Publications by authors named "Crestini C"

Lignin's complex and heterogeneous molecular structure poses significant challenges for accurate molar mass determination, which is important for its utilization in industrial applications, such as biochemicals, nanoparticles, biobased binders, and biofuels. This study evaluates the potential of Taylor Dispersion Analysis (TDA) for measuring lignin size and compares it with size-exclusion chromatography (SEC) and diffusion-ordered spectroscopy (DOSY) NMR. Using dual Gaussian fitting, flow-induced dispersion analysis (FIDA), a TDA-based method, successfully determined the average hydrodynamic radii of multiple species in solvent-fractionated soda grass lignin samples, producing results consistent with DOSY.

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The reductive catalytic fractionation (RCF) of second generation lignocellulosic biomass is an elegant one-pot process to obtain a highly delignified cellulose pulp, sugar-derived polyols, and depolymerized and stabilized lignin oils. However, the need of noble metal catalysts to prompt the reactions may impact the economic sustainability of the overall "lignin-first" biorefinery if the catalyst recovery and recyclability are not guaranteed. Herein, the use of a novel catalyst based on supported ruthenium over maghemite for the RCF of poplar sawdust is reported for the first time.

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Lignin represents a promising source of renewable energy. The development of CLEO (Cold processed Lignin Ethanol Oil) fuel introduces a novel lignin valorization approach, proposing its potential as maritime biofuel. However, its industrial success depends on enhancing fractionation yields and reducing solvent evaporation, which necessitates a detailed analysis of lignin properties, solvent types, and process parameters.

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In contrast to conventional non-biobased adsorbents, lignin emerges as a cost-effective and environmentally benign alternative for water treatment. This study identifies unexpected and unpredicted multifunctional properties of lignin nanoparticles (LNPs). LNPs, which are prepared by simple physical processes, demonstrated for the first time to behave as multifunctional materials able to adsorb and photodegrade methylene blue (MB) in aqueous medium upon UV irradiation.

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The development of strategies allowing either the production of high value phenolics, or the isolation of properties-enhanced materials from technical lignins represents a fundamental step in the industrial upcycling of technical lignins. Both aims are met by the strategy presented in the present work, relying on the coupling of solvent-based fractionation with the oxidative action of a new type of alkaline-stable genetically modified bacterial laccase. The described approach succeeded in the tandem, high-yield and selective isolation of valuable lignin-monomeric compounds (MCs) and high molecular weight and hydrophobicity-tailored polymerised materials (PMs) from two technical lignins, namely softwood kraft lignin (SKL), and wheat straw organosolv lignin (WSL).

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Article Synopsis
  • The increasing demand for sustainable manufacturing is driving interest in bio-based materials, particularly kraft lignin (KL), a byproduct of the pulp and paper industry.
  • KL was successfully integrated into a glassy epoxy system, partially replacing the traditional curing agent and prepolymer, resulting in composites with comparable thermo-mechanical properties and enhanced antioxidant capabilities.
  • Further evaluation of KL's particle size revealed that smaller nano-lignin significantly improves mechanical properties and clarity of the resulting epoxy composites, while glycidylization of KL allowed for a notable replacement of fossil-derived components in the epoxy formulation.
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Kraft lignin, a by-product from the production of pulp, is currently incinerated in the recovery boiler during the chemical recovery cycle, generating valuable bioenergy and recycling inorganic chemicals to the pulping process operation. Removing lignin from the black liquor or its gasification lowers the recovery boiler load enabling increased pulp production. During the past ten years, lignin separation technologies have emerged and the interest of the research community to valorize this underutilized resource has been invigorated.

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Background: Tannins have demonstrated antibacterial and antibiofilm activity, but there are still unknown aspects on how the chemical properties of tannins affect their biological properties. We are interested in understanding how to modulate the antibiofilm activity of tannins and in delineating the relationship between chemical determinants and antibiofilm activity.

Materials And Methods: The effect of five different naturally acquired tannins and their chemical derivatives on biofilm formation and planktonic growth of Typhimurium, , and was determined in the Calgary biofilm device.

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Nowadays sustainable nanotechnological strategies to improve the efficiency of conventional agricultural practices are of utmost importance. As a matter of fact, the increasing use of productive factors in response to the growing food demand plays an important role in determining the environmental impact of agriculture. In this respect, low-efficiency conventional practices are becoming obsolete.

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Invited for this month's cover is the work by Claudia Crestini and collaborators at Ca'Foscari University of Venice, Italy, and University of Insubria, Italy. The image shows the formation of low-molecular-weight compounds by the oxidative depolymerization of lignin by the laccase-Lig multienzymatic multistep system. The Research Article itself is available at 10.

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A laccase-Lig multienzymatic multistep system for lignin depolymerization was designed and developed. Studies were performed on pristine and fractionated lignins (Kraft and Organosolv) using a specific cascade of enzymes, that is, laccases from Bacillus licheniformis and from Funalia trogii, respectively for Kraft and Organosolv lignin, followed by the Lig system from Sphingobium sp. SYK-6 (β-etherases Lig E and Lig F, glutathione lyase Lig G).

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The extensive use of non-degradable microplastics in a wide plethora of daily life products is causing serious pollution problems. More ecofriendly solutions are therefore urgently needed. In this context, the use of lignin, a largely available aromatic polymer, may represent a viable option.

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The brewery industry annually produces huge amounts of byproducts that represent an underutilized, yet valuable, source of biobased compounds. In this contribution, the two major beer wastes, that is, spent grains and spent yeasts, have been transformed into carbon dots (CDs) by a simple, scalable, and ecofriendly hydrothermal approach. The prepared CDs have been characterized from the chemical, morphological, and optical points of view, highlighting a high level of N-doping, because of the chemical composition of the starting material rich in proteins, photoluminescence emission centered at 420 nm, and lifetime in the range of 5.

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Novel valorization routes for tannins were opened by the development of a simple, straightforward, robust, and flexible approach to the selective functionalization of condensed and hydrolyzable tannins. Irrespective of the different degrees of polymerization, different commercial tannins were efficiently functionalized by the generation of an ether linkage bound to a short linker carrying the desired functional group. Functionalizations could be realized at varying degrees of technical loadings, i.

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The development of sustainable biorefinery products is confronted, among others, with the challenge of lignin and tannin valorization. These abundant, renewable aromatic biopolymers have not been widely exploited due to their inherent structural complexity and high degrees of variability and species diversity. The lack of a defined primary structure for these polyphenols is further compounded with complex chemical alterations induced during processing, eventually imparting a large variety of structural features of extreme significance for any further utilization efforts.

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Microcapsules of sulfited tannin (ST-MCs) were generated for the first time via the sonochemical method. Their stability profile was assessed and set in the general context of tannin microcapsules (TMCs) generated under the same experimental conditions. The analytical data gathered in this work indicate an excellent stability of TMCs over time as well as under high temperature and pressure, which is a major milestone toward the meaningful applications of TMCs in industrial, pharmaceutical, and biomedical applications in which sterilization of TMCs might be a prerequisite.

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Both condensed and hydrolysable tannins represent versatile natural polyphenolic structures exhibiting a broad range of activities that could be exploited in various fields including nutraceutics, cosmesis, consumer care, household and pharmaceutical applications. Various tannins are commercially available nowadays for use in such application fields. We have analysed a representative selection of commercially available condensed and hydrolysable tannins for structural features and purity.

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Two different organosolv lignins (OSLs), that is, wheat straw and corn stover OSLs, were chemically and enzymatically functionalized. Functional groups were attached via the formation of stable ether bonds exploiting the reactivity of free phenolic OH groups along the lignin backbone. The functional groups introduced a range from compact charged and chargeable building blocks for the generation of surface-active lignins to oligomeric and polymeric species used in lignin block-copolymer productions.

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Organosolv pretreatment represents one of the most promising biomass valorization strategies for renewable carbon-based products; meanwhile, there is an overall lack of holistic approach to how extraction conditions affect the suitable end-usages. In this context, lignin extracted from silver birch ( L.) by a novel hybrid organosolv/steam-explosion treatment at varying process conditions (EtOH %; time; catalyst %) was analyzed by quantitative NMR (H-C HSQC; C NMR; P NMR), gel permeation chromatography, Fourier transform infrared (FT-IR), Pyr-gas chromatography-mass spectroscopy (GC/MS), and thermogravimetric analysis, and the physicochemical characteristics of the lignins were discussed regarding their potential usages.

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This Perspective describes the challenges and objectives associated to the development of new chemical technologies for the conversion of lignocellulose (non-food or waste) into chemicals and materials; it also provides an outlook on the sources, potential products, and issues to be addressed.

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Lignins were fractionated in a segmented continuous flow fractionation (SCFF) approach using isocratic or gradient elution profiles of different solvent systems at various flow rates and temperatures against adjustable pressure regimes. Superior control of parameters such as temperature and pressure in combination with the possibility of freely combinable solvent gradients allowed facile fractionation and generation of industrially interesting fractions differing in molecular weight properties and/or in physicochemical properties in a process that could be fully remotely controlled for automation and performance. Scale-up of the process was possible in linear and parallel mode.

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Article Synopsis
  • The use of nanoparticles is an effective method for improving lignin utilization, leveraging simple techniques with significant potential for various applications.
  • Different production methods and lignin sources have been explored, but the unique structures of lignin complicate comparisons among lignin nanoparticles (LNPs) regarding their properties and functions.
  • Two environmentally friendly techniques were optimized to create LNPs from the same type of lignin, allowing for in-depth analysis of their structural characteristics and their capacity for trapping and releasing methylene blue under varying pH conditions.
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Thymol and the corresponding brominated derivatives constitute important biological active molecules as antibacterial, antioxidant, antifungal, and antiparasitic agents. However, their application is often limited, because their pronounced fragrance, their poor solubility in water, and their high volatility. The encapsulation of different thymol derivatives into biocompatible lignin-microcapsules is presented as a synergy-delivering remedy.

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wood samples were subjected to consecutive stages of hydrothermal processing for hemicellulose solubilization and delignification with an ionic liquid, i.e., either 1-butyl-3-methylimidazolium hydrogen sulfate or triethylammonium hydrogen sulfate.

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Stimuli-responsive behavior of lignin microcapsules (LMCs) has been investigated along with the detailed characterization of their stability profiles. The disassembly of LMCs was found to be salt species-dependent, indicating the specific relevance of inherent kosmotropic and chaotropic characteristics. For the first time, a connection between the Hofmeister series and the stability profile of lignin microscale materials is established.

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