Synthesis, self-assembly, and catalytic activity of histidine-based structured lipopeptides for hydrolysis reactions in water

International audienc

Formulation induces direct DNA UVA photooxidation. Part I. Role of the formulating cationic surfactant

International audienc

Separation of unsaturated C18 fatty acids using perfluorinated-micellar electrokinetic chromatography: II) role of nano-structuration

International audienceThree fatty acids were separated by micellar electrokinetic chromatography (MEKC) using ammonium perfluorooctanoate as volatile surfactant. Characterizations of both injection buffer and background electrolyte have been performed by complementary techniques including scattering experiments (light, x-rays) and NMR. Different structures have been observed such as small micelles at low methanol content and larger aggregates at high methanol content. In both cases fatty acids interact specifically with the perfluorinated self-assemblies due to different geometrical constraints and different interactions between polar head groups, ensuring separation by MEKC

Chemical recycling of polyester textile wastes: shifting towards sustainability

International audienceAmongst all synthetic polymers used in the clothing industry, polyethylene terephthalate (PET) is the most widely used polyester, its fibres representing half the total PET global market (in comparison bottle PET being less than a third). Compared to bottle PET, the recycling of fabric PET fibres represents a challenge, both due to intrinsic structural differences (chain length and crystallinity) and to the presence of various additives (dyes, protection or finishing agents). Effective waste management requires addressing these additives through elimination or recycling processes. This review article aims to give an overview about all the existing means to recycle PET fibres. Textile recycling encompasses primary (closed-loop), secondary (mechanical), tertiary (chemical), and quaternary (incineration with energy recovery) processes. Mechanical recycling faces challenges due to PET's characteristics, including lower molecular weight and additives. Chemical recycling, particularly solvolysis processes (hydrolysis in neutral, acidic, or alkaline media, alcoholysis, glycolysis, aminolysis or enzymatic hydrolysis), offers a more advanced approach and will be described in detail, focusing both on the specific recycling of fibres when available and enlightening the advantages and drawbacks of each method. To discuss the environmental impact of each process, a quantitative analysis was conducted by defining the experimental domain represented by the temperature range and reaction time, and then calculating the energy-saving coefficient, as a green metric adapted to the diversity of textile PET recycling processes and data provided in the literature. This coefficient allows for discussing the relevance of using complex or non-renewable catalysts in processes, the positioning of enzymatic pathways, and the choice of reaction mechanisms applicable to the industry. A prospective approach was employed to identify key criteria for future advancements in green recycling. Subsequently, a comparative analysis of depolymerisation methods will be presented within the context of sustainable development goals (SDGs), green chemistry, and green metrics. Finally, using ε factors, this analysis will facilitate the detection and highlighting of pathways that show the most promise in terms of greening PET recycling.