Understanding calcium carbonate crystallization processes and the effects of saccharide surface interactions
- Degree Grantor:
- University of California, Santa Barbara. Chemical Engineering
- Degree Supervisor:
- Bradley Chmelka and Michael Doherty
- Place of Publication:
- [Santa Barbara, Calif.]
- Publisher:
- University of California, Santa Barbara
- Creation Date:
- 2016
- Issued Date:
- 2016
- Topics:
- Materials science, Inorganic chemistry, and Chemical engineering
- Keywords:
- Crystallization,
Vaterite,
Calcium carbonate,
Saccharide,
Calcite, and
Surface additive - Genres:
- Online resources and Dissertations, Academic
- Dissertation:
- M.S.--University of California, Santa Barbara, 2016
- Description:
Biological organisms are able to selectively synthesize and stabilize different polymorphs of calcium carbonate, including metastable vaterite and amorphous calcium carbonate (ACC), in a process known as biomineralization. Stabilization is accomplished by introducing other ions, such as magnesium or silicate, into the calcium carbonate material to stabilize the formation of less energetically favorable polymorphs, and also via interactions of biomolecules, such as proteins or saccharides, with the particle surface to slow the kinetics of the crystallization processes. In this work, the effects of two different saccharide surface additives, glucose and sucrose, on the crystallization process of amorphous calcium carbonate were investigated. The crystallization process was characterized using solid-state nuclear magnetic resonance (NMR) spectroscopy, wide-angle x-ray diffractometry (XRD), transmission and scanning electron microscopy (TEM and SEM), and nitrogen adsorption porosimetry. Both the glucose and sucrose adsorbates delayed the onset and progression of crystallization of amorphous calcium carbonate, though the respective products of the crystallization process differed. Adsorbed glucose surface favored the formation of the thermodynamically stable calcite polymorph, while adsorbed sucrose favored the formation of the metastable vaterite polymorph. The observed differences likely arose from the fact that glucose is a reducing saccharide that interacted with the surface of the amorphous calcium carbonate particles primarily via electrostatic interactions, while sucrose, a non-reducing saccharide, interacted with the particle surfaces via hydrogen bonding in addition to electrostatic interactions. Furthermore, initial studies of adsorbed maltose (reducing saccharide) and trehalose (non-reducing saccharide) revealed that these surface additives exhibited the same inhibition of crystallization.
- Physical Description:
- 1 online resource (82 pages)
- Format:
- Text
- Collection(s):
- UCSB electronic theses and dissertations
- Other Versions:
- http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqm&rft_dat=xri:pqdiss:10190199
- ARK:
- ark:/48907/f33n23jf
- ISBN:
- 9781369339673
- Catalog System Number:
- 990047189150203776
- Copyright:
- Katherine Brune, 2016
- Rights:
- In Copyright
- Copyright Holder:
- Katherine Brune
File | Description |
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Access: Public access | |
Brune_ucsb_0035N_13109.pdf | pdf (Portable Document Format) |