Imperial College London
Alternate

Dr Umang Shah

Faculty of Engineering, Department of Chemical Engineering

Principal Teaching Fellow
 
 
 
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Contact

 

+44 (0)20 7594 6604u.shah09 Website

 
 
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Location

 

ACEX 210ACE ExtensionSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Smith:2016:10.1208/s12248-016-9978-y,
author = {Smith, RR and Shah, UV and Parambil, JV and Burnett, DJ and Thielmann, F and Heng, JY},
doi = {10.1208/s12248-016-9978-y},
journal = {AAPS Journal},
pages = {103--109},
title = {The effect of polymorphism on surface energetics of D-mannitol polymorphs},
url = {http://dx.doi.org/10.1208/s12248-016-9978-y},
volume = {19},
year = {2016}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - The aim of this work was to assess the effect of different crystalline polymorphism on surface energetics of D-mannitol using finite dilution inverse gas chromatography (FD-IGC). Pure α, β and δ polymorphs were prepared via solution crystallisation and characterised by powder X-ray diffraction (P-XRD). The dispersive surface energies were found to range from 43 to 34 mJ/m(2), 50 to 41 mJ/m(2), and 48 to 38 mJ/m(2) , for α, β, and δ, respectively, for surface coverage ranging from 0.006 to 0.095. A deconvolution modelling approach was employed to establish their energy sites. The primary sites corresponded to maxima in the dispersive surface energy of 37.1 and 33.5; 43.3 and 39.5; and 38.6, 38.4 and 33.0; for α, β, and δ, respectively. This methodology was also extended to an α-β polymorph mixture to estimate the amount of the constituent α and β components present in the sample. The dispersive surface energies of the α-β mixture were found to be in the range of 48 to 37 mJ/m(2) with 40.0, 42.4, 38.4 and 33.1 mJ/m(2) sites. The deconvolution modelling method extracted the energy contribution of each of the polymorphs from data for the polymorphic mixture. The mixture was found to have a β-polymorph surface content of ∼19%. This work shows the influence of polymorphism on surface energetics and demonstrates that FD-IGC coupled with a simple modelling approach to be a powerful tool for assessing the specific nature of this energetic distribution including the quantification of polymorphic content on the surface.
AU  - Smith,RR
AU  - Shah,UV
AU  - Parambil,JV
AU  - Burnett,DJ
AU  - Thielmann,F
AU  - Heng,JY
DO  - 10.1208/s12248-016-9978-y
EP  - 109
PY  - 2016///
SN  - 1550-7416
SP  - 103
TI  - The effect of polymorphism on surface energetics of D-mannitol polymorphs
T2  - AAPS Journal
UR  - http://dx.doi.org/10.1208/s12248-016-9978-y
UR  - http://hdl.handle.net/10044/1/41385
VL  - 19
ER  -
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