1887
banner image
No data available.
Please log in to see this content.
You have no subscription access to this content.
No metrics data to plot.
The attempt to load metrics for this article has failed.
The attempt to plot a graph for these metrics has failed.
Glycine phases formed from frozen aqueous solutions: Revisited
Rent:
Rent this article for
USD
10.1063/1.4739532
/content/aip/journal/jcp/137/6/10.1063/1.4739532
http://aip.metastore.ingenta.com/content/aip/journal/jcp/137/6/10.1063/1.4739532

Figures

Image of FIG. 1.
FIG. 1.

Low-wavenumber Raman spectra of α-, β-, and γ-phases of glycine at room temperature and of X-phase at 224 K.

Image of FIG. 2.
FIG. 2.

Low-wavenumber Raman spectra of aqueous glycine solution during freezing with cooling rate 5 K/min at few typical temperatures.

Image of FIG. 3.
FIG. 3.

Low-wavenumber Raman spectra of frozen aqueous glycine solution during annealing at = 253 K for some selected times. Inset illustrates the temporal dependence of the intensities of ice band maximum (triangles) and β-glycine peak at 111 cm−1 (circles), and an exponential description in the case of β-glycine peak.

Image of FIG. 4.
FIG. 4.

Low-wavenumber Raman spectra of aqueous glycine solution quenched to liquid nitrogen and heated to 213 K (thin line is experimental data and thick line is a smoothing curve).

Image of FIG. 5.
FIG. 5.

Low-wavenumber Raman spectra illustrating the phase transitions of glycine from glassy to X-phase near 216 K (top panel) and from X- to β-phase near 226 K (bottom panel).

Image of FIG. 6.
FIG. 6.

Raman spectra of α-, β-, γ-, and X-phases of glycine at liquid nitrogen temperature.

Image of FIG. 7.
FIG. 7.

Powder x-ray diffraction patterns of the sample obtained by cooling aqueous glycine solution at a copper plate (top panel) and of the separated transparent plates of the “glassy phase” (bottom panel). The patterns with the highest intensity of the reflections from the “X-phase” are highlighted by color, to facilitate a comparison of the intensities of the reflections from “X-phase” and ice I. The reflections of the “X-phase” are marked by asterisks, the positions of the reflections of β-glycine and ice I are shown by ticks at the bottom of the diagrams.

Image of FIG. 8.
FIG. 8.

DSC curves of the frozen glycine aqueous solutions obtained at different conditions. (1) a droplet of glycine aqueous solution (20% w/w) was frozen directly in the DSC crucible from room temperature to 153 K (cooling rate 10 K/min) and then measured on heating (“method 3”); (2) the sample prepared by “method 2b” (30% w/w), glassy phase; (3) the sample prepared by “method 1a” (15% w/w); (4) DSC curve from Ref. 78 , scaled to the load of 10 mg; (5) the sample prepared by “method 2a” (30% w/w), mixture “as is,” before the separation of the glassy phase.

Image of FIG. 9.
FIG. 9.

X-ray diffraction patterns from the samples of the initially amorphous “glassy phase” (formed from the frozen aqueous glycine solution) annealed at several temperatures. Asterisks are the strongest reflections of the X-phase.

Tables

Generic image for table
Table I.

A summary of the sample preparation techniques used for DSC and x-ray diffraction study.

Generic image for table
Table II.

Apparent Raman line positions of α-, β-, γ-, and X-phases of glycine at 78 K.

Loading

Article metrics loading...

/content/aip/journal/jcp/137/6/10.1063/1.4739532
2012-08-10
2014-04-19
Loading

Full text loading...

This is a required field
Please enter a valid email address
752b84549af89a08dbdd7fdb8b9568b5 journal.articlezxybnytfddd
Scitation: Glycine phases formed from frozen aqueous solutions: Revisited
http://aip.metastore.ingenta.com/content/aip/journal/jcp/137/6/10.1063/1.4739532
10.1063/1.4739532
SEARCH_EXPAND_ITEM