http://www.bdtd.uerj.br/handle/1/3710 Fri, 11 Sep 2026 23:46:21 GMT 2026-09-11T23:46:21Z http://www.bdtd.uerj.br/handle/1/26115 Título: Microesferas de poli(estireno-co-divinilbenzeno) contendo escovas de poliestireno funcionalizadas com grupos 2,4,6-trimercaptotriazina para remoção de paládio(II) Autor: Cunha, Henrique Almeida Primeiro orientador: Costa, Marcos Antônio da Silva Abstract: The removal of residual palladium from active pharmaceutical ingredients (APIs) has become a critical issue in pharmaceutical manufacturing due to the strict limits established by the International Council for Harmonisation (ICH Q3D) for elemental impurities. Palladium, classified as a Class 2B element, is widely employed as a catalyst in carbon–carbon coupling reactions but may remain in the final product even after conventional purification steps. In this context, polymeric resins functionalized with 2,4,6-trimercaptotriazine (TMT) have emerged as selective scavengers for Pd(II), although commercial materials often exhibit slow adsorption kinetics, requiring long contact times. In this thesis, poly(styrene-co-divinylbenzene) (PS-DVB) microspheres with different porous structures and functionalization strategies were developed, including direct incorporation of TMT groups and surface modification through polystyrene brushes grown by surface-initiated atom transfer radical polymerization (SI-ATRP). The aim was to increase both the density and accessibility of chelating sites and to enhance palladium(II) removal kinetics in aqueous media. The synthesized resins were characterized by Fourier-transform infrared spectroscopy (FTIR), elemental analysis (CHNS), nitrogen adsorption, scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). Kinetic adsorption experiments were performed at different initial Pd(II) concentrations (15 and 30 mg·L⁻¹) and temperatures (20, 35, and 50 °C). The results revealed a dual temperature effect: higher temperatures enhanced the initial adsorption rate due to improved mass transfer, while the equilibrium adsorption capacity decreased, indicating a globally exothermic adsorption process. Among the evaluated materials, PS-DVB-Cl-TMT exhibited faster adsorption kinetics, whereas PS-DVB-TMT showed the highest final removal efficiency, exceeding 98% under optimized conditions. Overall, the findings demonstrate that resin architecture, functionalization route, and operating conditions play a decisive role in palladium removal performance. The developed materials show strong potential for application in API purification, enabling palladium levels to be reduced to meet regulatory requirements and providing guidance for the optimization of industrial metal-scavenging processes. Instituição: Universidade do Estado do Rio de Janeiro Tipo do documento: Tese Wed, 03 Jun 2026 00:00:00 GMT http://www.bdtd.uerj.br/handle/1/26115 2026-06-03T00:00:00Z http://www.bdtd.uerj.br/handle/1/26088 Título: Estudo de semicondutores compostos por Nb e Sn para aplicação na fotodegradação de azocorantes Autor: Maia, Adriane Elise Primeiro orientador: Rocha, Angela Sanches Abstract: Dyes are among the emerging contaminants of greatest concern, driving the development of abatement methods such as photocatalytic degradation. In this context, the present study aimed to synthesize and characterize niobium and tin oxides in both pure and mixed forms, evaluate their performance in the decolorization of the Reactive Yellow 4GL dye under UV and visible radiation, investigate the degradation mechanism using scavengers, and assess the feasibility of immobilizing these materials in chitosan-based composite films. The catalysts were obtained via a novel route using the sol-gel method in an ammoniacal medium, employing (NH4)3[NbO(C2O4)3]·nH2O as the Nb2O5 precursor and SnCl4·5H2O as the SnO2 precursor. Samples were synthesized with Nb2O5:SnO2 mass ratios of 100:0, 98:2, 80:20, 30:70, 5:95, 0.5:99.5, and 0:100, designated respectively as 100Nb, 98Nb, 80Nb, 70Sn, 95Sn, 99.5Sn, and 100Sn. The materials were characterized by XRD, nitrogen adsorption, FTIR, Raman, TG/DTG, SEM, EDS, XRF, DRS, and cyclic voltammetry. The results showed that calcination conditions directly influenced the formation of crystalline and amorphous phases, especially in the niobium-rich samples. For the tin-rich catalysts, the diffractograms indicated the formation of the cassiterite SnO2 phase, whereas the niobium-rich materials exhibited a greater contribution from amorphous or low-crystallinity phases. Incorporating one oxide into the other modified the textural and optical properties of the solids, leading to an increase in specific surface area for some compositions, a decrease in pore diameter, and changes in Eg values. DRS spectra indicated that the Sn-rich materials exhibited absorption in the UV-Vis region and apparent bandgap values compatible with use as semiconductors. SEM, EDS, and XRF results confirmed the presence of Nb and Sn in the solids. In photocatalytic tests, all catalysts were capable of promoting the decolorization of AR-4GL; however, 100Sn was the most active, achieving up to 61% decolorization of the pollutant and also causing its mineralization. The 100Sn, 99.5Sn, and 95Sn samples also exhibited catalytic activity after the second use, indicating the possibility of reuse. The study using scavengers showed that degradation occurs via a mechanism involving •OH radicals, O2•−, and excitons. Chitosan was obtained from shrimp shells, yielding a degree of deacetylation of 88.8% and a molar mass of 155.7 kDa. It was also found possible to immobilize the oxides in composite films of chitosan, graphite, and semiconductors, which exhibited an electrochemical response via cyclic voltammetry. Thus, the results obtained indicate that the synthesized Sn and Nb oxides are promising materials for application in the photodegradation of azo dyes. Instituição: Universidade do Estado do Rio de Janeiro Tipo do documento: Tese Tue, 30 Jun 2026 00:00:00 GMT http://www.bdtd.uerj.br/handle/1/26088 2026-06-30T00:00:00Z http://www.bdtd.uerj.br/handle/1/25840 Título: Síntese e caracterização de compostos de coordenação mistos de lantanídeos para emprego como marcadores de munições e avaliação dos seus parâmetros termométricos Autor: Silva, Júlia Pereira de Oliveira Primeiro orientador: Marques, Lippy Faria Abstract: In this work, we report the synthesis and structural characterization of new mixed-lanthanide compounds. Two main classes were investigated: mixed-lanthanide metal-organic frameworks (m-LnMOFs), with potential application as first-generation luminescent ammunition taggants when incorporated into gunpowder, and discrete mixed-lanthanide complexes, with potential application as second-generation taggants and in the field of luminescent thermometry. A new series of m-LnMOFs with the general formula [EuxGdyTb1-x-y(Hbtec)]n was synthesized and characterized in the solid state using various analytical and spectroscopic techniques, including a photophysical study. Due to their high thermal stability and tunable emissions, these materials were applied as selective ammunition taggants for .380 ACP (orange taggant), 9 mm Luger (red taggant), .40 S&W (yellow taggant), and 5.56 mm NATO (green taggant) calibers, allowing for the unequivocal distinction of different calibers based on their specific light emissions. Additionally, we propose incorporating the luminescent complex [Eu1.8Tb0.2(keto)6(bpy)2] into hollow-point projectiles for the .40 S&W caliber. Upon projectile deformation, the taggant is gradually released, enabling the visualization of the ballistic trajectory and tissue damage under UV light. Tests using ballistic gelatin and pork legs demonstrated the method's efficacy, showing great potential to assist forensic analyses, particularly during autopsies. Furthermore, three mixed discrete complexes were synthesized and characterized. Their emission spectra showed that the transições 5D4 → 7F5 (Tb3+) and 5D0 → 7F0 (Eu3+) transitions are temperature-dependent. Thus, the ratio between these intensities was employed as the thermometric parameter, characterizing a dual-emission ratiometric luminescent thermometer. These systems exhibited maximum relative sensitivities of 1.51 %K-1 at 343 K for [Eu0.4Tb1.6(keto)6(bpy)2], 2.38% K-1 at 353 K for [Eu0.6Tb1.4(keto)6(4,4’-dmbpy)2], and 5.48 %K-1 at 343 K for [Eu0.4Tb1.6(keto)6(4,4’-dmbpy)2], alongside high repeatability and low uncertainty, highlighting their potential as temperature sensors. The results demonstrated tunable luminescence emission in m-LnMOFs, as well as promising applications in forensics and thermometry for the discrete mixed-lanthanide complexes. Instituição: Universidade do Estado do Rio de Janeiro Tipo do documento: Tese Fri, 17 Jul 2026 00:00:00 GMT http://www.bdtd.uerj.br/handle/1/25840 2026-07-17T00:00:00Z http://www.bdtd.uerj.br/handle/1/25752 Título: A influência da concentração do HPA antraceno no gafanhoto semiaquático Cornops aquaticum associado à sua planta hospedeira Eichhornia crassipes na Amazônia Oriental Autor: Lima, Wilson Figueiredo de Primeiro orientador: Calderari, Mônica Regina da Costa Marques Abstract: This study evaluated trophic transfer and ecotoxicological effects of the polycyclic aromatic hydrocarbon (PAH) anthracene in an experimental aquatic system involving the aquatic macrophyte Eichhornia crassipes and the semiaquatic grasshopper Cornops aquaticum in Eastern Amazonia. The objective was to assess anthracene uptake, accumulation, bioaccumulation, and toxicity along the food chain, as well as to determine its influence on grasshopper survival and biological responses. To this end, controlled experiments were conducted using different concentrations of anthracene added to the water, with plants and grasshoppers exposed for defined periods. Quantification of the contaminant in plant compartments (leaves, petioles, and roots) and in grasshoppers (males and females) was performed by high-performance liquid chromatography with a diode array detector (HPLC–UV-DAD) following Soxhlet extraction. The results demonstrated that E. crassipes exhibited a high capacity for anthracene uptake and retention, with predominant accumulation in the roots, reaching maximum concentrations of 839.94 µg.g⁻¹. This pattern indicated that hydrophobic sorption was the primary mechanism governing contaminant retention, resulting in limited translocation to aerial tissues. Nevertheless, the presence of anthracene in leaves was sufficient to enable trophic transfer to C. aquaticum via dietary exposure. A strong positive correlation was observed between foliar anthracene concentrations and insect body burden (r = 0.89; p < 0.001), confirming active bioaccumulation. The highest mean concentrations were recorded in females (115.42 µg.g⁻¹), suggesting the influence of physiological and metabolic factors, possibly associated with detoxification enzymes such as cytochrome P450. Toxicity assays revealed a pronounced toxic effect, with a progressive reduction in survival as anthracene concentration and exposure rate increased. At the 0.10 g experiment, the greatest impact was observed, with only 10% of individuals surviving until the end of the experiment. Sex-related differences were evident, with females showing greater initial resistance at low doses, whereas males exhibited higher tolerance at elevated concentrations. Chemical analyses indicated wide variation in anthracene body burden among insects (0 to 4,022 µg.g⁻¹). The relationship between daily dose and survival revealed a critical metabolic threshold between 450 and 550 µg.g⁻¹.day⁻¹, associated with a sharp increase in mortality, indicating that daily exposure rate is a key determinant of toxicity, more relevant than the total amount accumulated at the end of the exposure period. It is concluded that E. crassipes simultaneously acts as a biogeochemical filter, sink, and secondary reservoir of anthracene, while C. aquaticum exhibits high sensitivity and predictable responses to contamination, reinforcing its potential as a trophic bioindicator of anthracene pollution. This study contributes to the understanding of bioaccumulation processes, trophic transfer, and environmental risk of persistent organic contaminants, and highlights the potential of these species as models for phytoremediation and biomonitoring studies in tropical aquatic ecosystems. Instituição: Universidade do Estado do Rio de Janeiro Tipo do documento: Tese Wed, 03 Jun 2026 00:00:00 GMT http://www.bdtd.uerj.br/handle/1/25752 2026-06-03T00:00:00Z