Browsing by Author "Segovia, Cesar"

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    Efficient Bio-Based Insulation Panels Produced from Eucalyptus Bark Waste
    (2024) Fuentealba, Cecilia; Segovia, Cesar; Pradena-Miquel, Mauricio; Cesar, Andres G.
    Traditional thermal insulation panels consume large amounts of energy during production and emits pollutants into the environment. To mitigate this impact, the development of bio-based materials is an attractive alternative. In this context, the characteristics of the Eucalyptus fiber bark (EGFB) make it a candidate for insulation applications. However, more knowledge about the manufacturing process and in-service performance is needed. The present study characterized the properties that determine the in-service behavior of the EGFB insulation panel. The assessment involved two different manufacturing processes. The results indicated that the hot plates and the saturated steam injection manufacturing system can produce panels with similar target and bulk density. The thermal conductivity fluctuated between 0.064 and 0.077 W/mK, which indicated good insulation, and the values obtained for thermal diffusivity (0.10-0.37 m mm2/s) and water vapor permeability (0.032-0.055 m kg/GN s) are comparable with other commercially available panels. To guarantee a good in-service performance, the panels need to be treated with flame retardant and antifungal additive. The good performance of the panel is relevant because bio-based Eucalyptus bark panels generate less CO2 eq and require less energy consumption compared to traditional alternatives, contributing to the sustainability of the forestry and the construction industry.
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    Preparation and Characterization of Lignin Nanoparticles from Different Plant Sources
    (2024) Ortega-Sanhueza, Isidora; Girard, Victor; Ziegler-Devin, Isabelle; Chapuis, Hubert; Brosse, Nicolas; Valenzuela, Francisca; Banerjee, Aparna; Fuentealba, Cecilia; Cabrera-Barjas, Gustavo; Torres, Camilo; Mendez, Alejando; Segovia, Cesar; Pereira, Miguel
    This article presents new research on producing lignin nanoparticles (LNPs) using the antisolvent nanoprecipitation method. Acetone (90%) served as the lignin solvent and water (100%) as the antisolvent, using five types of lignins from various sources. Comprehensive characterization techniques, including NMR, GPC, FTIR, TEM, and DLS, were employed to assess both lignin and LNP properties. The antioxidant activity of the LNPs was evaluated as well. The results demonstrated the successful formation of spherical nanoparticles below 100 nm with initial lignin concentrations of 1 and 2%w/v. The study highlighted the crucial role of lignin purity in LNP formation and colloidal stability, noting that residual carbohydrates adversely affect efficiency. This method offers a straightforward, environmentally friendly approach using cost-effective solvents, applicable to diverse lignin sources. The innovation of this study lies in its demonstration of a cost-effective and eco-friendly method to produce stable, nanometric-sized spherical LNPs. These LNPs have significant potential as reinforcement materials due to their reinforcing capability, hydrophilicity, and UV absorption. This work underscores the importance of starting material purity for optimizing the process and achieving the desired nanometric dimensions, marking a pioneering advancement in lignin-based nanomaterials.