Manuel Jose Lis

The compatibilization of essential oils and surfactants is a crucial factor when forming aggregates that should serve as a matrix to stabilize the core structure and develop the wrapping process with the shell components in the microencapsulation process of the essential oils. The aggregation structures formed with nonionic surfactants, such as Tween 80, and anionic surfactant SDS, and their thermodynamic values are well known in colloidal systems. Essential oils are natural, and in the same oil, there are a large number of organic compounds. They are often used in cosmetics, the food industry, and medicine. Although essential oils are widely incorporated into surfactant systems, the fundamental thermodynamic and interfacial mechanisms governing their coaggregation with surfactants remain poorly understood. Therefore, this paper investigates how cinnamon and clove oils influence surfactant aggregation, adsorption, and interfacial interactions in systems containing nonionic Tween 20, Tween 80, or Span 40 and anionic SDS. Combining surface tension, thermodynamic analyses, DLS, Zeta Potential, and optical microscopy will provide enough data to support our findings.

This study presents a sustainable circular economy approach to valorize raw wool waste by developing engineered, biodegradable bio-pellets as a functional replacement for styrene-butadiene rubber (SBR) infills in synthetic turf systems. To overcome physical limitations and address upcoming regulatory restrictions on microplastics (Regulation (EU) 2023/2055), raw wool was processed into dense pellets through controlled water inclusion and compounding with density-increasing mineral additives (Dolomite and Barite). Thermogravimetric Analysis (TGA) was utilized to precisely quantify the inorganic fractions and thermal stability of the resulting formulations. The physical, mechanical, and biomechanical behavior of the wool-based composites was comprehensively evaluated, focusing on Shock Absorption (SA), Vertical Deformation (VD), and Energy Restitution (ER) across different elastic subbases. Results confirm that the developed bio-pellets fit within the stablished ranges of international mechanical standards (EN 15330-1, FIFA, and World Rugby). Furthermore, moisture-induced swelling permanently enhances damping performance and prevents particle displacement, while the intrinsic hydrophilic nature of the keratin matrix could provide hydro-thermal stabilization and reduce electrostatic charges compared to conventional SBR crumbs. By leveraging existing fertilizer processing infrastructure, this work demonstrates a scalable route to transform a problematic agricultural waste into a high-performance, non-toxic, and eco-friendly material for advanced engineering applications.

Microencapsulation has become an indispensable technique across various industries that require the controlled release and stability of bioactive agents. In this study, the encapsulation of cinnamon essential oil (CEO), known for its antibacterial and anti-inflammatory properties, was study to enable controlled release when applied to textile substrates. This procedure involves defining and examining several steps to establish a stable, scalable complex coacervation methodology. To form a stable microcapsule matrix, CEO was emulsified using a combination of surfactants (Span 80, Tween 20, and Sodium Dodecyl Sulfate). After forming micelles containing CEO, two biopolymers (chitosan and gum Arabic) were used at various proportions to form a microcapsule shell via a layer-by-layer approach. Advanced characterization techniques, such as spectrophotometry and laser scattering, were used to evaluate microcapsule stability, size, and release kinetics, as well as to assess potential antibacterial activity. The presence of oil-containing microcapsules was confirmed using fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA). The results demonstrate that Span 80 concentrations of 0.4 and 0.7 g/L provided the most stable encapsulation environment and enabled a controlled CEO release profile after being applied to cotton substrates. In addition, the influence of the fabric’s chemical characteristics was clearly illustrated in the drug delivery experiments. However, antibacterial efficacy was limited due to the low CEO concentration within the microcapsules, indicating the need for further optimization. These findings provide valuable insights into the broader application of essential oil encapsulation, particularly within the pharmaceutical, textile, and cosmetic sectors.

The incorporation of ground tire rubber (GTR) into elastomeric compounds offers a sustainable route for recycling end-of-life tires; however, its effect on the structure–property relationships governing mechanical and dielectric performance remains insufficiently understood. In this study, NR/SBR composites containing 0–50 phr of devulcanized GTR were prepared and characterized through Fourier-transform infrared spectroscopy (FTIR), swelling analysis, thermogravimetric analysis (TGA), mechanical testing, and broadband dielectric spectroscopy. FTIR and swelling results revealed enhanced matrix–GTR interaction at intermediate GTR loadings (10–20 phr), evidenced by an increased intensity of sulfur-related bands and reduced swelling degree, indicating partial chemical integration of the recycled phase into the elastomer network. Mechanical testing showed that increasing GTR content increased stiffness at high loadings, while tensile strength, elongation at break, and toughness progressively decreased due to interfacial debonding mechanisms. TGA demonstrated that the main degradation temperature of the NR/SBR matrix remained essentially unchanged (418–425 °C) across all formulations, confirming preservation of thermal stability despite increasing structural heterogeneity. Dielectric spectroscopy (10⁻²–3 × 10⁶ Hz, 40–120 °C) revealed pronounced Maxwell–Wagner–Sillars interfacial polarization and thermally activated charge transport, with conductivity increasing with GTR content without evidence of electrical percolation, even at 50 phr. The results demonstrate that the performance of NR/SBR/GTR/SiO₂ composites is primarily controlled by the interfacial structure generated by the recycled phase. Intermediate GTR contents (10–20 phr) provide the most effective matrix–GTR interaction, while higher loadings mainly affect mechanical integrity and dielectric response through increased structural heterogeneity. These findings provide practical guidelines for designing sustainable elastomeric compounds with high recycled content while maintaining thermal stability and controlled electrical insulation properties.

Background: Nanoparticle size is a critical factor influencing diffusion behavior, interfacial interactions, and overall performance in biomedical and textile-based delivery systems. Aquilaria malaccensis (agarwood) oil (AO), an essential oil of cultural and commercial significance in Malaysia, has unique bioactive properties but remains underexplored in nanoparticle formulations due to challenges related to its volatility and poor water compatibility. Objectives: This study aims to develop a sustainable, size-tunable chitosan-based nanocarrier capable of efficiently encapsulating AO and to evaluate its physicochemical characteristics and compatibility with textile substrates for potential biomedical and functional textile applications. Methods: AO-loaded chitosan nanoparticles were produced using an emulsion-assisted ionic-gelation method, employing chitosan and sodium tripolyphosphate (TPP) without organic solvents. Particle size was modulated across a predefined design space. The optimised nanoparticle formulation was characterised for size, Polydispersity Index (PDI), zeta potential, encapsulation efficiency, loading capacity, and process yield. The optimised nanoparticles were subsequently applied onto cotton and polyester fabrics to assess wet pickup and incorporation behaviour. Results: The fabrication method produced nanoparticles ranging from 78.6 to 2425 nm with PDI values below 0.35. The optimised formulation yielded uniform particles of approximately 90.75 nm with a zeta potential of +17.6 mV, an encapsulation efficiency of 80.23%, a loading capacity of 24.84%, and a process yield of 15.49%. These properties indicate effective incorporation of hydrophobic AO within the chitosan–TPP matrix. When applied to textile substrates, the nanoparticles demonstrated favourable wet pickup and incorporation profiles on both cotton and polyester. Conclusions: Overall, this work presents a sustainable and size-tunable chitosan-based nanocarrier capable of incorporating AO, highlighting its promise for future development in dermal, pharmaceutical, and biofunctional textile applications. Future research will focus on evaluating biological activity, release behavior, and textile performance, thereby establishing the practical impact and broad applicability of these nanoparticles across diverse real-world scenarios.

Essential oils (EOs) are well-known in traditional medicine, pharmacy, the food industry, and cosmetics because they are readily available and have proven efficacy across a wide range of applications. They are natural, bio-based, and biodegradable, and when applied accurately, they exhibit effective action against microorganisms, viruses, and fungi. However, most organic EOs are volatile and have hydrophobic surface chemistry, making them unsuitable for direct bio-applications in textiles. Textiles offer a useful platform for applying essential oils to impart functions such as antimicrobial or deodorizing effects. While traditional textiles focused mainly on comfort and protection, the rise of functional textiles has created new opportunities to integrate natural compounds such as essential oils. Recently, a growing body of research has focused on integrating essential oils into textile materials, driven by the increasing demand for sustainable fabrics with added biofunctionality. This review highlights the latest advances in applying essential oils to textile substrates and examines the techniques used and the improvements achieved, including washing cycles, antibacterial efficiency ranges, and durability. We survey recent literature, including research papers, articles, and books, to identify the most common methods and clarify their underlying mechanisms.

Metal–organic frameworks (MOFs) have become a highly usable system in various sectors because of their highly ordered structure and high porosity providing them with high storage capacity. However, their use is sometimes forbidden in the food industry due to the presence of some organic compounds which have undesirable effects. Cyclodextrins, which are considered GRAS (Generally Recognized as Safe) by the FDA, comes as a very good alternative to previously used compounds for the development of the MOFs to be used in the food packaging industry, especially in the packaging sector. The cyclodextrin MOF does possess edible, biocompatible, as well as biodegradable characteristics and due to these reasons, they have gained attention from researchers in the food industry. In this review, we focus on the recent advancements in the field of CD MOFs. We have emphasized the synthesis of these MOFs through different techniques, formations of their inclusion complex with bioactive compounds, and their characterization. Finally, we discussed the use of CD MOFs as carriers for various highly volatile bioactive compounds and their ability to increase the solubility and stability of these bioactive compounds.