Matches in SemOpenAlex for { <https://semopenalex.org/work/W2296946114> ?p ?o ?g. }
Showing items 1 to 61 of
61
with 100 items per page.
- W2296946114 abstract "In summary, SPM data has shown that (1) Mg inhibits growth on all steps but relatively high Mg/Ca ratios are needed. Extracting the mechanism of interaction requires more modeling of the kinetic data, but step morphology is consistent with incorporation. (2) Citrate has several effects depending on the citrate/Ca ratio. At the lowest concentrations, citrate increases the step free energy without altering the step kinetics; at higher concentrations, the polar step is slowed. (3) Oxalate also slows the polar step but additionally stabilizes a new facet, with a [100]{sub Cc} step. (4) Etidronate has the greatest kinetic impact of the molecules studied. At 7{micro}M concentrations, the polar step slows by 60% and a new polar step appears. However, at the same time the [10-1]{sub Cc} increases by 67%. It should be noted that all of these molecules complex calcium and can effect kinetics by altering the solution supersaturation or the Ca to HPO{sub 4}{sup 2-} ratio. For the SPM data shown, this effect was corrected for to distinguish the effect of the molecule at the crystal surface from the effect of the molecule on the solution speciation. The goal of this paper is to draw connections between fundamental studies of more » atomic step motion and potential strategies for materials processing. It is not our intent to promote the utility of SPM for investigating processes in cement dynamics. The conditions are spectacularly different in many ways. The data shown in this paper are fairly close to equilibrium (S=1.6) whereas the nucleation of cements is initiated at supersaturation ratios in the thousands to millions. Of course, after the initial nucleation phase, the growth will occur at more modest supersaturations and as the cement evolves towards equilibrium certainly some of the growth will occur in regimes such as shown here. In addition to the difference in supersaturation, cements tend to have lower additive to calcium ratios. As an example, the additive to Ca ratio is {approx}10{sup -3} to 10{sup -4} for a pyrophosphate based cement (Grover et al., 2006). Where the in situ SPM approach provides unique insights is in providing details of where and how molecules inhibit or accelerate kinetics. This has the potential to aid in designing molecules to target specific steps and to guide synergistic combinations of additives. For example, it is unlikely that bulk techniques could deduce the simultaneous acceleration and inhibition effects of etidronate; or that citrate reduced growth rate by altering step density rather than step speed. In addition, SPM data translates to tractable questions for modelers. The questions changes from 'How does etidronate inhibit brushite growth?' to 'Why does etidronate bind strongly to the [101]{sub Cc} step while it doesn't to the [10-1]{sub Cc} step?' This is still a challenging question but it is far better defined. Given that step chemistries are generally different, it seems reasonable to expect that the greatest inhibition will be achieved not with one, but with several synergistically chosen additives. For example, the most effective growth inhibitors for brushite would target the two fast steps, namely the non-polar, [10-1]{sub Cc} and the polar, [101]{sub Cc} steps. Several molecules have been shown to slow the polar step, with etidronate as the most dramatic example. By contrast, only Mg was observed to slow the [10-1]{sub Cc} step. Thus, a combination of high concentrations of Mg to target the [10-1]{sub Cc} step with low concentrations of etidronate to target the polar steps, should be a more effective combination than either alone. However Mg is not a particularly good inhibitor in the sense that high concentrations are needed, and it is not specific. More ideally, an inhibitor would be designed to interact specifically with the [10-1] step, which would allow the two steps to be independently modified. Again, this provides an opportunity for tighter coupling with theoretical modeling. The question changes from 'What types of molecules will inhibit brushite growth' to 'What type of molecule will interact with the [10-1]{sub Cc} step?' Similarly, to increase resorption rate, it would be most efficacious to target the slow moving [-100] step, perhaps by targeting the hydroxyl group which seem to stabilize this step compared to its otherwise similar mirror, [100]. In short, there are a number of opportunities where molecular scale imaging can provide new information that has the prospect to aid in optimizing calcium phosphate cements. « less" @default.
- W2296946114 created "2016-06-24" @default.
- W2296946114 creator A5003209808 @default.
- W2296946114 creator A5013049079 @default.
- W2296946114 creator A5036900169 @default.
- W2296946114 creator A5068395403 @default.
- W2296946114 date "2009-05-31" @default.
- W2296946114 modified "2023-10-14" @default.
- W2296946114 title "Molecular mechanism of crystallization impacting calcium phosphate cements" @default.
- W2296946114 hasPublicationYear "2009" @default.
- W2296946114 type Work @default.
- W2296946114 sameAs 2296946114 @default.
- W2296946114 citedByCount "0" @default.
- W2296946114 crossrefType "journal-article" @default.
- W2296946114 hasAuthorship W2296946114A5003209808 @default.
- W2296946114 hasAuthorship W2296946114A5013049079 @default.
- W2296946114 hasAuthorship W2296946114A5036900169 @default.
- W2296946114 hasAuthorship W2296946114A5068395403 @default.
- W2296946114 hasBestOaLocation W22969461141 @default.
- W2296946114 hasConcept C111472728 @default.
- W2296946114 hasConcept C127413603 @default.
- W2296946114 hasConcept C138885662 @default.
- W2296946114 hasConcept C185592680 @default.
- W2296946114 hasConcept C191897082 @default.
- W2296946114 hasConcept C192562407 @default.
- W2296946114 hasConcept C203036418 @default.
- W2296946114 hasConcept C2777132085 @default.
- W2296946114 hasConcept C42360764 @default.
- W2296946114 hasConcept C519063684 @default.
- W2296946114 hasConcept C55493867 @default.
- W2296946114 hasConcept C89611455 @default.
- W2296946114 hasConceptScore W2296946114C111472728 @default.
- W2296946114 hasConceptScore W2296946114C127413603 @default.
- W2296946114 hasConceptScore W2296946114C138885662 @default.
- W2296946114 hasConceptScore W2296946114C185592680 @default.
- W2296946114 hasConceptScore W2296946114C191897082 @default.
- W2296946114 hasConceptScore W2296946114C192562407 @default.
- W2296946114 hasConceptScore W2296946114C203036418 @default.
- W2296946114 hasConceptScore W2296946114C2777132085 @default.
- W2296946114 hasConceptScore W2296946114C42360764 @default.
- W2296946114 hasConceptScore W2296946114C519063684 @default.
- W2296946114 hasConceptScore W2296946114C55493867 @default.
- W2296946114 hasConceptScore W2296946114C89611455 @default.
- W2296946114 hasLocation W22969461141 @default.
- W2296946114 hasLocation W22969461142 @default.
- W2296946114 hasOpenAccess W2296946114 @default.
- W2296946114 hasPrimaryLocation W22969461141 @default.
- W2296946114 hasRelatedWork W1964722019 @default.
- W2296946114 hasRelatedWork W1980494973 @default.
- W2296946114 hasRelatedWork W1988423447 @default.
- W2296946114 hasRelatedWork W1990203754 @default.
- W2296946114 hasRelatedWork W2024776273 @default.
- W2296946114 hasRelatedWork W2045022530 @default.
- W2296946114 hasRelatedWork W2143962568 @default.
- W2296946114 hasRelatedWork W2320217082 @default.
- W2296946114 hasRelatedWork W2748952813 @default.
- W2296946114 hasRelatedWork W2899084033 @default.
- W2296946114 isParatext "false" @default.
- W2296946114 isRetracted "false" @default.
- W2296946114 magId "2296946114" @default.
- W2296946114 workType "article" @default.