Abstract in English:

Abstract Polymeric fluids are widely applied in workover operations because of their ability to control well pressure, regulate filtrate loss, and preserve reservoir productivity. However, their performance is highly dependent on polymer stability, since degradation under thermal, mechanical, or chemical stresses can compromise rheology, weaken filtration control, and increase the risk of formation damage. Research since the 1970s has advanced toward developing improved formulations, aiming to enhance efficiency while reducing reservoir impairment. Laboratory characterization techniques have been essential in evaluating polymer degradation and fluid–rock interactions, generating insights for polymer selection and fluid design. Within this context, this study proposes a literature review on polymeric fluids in workover operations, with emphasis on the role of polymers in fluid formulation and performance. The review also addresses operational fundamentals and technical challenges, focusing on thermal stability, degradation mechanisms, and strategies to minimize formation damage through adequate formulation and characterization approaches.

Abstract in English:

Abstract This study presents the cold plasma polymerization of citronellol, a natural monoterpene, as a route to obtain antibacterial polymeric films. A 10 µL volume of citronellol was polymerized under argon plasma at 100 Pa, yielding a solid film (Pcit). SEM analysis revealed a heterogeneous, branched surface with a roughness Ra of 7.53 ± 2.19 µm and Rz of 50.57 ± 24.26 µm. Water contact angle measurements indicated moderate hydrophilicity (62°). XPS and FTIR analyses confirmed the presence of oxygen-containing functional groups, while OES detected reactive carbon- and oxygen-containing species generated during plasma operation. Hemolysis tests showed excellent blood compatibility (<5%), and antimicrobial assays revealed inhibition zones of 12 ± 1 mm for E. coli and 10 ± 1 mm for S. aureus. Overall, these results indicate that plasma-polymerized citronellol yields functional surfaces with promising potential for biomedical and antibacterial applications.

Abstract in English:

Abstract Growing demand for lightweight, durable, and sustainable materials has increased interest in hybrid natural-synthetic fiber composites for structural and wear-critical applications. Research and industrial adoption are strong in Europe, North America, and the Asia-Pacific region, with Europe leading automotive and construction sectors due to sustainability-driven policies. This study examined the effect of stacking sequence on the mechanical, tribological, and hygroscopic performance of banana-aramid hybrid epoxy laminates fabricated by compression moulding. Four configurations were evaluated: all-banana (A), aramid-skinned banana core (B), alternating banana-aramid layers (C), and aramid-dominated laminates (D). Tensile, compressive, impact, hardness, water absorption, and wear properties were assessed. Sample C showed the highest tensile strength (36.80 MPa), while Sample D exhibited superior compressive strength (45.56 MPa), hardness (77 Shore D), impact resistance (13.89 kJ/m2), lowest water absorption (0.0712%), and best wear resistance (0.0006 mm). These results confirm that optimized stacking sequences enable high-performance, sustainable hybrid composites.

Abstract in English:

Abstract Active packaging often contains essential oils and plant extracts, which are predominantly hydrophobic. Surfactants are added to stabilize the matrix, improve the dispersion, and ultimately enhance the effectiveness of the active compounds. In the present study evaluate how different surfactants affect Bergamot essential oil incorporated into chitosan and sodium alginate-based packaging film. The incorporation of surfactants leads to enhancement in film thickness and elongation at break, and tensile strength was reduced, which is attributed to altered intermolecular hydrogen bonding and increased chain mobility. XRD and FTIR analyses revealed chemical interactions between additives and polymeric chains that reduced crystallinity and peak intensities. Furthermore, optical, color, and functional properties including water vapor transmission rate (WVTR), swelling index, water contact angle, and antioxidant activity were analyzed. Overall, the results demonstrated that the strategic selection of surfactant enables the development of high-performance material for sustainable active packaging applications.

Abstract in English:

Abstract Bacterial cellulose is a biopolymer valued for its purity, biocompatibility, and versatility, but its production typically depends on synthetic media, limiting sustainability and hindering the incorporation of functional compounds during biosynthesis. The effects of plant-derived extracts on the physicochemical and biological properties of bacterial cellulose remain poorly understood. This study evaluates the use of an aqueous extract of Erythrina mulungu as an alternative culture medium capable of producing and functionalizing bacterial cellulose simultaneously. Over 20 days, hydrated membranes were obtained with an average productivity of 186.41 g/L. Infrared spectroscopy confirmed characteristic cellulose functional groups, while X‑ray diffraction revealed reduced crystallinity in mulungu‑derived membranes (46%) compared to saline‑derived membranes (72%). Antimicrobial assays showed inhibition of Escherichia coli and Staphylococcus aureus. Antioxidant activity reached 14.70% for the extract, 10.14% for mulungu‑derived cellulose, and 1.50% for saline‑derived cellulose. The extract enhanced functional properties, supporting applications requiring antimicrobial and antioxidant performance.

Abstract in English:

Abstract This study produces and characterizes immiscible blend systems made with high-density polyethylene (HDPE) and post-industrial polyamide 11 (PA11) obtained from offshore. Blends were prepared at an 80/20 (wt.%) HDPE/PA11 ratio. To enhance phase compatibility, high-density polyethylene grafted with maleic anhydride (HDPE-g-MA) was employed as a conventional compatibilizer at 1.5 wt.% content. In addition, the effect of silicon dioxide nanoparticles (nSiO2) incorporated at 2 and 4 wt.% contents was evaluated. The compositions were analyzed in the presence and absence of the compatibilizer. Mechanical, thermal, rheological, and morphological analyses showed that HDPE-g-MA led to a slight improvement in the interfacial interaction between the immiscible polymer phases. Moreover, the addition of nSiO2, in the presence of the traditional compatibilizer, led to the most favorable balance of thermal and mechanical performance, suggesting that nSiO2 nanoparticles may act as effective co-compatibilizers in HDPE/HDPE-g-MA/PA11 systems.

Abstract in English:

Abstract The increasing frequency of organic solvent pollution has raised urgent demands for efficient, sustainable, and recyclable materials for solvent-water separation. In this study, we report a green, facile strategy to fabricate a superhydrophobic melamine sponge (MS) modified with poly(furfuryl alcohol) (PFA) using a zinc-based deep eutectic solvent (DES) system. The DES, composed of choline chloride and ZnCl2, served dually as both the polymerization medium and catalytic agent for the in-situ polymerization of furfuryl alcohol on the MS skeleton. The resulting PFA-coated MS (PFA/MS) retained its intrinsic porous 3D network while acquiring significantly enhanced surface roughness and hydrophobicity. Water contact angle measurements confirmed superhydrophobicity (167.6°), and the sponge exhibited high selectivity and sorption capacity toward a wide range of organic solvents. This environmentally benign, scalable approach offers a promising platform for the development of reusable sorbents in oil spill cleanup and industrial wastewater treatment.

Abstract in English:

Abstract Electrospun PCL-based scaffolds have been proposed for wound healing. However, to deal with bacterial infections, the incorporation of natural compounds into the PCL matrix could be a promising alternative. Stryphnodendron adstringens (Barbatimão) extract and Melaleuca alternifolia (Melaleuca) oil are known due to their antibacterial, antifungical, and anti-inflammatory properties, interesting for healing applications. This paper proposed the development of electrospun PCL scaffolds containing a combination of barbatimão and melaleuca compounds. The obtained samples were 20B/80M and 80B/20M, in which B refers to Barbatimão and M for Melaleuca. The samples were characterized via X-ray diffraction, Raman spectroscopy, tensile test, contact angle analysis, optical microscopy, and cytotoxicity. The incorporation of the natural compounds did not alter the structure of PCL and higher concentration of Barbatimão indicated an enhancement in antimicrobial properties against S. aureus, with reduction of 33.3% on biofilm formation. Hence, the proposed scaffolds could be promising material for wound healing applications.