简介:6-aminopenicillanicacid(6-APA)crystalsobtainedunderdifferentphysicalandchemicalconditionsofthesolutionsmaypresentdifferenthabits.Thehabitsofdiamond-shapedplatesaredesirablecomparedwithotherhabitsof6-APAcrystals.Toobtainideal6-APAcrystals,theeffectsofthemixedsolventsandadditiveson6-APAcrystalhabitswereinvestigated.Ethanoloracetonewasusedastheorganicsolvent,andimpuritiesexistinginthe6-APApurificationprocesswereusedastheadditives.6-APAgrowthhabitswerechangedwhentheconcentrationsofethanol,acetoneorphenylaceticacidwereincreasedtoexceedtheircriticalconcentration.Theobservedresultsshowthatthedominantfaceon6-APAcrystalswasidentifiedtobe{020},buttheoverallhabitwascontrolledbytherelativegrowthratesofthe{101}and{002}faces.Crystalgrowthratesandhabitscanbeappreciablychangedbyspecificadsorptionofadditivesoncrystalfaces.Insomecasessolventmoleculescanactinasimilarwayandmayberegardedasbulkadditives.Theeffectsofadditivesandorganicsolventson6-APAcrystalhabitsweretheresultsofadsorptioneffect,whichfittedtheexperimentalresultsquitewell.