws li fatty cawv, fatty acid thiab fatty amine nyob rau hauv lub ntsej muag daim npog qhov ncauj, lub zog ntawm daim nyias nyias yog ho txhim kho. Qhov no yog vim hais tias emulsifier molecules cuam tshuam nrog cov polar molecules xws li cawv, acid thiab amine nyob rau hauv lub interface adsorption txheej los tsim ib tug complex, uas ua rau kom lub zog ntawm lub interface lub ntsej muag daim npog qhov ncauj.

Cov emulsifier uas muaj ntau tshaj li ob lub surfactants yog cov emulsifier sib xyaw. Vim muaj kev sib cuam tshuam zoo ntawm cov molecules, qhov nro ntawm lub ntsej muag tau txo qis, tus nqi ntawm emulsifier adsorbed ntawm lub interface yog nce ntxiv, thiab qhov ceev thiab lub zog ntawm lub ntsej muag interfacial lub ntsej muag tau nce.

Thaum lub sij hawm tsim ntawm emulsion, lub interfacial nro ntawm cov roj thiab dej yog heev txo vim muaj kev koom tes ntawm surfactants, thiab nws ua ib tug ruaj khov emulsion. Txawm li cas los xij, tseem muaj roj-dej interfacial nro hauv emulsion uas tsis tuaj yeem ncav cuag xoom vim CMC lossis kev txwv tsis pub solubility. Yog li ntawd, tshuaj pleev ib ce yog ib qho thermodynamic tsis ruaj khov.

Lub interfacial nro ntawm cov roj thiab dej ntawm micro emulsion yog tsawg heev uas nws tsis tuaj yeem ntsuas. Nws yog ib qho thermodynamic ruaj khov system. Qhov no feem ntau yog ua tiav los ntawm kev ntxiv ob hom surfactant nrog cov khoom sib txawv kiag li (xws li cov cawv me me xws li pentanol, hexanol, thiab heptanol, hu ua co surfactants), uas tuaj yeem txo qhov cuam tshuam ntawm lub ntsej muag mus rau theem me me, txawm tias ua rau muaj txiaj ntsig tsis zoo tam sim ntawd. Qhov no tuaj yeem piav qhia los ntawm Gibbs 'kev sib npaug adsorption rau ntau lub tshuab hluav taws xob.

 

3. Hom emulsion

Hom

Feem ntau emulsion, ib theem yog dej los yog aqueous tov, thiab lwm yam yog cov organic teeb meem uas yog insoluble nrog dej, xws li roj, ciab, thiab lwm yam.emulsion tsim los ntawm dej thiab roj yuav muab faib ua peb hom:

(a) Roj hauv hom dej (O'W)
(e) Cov mis nyuj sib xyaw (W / O / W)
(b) Roj hauv hom dej (W / O)

(1) Roj / dej (0 / W) emulsion, roj dispersed hauv dej. Roj yog ib theem dispersed (thaum sab hauv), thiab dej yog ib tug tas mus li theem (sab nraud theem) roj nyob rau hauv dej emulsion, uas yuav diluted nrog dej. Xws li mis nyuj, taum pauv mis, thiab lwm yam.

(2) Dej / roj (W / 0) emulsion, dej dispersed hauv roj. Dej yog ib theem dispersed (thaum sab hauv) thiab roj yog ib theem txuas ntxiv (sab nraud theem) ntawm cov dej hauv cov roj emulsion. Hom emulsion no tuaj yeem diluted nrog roj. Xws li cov khoom siv butter, roj av, thiab lwm yam.

(3) Nplhaib zoo li emulsions, tsim los ntawm alternating dispersion ntawm dej thiab roj theem txheej txheej, feem ntau tuaj nyob rau hauv ob daim ntawv: roj nyob rau hauv dej thiab roj nyob rau hauv roj 0/W/0 (ie dej theem nrog dispersed roj droplets tshem tawm nyob rau hauv roj theem thiab dej nyob rau hauv roj thiab dej nyob rau hauv dej W / 0 / W (piv txwv li roj theem nrog dispersed dej nyob rau hauv cov dej tee susem) muaj nyob rau hauv cov roj crude.

 

Txoj kev kuaj xyuas hom emulsion

(1) Dilution method

Dilute lub emulsion nrog cov kua tib yam li cov theem tas mus li. Cov dej soluble emulsion yog roj / dej hom, thiab cov roj soluble emulsion yog dej / roj hom.
Piv txwv li, mis nyuj yuav diluted los ntawm dej, tab sis tsis tuaj yeem miscible nrog zaub roj. Nws tuaj yeem pom tias cov mis nyuj yog O / W emulsion.

(2) Txoj kev coj ua

Lub conductivity ntawm dej thiab roj sib txawv heev, thiab cov conductivity ntawm cov roj / dej emulsion yog ntau pua lub sij hawm loj dua cov dej / roj. Yog li ntawd, ob lub electrodes tau muab tso rau hauv emulsion thiab neon txuas nrog hauv cov voj voog, thiab roj / dej teeb yog nyob rau.

(3) Txoj kev Staining

Ntxiv 2-3 tee ntawm cov roj-raws li los yog dej-raws li dyes rau hauv lub raj kuaj, thiab txiav txim rau hom emulsion raws li hom dye tuaj yeem ua rau lub sijhawm tsis tu ncua sib npaug.

(4) Lim daim ntawv ntub txoj kev

Tso cov tshuaj pleev rau ntawm daim ntawv lim. Yog tias cov kua tuaj yeem nthuav dav sai thiab me me poob rau hauv qhov chaw, cov tshuaj pleev yog roj hauv dej; yog tias cov tshuaj pleev plhu tsis nthuav dav, cov roj hauv hom dej.

(5) Optical refraction method

Qhov sib txawv refractive index ntawm dej thiab roj rau lub teeb yog siv los txheeb xyuas hom emulsion. Yog tias cov emulsion yog roj hauv dej, cov khoom ua si lub luag haujlwm sib sau ua ke, thiab tsuas yog sab laug ntawm cov khoom tuaj yeem pom nrog lub tshuab tsom; Yog tias cov emulsion yog dej hauv cov roj, cov khoom ua si lub luag haujlwm ntawm astigmatism, thiab tsuas yog cov qauv zoo ntawm cov khoom tuaj yeem pom nrog lub tshuab tsom;

Cov yam tseem ceeb cuam tshuam rau hom emulsion

(1) Phase ntim:

Theem ntim txoj kev xav tau tawm tswv yim los ntawm 0stwald los ntawm geometric foundations. Qhov kev xav yog tias kev xav tias cov hlaws dej ntawm cov tshuaj pleev ib ce yog qhov loj thiab cov spheres, cov theem ntim feem ntawm cov kua hlaws tsuas tuaj yeem suav txog 74.02% ntawm tag nrho cov ntim thaum lawv ntim ntau tshaj plaws. Yog hais tias cov theem ntim ntawm cov kua hlaws dai yog ntau dua 74.02%, cov tshuaj pleev yuav deformed los yog puas.

(a) Uniform droplet nplua nuj pawg woven emulsion
(b) Tsis sib xws droplet ntom stacking emulsion
(c) Cov kua dej uas tsis yog kheej kheej yuav tsum tau stacking thiab emulsion (tsis ruaj khov)

Siv cov O / W hom emulsion ua piv txwv, yog tias cov theem ntawm cov roj ntau dua 74.02%, emulsion tsuas tuaj yeem tsim W / 0 hom, thaum O / i hom tsawg dua 25.98%, thiab thaum feem ntau yog 25.98% -74.02%, nws tuaj yeem tsim 0 / W lossis W0 hom.

 

Molecular Structure thiab Properties of Emulsifiers - Wedge Theory

Lub voj voog txoj kev xav yog ua raws cov qauv spatial ntawm emulsifiers los txiav txim seb hom emulsion. Lub voj voog txoj kev xav qhia tias qhov chaw hla ntu ntawm hydrophilic thiab hydrophobic pawg hauv emulsifiers tsis sib npaug. Cov molecules ntawm emulsifiers yog saib raws li wedges, nrog ib kawg loj thiab lwm yam me me. Qhov kawg me me ntawm cov emulsifier tuaj yeem muab tso rau hauv qhov chaw ntawm cov tee dej zoo li lub npoo thiab teeb tsa hauv kev taw qhia ntawm cov roj-dej interface. Lub hydrophilic polar kawg txuas mus rau theem aqueous, thaum lub lipophilic hydrocarbon saw txuas mus rau hauv cov roj theem, ua rau muaj zog interfacial ntxiv.

 

Kev cuam tshuam ntawm Emulsifier Khoom ntawm emulsion Hom

Ntxiv rau qhov cuam tshuam ntawm yam xws li emulsion muaj pes tsawg leeg cov ntaub ntawv thiab emulsion tsim cov xwm txheej, cov xwm txheej sab nraud kuj muaj kev cuam tshuam rau hom emulsion. Piv txwv li, qhov hydrophilic thiab lipophilic xwm ntawm phab ntsa emulsion muaj zog, thiab O / W emulsion yog ib qho yooj yim tsim thaum lub hydrophilic xwm ntawm emulsion phab ntsa muaj zog, thaum W / 0 emulsion yooj yim tsim thaum lipophilic xwm ntawm lub emulsion phab ntsa muaj zog. Yog vim li cas yog cov kua yuav tsum tau tswj ib txheej ntawm nruam theem ntawm phab ntsa, thiaj li hais tias nws tsis yooj yim rau dispersed mus rau hauv cov kua hlaws dai thaum nplawm. Iav yog hydrophilic thaum yas yog hydrophobic, yog li tus qub yog nquag tsim O / W emulsions thaum lub tom kawg yog nquag tsim W / 0 emulsions.

 

Txoj kev xav ntawm Aggregation Velocity ntawm Ob Theem

Lub coalescence ceev txoj kev xav pib los ntawm kev cuam tshuam ntawm coalescence ceev ntawm ob hom tee uas ua rau lub emulsion ntawm lub emulsion, thiab txiav txim hais tias lub coalescence ceev ntawm ob hom tee droplets nyob ntawm lub coalescence ceev ntawm ob hom tee thaum lub emulsion, shark, thiab tua ua ke npog npog.

 

Kub

Kev nce hauv qhov kub yuav txo qis cov dej ntawm cov pab pawg hydrophilic, yog li txo cov hydrophilicity ntawm molecules. Yog li, 0 / w emulsion tsim ntawm qhov kub qis yuav hloov mus rau W / 0 emulsion thaum cua sov. Qhov kev hloov pauv kub no yog qhov kub ntawm qhov kub ntawm qhov hydrophilic thiab lipophilic zog ntawm cov surfactant mus txog qhov tsim nyog sib npaug, hu ua theem hloov pauv kub PIT.

Txawm li cas los xij, thaum lub concentration ntawm emulsifier loj txaus los kov yeej cov khoom ntawm cov khoom ntub dej ntawm cov khoom siv emulsifier, hom emulsion tsim tsuas yog nyob ntawm qhov xwm ntawm emulsifier nws tus kheej thiab tsis muaj dab tsi ua rau hydrophilicity thiab lipophilicity ntawm phab ntsa hlab ntsha.