Simoní Da Ros

Cellulose‐derived materials, like paper and cellulose acetate, are known to be vulnerable to degradation within museum collections. Studies have been conducted and degradation markers have been identified on these materials. However, the degradation of man‐made cellulose‐derived fibers in collections is not well understood. This study aims to provide insights into historical cellulose acetate and regenerated cellulose textiles to quantify their physical and chemical changes during degradation using accelerated ageing experiments. Potential physical and chemical markers for degradation are identified, including changes in surface morphology, mass loss, discoloration and changes in spectral bands. These markers can be used to improve understanding of the degradation mechanisms of historical cellulose acetate and regenerated cellulose textiles and guide the development of conservation strategies. These findings have important implications for understanding the stability of man‐made cellulosic fibers in museum collections.

Systematic condition and analytical surveys were carried out on Zoe Leonard’s (b. 1961) Mouth Open, Teeth Showing 2000, an installation artwork in Tate’s collection consisting of 162 children’s dolls. The dolls were manufactured at various points within the 20th century and encompass several potentially problematic synthetic polymers found in modern and contemporary museum collections. To explore the doll materials and conservation condition, a multi-analytical approach was used to identify key synthetic polymer types and additives present, including portable and bench analytical techniques. Challenging degradation phenomena associated with different types of doll have been discussed and related to their material composition, which has helped our understanding of the conservation challenges inherent to this contemporary artwork.

Ethylene production via oxidative coupling of methane (OCM) represents an interesting route for natural gas upscaling, being the focus of intensive research worldwide. Here, OCM developments are analysed in terms of kinetic mechanisms and respective applications in chemical reactor models, discussing current challenges and directions for further developments. Furthermore, some thermodynamic aspects of the OCM reactions are also revised, providing achievable olefins yields in a wide range of operational reaction conditions. Finally, OCM catalysts are reviewed in terms of respective catalytic performances and thermal stability, providing an executive summary for future studies on OCM economic feasibility.