<div align="center"><img
src="http://www.plosone.org/article/fetchObject.action?uri=info:doi/10.1371/journal.pone.0068486.g002&representation=PNG_M" /></div>
<strong>Figure 2. Synthesis of Upsalite. i)</strong> In the first step MgO (s) is mixed with methanol under 3 bar
CO<sub>2</sub> pressure at 50°C. <strong>ii)</strong> After 2.5 h the HOMgOCH<sub>3</sub> is formed in the
solution, the pressure is lowered to 1 bar and the heating is turned off. At the same time the methanol reacts with the CO<sub>2</sub> and
forms CH<sub>3</sub>OCOOH (methyl hemicarbonic acid). <strong>iii)</strong> HOMgOCH<sub>3</sub> reacts with
CH<sub>3</sub>OCOOH and forms water and H<sub>3</sub>COCOOMgOCH<sub>3</sub> (methyl esther of magnesium methyl
carbonate). At this point the solution changes colour from white to light yellow. <strong>iv)</strong>
H<sub>3</sub>COCOOMgOCH<sub>3</sub> reacts with the water formed in step iii) and forms HOMgOCOOCH<sub>3</sub> (or
MgCO<sub>3</sub>·CH<sub>3</sub>OH) which upon <strong>v)</strong> heating at 70°C releases
CH<sub>3</sub>OH and forms MgCO<sub>3</sub>.
doi:<a href="http://dx.doi.org/10.1371/journal.pone.0068486.g002" target="_blank">10.1371/journal.pone.0068486.g002</a> <img
src="../scipics/_ext.png" />
. . .
Synthesis
In the current work 4 g magnesium MgO powder was placed in a glass bottle together with 60 ml methanol and a stirring magnet. The solution was put
under 3 bar CO<sub>2</sub> pressure and heated to 50°C. After approximately 4 hours the mixture was allowed to cool to RT and the
carbon dioxide pressure was lowered to 1 bar, and the reaction continued until a gel had formed. When a gel was obtained, the carbon dioxide pressure
was removed and the gel was allowed to solidify and dry at ~70°C during 3 days. A schematic description of the synthesis is found in Fig. 2.
– Forsgren J, Frykstrand S, Grandfield K, Mihranyan A, Strømme M (2013) <strong>A Template-Free, Ultra-Adsorbing, High Surface Area
Carbonate Nanostructure.</strong> PLoS ONE 8(7): e68486. doi:<a href="http://dx.doi.org/10.1371/journal.pone.0068486"
target="_blank">10.1371/journal.pone.0068486</a> <img src="../scipics/_ext.png" /> |