In order to understand much of the chemistry that underpins astronomical phenomena (e.g. star and planet formation) it is essential to probe the physico-chemistry of ice surfaces under astronomical conditions. The physical properties and chemical reactivity of such icy surfaces depends upon its morphology. Thus it is necessary to explore how the morphology of astrochemical ices is influenced by their local environment (e.g. temperature and pressure) and the mechanisms by which they are processed. In this paper we report the results of a series of experiments to explore the morphology of a variety of molecular ices using VUV spectroscopy. Spectral signatures are found that may allow the morphology of such ices to be identified.

Various fluorescence techniques and cloud point measurements have been used to study the effects of altering the hydrophilic/hydrophobic balance in a series of N-isopropylacrylamide (NIPAM)/N,N-dimethylacrylamide (DMAC) statistical copolymers upon the smart thermal responses of these systems in dilute aqueous solution. As expected, incorporation of DMAC into the polymer structure raises its lower critical solution temperature to an extent dependent upon DMAC content. However, use of such a hydrophilic modifier reduces the magnitude of the collapse transition that characterizes the macromolecule's thermal response. In PNIPAM, the LCST is associated with a conformational transition between a coil and a globule. However, introduction of DMAC derivatives into the polymer expands its “globular” form into a much more open structure that progressively loses its capacity for solubilization of organic guests. Consequently, although copolymerization with more polar monomers can be used to raise the LCST of NIPAM-based thermoresponsive polymers, the value of this approach will be limited in applications requiring switchable carrier/release properties.