Towards the understanding and prediction of material changes during micronisation using atomic force microscopy.

In this study we aim to explore the potential links between the mechanical properties, micronisation behaviour and surface energy of carbamazepine polymorphs using atomic force microscopy (AFM) measurements of material properties at the nanoscale. Carbamazepine Forms I, II and III were prepared and confirmed using X-ray powder diffraction (XRPD). AFM measurements of indentation hardness, Young's modulus and surface energy were made on the starting material.

Unified approach to ion transport and structural relaxation in amorphous polymers and glasses.

Kinetic data for structural relaxation in silver iodomolybdates at the glass transition temperature (Tg) are obtained by high-pressure differential scanning calorimetry (HP-DSC) and are compared with activation energies (EA) and volumes (VA) obtained earlier from conductivities below Tg. The results are fitted to an empirical equation, EA = MVA, and displayed in the form of a master plot of EA versus VA, an approach previously applied to strongly coupled systems, including polymer electrolytes and molten salts above their glass transition temperatures. The parameter M emerges as a localized modulus, expressive of interatomic forces within the medium, linking together EA,sigma, VA,sigma and EA,s, VA,s, the "apparent" activation parameters for ionic conductivity and structural relaxation, respectively.

High pressure differential scanning calorimetry investigations on the pressure dependence of the melting of paracetamol Polymorphs I and II.

A high pressure differential scanning calorimeter (HP-DSC) has been used to investigate the pressure dependence of the melting of the monoclinic (Form I) and orthorhombic (Form II) polymorphs of paracetamol (acetaminophen). DSC scans obtained at ambient pressure show that the stable monoclinic form melts at 442 K while the metastable orthorhombic form melts at 430 K. HP-DSC scans obtained for pressures up to about 450 MPa show that the melting temperatures of both Forms I and II increase with increasing pressure, but the latter more rapidly than the former.