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Purpose of Review The potential of nanotechnology and nanocomposites in various sectors of research and application is promising and attracting increasing investment. The purpose of this paper is to provide a review of the preparation of nanomaterials from different cellulosic sources including wood. The transformation of cellulose down to the nanoscale endow these nanomaterials with new properties that give cellulose many new industrial applications in different fields, and an overview of the sound markets that can be impacted by cellulose nanomaterials is provided. Recent Findings Unexpected and attractive properties can be observed when decreasing the size of a material down to the nanoscale. Cellulose is no exception to the rule. Cellulose nanomaterials exhibit specific outstanding properties and are potentially useful for a large number of industrial applications. Now, after intensive research, several initiatives have emerged in the perspective of producing cellulose nanomaterials at large scale. A number of organizations have announced cellulose nanomaterial demonstration plants. Summary Despite being the most available natural polymer on earth, it is only quite recently that cellulose has gained prominence as a nanostructured material. Different forms of cellulose nanomaterials, resulting from a top-down deconstructing strategy (cellulose nanocrystals-CNCs, cellulose nanofibrils-CNFs) or bottom-up strategy (bacterial cellulose-BC) can be prepared. Multiple mechanical shearing actions applied to cellulosic fibers release more or less individually the nanofibrils. A controlled strong acid hydrolysis treatment can be applied to cellulosic fibers allowing dissolution of amorphous domains. The mechanical modulus of crystalline cellulose is the basis of many potential applications.

Purpose of Review For the past few decades, consumers have increasingly demanded biodegradable, petroleum-free, and safe products for the environment, humans, and animals, with improved performance. In terms of energy consumption, modern society has progressively sought to reduce fossil fuel utilization and greenhouse gas emissions. This review presents and discusses the possibilities of using biomass residues that are derived from forest operations and wood manufacturing to produce biofuels and biomaterials as sustainable alternatives that could boost the development of renewable technologies and bio-economy. Recent Findings Forest biomass residues are composed primarily of cellulose, hemicellulose, and lignin in varying proportions depending upon the species. Residues from forest operations have heterogeneous compositions due to the presence of branches, foliage, tree tops, and bark, compared with those derived from wood manufacturing industries. Several technological approaches have been developed to add value to forest biomass residues through their conversion to biomaterials such as wood-based composite panels, wood-plastic composites, wood pellets, and biofuels, such as biochar, bio-oil, syngas (thermochemical approach), and biogas (biochemical approach). Summary Forest biomass residues are valuable lignocellulosic materials, but research is still required regarding their conversion into value-added products given their heterogeneous compositions and varied physicochemical properties. Obstacles such as transportation costs and their complex structural and chemical mechanisms that resist decomposition need to be better overcome in developing high-quality and economically viable biofuels and biomaterials. In contrast, wood-based panels, composites, pellets, and biofuels produced by the wood manufacturing industries exhibit superior properties and characteristics for commercialization. Recent studies regarding valorization of forest biomass residues are a welcome recognition of the need to transition to a sustainable economy, and a definitive strategy for achieving objectives that have been set for reducing greenhouse gas emissions.

Purpose of review This review explores the opportunities and challenges associated with using unconventional and underutilized wood sources, such as fast-growing species, logging residues, fire-damaged wood, and post-consumer wood, to manufacture wood-based composite panels (WBCPs), particularly particleboard, medium-density fiberboard (MDF), and oriented strand board. This paper also discusses recent advancements in lightweight and multifunctional panels, with new features such as fire resistance, electrical conductivity, electromagnetic shielding, and antibacterial laminates. Recent findings Climate change, wildfires, and competition from the energy sector threaten current sources of fiber supply for WBCP manufacturing in some regions. Logging residues are abundant but underutilized in some areas, and the abundance of fire-damaged wood is expected to increase in the coming years due to climate change. These raw materials’ effects on panel properties and technological limitations are discussed. Recycled wood is increasingly used for non-structural panels, but challenges remain when it comes to recycling panels, particularly post-consumer MDF. Conventional and emerging materials used in lightweight and multifunctional panels are also presented. Natural substances like cellulose, nanocellulose, chitosan, lignin, protein, and phytic acid are promising alternatives to conventional fire retardants. Innovative products such as MDF that contains carbon-based conductive fibers and antimicrobial laminates that use green-synthesized metal compounds are also reported. Summary This review shows that the WBCP industry can improve its sustainability by optimizing and diversifying wood sources, better managing and recycling post-consumer panels, and using more environmentally friendly materials. The hazardous chemicals in adhesives, fire retardants, and coatings are the main obstacles to recycling panels and creating a more circular economy within the WBCP industry.

Purpose of Review Conventional formaldehyde-based adhesives for wood-based composite panels are subject to significant concerns due to their formaldehyde emissions. Over the past decade, the wood adhesive industry has undergone a considerable transformation that is characterized by a major push in bio-adhesive development. Various bio-based materials have been explored to create alternatives to conventional formaldehyde-based adhesives. Moreover, growing interest in circularity has led to increasingly exploiting industrial coproducts and by-products to find innovative solutions. Recent Findings Industrial production generates many coproducts that can serve as renewable resources to produce eco-friendly materials. These coproducts offer alternative supply sources for material production without encroaching on food production. Many bio-based compounds or coproducts, such as saccharides, proteins, tannins, and lignocellulosic biomass, can also be used to develop bio-based adhesives. As part of ongoing efforts to reduce formaldehyde emissions, new hardeners and crosslinkers are being developed to replace formaldehyde and bio-scavengers. Other alternatives, such as binderless panels, are also emerging. Summary This review focuses on sources of bio-based material derived from by-products of various industries, which have many advantages and disadvantages when incorporated into adhesives. Modification methods to enhance their properties and performance in wood-based panels are also discussed. Additionally, alternatives for developing low-emission or formaldehyde-free adhesives are addressed, including hardeners, bio-scavengers, and binderless options. Finally, the environmental impact of bio-based adhesives compared to that of synthetic alternatives is detailed.

Purpose of Review The main goal of this study was to review the latest developments in the use of wood-based building materials and systems over the last 5 years. The methodology was carried out by using the systematic review procedure. This study considered only peer-reviewed articles written in English published over the last 5 years (2018 to 2022) on materials used in structural systems and building envelopes. Recent Findings The energy demand for cooling and heating represents from 40 to 60% of a building’s energy consumption depending on the energy mix. Every increase in energy efficiency increases the pressure on the energy embedded in the materials. In this context, bio-based and especially wood-based materials are gaining popularity. Their use is significant in structural and envelope systems, making them a powerful tool for working on both efficiency and embedded energy. Furthermore, the building construction industry is among the most significant in the economy of industrialized countries. Summary Forests are a carbon asset for our societies. Since buildings have been identified as a global warming mitigation tool, an increase in the use of wood and bio-based products should be considered. To support a better scientific understanding of building carbon sequestration under climate changes, a thorough understanding of structural and envelope systems is needed. Various materials are used in these complex systems, and a variety of assembly options are available. In structural systems, research has tended to be incremental over the last 5 years, with a focus on prefabrication and hybrid structures. As new designs and materials are introduced in the future, building physics principles will become increasingly important to ensure the quality of building envelopes. This review presents the latest research related to wood structural and envelope systems to support their use in the construction industry.

Purpose of Review In the last decade, a transformation has occurred in the coating industry. While, in the past, the industry was primarily focused on reducing volatile organic compounds (VOC) and formaldehyde emissions, it is now circularity driving this industry. In this paper, we present several advances that have been made, as well as key trends in the wood coatings industry. Recent Findings Replacing petroleum-based chemicals in coating formulations is at the heart of current research. In recent years, various biosourced molecules from animal and plant sources have been the subject of many studies aiming to incorporate them in coatings. Despite all the progress made in the last few years, coating producers are still facing many challenges regarding the availability and quality of biobased raw materials and balancing performance versus cost. Summary While most of the sustainable coating solutions discussed in this review focus on well-known and widely accepted coating chemistries and technologies (water-based and photopolymerizable polyurethanes (PUs), acrylics, and epoxies), we also present new technologies that are expected to gain significant importance in the next few years such as layer-by-layer (LBL), polyelectrolyte complexes, and isocyanate-free PU.

Purpose of Review Intensive forest management practices are being implemented worldwide to meet future global demand for wood and wood products while facilitating the protection of natural forest ecosystems. A potential decline in wood properties associated with rapid tree growth makes it essential to quantify the potential impact of intensive management on the process of wood formation and, in turn, on its suitability for various end-uses. Recent Findings Wood produced over short rotations is generally of lower quality because wood properties tend to improve with cambial age (i.e. the number of annual growth rings from the pith). The intensification of silvicultural practices can thus have measurable consequences for the forest products value chain. The use of new planting material from tree improvement programs could offset such effects, but questions arise as to the effects of a changing climate on wood produced from these plantations and the best silvicultural approaches to manage them. Summary Based on these recent findings, we provide reflections on the need for a modelling framework that uses the effects of cambial age, ring width and position along the stem to summarise the effects of tree growth scenarios on wood properties. We then present challenges related to our limited understanding of the effects of several drivers of wood properties, such as climate variation, genetic material, and forest disturbances, among others, and highlight the need for further data collection efforts to better anticipate the quality attributes of the future wood fibre resource. We conclude by providing examples of promising new tools and technologies that will help move wood quality research forward by allowing (1) fast, efficient characterisation of wood properties, and (2) up-scaling predictions at the landscape level to inform forest management decisions.

Purpose of Review Forest and wood products are often characterized by a uniformity of quality attributes, which necessitates the development of rapid and non-destructive quality evaluation methods to ensure their optimal quality. Near-infrared spectroscopy (NIRS) represents a highly suitable approach for the characterization of organic compounds, and is generally combined with sophisticated multivariate analysis methods. This review article presents a range of scientific and technical reports showcasing the successful use of NIRS for evaluating forest and wood products, mainly published within the past 5 years. Recent Findings Continuous advancements in spectral imaging techniques and the integration of big-data analytics have greatly enhanced the capabilities of NIR instrumentation, enabling its widespread application across diverse fields. Although NIR spectral imaging methods do have some limitations when it comes to online grading, they can still be used to test small quantities of samples at a batch level. Moreover, the ever-increasing use of handheld devices has made NIRS easily accessible. Summary We aim to provide a summary of new research in basic spectroscopic research, integrating the improvements of spectral imaging methods and big-data analytics. Furthermore, low-cost and portable devices have been produced, enabling remote analysis and further expanding the scope of NIRS applications. Looking forward, we anticipate that continued advancements in this field will enable even wider applications of NIRS for online or at-line quality monitoring in diverse fields.

Purpose of Review Wood can be protected from biological deterioration thereby prolonging its longevity and contribution to carbon sequestration. Wood protection is only useful if it is inexpensive and can be done at scale, and with minimal adverse environmental impacts. It is difficult to meet all these criteria but some approaches come close. They are described in this paper with an emphasis on new research findings and directions to inform current research on carbon sequestration by wood. Recent Findings Research on wood protection with the exception of nano-wood preservatives is gradually shifting away from the use of synthetic biocidal chemical treatments to the use of naturally durable wood or protectants and treatments that deny organisms access to wood (barriers) or restrict essential requirements for their growth. The latter approach is attracting attention, and welcome new entrants to the field of wood protection, because of its potential to enhance carbon sequestration at a meaningful scale. Summary We expect increasing regulatory and cost pressure on traditional approaches to wood protection using synthetic biocides and an acceleration of the trend evident in the recent past of protecting wood by modifying its molecular structure to exclude water, or growing trees in plantations that produce naturally durable wood. The strengthening of this trend will create many opportunities to research the properties and applications of ‘new’ durable wood products. In addition, we predict a major reorientation of the field to develop, test and model novel approaches to wood protection for atmospheric carbon sequestration. We conclude that future work will likely include research on protection of: (1) novel cellulose or lignin composites used as replacements for plastic; (2) massive timber composites used in tall buildings and other large infrastructure; (3) huge quantities of low-quality wood used specifically for carbon containment.

Purpose of review Transparent wood (TW) has attracted much interest from researchers as an emerging optical load-bearing material because of its advanced characteristics. These advantages mainly include being renewable, existing abundant reserves, low cost, interesting optical properties, outstanding mechanical performance, and low thermal conductivity. This review summarizes the current research activities that center on the development of transparent wood. Recent findings This review first addresses wood structural features and chemical composition. The effects of lignin removal, wood species, and resin types on the properties of transparent wood have been explored by researchers. Moreover, many studies highlight the properties of transparent wood, including optical and thermal properties and mechanical performance. An increasing number of studies have focused on the preparation of functional transparent wood and its commercial application. Summary We summarize transparent wood research processes and perspectives on several issues that need further exploration. Lignin removal is one of the most important factors in the processing of transparent wood. Thus, more efficient and greener methods need to be developed to achieve lignin removal or modification to suit the requirements of high-performance transparent wood. The main research objectives would be new functional properties such as electromagnetic shielding, intelligent photoelectric response, high hardness, and electrical conductivity of transparent wood. Graphical abstract