Ib qho macromolecular compound yog Txhais, muaj pes tsawg leeg, yam ntxwv, khoom

2024 Tus sau: Angel Austin | [email protected]. Kawg hloov kho: 2024-01-02 17:48

Cov khoom hnyav molecular hnyav yog cov polymers uas muaj qhov hnyav molecular. Lawv tuaj yeem yog cov organic thiab inorganic compounds. Paub qhov txawv ntawm cov tshuaj amorphous thiab crystalline, uas muaj cov nplhaib monomeric. Cov tom kawg yog macromolecules txuas nrog cov tshuaj lom neeg thiab kev sib koom ua ke. Hauv cov ntsiab lus yooj yim, lub siab-molecular compound yog cov polymer, uas yog, cov tshuaj monomeric uas tsis hloov lawv cov huab hwm coj thaum tib yam "hnyav" cov khoom txuas nrog lawv. Txwv tsis pub, peb yuav tham txog oligomer.

Kev tshawb fawb ntawm macromolecular compounds kawm dab tsi?

Cov chemistry ntawm macromolecular polymers yog kev kawm ntawm cov saw hlau molecular uas muaj cov monomeric subunits. Qhov no suav nrog thaj tsam loj ntawm kev tshawb fawb. Ntau cov polymers yog qhov tseem ceeb ntawm kev lag luam thiab kev lag luam tseem ceeb. Hauv tebchaws Amelikas, nrog rau kev tshawb pom ntawm cov pa roj carbon monoxide, ib txoj haujlwm loj tau tsim los tsim cov nroj tsuag rau kev tsim cov polyethylene. Ethane los ntawm natural gas yog hloov dua siab tshiabrau hauv ethylene, lub monomer los ntawm polyethylene tuaj yeem ua tau.

A polymer li macromolecular compound yog:

• Txhua yam ntawm cov khoom ntuj lossis hluavtaws ua los ntawm cov molecules loj heev hu ua macromolecules.
• Ntau yam tshuaj yooj yim dua hu ua monomers.
• Polymers tsim ntau yam khoom hauv cov kab mob muaj sia, suav nrog, piv txwv li, cov proteins, cellulose, thiab nucleic acids.
• Ntxiv rau, lawv tsim cov hauv paus ntawm cov zaub mov xws li pob zeb diamond, quartz thiab feldspar, nrog rau cov khoom tsim los ntawm tib neeg xws li pob zeb, iav, ntawv, yas thiab roj hmab.

Lo lus "polymer" qhia txog tus lej ntawm cov monomer tsis kawg. Thaum tus nqi ntawm cov monomers siab heev, cov compound yog qee zaum hu ua polymer siab. Nws tsis txwv rau monomers nrog tib cov tshuaj muaj pes tsawg leeg lossis molecular hnyav thiab qauv. Qee lub ntuj siab molecular hnyav organic tebchaw yog tsim los ntawm ib hom monomer.

Txawm li cas los xij, feem ntau cov khoom siv ntuj thiab hluavtaws yog tsim los ntawm ob lossis ntau hom monomers; Cov polymers no hu ua copolymer.

Natural substances: Dab tsi yog lawv lub luag haujlwm hauv peb lub neej?

Organic siab molecular hnyav cov organic tebchaw ua lub luag haujlwm tseem ceeb hauv tib neeg lub neej, muab cov ntaub ntawv tsim nyog thiab koom nrog cov txheej txheem tseem ceeb.

• Piv txwv li, cov khoom ntawm tag nrho cov nroj tsuag yog tsim los ntawm polymers. Cov no suav nrog cellulose, lignin thiab ntau yam resins.
• Pulp yogpolysaccharide, ib tug polymer ua los ntawm qab zib molecules.
• Lignin yog tsim los ntawm txoj haujlwm peb-dimensional network ntawm polymers.
• tsob ntoo resins yog polymers ntawm ib qho yooj yim hydrocarbon, isoprene.
• Lwm tus paub isoprene polymer yog roj hmab.

Lwm yam tseem ceeb ntawm cov polymers muaj xws li cov proteins, uas yog polymers ntawm amino acids, thiab nucleic acids. Lawv yog hom nucleotides. Cov no yog cov molecules complex uas muaj nitrogen-muaj hauv paus, suab thaj thiab phosphoric acid.

Nucleic acids nqa cov ntaub ntawv caj ces hauv lub cell. Starches, ib qho tseem ceeb ntawm kev noj haus lub zog los ntawm cov nroj tsuag, yog ntuj polymers ua los ntawm qabzib.

Tshuaj ntawm macromolecular compounds tso tawm inorganic polymers. Lawv kuj pom muaj nyob rau hauv xwm, nrog rau pob zeb diamond thiab graphite. Ob leeg yog ua los ntawm carbon. Tsim nyog paub:

• Nyob hauv pob zeb diamond, carbon atoms txuas nrog hauv peb-dimensional network uas muab cov khoom nws hardness.
• Nyob rau hauv graphite, siv los ua roj nplua nyeem thiab xaum "ua", carbon atoms daim ntawv cog lus hauv cov dav hlau uas tuaj yeem xaub hla ib leeg.

Ntau cov polymers tseem ceeb muaj cov pa oxygen lossis nitrogen atoms nrog rau cov pa roj carbon atoms hauv cov pob txha. Xws li cov ntaub ntawv macromolecular nrog oxygen atoms suav nrog polyacetals.

Qhov yooj yim polyacetal yog polyformaldehyde. Nws muaj lub siab melting point, yog crystalline, puas resistant thiabkev ua ntawm cov kuab tshuaj. Acetal resins yog cov hlau zoo li ntau dua li lwm cov yas thiab siv los tsim cov tshuab xws li cov iav thiab cov kabmob.

Cov khoom tau txais kev dag ntxias

Synthetic macromolecular compounds yog tsim nyob rau hauv ntau hom kev tshwm sim:

1. Ntau yam yooj yim hydrocarbons xws li ethylene thiab propylene tuaj yeem hloov mus ua polymers los ntawm kev ntxiv ib lub monomer tom qab lwm rau cov saw loj.
2. Polyethylene, tsim los ntawm kev rov ua dua ethylene monomers, yog cov khoom siv polymer ntxiv. Nws tuaj yeem muaj txog li 10,000 monomers txuas nrog cov hlua ntev helical. Polyethylene yog crystalline, translucent, thiab thermoplastic, txhais tau tias nws softens thaum rhuab. Nws yog siv rau coatings, ntim, molded qhov chaw, thiab fwj thiab ntim.
3. Polypropylene kuj yog crystalline thiab thermoplastic, tab sis nyuaj dua polyethylene. Nws cov molecules tuaj yeem muaj 50,000-200,000 monomers.

Cov khoom sib xyaw no yog siv hauv kev lag luam textile thiab molding.

Lwm cov khoom siv polymers suav nrog:

• polybutadiene;
• polyisoprene;
• Ypolychloroprene.

Txhua yam tseem ceeb hauv kev tsim cov roj hmab hluavtaws. Qee cov polymers, xws li polystyrene, yog iav thiab pob tshab ntawm chav tsev kub, thiab kuj yog thermoplastic:

1. Polystyrene tuaj yeem dyed txhua xim thiab siv los ua cov khoom ua si thiab lwm yam yaskhoom.
2. Thaum ib lub atom hydrogen hauv ethylene hloov los ntawm chlorine atom, vinyl chloride yog tsim.
3. Nws polymerizes rau hauv polyvinyl chloride (PVC), tsis muaj xim, tawv, tawv, cov khoom siv thermoplastic uas tuaj yeem ua rau ntau hom, suav nrog foams, films, thiab fibers.
4. Vinyl acetate, tsim los ntawm cov tshuaj tiv thaiv ntawm ethylene thiab acetic acid, polymerizes rau hauv amorphous, mos resins siv los coatings thiab adhesives.
5. Nws copolymerizes nrog vinyl chloride los tsim ib tsev neeg loj ntawm cov ntaub ntawv thermoplastic.

Ib txoj kab hluav taws xob uas ua los ntawm kev rov ua dua ntawm ester pawg raws cov saw tseem ceeb yog hu ua polyester. Qhib saw polyesters yog tsis muaj xim, crystalline, thermoplastic cov ntaub ntawv. Cov hluavtaws macromolecular compounds uas muaj qhov hnyav molecular (los ntawm 10,000 txog 15,000 molecules) yog siv los tsim cov yeeb yaj kiab.

Ntshav hluavtaws polyamides

Polyamides suav nrog cov casein proteins uas tshwm sim hauv cov mis nyuj thiab zein pom hauv pob kws, uas yog siv los ua cov yas, fibers, adhesives thiab coatings. Tsim nyog nco:

• Synthetic polyamides suav nrog urea-formaldehyde resins, uas yog thermosetting. Lawv yog siv los ua cov khoom molded thiab ua cov nplaum thiab coatings rau textiles thiab ntawv.
• Kuj tseem ceeb yog cov polyamide resins hu ua nylon. Lawv yogruaj, resistant rau kub thiab abrasion, non-toxic. Lawv tuaj yeem dyed. Nws siv nto moo tshaj plaws yog textile fibers, tab sis lawv muaj ntau lwm yam siv.

Lwm tsev neeg tseem ceeb ntawm cov khoom siv hluavtaws siab molecular hnyav tshuaj lom neeg muaj cov kab rov ua dua ntawm pawg urethane. Polyurethanes yog siv rau hauv kev tsim cov elastomeric fibers hu ua spandex thiab hauv kev tsim cov tsho loj.

Lwm chav kawm ntawm polymers yog cov organic-inorganic compounds:

1. Cov neeg sawv cev tseem ceeb tshaj plaws ntawm tsev neeg ntawm cov polymers no yog silicones. Cov ntsiab lus siab molecular hnyav muaj alternating silicon thiab oxygen atoms nrog cov organic pawg txuas rau txhua tus ntawm silicon atoms.
2. Tsawg molecular hnyav silicones yog roj thiab roj.
3. Cov tsiaj hnyav dua molecular yog ntau yam khoom siv elastic uas nyob twj ywm mos txawm tias qhov kub thiab txias heev. Lawv kuj tseem ruaj khov ntawm qhov kub thiab txias.

Polymer tuaj yeem yog peb-dimensional, ob-dimensional thiab ib leeg. Cov chav nyob rov qab feem ntau yog tsim los ntawm carbon thiab hydrogen, thiab qee zaum oxygen, nitrogen, sulfur, chlorine, fluorine, phosphorus, thiab silicon. Txhawm rau tsim cov saw hlau, ntau chav nyob yog chemically txuas lossis polymerized ua ke, yog li hloov cov yam ntxwv ntawm cov khoom hnyav molecular.

Cov yam ntxwv dab tsi ua cov tshuaj macromolecular muaj?

Feem ntau ntawm cov polymers uas ua tau yog thermoplastic. Tom qabcov polymer yog tsim, nws tuaj yeem ua kom sov thiab hloov dua tshiab. Cov cuab yeej no ua rau nws yooj yim los tuav. Lwm pab pawg ntawm cov thermosets tsis tuaj yeem muab rov qab: ib zaug cov polymers tau tsim, rov ua kom rov ua dua yuav decompose tab sis tsis yaj.

Yam ntxwv ntawm macromolecular compounds ntawm polymers ntawm cov piv txwv ntawm pob:

1. Tuaj yeem tiv taus tshuaj lom neeg. Xav txog tag nrho cov dej ntxuav hauv koj lub tsev uas tau ntim rau hauv cov yas. Piav tag nrho cov kev tshwm sim ntawm kev sib cuag nrog lub qhov muag, tab sis ntawm daim tawv nqaij. Nov yog pawg txaus ntshai ntawm polymers uas yaj txhua yam.
2. Txawm hais tias qee cov yas tau yooj yim deformed los ntawm cov kuab tshuaj, lwm cov yas tau muab tso rau hauv cov pob tsis tawg rau cov kuab tshuaj hnyav. Lawv tsis txaus ntshai, tab sis tuaj yeem ua mob rau tib neeg xwb.
3. Cov kev daws teeb meem ntawm cov tshuaj macromolecular feem ntau yog muab rau hauv cov hnab yas yooj yim kom txo cov feem pua ntawm lawv cov kev cuam tshuam nrog cov khoom hauv lub thawv.

Raws li txoj cai dav dav, cov polymers yog qhov hnyav heev nrog rau qib tseem ceeb ntawm lub zog. Xav txog ntau yam kev siv, los ntawm cov khoom ua si mus rau cov qauv ntawm qhov chaw nres tsheb, lossis los ntawm cov nylon fiber ntau hauv cov tights rau Kevlar siv hauv lub cev armor. Qee cov polymers ntab hauv dej, lwm tus hauv dej. Piv nrog rau qhov ntom ntawm pob zeb, pob zeb, hlau, tooj liab lossis txhuas, tag nrho cov yas yog cov khoom siv hnyav.

Cov khoom ntawm macromolecular compounds txawv:

1. Polymers tuaj yeem ua cov thermal thiab hluav taws xob insulators: cov khoom siv, cov hlua, cov hluav taws xob hluav taws xob thiab cov xaim hluav taws xob uas tsim los yog coated nrog cov ntaub ntawv polymeric.
2. Cov khoom siv hauv chav ua noj kub resistant nrog lub lauj kaub thiab lub lauj kaub tais diav, lub lauj kaub kas fes, lub tub yees thiab lub tub yees ua npuas ncauj, cov khob insulated, txias thiab microwave-zoo tais diav.
3. Cov ris tsho hauv qab thermal hnav los ntawm ntau tus neeg caij ski yog ua los ntawm polypropylene, thaum cov fibers hauv lub caij ntuj no tsho yog ua los ntawm acrylic thiab polyester.

Cov khoom hnyav molecular hnyav yog cov tshuaj uas tsis muaj kev txwv ntawm cov yam ntxwv thiab xim. Lawv muaj ntau yam khoom uas tuaj yeem txhim kho ntxiv nrog ntau yam khoom ntxiv los nthuav dav daim ntawv thov. Polymers tuaj yeem ua lub hauv paus rau kev xyaum paj rwb, txhob lo lo ntxhuav thiab ntaub plaub, porcelain thiab marble, aluminium thiab zinc. Hauv kev lag luam khoom noj khoom haus, lawv tau siv los muab cov khoom siv tau los ntawm fungi. Piv txwv li, kim xiav cheese. Nws tuaj yeem noj tau zoo ua tsaug rau kev ua cov polymer.

Kev ua haujlwm thiab kev siv cov txheej txheem polymer

Polymers tuaj yeem ua tiav ntau txoj hauv kev:

• Extrusion tso cai rau tsim cov fibers nyias lossis hnyav hnyav, cov yeeb yaj kiab, lub raj mis khoom noj.
• Kev txhaj tshuaj molding ua rau nws muaj peev xwm tsim qhov chaw nyuaj, xws li cov tsheb loj hauv lub cev.
• Plastics tuaj yeem muab pov rau hauv cov thoob lossis sib xyaw nrog cov kuab tshuaj los ua cov nplaum los yog xim.
• Elastomers thiab qee cov yas yog stretchable thiab hloov tau.
• Qee cov yas nthuav dav thaum ua tiav los tuav lawv cov duab, xws li lub raj mis haus dej.
• Lwm cov polymers tuaj yeem ua npuas, xws li polystyrene, polyurethane thiab polyethylene.

Cov khoom ntawm macromolecular tebchaw sib txawv nyob ntawm qhov kev ua haujlwm txhua yam thiab txoj kev tau txais cov khoom. Qhov no ua rau nws muaj peev xwm siv tau rau hauv ntau yam kev lag luam. Lub ntsiab macromolecular compounds muaj ntau lub hom phiaj ntau dua li qhov sib txawv ntawm cov khoom tshwj xeeb thiab cov txheej txheem ntawm kev npaj. Universal thiab "whimsical" "nrhiav lawv tus kheej" hauv cov khoom noj thiab kev tsim kho:

1. Cov khoom hnyav molecular yog tsim los ntawm cov roj, tab sis tsis tas li.
2. Ntau cov polymers yog tsim los ntawm rov ua dua yav tas los tsim los ntawm cov nkev, thee lossis roj crude.
3. Qee lub tsev yog tsim los ntawm cov khoom siv txuas ntxiv dua tshiab xws li polylactic acid (los ntawm pob kws lossis cellulose thiab paj rwb linters).

Nws kuj nthuav tias lawv yuav luag tsis tuaj yeem hloov:

• Polymers tuaj yeem siv los ua cov khoom uas tsis muaj lwm yam khoom siv.
• Lawv ua rau cov yeeb yaj kiab tsis muaj dej tsis zoo.
• PVC yog siv los ua cov raj kho mob thiab cov hnab ntshav uas txuas ntxiv lub neej txee ntawm cov khoom thiab nws cov derivatives.
• PVC muaj kev nyab xeeb xa cov pa hluav taws xob rau cov tubing uas tsis yog nplaim taws.
• Thiab cov khoom siv los tiv thaiv thrombogenic xws li heparin tuaj yeem suav nrog hauv qeb ntawm PVC catheters hloov tau.

Ntau yam khoom siv kho mob tsom mus rau cov yam ntxwv ntawm cov tshuaj macromolecular kom ua haujlwm tau zoo.

Kev daws cov tshuaj macromolecular thiab lawv cov khoom

Vim tias qhov loj ntawm cov theem dispersed yog qhov nyuaj rau kev ntsuas thiab cov colloids nyob rau hauv daim ntawv ntawm cov kev daws teeb meem, lawv qee zaum txheeb xyuas thiab ua tus yam ntxwv ntawm lub cev thiab kev thauj mus los.

Colloid theem	Hard	Kev daws teeb meem	Dimensional indicators
	Yog tias cov colloid muaj cov theem khoom tawg mus rau hauv cov kua, cov khoom siv yuav tsis tawg los ntawm daim nyias nyias.	Dissolved ions los yog molecules yuav diffuse los ntawm daim nyias nyias ntawm tag nrho diffusion.	Vim qhov kev cais me me, cov khoom colloidal tsis tuaj yeem dhau los ntawm UF daim nyias nyias pores me dua lawv qhov loj.
Kev sib xyaw ua ke ntawm cov kev daws teeb meem ntawm macromolecular compounds	Qhov tseeb ntawm qhov tseeb cov kuab tshuaj yuav nyob ntawm qhov kev sim siv los cais nws ntawm cov khoom colloidal uas tau tawg mus rau hauv cov kua.	Nyob ntawm cov tshuaj tiv thaiv ntawm cov tshuaj macromolecular thaum ua cov kev tshawb fawb solubility kom yooj yim hydrolyzed tshuaj xws li Al, Eu, Am, Cm.	Qhov me me qhov pore loj ntawm ultrafiltration membrane, qhov qis dua qhov concentrationdispersed colloidal hais seem nyob rau hauv cov kua ultrafiltered.

A hydrocolloid txhais tau tias yog lub kaw lus colloidal uas cov khoom ntawm macromolecular molecules yog hydrophilic polymers dispersed hauv dej.

Kev Txhaum Dej	Kev tiv thaiv kub	Kev vam meej ntawm txoj kev tsim khoom
Hydrocolloid yog colloidal particles dispersed hauv dej. Nyob rau hauv cov ntaub ntawv no, qhov piv ntawm ob lub Cheebtsam cuam tshuam rau daim ntawv ntawm cov polymer - gel, tshauv, kua xeev.	Hydrocolloids tuaj yeem hloov tsis tau (hauv ib lub xeev) lossis thim rov qab. Piv txwv li, agar, reversible hydrocolloid ntawm seaweed extract, tuaj yeem muaj nyob rau hauv cov gel thiab cov khoom hauv lub xeev, los yog hloov ntawm cov xeev nrog ntxiv lossis tshem tawm cov cua sov.	Tau txais cov tshuaj macromolecular, zoo li hydrocolloids, nyob ntawm qhov chaw ntuj. Piv txwv li, agar-agar thiab carrageenan yog muab rho tawm los ntawm seaweed, gelatin tau los ntawm hydrolysis ntawm bovine thiab ntses proteins, thiab pectin yog muab rho tawm los ntawm citrus peels thiab kua pomace.
Gelatin khoom qab zib, ua los ntawm hmoov, muaj cov hydrocolloid sib txawv hauv lawv cov muaj pes tsawg leeg. Nws muaj dej tsawg.	Hydrocolloids yog siv rau hauv cov khoom noj uas cuam tshuam rau kev ntxhib los mos los yog viscosity (xws li ntses). Txawm li cas los xij, qhov sib xws twb nyob ntawm txoj kev kho cua sov.	Hydrocolloids-raws li kev kho mob hnav khaub ncaws yog siv los kho cov tawv nqaij thiab qhov txhab. ATkev tsim khoom yog ua raws li cov thev naus laus zis sib txawv, thiab tib lub polymers tau siv.

Lwm cov hydrocolloids tseem ceeb yog xanthan gum, gum arabic, guar gum, locust taum gum, cellulose derivatives xws li carboxymethyl cellulose, alginate thiab starch.

Kev sib cuam tshuam ntawm cov tshuaj macromolecular nrog lwm cov khoom

Cov rog hauv qab no ua lub luag haujlwm tseem ceeb hauv kev sib cuam tshuam ntawm colloidal hais:

• Repulsion yam tsis xav txog qhov ntim: qhov no yog hais txog qhov tsis muaj kev sib tshooj ntawm cov khoom siv.
• Electrostatic kev sib cuam tshuam: Colloidal hais feem ntau nqa hluav taws xob thiab yog li nyiam los yog sib ntaus sib tua. Kev them nqi ntawm ob qho tib si ntu ntu thiab tawg, nrog rau kev txav mus los ntawm theem, yog yam cuam tshuam rau qhov kev cuam tshuam no.
• Van der Waals rog: Qhov no yog vim muaj kev cuam tshuam ntawm ob lub dipoles, uas yog nyob mus ib txhis los yog induced. Txawm hais tias cov khoom tsis muaj dipole mus tas li, kev hloov pauv ntawm electron ntom ntom ua rau lub dipole ib ntus hauv cov khoom.
• Entropy rog. Raws li txoj cai thib ob ntawm thermodynamics, lub kaw lus nkag mus rau hauv lub xeev uas entropy yog maximized. Qhov no tuaj yeem ua rau kev tsim kom muaj zog txawm tias nyob nruab nrab ntawm qhov nyuaj.
• Steric rog ntawm polymer-coated nto los yog nyob rau hauv cov kev daws teeb meem uas tsis yog-adsorbent analog tau modulate interparticle rog, tsim ib tug ntxiv steric repulsive quab yuam uasyog feem ntau entropic nyob rau hauv cov xwm, los yog ib tug quab yuam ntawm depletion nyob rau hauv nruab nrab.

Cov nyhuv tom kawg tab tom nrhiav nrog cov txheej txheem tshwj xeeb superplasticizers tsim los ua kom muaj kev ua haujlwm ntawm pob zeb thiab txo nws cov ntsiab lus dej.

Polymer crystals: lawv pom qhov twg, lawv zoo li cas?

Cov tshuaj tiv thaiv siab molecular suav nrog cov muaju, uas suav nrog hauv qeb ntawm cov tshuaj colloidal. Qhov no yog ib qho kev txiav txim siab ntawm cov khoom uas tsim ntawm qhov deb heev (feem ntau ntawm qhov kev txiav txim ntawm ob peb millimeters rau ib centimeter) thiab zoo ib yam li lawv cov atomic lossis molecular counterparts.

Npe ntawm cov hloov pauv colloid	Kev txiav txim piv txwv	Production
Precious Opal	Ib qho piv txwv zoo tshaj plaws ntawm qhov tshwm sim no muaj nyob hauv cov xim ntshiab ntawm pob zeb	Qhov no yog qhov tshwm sim ntawm cov khoom ntim ze ntawm amorphous colloidal silicon dioxide (SiO2) spheres

Cov khoom kheej kheej no tau tso rau hauv cov khoom siv silicic heev. Lawv tsim cov khoom loj heev tom qab xyoo ntawm sedimentation thiab compression nyob rau hauv qhov kev txiav txim ntawm hydrostatic thiab gravitational rog. Periodic arrays ntawm submicrometer spherical particles muab zoo sib xws interstitial void arrays uas ua raws li ib tug natural diffraction grating rau pom lub teeb tsis, tshwj xeeb tshaj yog thaum interstitial spacing yog tib yam kev txiav txim ntawm magnitude li qhov teeb meem lub teeb yoj.

Yog li no, pom tias vim kev ntxub ntxaugCoulomb kev sib cuam tshuam, hluav taws xob macromolecules hauv qhov nruab nrab aqueous tuaj yeem pom qhov ntev-ntau zoo li siv lead ua kev sib raug zoo nrog qhov sib txawv ntawm cov khoom feem ntau loj dua li txoj kab uas hla ntawm ib tus neeg.

Nyob rau hauv tag nrho cov no, cov crystals ntawm ib tug natural macromolecular compound muaj tib lub ci ntsa iab iridescence (los yog ua si ntawm cov xim), uas tuaj yeem raug ntaus nqi rau kev sib txawv thiab kev cuam tshuam ntawm cov teeb pom kev zoo. Lawv txaus siab rau Bragg txoj cai.

Ntau qhov kev sim ntawm txoj kev tshawb fawb ntawm qhov hu ua "colloidal crystals" tau tshwm sim los ntawm cov txheej txheem yooj yim uas tau tsim nyob rau 20 xyoo dhau los kom tau txais cov khoom sib xyaw monodisperse colloids (ob leeg polymeric thiab ntxhia). Los ntawm ntau yam txheej txheem, kev tsim ntawm qhov kev txiav txim ntev ntev yog paub thiab khaws cia.

Kev txiav txim siab ntawm qhov hnyav molecular

Molecular hnyav yog cov khoom tseem ceeb ntawm cov tshuaj, tshwj xeeb tshaj yog rau cov polymers. Nyob ntawm cov khoom ntawm cov qauv, ntau txoj kev xaiv:

1. Molecular hnyav nrog rau cov qauv molecular ntawm molecules tuaj yeem txiav txim siab siv qhov loj spectrometry. Siv cov txheej txheem infusion ncaj qha, cov qauv tuaj yeem raug txhaj ncaj qha rau hauv lub ntsuas kom paub meej tias tus nqi ntawm cov khoom paub lossis muab cov yam ntxwv ntawm tus yam ntxwv tsis paub.
2. Cov ntaub ntawv hnyav molecular ntawm polymers tuaj yeem txiav txim siab siv txoj hauv kev xws li qhov loj me tsis suav nrog chromatography rau viscosity thiab loj.
3. rauKev txiav txim siab qhov hnyav molecular ntawm polymers yuav tsum nkag siab txog kev solubility ntawm ib qho polymer.

Tag nrho cov huab hwm coj ntawm ib lub tebchaw yog sib npaug rau cov lej ntawm tus kheej atomic masses ntawm txhua lub atom hauv molecule. Cov txheej txheem yog ua raws li tus qauv:

1. Kev txiav txim siab cov mis molecular ntawm lub molecule.
2. Siv lub sij hawm kom pom cov atomic loj ntawm txhua lub caij hauv ib lub molecule.
3. Mua qhov atomic loj ntawm txhua lub ntsiab lus los ntawm tus naj npawb ntawm atoms ntawm lub caij hauv lub molecule.
4. Tus lej tshwm sim yog sawv cev los ntawm tus lej sau ib sab ntawm lub cim cim hauv cov qauv molecular.
5. Txuas tag nrho cov txiaj ntsig ua ke rau txhua lub atom hauv molecule.

Ib qho piv txwv ntawm qhov yooj yim uas tsis muaj qhov hnyav molecular xam: Txhawm rau nrhiav qhov hnyav molecular ntawm NH _{3, thawj kauj ruam yog nrhiav cov atomic masses ntawm nitrogen (N) thiab hydrogen (H). Yog li, H=1, 00794N=14, 0067.}

Tom qab ntawd muab cov atomic loj ntawm txhua lub atom los ntawm tus naj npawb ntawm atoms hauv cov compound. Muaj ib lub atom nitrogen (tsis muaj subscript yog muab rau ib atom). Muaj peb hydrogen atoms, raws li qhia los ntawm subscript. So:

• Molecular hnyav ntawm ib yam khoom=(1 x 14.0067) + (3 x 1.00794)
• Molecular hnyav=14.0067 + 3.02382
• Result=17, 0305

Ib qho piv txwv ntawm kev xam qhov hnyav molecular Ca₃(PO₄)_{2 yog ntau txoj kev xaiv xam:}

Los ntawm lub sijhawm lub sijhawm, atomic masses ntawm txhua lub caij:

• Ca=40, 078.
• P=30, 973761.
• O=15.9994.

Qhov nyuaj yog xam seb muaj pes tsawg ntawm txhua lub atom nyob hauv qhov sib xyaw. Muaj peb lub calcium atoms, ob lub phosphorus atoms thiab yim oxygen atoms. Yog hais tias qhov kev koom ua ke yog nyob rau hauv kab lus, muab cov subscript tam sim ntawd tom qab lub cim cim los ntawm subscript uas kaw cov kab lus. So:

• Molecular hnyav ntawm ib yam khoom=(40.078 x 3) + (30.97361 x 2) + (15.9994 x 8).
• Molecular hnyav tom qab xam=120, 234 + 61, 94722 + 127, 9952.
• Result=310, 18.

Cov duab tsis sib xws ntawm cov ntsiab lus suav nrog kev sib piv. Qee qhov ntawm lawv muaj ntau pua tus nqi, yog li cov tshuab automated tam sim no siv nrog cov ntaub ntawv ntawm tag nrho cov nqi g/mol.