Lub ntsiab lus tseem ceeb ntawm kab lus no yuav yog ib qho colloidal particle. Ntawm no peb yuav xav txog lub tswvyim ntawm colloidal tov thiab micelles. Thiab kuj tau paub nrog lub ntsiab hom ntau haiv neeg ntawm hais txog colloidal. Cia wb nyob nyias nyias ntawm ntau yam ntawm lub sij hawm nyob rau hauv kev kawm, qee tus neeg lub tswv yim thiab ntau ntxiv.
Introduction
Lub tswv yim ntawm ib qho colloidal yog ze ze rau ntau yam kev daws teeb meem. Ua ke, lawv tuaj yeem tsim ntau yam microheterogeneous thiab dispersed systems. Cov khoom tsim cov tshuab no feem ntau yog qhov loj ntawm ib mus rau ib puas microns. Ntxiv nrog rau qhov pom ntawm qhov chaw uas muaj kev sib cais kom meej ntawm qhov nruab nrab ntawm qhov nruab nrab thiab theem, cov khoom colloidal yog cov yam ntxwv ntawm cov cuab yeej tsis muaj kev ruaj ntseg, thiab cov kev daws teeb meem lawv tus kheej tsis tuaj yeem tsim spontaneously. Lub xub ntiag ntawm ntau yam hauv cov qauv ntawm cov qauv sab hauv thiab qhov ntau thiab tsawg ua rau kev tsim cov txheej txheem ntau kom tau txais cov khoom.
Lub tswvyim ntawm lub kaw lus colloidal
Hauv cov kev daws teeb meem colloidal, cov khoom hauv tag nrho lawvaggregates cov txheej txheem ntawm ib hom dispersed, uas yog nruab nrab ntawm cov kev daws teeb meem, uas txhais tau tias muaj tseeb thiab ntxhib. Nyob rau hauv cov kev daws teeb meem no, tee, hais, thiab txawm npuas uas ua rau lub dispersed theem muaj ntau thiab tsawg los ntawm ib mus rau ib txhiab nm. Lawv raug faib nyob rau hauv lub thickness ntawm dispersed nruab nrab, raws li ib tug txoj cai, nruam, thiab txawv los ntawm cov thawj system nyob rau hauv muaj pes tsawg leeg thiab / los yog lub xeev ntawm aggregation. Txhawm rau kom nkag siab zoo dua lub ntsiab lus ntawm cov ntsiab lus zoo li no, nws yog qhov zoo dua los txiav txim siab nws tawm tsam keeb kwm ntawm cov kab ke uas nws tsim.
Define properties
Ntawm cov khoom ntawm cov tshuaj colloidal, cov ntsiab lus tuaj yeem txiav txim siab:
- Kev tsim cov khoom tsis cuam tshuam nrog txoj kev pom kev.
- Pob tshab colloids muaj peev xwm ua kom tawg lub teeb rays. Qhov tshwm sim no hu ua Tyndall effect.
- Tus nqi ntawm cov khoom colloidal yog tib yam rau cov tshuab tawg, vim tias lawv tsis tuaj yeem tshwm sim hauv kev daws teeb meem. Nyob rau hauv Brownian motion, dispersed hais tsis tuaj yeem los nag, uas yog vim lawv cov txij nkawm nyob rau hauv lub xeev ntawm lub davhlau.
hom tseem ceeb
Kev faib tawm cov chav nyob ntawm cov tshuaj colloidal:
- Ib qho kev ncua ntawm cov khoom hauv cov pa roj yog hu ua pa taws.
- Ib qho kev ncua ntawm cov kua hauv cov pa roj yog hu ua pos.
- Los ntawm cov khoom me me ntawm cov khoom lossis cov kua, tshem tawm hauv cov pa nruab nrab, ib qho aerosol yog tsim.
- Ib qhov tso pa tawm hauv cov kua lossis cov khib nyiab hu ua ua npuas ncauj.
- Emulsion yog cov kua dej ncua hauv cov kua.
- Sol yog ib qho kev sib caishom ultramicroheterogeneous.
- Gel yog ncua kev kawm 2 yam. Tus thawj tsim ib lub moj khaum peb-dimensional, cov voids uas yuav tau sau nrog ntau yam uas tsis muaj molecular hnyav hnyav hnyav.
- Ib qho kev ncua ntawm cov khoom siv hauv cov kua yog hu ua kev ncua.
Hauv tag nrho cov tshuab colloidal no, qhov loj me tuaj yeem sib txawv heev nyob ntawm lawv qhov chaw ntawm keeb kwm thiab lub xeev ntawm kev sib sau. Tab sis txawm hais tias txawm tias muaj ntau hom kab ke nrog cov qauv sib txawv, lawv txhua tus yog colloidal.
Txoj kev sib txawv ntawm cov khoom
Cov ntsiab lus tseem ceeb nrog qhov ntev ntawm colloidal tau muab faib ua cov hauv qab no raws li hom qauv sab hauv:
- Suspensoids. Lawv kuj tseem hu ua irreversible colloids, uas tsis tuaj yeem nyob ntawm lawv tus kheej rau lub sijhawm ntev.
- Micellar-type colloids, lossis, raws li lawv kuj hu ua, semi-colloids.
- Reversible hom colloids (molecular).
Cov txheej txheem ntawm kev tsim cov qauv no txawv heev, uas ua rau nyuaj rau cov txheej txheem kev nkag siab ntawm cov ncauj lus kom ntxaws, ntawm qib ntawm chemistry thiab physics. Colloidal hais, los ntawm cov hom kev daws teeb meem no, muaj cov duab sib txawv thiab cov xwm txheej rau cov txheej txheem ntawm kev tsim ib qho system.
Kev txiav txim siab ntawm kev tshem tawm
Suspensoids yog cov kev daws teeb meem nrog cov ntsiab lus hlau thiab lawv qhov kev hloov pauv hauv daim ntawv oxide, hydroxide, sulfide thiab lwm yam ntsev.
Txhua tusCov ntsiab lus ntawm cov khoom hais saum toj no muaj cov molecular lossis ionic crystal lattice. Lawv tsim ib theem ntawm cov khoom sib cais - suspensoid.
Ib qho tshwj xeeb uas ua rau nws muaj peev xwm paub qhov txawv ntawm qhov raug ncua yog qhov muaj qhov sib txawv ntau dua. Tab sis lawv muaj kev sib tshuam los ntawm qhov tsis muaj lub zog ruaj khov rau kev tawg.
Lub irreversibility ntawm suspensoids yog piav los ntawm qhov tseeb hais tias cov sediment ntawm cov txheej txheem ntawm lawv steaming tsis pub ib tug neeg kom tau sols dua los ntawm tsim kev sib cuag ntawm cov sediment nws tus kheej thiab cov dispersed nruab nrab. Tag nrho cov suspensoids yog lyophobic. Hauv cov kev daws teeb meem no hu ua colloidal hais txog cov hlau thiab ntsev derivatives uas tau crushed los yog condensed.
Txoj kev tsim khoom tsis txawv ntawm ob txoj hauv kev uas cuam tshuam cov txheej txheem ib txwm tsim:
- Tau txais los ntawm kev tawg (sib tsoo lub cev loj).
- Tus qauv ntawm condensation ntawm ionic thiab molecularly yaj tshuaj.
Kev txiav txim siab ntawm micellar colloids
Micellar colloids kuj tseem hu ua semi-colloids. Cov khoom uas lawv tsim tuaj yeem tshwm sim yog tias muaj qhov txaus siab ntawm amphiphilic hom molecules. Xws li cov molecules tuaj yeem tsim cov khoom hnyav molecular nkaus xwb los ntawm kev koom ua ke rau hauv ib qho sib xyaw ntawm cov molecule - micelle.
Molecules ntawm amphiphilic xwm yog cov qauv uas muaj hydrocarbon radical nrog cov tsis muaj thiab cov khoom zoo ib yam li cov kuab tshuaj tsis-polar thiab ib pawg hydrophilic, uaskuj hu ua polar.
Micelles yog cov agglomeration tshwj xeeb ntawm cov molecules tsis tu ncua uas tau tuav ua ke feem ntau los ntawm kev siv lub zog tawg. Micelles yog tsim, piv txwv li, nyob rau hauv aqueous daws ntawm detergents.
Kev txiav txim siab ntawm molecular colloids
Molecular colloids yog cov khoom sib xyaw ua ke ntawm ob qho tib si ntuj thiab hluavtaws. Qhov hnyav molecular tuaj yeem nyob ntawm 10,000 mus rau ntau lab. Molecular fragments ntawm cov khoom no muaj qhov loj ntawm colloidal particle. Cov molecules lawv tus kheej hu ua macromolecules.
Cov tshuaj ntawm ib hom macromolecular uas raug rau dilution yog hu ua tseeb, homogeneous. Lawv, nyob rau hauv cov ntaub ntawv ntawm heev dilution, pib ua raws li cov kev cai dav dav rau diluted formulations.
Tau txais cov tshuaj colloidal ntawm hom molecular yog ib txoj haujlwm yooj yim. Nws txaus los ua kom cov khoom qhuav thiab cov kuab tshuaj sib thooj tuaj rau hauv kev sib cuag.
Daim ntawv tsis-polar ntawm macromolecules tuaj yeem yaj hauv hydrocarbons, thaum daim ntawv polar tuaj yeem yaj hauv cov kuab tshuaj polar. Ib qho piv txwv ntawm tom kawg yog kev sib cais ntawm ntau cov proteins hauv cov kua dej thiab ntsev.
Rov qab tau cov tshuaj no yog hu ua vim qhov ua rau lawv mus rau evaporation nrog ntxiv ntawm qhov tshiab ntawm cov seem qhuav ua rau molecular colloidal hais los ua cov tshuaj. Cov txheej txheem ntawm lawv cov kev sib cais yuav tsum mus dhau ib theem uas nws swells. Nws yog ib tug yam ntxwv feature uas distinguishes molecular colloids, nyob rautawm tsam keeb kwm yav dhau los ntawm lwm lub tshuab tau tham saum toj no.
Nyob rau hauv cov txheej txheem ntawm o, cov molecules uas tsim cov kuab tshuaj nkag mus rau hauv cov khoom tuab ntawm cov polymer thiab yog li thawb cov macromolecules sib nrug. Cov tom kawg, vim lawv qhov loj me, pib maj mam diffuse rau hauv kev daws teeb meem. Sab nraud, qhov no tuaj yeem pom nrog qhov nce ntawm cov nqi ntawm cov polymers.
Micelle device
Micelles ntawm colloidal system thiab lawv cov qauv yuav yooj yim rau kev kawm yog tias peb xav txog cov txheej txheem tsim. Cia peb ua ib qho AgI particle ua piv txwv. Hauv qhov no, cov khoom ntawm ib hom colloidal yuav raug tsim thaum lub sijhawm cov tshuaj tiv thaiv hauv qab no:
AgNO3+KI à AgI↓+KNO3
Molecules ntawm cov nyiaj iodide (AgI) tsim cov khoom siv tsis sib xws, sab hauv uas cov siv lead ua lattice yuav tsim los ntawm cov nyiaj cations thiab iodine anions.
Cov txiaj ntsig tau pib muaj cov qauv amorphous, tab sis tom qab ntawd, thaum lawv maj mam crystallize, lawv tau txais cov qauv zoo li qub.
Yog tias koj noj AgNO3 thiab KI hauv lawv qhov sib npaug, ces crystalline particles yuav loj hlob thiab ncav cuag qhov loj me, tshaj qhov loj ntawm colloidal particle nws tus kheej, thiab sai sai. dej nag.
Yog tias koj noj ib qho ntawm cov tshuaj ntau dhau, koj tuaj yeem tsim cov tshuaj stabilizer tawm ntawm nws, uas yuav qhia txog kev ruaj ntseg ntawm colloidal hais txog nyiaj iodide. Yog muaj AgNO3cov tshuaj yuav muaj ntau qhov zoo nyiaj ions thiab TSIS MUAJ 3 -. Nws yog ib qho tseem ceeb kom paub tias cov txheej txheem ntawm kev tsim ntawm AgI siv lead ua lattices ua raws li txoj cai Panet-Fajans. Yog li ntawd, nws muaj peev xwm mus txuas ntxiv tsuas yog nyob rau hauv lub xub ntiag ntawm ions uas tsim cov tshuaj no, uas nyob rau hauv cov tshuaj no yog sawv cev los ntawm silver cations (Ag+)..
Cov Argentum ions zoo yuav txuas ntxiv ua tiav ntawm theem ntawm kev tsim cov siv lead ua lattice ntawm cov tub ntxhais, uas yog ruaj khov rau hauv cov qauv micelle thiab sib txuas lus hluav taws xob muaj peev xwm. Nws yog vim li no tias cov ions uas tau siv los ua kom tiav kev tsim kho ntawm cov kab hluav taws xob nuclear hu ua qhov muaj peev xwm txiav txim siab ions. Thaum lub sij hawm tsim ntawm ib tug colloidal particle - micelles - muaj lwm yam nta uas txiav txim ib los yog lwm yam kev kawm ntawm cov txheej txheem. Txawm li cas los xij, txhua yam tau txiav txim siab ntawm no siv qhov piv txwv nrog hais txog cov ntsiab lus tseem ceeb tshaj plaws.
Qee lub tswv yim
Lub sij hawm colloidal particle yog ze ze rau lub adsorption txheej, uas yog tsim ib txhij nrog ions ntawm ib tug tej zaum-txiav hom, thaum lub sij hawm adsorption ntawm tag nrho cov counterions.
A granule yog cov qauv tsim los ntawm cov tub ntxhais thiab cov txheej txheem adsorption. Nws muaj peev xwm hluav taws xob zoo ib yam li E-muaj peev xwm, tab sis nws tus nqi yuav me dua thiab nyob ntawm tus nqi pib ntawm counterions hauv txheej adsorption.
Coagulation ntawm colloidal hais yog txheej txheem hu ua coagulation. Hauv cov txheej txheem dispersed, nws ua rau tsim cov khoom me mecov loj. Cov txheej txheem yog tus cwj pwm los ntawm kev sib koom ua ke ntawm cov khoom siv me me los tsim cov qauv coagulative.
