Hygrothermal effects on painted carbon fibre composite surfaces

In this article, the effect of hygrothermal aging on the painted surface finish of unidirectional and fabric carbon fibre composite laminates, with and without surfacing film was investigated. The results highlighted the importance of ensuring that the composite surface directly beneath the paint layer is made from a uniform material with a consistent thickness in order to minimise surface defects from occurring during aging. The surfacing film was found to minimise the print through development on the painted unidirectional and twill composite surfaces. However, the surfacing film layer was found to intermingle with the carbon fibre plies during cure, which resulted in an uneven film thickness that caused increased levels of orange peel. The twill laminate painted surface produced high levels of print through and surface waviness that was caused by the large resin rich regions located within the tow intersections at the surface which enlarged due to thermal expansion and swelling of the matrix with hygrothermal aging. It was also noted that the small resin rich regions between the individual carbon fibres on the unidirectional composite surface were sufficiently large to print through the painted surface

Versatile, High Quality and Scalable Continuous Flow Production of Metal-Organic Frameworks

Further deployment of Metal-Organic Frameworks in applied settings requires their ready preparation at scale. Expansion of typical batch processes can lead to unsuccessful or low quality synthesis for some systems. Here we report how continuous flow chemistry can be adapted as a versatile route to a range of MOFs, by emulating conditions of lab-scale batch synthesis. This delivers ready synthesis of three different MOFs, with surface areas that closely match theoretical maxima, with production rates of 60 g/h at extremely high space-time yields

Dynamic porosity and transport properties of membrane materials

There are numerous reasons why the exploration of dynamic free volume is particularly important for membrane materials; a few of these include the ability to gain knowledge on plasticization and competitive sorption effects on transport properties. Positron annihilation lifetime spectroscopy (PALS) is a versatile characterisation technique able to measure angstrom to meso sized pores in a variety of materials including polymeric, hybrid, and inorganic membrane materials. Within this work we present the PALS technique and its ability to determine the pore sizes and free volume distribution of a variety of membrane materials. We demonstrate how PALS can be used to observe structural changes in different environments so that we can get a better understanding of how materials behave in dynamic environments. This capability enables understanding of the material behaviour for the particular application environment being investigated and allows us to better tailor the material chemistry and processing to optimize performance

Dynamic porosity and transport properties of membrane materials

There are numerous reasons why the exploration of dynamic free volume is particularly important for membrane materials; a few of these include the ability to gain knowledge on plasticization and competitive sorption effects on transport properties. Positron annihilation lifetime spectroscopy (PALS) is a versatile characterisation technique able to measure angstrom to meso sized pores in a variety of materials including polymeric, hybrid, and inorganic membrane materials. Within this work we present the PALS technique and its ability to determine the pore sizes and free volume distribution of a variety of membrane materials. We demonstrate how PALS can be used to observe structural changes in different environments so that we can get a better understanding of how materials behave in dynamic environments. This capability enables understanding of the material behaviour for the particular application environment being investigated and allows us to better tailor the material chemistry and processing to optimize performance