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.

Concrete is a material with high compressive strength, but predisposed to shrinkage cracking, rapid cracks propagation, and brittle failures. The incorporation of fibre is an acceptable solution to reduce these limitations. However, high cost and energy consumption related to man-made fibres have placed natural fibres as an attractive sustainable alternative, especially considering that different natural fibres are industrial waste (as the Eucalyptus globulus bark fibre). Still, natural fibres can produce an important reduction of concrete strength. Hence, the objective of this study is to evaluate the effects of Eucalyptus globulus bark fibre in traditional concrete mechanical properties as compressive and flexural strength. For this, an experimental program was developed in such a way that reduces the results uncertainties and increases the power of decision regarding the percentage and fibre conditions of the samples. The results indicate that, unlike other natural fibres, the traditional mechanical properties have a slight reduction and acceptable workability. This fact is more evident in the samples with 0.50% fibre with respect to the weight of cement. Therefore, reinforcing mortars and concrete with Eucalyptus globulus bark fibres emerges as an eco-friendly building alternative to reuse this industrial waste.

One of the most important by-products generated in the forestry industry is the bark obtained during the debarking process. Pine (Pinus radiata D. Don) and eucalyptus (Eucalyptus globulus L.) are the main important tree species exploited in the Chilean forestry industry. The bark of P. radiata D. Don is an interesting source of extracts, rich in condensed tannins, with potential uses in biopolymer and bioadhesive preparation. Conversely, the E. globulus bark extracts are rich in hydrolyzable tannins with few applications. Nevertheless, the forest industry generates a high volume of these by-products, simultaneously. Then, it is interesting to determine a suitable process for the joint valorization of both forest by-products at a large scale. In this work, alkaline extraction (NaOH and Na₂SO₃) was performed at a pilot scale of a mixture of E. globulus and P. radiata barks prepared at different ratios (0%–100%). The effect of bark mixture composition on the resulting extract’s properties was evaluated. All extracts were characterized according to their chemical composition by FTIR-ATR, MALDI-TOF, and molecular weight distribution (GPC). In addition, the Stiasny number was tested to determine the potential use of extracts in bioadhesive formulation. The self-condensation reaction of resulting extracts was studied using Dynamic Mechanical Analysis (DMA) and Automated Bond Evaluation System (ABES) techniques. Results show a good interaction between condensed and hydrolyzable tannins from both species’ barks. It also demonstrated the potential application of the obtained extracts, for a bark ratio of 50:50, in the formulation of bioadhesives for particleboard manufacture. The obtained product showed a similar performance to that of the bioadhesive formulated with the extract obtained using only P. radiata bark.

Commercial forest plantations in Chile are dominated by pine (Pinus radiata) and eucalyptus (Eucalyptus globulus). Tree bark is the main by-product of the forestry industry and has low value, but great potential for use as an agricultural substrate. However, the direct use of bark fibers may cause plant phytotoxicity due to the presence of polyphenolic and other compounds. This study aims to evaluate the physicochemical properties of E. globulus and P. radiata bark after water extraction treatments. The phytotoxicity of the resulting extracted bark alone and that mixed with commercial substrates (coconut fiber, moss, peat, and composted pine) at different ratios (25 to 75 wt%) were assessed using the Munoo-Liisa vitality index (MLVI) test. For all treatments, the seed germination and growth of radish (Raphanus sativus) and Chinese cabbage (Brassica rapa) species were evaluated and compared to a commercial growing medium (peat) as a control. The optimal mixture for seed growth was determined to be 75% extracted E. globulus bark fiber and 25% commercial substrates such as peat (P), coconut fiber (C), moss (M), and composted pine (CP), as indicated by the MLVI and germination results. Two phytostimulant products, chitosan and alginate-encapsulated fulvic acid, were added to the best substrate mixture, with the purpose of improving their performance. Encapsulated fulvic acid at 0.1% w/v was effective in promoting plant growth, while chitosan at all of the concentrations studied was effective only for mixture 75E-25CP. The mixture of E. globulus fiber and commercial substrates, containing a high proportion of water-extracted fiber (75%), shows the potential to be used in the growth of horticultural crops and in the plant nursery industry.

The aim of this study was to compare the effects of a pine (Pinus radiata D. Don) bark extract (PBE) with a quebracho (Schinopsis balansae Engl.) extract (QTE) on methane (CH₄) production and in vitro rumen fermentation parameters. A forage diet supplemented with PBE or QTE (0, 2 and 4% dry matter (DM) basis) was incubated for 24 h to determine in vitro DM disappearance (IVDMD), CH₄, volatile fatty acids (VFA), and ammonia nitrogen (NH₃-N) production. Differences were analyzed using Tukey’s test, orthogonal contrasts, hierarchical clustering heatmap (HCH), and principal component analysis (PCA). Both extracts (4% DM) decreased butyrate (Bu; p = 0.001), CH₄ (p = 0.005), total VFA (p < 0.001), and NH₃-N (p = 0.006) production and increased acetate (Ac; p = 0.003) without affecting the partitioning factor (p = 0.095). Propionate (Pr; p = 0.016) was increased, whereas IVDMD (p = 0.041) was decreased with QTE (4% DM). The inclusion of QTE (2% DM) decreased CH₄ production (p = 0.005) and the (Ac + Bu)/Pr ratio (p = 0.003), whereas PBE (2% DM) decreased the NH₃-N (p = 0.006) and total VFA production (p < 0.001). The HCH and PCA indicate a negative correlation (r = −0.93; p < 0.001) between CH₄ production and tannins. In conclusion, PBE shares many of the effects generated by QTE on ruminal fermentation, although the magnitude of these effects depends on concentration. The PBE could be used as an additive in ruminant diets to reduce CH₄ and NH₃-N production without reducing IVDMD or increasing propionate, but further in vivo studies are required to clarify its effects on animal production.

This study aimed to explore alternative substrates for growing forest species using eucalyptus bark. It evaluated the potential of extracted Eucalyptus globulus fiber bark as a substitute for commercial growing media such as coconut fiber, moss, peat, and compost pine. We determined the physicochemical parameters of the growing media, the germination rate, and the mean fresh and dry weights of seedlings. We used the Munoo-Liisa Vitality Index (MLVI) test to evaluate the phytotoxicity of the bark alone and when mixed with commercial substrates. Generally, the best mixture for seed growth was 75% extracted eucalyptus bark fiber and 25% commercial substrates. In particular, the 75E-25P (peat) mixture is a promising substitute for seedling growth of Pinus radiata, achieving up to 3-times higher MLVI than the control peat alone. For Quillaja saponaria, the best growth substrate was the 50E-50C (coconut fiber) mixture, which had the most significant MLVI values (127%). We added chitosan and alginate-encapsulated fulvic acid phytostimulants to improve the performance of the substrate mixtures. The fulvic acid, encapsulated or not, significantly improved MLVI values in Q. saponaria species and P. radiata in concentrations between 0.05 and 0.1% w/v. This study suggests that mixtures with higher levels of extracted fiber are suitable for growing forest species, thus promoting the application of circular economy principles in forestry.