%0 Journal Article %1 Olderoy2009 %A Olderoy, M. O. %A Xie, M. L. %A Strand, B. L. %A Flaten, E. M. %A Sikorski, P. %A Andreassen, J. P. %D 2009 %I Amer Chemical Soc %J Crystal Growth & Design %K ACID; AGGREGATION; CELLS; COMPOSITES; IN-VITRO; MECHANISM; MICROCAPSULES; MODEL; WATER %N 12 %P 5176--5183 %R 10.1021/cg9005604 %T Growth and Nucleation of Calcium Carbonate Vaterite Crystals in Presence of Alginate %V 9 %X Structural biocomposites found in nature often have a well-defined organization on the nanometer scale. For mineralized materials, interactions between organic and inorganic phases are important for controlling crystal size, morphology, and spatial arrangement, which is a requirement when structural biomaterials are designed. In this paper, we studied influence of low concentrations of alginate on calcium carbonate crystallization by seeded and unseeded experiments, at controlled activity-based supersaturations. Crystal growth and nucleation were characterized by scanning electron microscopy (SEM), calcium concentration measurements, and crystal volume distribution measurements through the crystallization experiments. Alginate concentrations as low as 10 ppm were found to have a significant effect on growth of vaterite seeds, resulting in decreased growth rates and extensive agglomeration, compared to the case without alginate. For increased alginate concentrations (100 and 200 ppm), vaterite seed growth rates were decreased further. The decreased growth rates were probably caused by adsorption of alginate onto the active growth sites of the crystal surface. Alginate with 65% G-units (HighG) reduced the growth rate more than alginate with 43% G-units (LowG), which may be accounted for by the greater G-block length, and thus higher affinity to calcium, in HighG alginate. The unseeded experiments showed that mainly small vaterite crystals nucleated with 100 ppm alginate present, after an induction time of 50-80 min, while large calcite crystals were formed after sonic time by transformation from vaterite. The decreased crystal growth rates and higher nucleation rates caused by increased concentrations of alginate explain how small size mineral particles can be formed in alginate gel networks to form nanostructured composite materials.

@article{Olderoy2009, __markedentry = {[phpts:6]}, abstract = {Structural biocomposites found in nature often have a well-defined organization on the nanometer scale. For mineralized materials, interactions between organic and inorganic phases are important for controlling crystal size, morphology, and spatial arrangement, which is a requirement when structural biomaterials are designed. In this paper, we studied influence of low concentrations of alginate on calcium carbonate crystallization by seeded and unseeded experiments, at controlled activity-based supersaturations. Crystal growth and nucleation were characterized by scanning electron microscopy (SEM), calcium concentration measurements, and crystal volume distribution measurements through the crystallization experiments. Alginate concentrations as low as 10 ppm were found to have a significant effect on growth of vaterite seeds, resulting in decreased growth rates and extensive agglomeration, compared to the case without alginate. For increased alginate concentrations (100 and 200 ppm), vaterite seed growth rates were decreased further. The decreased growth rates were probably caused by adsorption of alginate onto the active growth sites of the crystal surface. Alginate with 65% G-units (HighG) reduced the growth rate more than alginate with 43% G-units (LowG), which may be accounted for by the greater G-block length, and thus higher affinity to calcium, in HighG alginate. The unseeded experiments showed that mainly small vaterite crystals nucleated with 100 ppm alginate present, after an induction time of 50-80 min, while large calcite crystals were formed after sonic time by transformation from vaterite. The decreased crystal growth rates and higher nucleation rates caused by increased concentrations of alginate explain how small size mineral particles can be formed in alginate gel networks to form nanostructured composite materials.}, added-at = {2011-11-04T13:47:04.000+0100}, af = {Olderoy, Magnus O.EOLEOLXie, MinliEOLEOLStrand, Berit L.EOLEOLFlaten, Ellen M.EOLEOLSikorski, PawelEOLEOLAndreassen, Jens-Petter}, author = {Olderoy, M. O. and Xie, M. L. and Strand, B. L. and Flaten, E. M. and Sikorski, P. and Andreassen, J. P.}, biburl = {https://www.bibsonomy.org/bibtex/284f718796744f8e453792edd0b43fb26/pawelsikorski}, c1 = {[Olderoy, Magnus O.; Xie, Minli; Sikorski, Pawel] Norwegian Univ Sci & Technol, Dept Phys, NO-7491 Trondheim, Norway.EOLEOL[Strand, Berit L.] Norwegian Univ Sci & Technol, Dept Biotechnol, NO-7491 Trondheim, Norway.EOLEOL[Flaten, Ellen M.; Andreassen, Jens-Petter] Norwegian Univ Sci & Technol, Dept Chem Engn, NO-7491 Trondheim, Norway.}, doi = {10.1021/cg9005604}, em = {magnus.olderoy@ntnu.no}, fu = {Research Council of Norway [182047]; Norwegian Foundation for HealthEOLEOLand Rehabilitation}, fx = {We acknowledge The Research Council of Norway for financial supportEOLEOLunder the NANOMAT program (project number 182047) and aid front EXTRAEOLEOLfunds from the Norwegian Foundation for Health and Rehabilitation viaEOLEOLThe Norwegian Diabetes Association (BLS). We would also like toEOLEOLacknowledge NTNU Nanolab for support with Hitachi S-5500 SEMEOLEOLexperiments.}, ga = {525BL}, interhash = {3dc2ab8b413cd56cd264e6172bb4bce5}, intrahash = {84f718796744f8e453792edd0b43fb26}, j9 = {CRYST GROWTH DES}, ji = {Cryst. Growth Des.}, journal = {Crystal Growth \& Design}, keywords = {ACID; AGGREGATION; CELLS; COMPOSITES; IN-VITRO; MECHANISM; MICROCAPSULES; MODEL; WATER}, la = {English}, month = dec, nr = {39}, number = 12, owner = {phpts}, pa = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, pages = {5176--5183}, pg = {8}, pi = {WASHINGTON}, publisher = {Amer Chemical Soc}, rp = {Olderoy, MO, Norwegian Univ Sci & Technol, Dept Phys, NO-7491EOLEOLTrondheim, Norway.}, sc = {Chemistry, Multidisciplinary; Crystallography; Materials Science,EOLEOLMultidisciplinary}, sn = {1528-7483}, tc = {0}, timestamp = {2011-11-04T13:47:20.000+0100}, title = {Growth and Nucleation of Calcium Carbonate Vaterite Crystals in Presence of Alginate}, ut = {ISI:000272188000028}, volume = 9, year = 2009 }