Tsis muaj cov ntsiab lus hauv qhov uas ntshiab. Yeej, lawv yog tag nrho cov mixs. Lawv, nyob rau hauv lem, yuav ua tau heterogeneous los yog homogeneous. Lawv yog tsim los ntawm cov khoom nyob rau hauv lub xeev ntawm aggregation, yog li tsim ib tug tej yam dispersion system nyob rau hauv uas muaj ntau theem. Tsis tas li ntawd, cov khoom sib tov feem ntau muaj qhov nruab nrab dispersion. Nws lub ntsiab lus yog nyob rau hauv qhov tseeb hais tias nws yog suav hais tias yog ib qho tseem ceeb nrog ib tug loj ntim nyob rau hauv uas ib co tshuaj yog faib. Nyob rau hauv ib tug dispersed system, lub theem thiab nruab nrab yog nyob rau hauv xws li ib tug txoj kev uas muaj ib tug hais ntawm interface ntawm lawv. Yog li ntawd, nws yog hu ua heterogeneous los yog heterogeneous. Raws li qhov no, qhov kev txiav txim ntawm qhov chaw, thiab tsis yog cov khoom tag nrho, yog qhov tseem ceeb heev.
Disperse system classification
Phase, raws li koj paub, yog sawv cev los ntawm cov khoom uas muaj lub xeev sib txawv. Thiab cov ntsiab lus no tau muab faib ua ntau hom. Lub xeev ntawm aggregation ntawm lub dispersed theem nyob ntawm kev sib xyaw ua ke ntawmib puag ncig, ua rau 9 hom tshuab:
- Gas. Ua kua, khoom thiab lub ntsiab lus nug. Homogeneous sib tov, pos huab, plua plav, aerosols.
- Kua dispersed theem. Gas, khoom, dej. Ua npuas ncauj, emulsions, sols.
- Tshuaj dispersed. Ua kua, roj thiab cov khoom siv hauv qhov no. Av, txhais tau tias hauv tshuaj lossis tshuaj pleev ib ce, pob zeb.
Raws li txoj cai, qhov loj ntawm qhov kev sib cais yog txiav txim siab los ntawm qhov loj ntawm cov theem hais. Muaj kev faib tawm hauv qab no:
- ntxhi (txheej txheem);
- thin (colloidal thiab cov ntsiab lus tseeb).
Particles ntawm dispersion system
Thaum tshuaj xyuas cov sib tov ntxhib, ib tus tuaj yeem pom tias cov khoom ntawm cov khoom sib txuas hauv cov qauv tuaj yeem pom ntawm qhov muag liab qab, vim qhov tseeb tias lawv qhov loj me yog ntau tshaj 100 nm. Suspensions, raws li txoj cai, xa mus rau ib qho system uas cov theem dispersed yog cais los ntawm qhov nruab nrab. Qhov no yog vim lawv suav hais tias yog opaque. Kev tshem tawm tau muab faib ua emulsions (cov kua dej tsis txaus), aerosols (cov khoom zoo thiab cov khib nyiab), tshem tawm (cov khoom hauv dej).
Ib yam khoom colloidal yog txhua yam uas muaj qhov zoo uas muaj lwm yam sib npaug sib npaug ntawm nws. Uas yog, nws yog tam sim no, los yog, nws yog ib feem ntawm lub dispersed theem. Qhov no yog lub xeev thaum ib yam khoom raug faib tag nrho rau lwm qhov, lossis hauv nws qhov ntim. Hauv cov piv txwv mis nyuj, kua roj yog dispersed nyob rau hauv ib tug aqueous tov. Hauv qhov no, qhov me me molecule nyob hauv 1nanometer thiab 1 micrometer, ua rau nws pom tsis tau rau lub tshuab ntsuas qhov muag thaum sib tov ua homogeneous.
Ntawd yog, tsis muaj ib feem ntawm kev daws teeb meem muaj ntau dua lossis tsawg dua ntawm cov txheej txheem tawg dua li lwm yam. Peb tuaj yeem hais tias nws yog colloidal hauv qhov xwm txheej. Qhov loj dua yog hu ua ntu txuas ntxiv lossis qhov nruab nrab dispersion. Txij li thaum nws qhov loj me thiab kev faib tawm tsis hloov pauv, thiab cov ntsiab lus hauv nqe lus nug tau muab faib rau nws. Hom colloids muaj xws li aerosols, emulsions, foams, dispersions, thiab sib tov hu ua hydrosols. Txhua qhov system no muaj ob theem: ib qho tawg thiab ib ntu txuas ntxiv.
Colloids los ntawm keeb kwm
Kev txaus siab rau cov khoom no muaj nyob hauv txhua qhov kev tshawb fawb thaum pib ntawm lub xyoo pua 20th. Einstein thiab lwm tus kws tshawb fawb ua tib zoo kawm lawv cov yam ntxwv thiab kev siv. Thaum lub sijhawm, qhov kev tshawb fawb tshiab no yog qhov chaw tshawb fawb rau cov kws tshawb fawb, cov kws tshawb fawb thiab cov tuam txhab tsim khoom. Tom qab qhov siab tshaj plaws ntawm kev txaus siab txog xyoo 1950, kev tshawb fawb txog colloids poob qis heev. Nws yog qhov nthuav kom nco ntsoov tias txij li tsis ntev los no tau tshwm sim ntawm ntau lub hwj chim microscopes thiab "nanotechnologies" (kev kawm ntawm cov khoom ntawm qee qhov me me), tau muaj kev txaus siab rau kev tshawb fawb tshiab hauv kev kawm ntawm cov ntaub ntawv tshiab.
Ntau txog cov tshuaj no
Muaj cov ntsiab lus pom ob qho tib si hauv cov xwm txheej thiab hauv cov kev daws teeb meem uas muaj cov khoom siv colloidal. Piv txwv li, mayonnaise, tshuaj pleev ib ce, thiab lubricants yog hom khoom emulsions, thiab mis nyuj yog qhov zoo sib xws.ib tug sib tov pom nyob rau hauv cov xwm. Colloidal foams suav nrog whipped cream thiab shaving ua npuas ncauj, thaum cov khoom noj muaj xws li butter, marshmallows, thiab jelly. Ntxiv nrog rau cov khoom noj, cov tshuaj no muaj nyob rau hauv daim ntawv ntawm tej yam alloys, xim, inks, detergents, insecticides, aerosols, styrofoam, thiab roj hmab. Txawm tias cov khoom zoo nkauj zoo li huab, hlaws thiab opals muaj cov khoom sib xyaw ua ke vim tias lawv muaj lwm yam khoom sib npaug ntawm lawv.
Tau txais cov khoom sib xyaw colloidal
Los ntawm kev nce cov molecules me me mus rau thaj tsam ntawm 1 txog 1 micrometer, lossis los ntawm kev txo cov khoom loj rau tib qhov loj. Colloidal tshuaj tuaj yeem tau txais. Ntxiv ntau lawm yog nyob ntawm hom khoom siv nyob rau hauv lub dispersed thiab tas mus li theem. Colloids coj txawv dua li cov kua li niaj zaus. Thiab qhov no tau pom nyob rau hauv kev thauj mus los thiab physico-chemical zog. Piv txwv li, ib daim nyias nyias yuav tso cai rau ib qho kev daws teeb meem nrog cov khoom molecules txuas nrog cov kua molecules kom dhau los ntawm nws. Thaum cov khoom colloidal uas muaj cov khoom tawg los ntawm cov kua yuav raug ncab los ntawm daim nyias nyias. Qhov sib luag ntawm kev faib khoom yog sib xws mus txog qhov sib npaug ntawm qhov sib npaug ntawm qhov sib npaug ntawm qhov sib txawv ntawm tag nrho cov khoom thib ob.
Cov ntsiab lus tseeb
Colloid dispersion yog sawv cev raws li homogeneous sib tov. Lub caij muaj ob lub tshuab: ntu ntu thiab tawg. Qhov no qhia tau hais tias cov ntaub ntawv no muaj feem xyuam nrogcov kev daws teeb meem tiag tiag, vim hais tias lawv muaj feem cuam tshuam ncaj qha rau cov khoom sib xyaw saum toj no, muaj ntau yam khoom siv. Nyob rau hauv ib tug colloid, qhov thib ob muaj cov qauv ntawm cov me me hais los yog tee, uas yog tusyees faib nyob rau hauv thawj. Los ntawm 1 nm mus rau 100 nm yog qhov loj me uas tsim cov theem dispersed, los yog cov khoom, nyob rau hauv tsawg kawg yog ib qhov ntev. Nyob rau hauv no ntau yam, lub dispersed theem yog homogeneous sib tov nrog rau qhov ntau thiab tsawg, peb muaj peev xwm npe approximate ntsiab uas haum cov lus piav qhia: colloidal aerosols, emulsions, foams, hydrosols. Muaj feem cuam tshuam los ntawm cov tshuaj muaj pes tsawg leeg ntawm qhov chaw yog cov khoom lossis cov tee tam sim no hauv cov qauv hauv nqe lus nug.
Cov kev daws teeb meem thiab cov tshuab
Ib tug yuav tsum coj mus rau hauv tus account qhov tseeb hais tias qhov luaj li cas ntawm lub dispersed theem yog ib tug nyuaj-rau-kev ntsuas qhov sib txawv nyob rau hauv lub system. Cov kev daws teeb meem yog qee zaum tus cwj pwm los ntawm lawv tus kheej cov khoom. Txhawm rau ua kom yooj yim rau kev nkag siab cov ntsuas ntawm cov khoom sib xyaw, cov colloids zoo li lawv thiab yuav luag zoo ib yam. Piv txwv li, yog hais tias nws muaj ib tug kua-dispersed, khoom daim ntawv. Yog li ntawd, cov khoom yuav tsis dhau los ntawm daim nyias nyias. Thaum lwm yam khoom xws li yaj ions lossis molecules tuaj yeem dhau los ntawm nws. Yog tias nws yooj yim dua los txheeb xyuas, nws hloov tawm tias cov khoom tawg tau dhau los ntawm daim nyias nyias, thiab nrog rau theem txiav txim siab, colloidal hais tsis tuaj yeem.
Qhov tsos thiab ploj ntawm cov yam ntxwv xim
Vim cov nyhuv Tyndall, qee yam ntawm cov tshuaj no yog translucent. Hauv cov qauv ntawm lub caij, nws yog qhov tawg ntawm lub teeb. Lwm qhov system thiab formulations tuaj nrogqee qhov ntxoov ntxoo lossis txawm tias opaque, nrog rau qee yam xim, txawm tias qee qhov tsis kaj. Ntau yam khoom paub, suav nrog butter, mis nyuj, qab zib, aerosols (fog, smog, pa luam yeeb), asph alt, xim, xim, kua nplaum, thiab dej hiav txwv ua npuas ncauj, yog colloids. Txoj kev tshawb no tau nthuav tawm hauv xyoo 1861 los ntawm tus kws tshawb fawb Scottish Thomas Graham. Qee zaum, colloid tuaj yeem suav tias yog homogeneous (tsis yog heterogeneous) sib tov. Qhov no yog vim qhov sib txawv ntawm "kua" thiab "granular" teeb meem qee zaum tuaj yeem yog qhov teeb meem ntawm txoj hauv kev.
Hydrocolloid hom tshuaj
Cov tshuaj no tau txhais tias yog lub kaw lus colloidal uas cov khoom tawg tau tawg hauv dej. Hydrocolloid cov ntsiab lus, nyob ntawm seb cov kua ntau npaum li cas, tuaj yeem ua rau ntau lub xeev, piv txwv li, gel lossis sol. Lawv yog irreversible (ib leeg-cov khoom) los yog thim rov qab. Piv txwv li, agar, hom thib ob ntawm hydrocolloid. Tej zaum yuav muaj nyob rau hauv gel thiab sol xeev, thiab hloov ntawm cov xeev nrog cov cua sov ntxiv lossis tshem tawm.
Ntau cov hydrocolloids tau muab los ntawm cov khoom ntuj tsim. Piv txwv li, carrageenan yog muab rho tawm los ntawm algae, gelatin yog los ntawm bovine rog, thiab pectin yog los ntawm citrus tev thiab kua pomace. Hydrocolloids yog siv rau hauv cov zaub mov feem ntau cuam tshuam rau kev ntxhib los mos lossis viscosity (sauce). Kuj tseem siv tau rau kev tu tawv nqaij lossis ua cov tshuaj kho tom qab raug mob.
yam ntxwv tseem ceeb ntawm colloidal systems
Los ntawm cov ntaub ntawv no nws tuaj yeem pom tau tias cov tshuab colloidal yog ib ntu ntawm cov khoom tawg. Lawv, nyob rau hauv lem, tuaj yeem yog kev daws teeb meem (sols)los yog gels (jelly). Cov qub yog nyob rau hauv feem ntau yog tsim los ntawm kev nyob chemistry. Cov tom kawg yog tsim nyob rau hauv cov sediments uas tshwm sim thaum lub sij hawm coagulation ntawm cov sols. Cov kev daws teeb meem tuaj yeem yog aqueous nrog cov organic tshuaj, nrog cov tsis muaj zog lossis muaj zog electrolytes. Qhov luaj li cas ntawm lub dispersed theem ntawm colloids yog los ntawm 100 mus rau 1 nm. Lawv tsis tuaj yeem pom ntawm qhov muag liab qab. Raws li kev daws teeb meem, theem thiab nruab nrab yog qhov nyuaj rau kev sib cais.
Kev faib tawm los ntawm hom particles ntawm cov theem tawg
Multimolecular colloids. Thaum, nyob rau hauv kev sib cais, atoms los yog me me molecules ntawm cov khoom (muaj ib tug txoj kab uas hla ntawm tsawg tshaj li 1 nm) ua ke ua ke los ua ib feem ntawm qhov ntau thiab tsawg. Nyob rau hauv cov sols no, lub dispersed theem yog ib tug qauv uas muaj aggregates ntawm atoms los yog molecules nrog ib tug molecular loj ntawm tsawg tshaj li 1 nm. Piv txwv li, kub thiab sulfur. Hauv cov colloids no, cov khoom yog tuav ua ke los ntawm van der Waals rog. Lawv feem ntau muaj tus cwj pwm lyophilic. Qhov no txhais tau hais tias muaj kev cuam tshuam loj heev.
High molecular hnyav colloids. Cov no yog cov khoom uas muaj cov molecules loj (hu ua macromolecules), uas, thaum yaj, tsim ib txoj kab uas hla. Cov tshuaj no hu ua macromolecular colloids. Cov txheej txheem dispersed no feem ntau yog cov polymers uas muaj qhov hnyav heev molecular. Ntuj macromolecules yog cov hmoov txhuv nplej siab, cellulose, proteins, enzymes, gelatin, thiab lwm yam. Cov khoom muaj xws li hluavtaws polymers xws li nylon, polyethylene, plastics, polystyrene, thiab lwm yam.e. Lawv feem ntau yog lyophobic, uas txhais tau hais tias nyob rau hauv rooj plaub no qhov kev cuam tshuam tsis muaj zog ntawm cov khoom.
Associated colloids. Cov no yog cov khoom uas, thaum yaj nyob rau hauv nruab nrab, coj zoo li ib txwm electrolytes ntawm tsawg concentration. Tab sis lawv yog colloidal hais nrog ib tug loj enzymatic tivthaiv ntawm lub Cheebtsam vim yog tsim ntawm aggregated ntsiab. Cov aggregate particles li tsim yog hu ua micelles. Lawv cov molecules muaj ob pawg lyophilic thiab lyophobic.
Micelles. Lawv yog pawg los yog sib sau ua ke tsim los ntawm kev sib koom ua ke ntawm colloid hauv kev daws. Piv txwv li yog xab npum thiab xab npum. Qhov tsim tshwm sim saum toj no ib qho Kraft kub, thiab siab dua ib qho tseem ceeb micellization concentration. Lawv muaj peev xwm tsim ions. Micelles tuaj yeem muaj txog li 100 molecules lossis ntau dua, piv txwv li sodium stearate yog ib qho piv txwv. Thaum nws yaj hauv dej, nws tso ions.
