Study Of The Nucleation And Growth Of Calcium Oxalate Crystals On The L-cys Self-assembled Monolayer

In this paper, we used the X-ray diffraction (XRD) and scanning electron microscopy(SEM) as the characterization method, to study the nucleation and growth process of calciumoxalate (CaOxa) crystal in NaCl solution and L-cysteine self-assembled monolayer.In aqueous sodium chloride solution (pH=3.0), monohydrate calcium oxalate (COM) andcalcium oxalate dihydrate (COD) were both formed but disorderly growth. COD crystals with(411) plane were prefer to formed on L-cysteine SAM. Further discussion the reasons for theformation of COM and COD in solution at the same time, the reasons for of the formation ofCOD on L-cysteine SAM and its (411) surface sources.In aqueous sodium chloride solution of pH=5.0and7.0, both formed the hexagonalCOM. Hexagons and elongated hexagonal COM were formed on L-cysteine SAM in differentpH, respectively, and discussed the reasons for (100) plane preferential growth and possiblereasons for its shape appearance changed.In aqueous sodium chloride solution (pH=9.0), the single crystal and contact twincrystals of hydrated calcium oxalate were both formed. Only the penetrate twin crystals wereon L-cysteine SAM. The possible reasons for the formation of different twin crystals havebeen discussed.Urea under the acidic and heated conditions would hydrolysis slowly to make thesolution pH increased. We used urea to release the oxalate ion slowly and prepared the largesize calcium oxalate crystals.