Resumo em Inglês:

Abstract The post-industrial recycled ABS (ABSpost) was used to produce a new material based on graphene oxide (GO), aimed at high-quality products again, as households and electronic applications. The GO was prepared from the oxidation of graphite, and the influence of the different amounts of filler on the mechanical, rheological, and thermal properties of ABSpost was investigated. The X-ray microtomography showed a uniform dispersion of GO fillers in the ABSpost matrix in small amounts (0.05 and 0.1 wt%), improving some properties, such as elongation at break, toughness, and impact strength. The thermal conductivity of the ABSpost also increases by 30% with the addition of only 0.1 wt% of GO. Adding a small amount of GO in a recycled ABS is a strategy to deal with the current problem of electronic housing waste and use this material to minimize its environmental impact.

Resumo em Inglês:

Abstract This study aimed to investigate the therapeutic potential of a nanoparticle formulation containing the immunodominant peptide SSIEFARL from Herpes simplex virus 2 glycoprotein B A against genital herpes. A nanoparticle formulation (NanoSSIEFARL) was engineered and characterized for its physicochemical and immunomodulatory properties. NanoSSIEFARL displayed mean particle size of 212 ± 5 nm, polydispersity index of 0.12 ± 0.01 and zeta potential of -7.4 ± 2.5 mV, exhibiting spherical morphology. pH stability remained consistent over 30 days (day 0: 4.5 ± 0.5; day 30: 5.0 ± 0.5). A novel high-performance liquid chromatography method was validated for SSIEFARL quantification. Peptide association efficiency reached 98.3% ± 2.1, with 41.6% ± 4.4 peptide release from nanoparticles after 4 hours. Cytotoxicity assessment revealed cellular viability exceeding 90%, with macrophage uptake observed after 4 hours. Altogether, these results suggest that NanoSSIEFARL is a promising candidate for effective immunotherapy against genital herpes.

Resumo em Inglês:

Abstract This paper analyzed the thermal and mechanical properties of natural rubber/curaua fiber composite with different weight contents (2.5% to 15%). Alkali treatment was used to modify the surface of curaua fiber and improve interfacial bonding. Results showed that alkali treatment did not affect the dispersion pattern of composites. TGA revealed that both fiber content and treatment minimally influenced the thermal stability of composites. However, thermal conductivity showed up to 34,2% reductions compared to the matrix for low fiber contents, with an increased tendency for higher contents. The tensile strength of composites showed improvements up to 161% for 2.5% loads, but there was a decreasing tendency when filler load increased, indicating problems with dispersed phase distribution. Overall, composites made with treated fibers exhibited better mechanical properties than those without treatment, showing better interfacial adhesion, and the 2.5% fiber content presented the best combination of thermal and mechanical properties.

Resumo em Inglês:

Abstract Superabsorbent hydrogels were produced using a graft copolymerization technique, utilizing hydrolyzed collagen obtained from hide trimming waste and acrylic acid as the monomer. Methylenebisacrylamide (MBA) was employed as a crosslinker. The concentrations of acrylic acid and MBA were systematically optimized to obtain maximum swelling capacity. The maximum swelling capacity was 156 g/g in distilled water. The structure of the superabsorbent was verified using FTIR spectroscopy, and the morphology was identified using SEM. Various salt solutions (NaCl, KCl, MgCl2, and CaCl2) and solutions with pH levels spanning from 1 to 13 were also utilized to evaluate the swelling capacity of hydrogels.

Resumo em Inglês:

Abstract Microplastic pollution poses a significant environmental and health challenge due to its persistence and pervasive distribution across ecosystems. This study investigates public perceptions of microplastics, focusing on their environmental and health impacts, through semi-structured interviews with 96 participants from diverse educational backgrounds in Rio de Janeiro, Brazil. Sentiment analysis, hierarchical clustering, and machine learning techniques were employed to analyze the data. Participants ' educational levels and interview locations influenced substantial variability in awareness and attitudes towards microplastics. Academic groups, particularly those specialized in environmental sciences, expressed higher concerns than less specialized or non-academic groups. Sentiment analysis indicated a predominance of neutral to mildly positive sentiments, with 36 distinct clusters identified. The study highlights the need for targeted educational interventions to bridge knowledge gaps and promote pro-environmental behaviors. The results underscore the role of academic background in shaping public perceptions, suggesting tailored communication strategies to mitigate microplastic pollution.

Resumo em Inglês:

Abstract Starch is a biopolymer that is abundant in nature, low-cost, biodegradable, and can be transformed into a thermoplastic material. This work evaluates the films’ physicochemical, thermal, and mechanical properties based on low-density polyethylene (LDPE) and thermoplastic starch (TPS) from beans. Films of four formulations of LDPE with TPS (0, 5, 10, and 15%) were formulated by the extrusion process. The films were evaluated for thickness, color, mechanical properties (tensile strength, Young’s modulus, elongation at break), barrier, and morphological properties. The barrier properties (WVTR and WVP) significantly increased when TPS was incorporated into the films. While the tensile strength and Young’s modulus did not present changes with the addition of TPS, the elongation at break increased from 204.14 to 343.81% with the addition of TPS. Adding TPS to an LDPE matrix modifies its physico-mechanical properties favorably so that it can be applied as a material for flexible packaging.

Resumo em Inglês:

Abstract This study developed biocomposite films from poly(vinyl alcohol) (PVA), sugar cane bagasse (SCB), and banana peel fibers (BF) or starch-rich banana flour (BS). Morphological analysis revealed filler distribution and fluid percolation within the polymer matrix. Physicochemical analysis indicated stronger interactions between components in BF-containing films. Mechanical strength decreased significantly in SCB-containing films, while biodegradation increased, particularly with banana waste. Water absorption was higher in PVA-BF-SCB and PVA-BS-CSB biocomposites. Incorporating SCB and banana waste into PVA films presents a promising approach for developing biodegradable composite packaging materials, potentially replacing low-density polyethylene in applications like seedling production. This biodegradable material can be applied directly to the environment.

Resumo em Inglês:

Abstract Composite materials have emerged as a viable alternative to metals due to their lighter weight and superior mechanical properties; however, due to the trade-off between performance and cost, they have yet to gain widespread adoption. Despite environmental legislation constantly being updated, producers of various equipment and structures are hesitant to incorporate composite technologies into standard constructions and products, primarily for economic reasons. As a consequence, recent advancements in composite-producing processes have focused on the usage of carbon composites and automated robotics incorporation for ecologically conscious, stable, and affordable production. Therefore, it is essential to investigate current methodologies for industrial carbon composite material production and manufacturing processes to determine the most optimal composite production and implementation criteria.

Resumo em Inglês:

Abstract Poly(ε-caprolactone) (PCL) is a biodegradable polyester with promising properties in tissue engineering, particularly in the creation of living structures for regenerative medicine. This study focused on the surface properties of electrospun PCL membranes combined with bone powder, treated using Dielectric Barrier Discharge (DBD) plasma in argon and atmospheric air environments. The electrospinning technique was employed for its ability to produce fibrous scaffolds that mimic the extracellular matrix, enhancing cell adhesion and proliferation. Scanning Electron Microscopy (SEM) results indicated that the morphology of the electrospun samples remained unchanged, exhibiting random fiber orientation and the presence of hydroxyapatite, although it was not fully incorporated. Infrared spectroscopy confirmed the characteristic polymer groups, and contact angle measurements demonstrated the hydrophobic nature of the films. However, increasing the plasma exposure did not entirely convert the surface to a hydrophilic state.

Resumo em Inglês:

Abstract Determining elastomer content in ternary rubbers via infrared (IR) spectroscopy presents challenges due to spectral band overlap.Coupled techniques could be a solution, but in certain cases it can also involve overlapping events resulting in greater errors. The best option is to use an instrumental technique with appropriate conditions that avoid overlapping. This paper presents the development of transmission/reflection IR methodologies for the content determination of a blend with natural rubber, styrene-butadiene copolymer, and polybutadiene (NR/SBR/BR), with A887 and A1375 bands for NR and A699 for SBR. The BR content, which was calculated by subtraction of the NR and SBR results from the IR methodology, is confirmed by acid-resistance quantitative data. The methodologies errors (2 to 6%), with non-overlapping bands, encompass what is found in the literature (5%). Such development ensures the determination of elastomer content in ternary rubbers with fast and accurate methodologies.

Resumo em Inglês:

Abstract This research paper is about the calculation of the diffusion coefficient and the oxygen concentration profile along polypropylene samples exposed to photooxidation in a dry environment. In this degradation process, oxygen diffusion is anomalous, as it is affected by structural modifications that occur over the exposure time. Thus, the diffusion coefficient starts to depend on time and the common solutions for Fick's 2nd Law for diffusion become inoperative for importante time intervals. In this work, a modification is proposed in the calculation of the diffusivity and, consequently, of the solution for the oxygen concentration profile in diffusion.

Resumo em Inglês:

Abstract Since the 1940s, the rise in plastic manufacturing has led to increasing plastic waste and environmental damage, driving the need for biodegradable plastics like polyhydroxybutyrate (PHB). PHB is sustainably produced through microbial fermentation using agricultural and industrial waste and is applied in packaging, agriculture, biomedicine, and 3D printing due to its biodegradability and biocompatibility. Advances from 1990 to 2023 include optimized genetic engineering in bacterial strains like Cupriavidus necator, low-cost feedstocks such as molasses, and scalable bioreactor designs for efficient large-scale production. Mixed microbial cultures in wastewater treatment plants exemplify innovations that combine PHB production with pollution mitigation. A bibliometric analysis of Science Direct highlights China’s leading role in PHB research, evidenced by the highest publication and citation rates. This study enhances the literature by revealing significant trends and advancements in PHB development.