Polymers are extensively used in food and beverage packaging to shield against contaminants and external damage due to their barrier properties, protecting the goods inside and reducing waste. However, current trends in polymers for food, water, and beverage applications are moving forward into the design and preparation of advanced polymers, which can act as active packaging, bearing active ingredients in their formulation, or controlling the head-space composition to extend the shelf-life of the goods inside. In addition, polymers can serve as sensory polymers to detect and indicate the presence of target species, including contaminants of food quality indicators, or even to remove or separate target species for later quantification. Polymers are nowadays essential materials for both food safety and the extension of food shelf-life, which are key goals of the food industry, and the irruption of smart materials is opening new opportunities for going even further in these goals. This review describes the state of the art following the last 10 years of research within the field of food and beverage polymer’s applications, covering present applications, perspectives, and concerns related to waste generation and the circular economy.

Aramids, renowned for their high-performance attributes, find applications in critical fields such as protective equipment, aerospace components, and industrial filters. However, challenges arise in scenarios in which frequent washing is impractical, leading to bacterial proliferation, especially in textiles. This study outlines a straightforward and scalable method for preparing aramid-coated textiles and films endowed with inherent bactericidal activity, achieved by reacting parent aramids with vanillin. The functionalization of the aramids with bactericide moieties not only preserved the high-performance characteristics of commercial aramids but also improved their crucial mechanical properties. Tensile tests revealed an increase in Young's modulus, up to 50% compared to commercial m-aramid, accompanied by thermal performance comparable to commercial m-aramids. The evaluation of these coated textiles as bactericidal materials demonstrated robust effectiveness with A parameters (antibacterial activity) of 4.31 for S. aureus and 3.44 for K. pneumoniae. Reusability tests (washing the textiles in harsh conditions) underscored that the bactericide-coated textiles maintain their performance over at least 5 cycles. Regarding practical applications, tests performed with reconstructed human epidermis affirmed the nonirritating nature of these materials to the skin. The distinctive qualities of these metal-free intrinsic bactericidal aramids position them as ideal candidates for scenarios demanding a synergy of high performance and bactericidal properties. Applications such as first responders' textiles or filters stand to benefit significantly from these advanced materials.

Gradient porous materials, particularly carbon-based materials, hold immense potential in the fields of batteries, energy storage, electrocatalysis, and sensing, among others, by synergistically combining the attributes associated with each pore size within a unified structural framework. In this study, we developed a gradient porous aramid (GP-Aramid) by incorporating cellulose acetate as a porosity promoter in the polymer casting solution in different proportions. These GP-Aramids were subsequently transformed into their pyrolyzed counterparts (GP-Pyramids), retaining their original structures while displaying diverse cellular or dense microstructures inherited from the parent aramid, as confirmed via scanning electron microscopy. X-ray diffraction spectra provided evidence of the conversion of aramids into carbonaceous materials. The materials showed structural defects observed through the intensity ratio of the G and D bands (ID/IG = 1.05) in the Raman spectra, while X-ray photoelectron spectra (XPS) revealed that the carbonization process yielded pyrolyzed carbon materials unusually rich in nitrogen (6%), oxygen (20%), and carbon (72%), which is especially relevant for catalysis applications. The pyrolyzed materials showed bulk resistivities from 5.3 ± 0.3 to 34.2 ± 0.6 depending on the meta- or para-orientation of the aramid and the porous structure. This work contributes to understanding these gradient porous aromatic polyamides’ broader significance and potential applications in various fields.