This study aimed to evaluate the effect of needle-like zinc oxide nanostructures (ZnO-NN) on the physical, chemical, and antibacterial properties of experimental methacrylate-based dental sealers. ZnO-NN was synthesized and characterized. ZnO-NN was added to a co-monomer blend at 20, 30, and 40 wt.%. One group without ZnO-NN was used as a control. The dental resin sealers were evaluated for their flow, film thickness, water sorption, solubility, radiopacity, degree of conversion (DC), dental-sealer interface characterization via micro-Raman, and antibacterial activity. ZnO-NN presented a mean needle diameter of 40 nm and 16 m²/g of surface area. There was no difference among groups containing ZnO-NN regarding their flow. The ZnO-NN addition significantly increased the film thickness. Water sorption and solubility tests showed no difference among groups. The radiopacity increased, and DC decreased with higher concentrations of ZnO-NN. Micro-Raman suggested that ZnO-NN was in close contact with root canal dentin. Overall, the incorporation of ZnO-NN provided an antibacterial effect against Enterococcus faecalis without a significant detrimental impact on the physical and chemical functionality of the material. The use of ZnO-NN as an inorganic filler is a potential application within dental materials intended for root canal treatment.

Recent increases in the demand for automotive lithium-ion batteries (LIBs) have led to higher needs for critical materials like lithium, cobalt, nickel, and graphite. Consequently, recovering materials from spent batteries has gained importance. This study aimed to (1) develop a mechanical pretreatment method for separating and concentrating materials from spent NCM₈₁₁ cells and (2) evaluate the economic, environmental, and shortage potentials of these fractions. The pretreatment involved grinding and granulometric separation, producing six particle-size fractions. The main novelty of the study was the assessment to identify the particle size fractions which are priorities for recycling for decision-making by recycling companies, optimizing their resources and efforts. Analysis showed that the finest fraction (n < 0.5 mm) had 85% of lithium, 77.4% of cobalt, 75.1% of manganese, and 68.5% of nickel. This fraction represented 40.4% of the processed mass and had the highest economic value (USD 3669/ton NCM cell). This fraction was also prioritized for recycling due to its superior environmental impact (103,788 kg CO₂-eq/ton NCM cell) and scarcity considerations. Furthermore, the black mass of NCM was the priority for recycling and had greater economic, environmental, and supply risk potential than the black mass of LFP cells.

Processos tecnológicos de manufatura aditiva, como a de impressão 3D, vem permitindo transcender os limites do desenvolvimento dos produtos atuais a um custo menor em de forma mais rápida. Nos últimos anos a impressão 3D se tornou mais fácil de usar e mais barata, tornando acessível para diferentes mercados. A literatura vem demonstrando que há uma grande demanda para conceber materiais mais sustentáveis para fabricação de bens de consumo por impressão 3D o que inclui, por exemplo, a utilização de resíduos de processos industriais da indústria moveleira como pós e serragens incorporados a matrizes poliméricas. Neste trabalho, foi utilizada a combinação de PLA com resíduos de pó de madeira com objetivo de criar um filamento com aspecto de madeira, com propriedades mecânicas melhores do que o filamento sem a adição da carga e assim mais sustentável. Para isto, fez-se primeiramente a caracterização do pó de madeira para determinar os melhores parâmetros de processo e após foram determinadas três formulações diferentes e extrudadas para a produção dos filamentos. Ao final foram analisadas quanto a suas propriedades de interesse.