Ngokuqinisekileyo wakha weva ngekristali, kunokwenzeka ukuba ngeli xesha ingqondo yakho ibone idayimani enkulu, iamethiste okanye itopazi. Ngokuqinisekileyo, eli qela libandakanya ezininzi ezaziwayo "Amatye axabisekileyo", kodwa ikristale ayililo ihlelo elibandakanya ngokucacileyo intsimi yobucwebe.
I-crystal yinto yokugqibela yenkqubo enomdla eyaziwa ngokuba yi-crystallization, ebonakaliswa ngokubangela ukuqina okuhambisanayo okwenziwe "ngobuso", eziyinxalenye yeenqwelomoya ezahlukeneyo.
Iimpawu zokomelela okuvela kwi-crystallization
Ubungakanani bekristale luphawu oluguqukayo, kuluhlu olubanzi lweemilinganiselo. "Amakhulu" amakristali anokufunyanwa anokulinganiswa ngeyunithi yomgama "wemitha", ngokunjalo fumana iikristali kumele ukuba kunjalo ibonakaliswe ngokwe "microns", kuba ubungakanani bayo obuncinci bubenza bathelekiswe neentsholongwane ezinjengeebhaktheriya, ezibonakala kuphela kwimicroscope.
Njengoko sele kukhankanyiwe, iinkqubo ze-crystalline zikhokelela kwimveliso yokucoceka okuphezulu, yiyo loo nto sisungule, ngaphambili kwinkcazo, ukuba iikristali ziyafanaOko kukuthi, ukwakhiwa kwemveliso kuhlala kunexabiso elingaguquguqukiyo ngalo naliphi na ixesha kumthamo wento eqinileyo, ekwathetha ukuba iimpawu zomzimba kunye neekhemikhali zihlala zingatshintshi kulo lonke iqhekeza, kwaye kwimeko yokujonga umahluko ngenxa yokuphazamiseka, utshintsho luya kwenzeka kuzo zonke iintlobo. Lo mgangatho wenza iikristali ezixabisekileyo kwimimandla eyahlukeneyo, ukusukela ekuxabisweni komgangatho wezinto, ukuya kwi Ukusetyenziswa kwenkqubo ye-crystallization njengenkqubo yokwahlula izinto.
Iimveliso zeCrystalline zinokwahlulwa kwinqanaba lebhubhoratri, ngokuphendula okulawulwayo kwiindibano ezilinganisa iinkqubo ezizenzekelayo ezenzeka kwindalo. Enye yeenzuzo eziphambili zeekristali ezifunyenwe kwiinkqubo ezilawulwayo kukuba zibonisa iimilo eziqhelekileyo, ezihambelana ngokuchanekileyo namanani eepoligoni ngokuchanekileyo okukhulu.
Kwikristale, kufuneka sahlule ubuso obuyinxalenye yomkhwa wokwenene wekristali (iimpawu ze-morphological), kwaye ngokusekwe kwinani labo, sinokuthi siqwalasele imilo esisiseko yokuqina. Ngokwesiqhelo kwi yikristale ichazwa ngokudibana kweemilo ezininzi ezisisiseko, ezona ziphambili zezi zilandelayo:
- Isibonelelo: Iglasi ebunjwe bubuso obucwangcisiweyo, ngaphandle kokulingana.
- IPinacoid: Yenziwe bubuso obulinganayo obulinganayo omnye komnye ngokubhekisele kwi-axis yolingano.
- Ispenoid: Ubuso obulinganayo obenza obu buxoki buqinileyo bujikeleze i-axis ebini.
- Ibhanti: Yenziwe ngobuso be-homologous obenza indawo. Ukuba "yindawo yekristale" ichazwa njengeseti yobuso ehambelana kwicala elinye, elihambelana nomphetho ofanayo.
Ubume beekristali ezivela kwindawo yangaphakathi yokujonga zinokuthi zithathelwe ingqalelo yinkqubo engaphezulu okanye encinci, efanayo kunye nenkqubo ye-anisotropic yento echithakeleyo ephuhlisa ubume kwiindawo ezahlukeneyo esithubeni. Ngaphakathi kweempawu zeekristali, inzala ihlala ivuswa yinto yokuba inqaku ngalinye uphinda rhoqo kwindawo ekuhlalwa kuyo yimathiriyeli. Kwi-crystallography, into echaphazela esi senzo ibizwa ngokuba inguqulelo.
Inkqubo yeCrystallization
Ukuze i-crystallization yenzeke, kufuneka siqale kwinto enokuthi ihlelwe njenge "Ikristale", kwaye oku kuchazwa ngenxa yokuba amasuntswana ayenzayo, nokuba ngawokwakheka kwe-athomu, yemolekyuli okanye ye-ionic, aneempawu zobungqingili, amaxesha ngamaxesha kunye nolingano.
Yonke le nkqubo iyenziwa isebenze xa kwindawo ethile ngekristali, amasuntswana aqala ukuzilungisa, kwinqanaba elaziwa njenge yenucleation. Yonke le nkqubo ibandakanya, ukongeza kukwahluka okubonakalayo ngokulandelelana kwamasuntswana, inkqubo yotshintsho kwimeko ye-thermodynamic, ejolise kwimbuyekezo yokuphazamiseka okwenziwe lutshintsho kumandla asimahla eGibbs, aphawulwe imicimbi emithathu:
- Utshintsho kumandla emichiza.
- Ukudalwa konxibelelwano phakathi kwendawo ye-nucleation kunye nalo lonke isigaba esilinganayo.
- Umahluko kumthamo kunye nokumila kwale nkqubo kubandakanya ukubangela ukungavisisani.
Inqanaba elilandelayo livela, xa ulwakhiwo lwesiseko se-nucleation luzinzile. Isinyathelo esilandelayo yinto enengqiqo kunye nokuqikelela, xa sinesakhiwo esisisiseko siya kungena kwinkqubo ukukhula, apho utshintsho kubukhulu be-nucleus bujongwa. Kancinci kancinci, oku kunyuka kuya kubangela ukuyilwa kobuso, de kube ikristale ifumane umkhwa ochazwe kakuhle.
Indlela yokukhula kwekristale
Ithiyori equlunqwe nguVolmer icacisa indlela ukukhula kwekristale eyenzeka ngayo, eqinisekisa ukuba, malunga nesakhiwo esisiseko esivela kwi-nucleation yento yekristali, umaleko wokufunxa, esebenza njengonxibelelwano, kwaye ukongeza koku, ikhuthaza ukufuduka kwamasuntswana ayijikelezileyo, ahamba ngokuhambelana nomphezulu. Iziphumo zale nkqubo zichazwa njengolwakhiwo oluchazwe kwindawo-mbini.
Ngokwabo, uKossel noStraski, bazimisele ukuba Umsebenzi woomatshini uyafuneka ukufezekisa ukulungiswa kwe-ion kumphezulu woluhlu, kwaye kuxhomekeke kwindawo yalo.
Ukuphuhliswa kwemodeli echaza ukukhula kufuna uqikelelo lweendawo zokugcwala apho kugqalwa khona inqanaba lotshintsho oluphezulu (indawo yommandla ophezulu). Oku kubonisa ukuba ukukhula kwekristale kwenzeka kumaleko.
I-crystallization njengendlela yokwahlula
Kuba ikristale yenziwa ngento eyohlobo olunye, ukusetyenziswa kwayo njengendlela yokwahlulahlula izinto ngokukhethekileyo kwandisiwe, phakathi kweendlela ezininzi, apha ngezantsi, siza kuchaza ukuba abo basebenzisa kakhulu baquka:
- Ukongeza isinyibilikisi esitshaUkuba siyabazi ubunjani beemveliso esiziphetheyo, singasebenzisa le ndlela, enesiseko sokudibanisa isinyibilikisi esitsha esinxibelelana nesinyibilikisi ekuntywiliselwa kuso isinyibilikisi. Xa isinyibilikisi esitsha ngokukhetha siqala ukunxibelelana ne-homologue yayo, i-solute precipitates, eqala inkqubo ye-crystallization.
- Ukupholisa kwindawo ephezulu yokunyibilika: Xa sinesisombululo esine-high-concentration, esenziwe kubushushu obuphezulu, kwaye siyifaka kwinkqubo yokupholisa, sifumana imeko ye-supersaturation, apho isixa esikhulu sesinyibilikisi siyanyibilika kunokuba isinyibilikisi sinokwamkela, kwezo zintsha iimeko zobushushu. Ukuba inkqubo yokunciphisa ubushushu yenziwe ngendlela elawulwayo, sinokuba nefuthe kubungakanani bekristale esiza kuyifumana.
- Sublimation: Obu buchule bunokusetyenziswa kuphela kwimixube ye-crystalline ebonisa uxinzelelo oluphezulu lomphunga, ngendlela yokuba utshintsho ukusuka kwisigaba segesi ukuya esiqinileyo akufuneki ukuba kudlule kwindawo yokunyibilika.