Review Articles

Challenges associated with the recyclability and end-of-life management of plastics are leading to a search for more environmentally friendly alternatives. The amount of conventional plastic that is recycled represents a tiny percentage of what is made. Most is sent to landfills or simply accumulates in the environment, which presents a challenge due to the generation of micro- and nanoplastics. Next-generation bioplastics have emerged as an option in recent years. Polyhydroxyalkanoates, polylactic acid, thermoplastic starch, lignocellulosic biocomposites, protein-based materials, seaweed, among others, can be regarded as promising alternatives to conventional plastics. These materials are innovative; some, such as polylactic acid and thermoplastic starch, are already established in the market, while others have recently gained ground in various sectors, including lignocellulosic biocomposites in the automotive industry and bioplastics based on marine algae for food packaging. However, this transition should not be limited to replacement. The study analyzes recent advances in next-generation bioplastics, including classification and potential applications. The study also explores key challenges and regulatory perspectives.

Round bamboo is a critical natural construction material in tropical and subtropical regions because of its high strength, light weight, excellent mechanical properties, and simplicity of access to resources. With the advancement of technology and changes in aesthetics, the design of round bamboo architecture has taken on different development directions, such as simplicity, practicality, and innovative design. The structural components and connection methods are approaching standardization, and the products’ applications are expanded beyond the confines of the home to include commercial spaces and other application scenarios. The current situation, problems, and development direction of round bamboo structures in terms of material production process, modification technology, and standardized processing are summarized in this study. Also discussed are advantages, structural characteristics, and development rules of round bamboo components as building materials, as well as the evolution and innovative development of connection methods. The purpose of this study is to provide references for the innovation and development of round bamboo.

Graphical Abstract

This paper attempts to provide a general characterization of the properties and applications of plant cellulose (PC) based on literature data regarding its sources, discovery, fractional composition and cell dimensions, the microphysical structure of the fibrous component, its content in wood and non-woody plants, functional properties, traditional uses, and selected contemporary opportunities to expand the use of this material in the production of new types of industrial products. This topic can be useful from systematic, informational, and practical perspectives for engineers involved in teaching plant cellulose technology, for researchers and practitioners searching for substitute materials as alternatives to synthetic polymers and fossil-fuel-derived chemicals, and for paper mills seeking opportunities to mitigate the effects of declining demand for printing papers through the development of other PC-based products. The issues discussed in this article may serve as a starting point for the development of an expanded version of this study, supplemented with additional PC properties and applications not identified by the author, and ultimately for the preparation of a book that would include a comprehensive discussion of specific PC applications.

Growing demand for environmentally sustainable wearable electronics is driving the development of high-performance electromechanical sensing materials from carbonized renewable resources. Despite rapid progress, key challenges remain in understanding how biomass carbonization pathways influence conductive network formation and electromechanical sensing performance. This review first analyzes the conversion of biomass feedstocks into conductive biocarbon through pyrolysis and hydrothermal carbonization, highlighting strategies for tuning hierarchical graphitic structure. Then, the review elucidates the electromechanical mechanisms governing strain sensing behavior in biocarbon composites, correlating microstructural evolution with key strain sensor metrics. By synthesizing recent advancements and identifying critical bottlenecks, this review aims to provide a roadmap for advancing next-generation, eco-friendly flexible biocarbon strain sensors from laboratory prototypes to practical applications.

This review considers published evidence supporting ways in which self-assembly and interdigitated structures that emerge during sheet formation contribute to mechanical strength and structural development in nanopaper and conventional paper-like sheets. Interdigitation is defined here as a form of three-dimensional connectivity within fibrous networks, including elements of parallel interaction, minor weaving, physical entanglement, and inter-diffusion among fibers, fibrils, and nano-scale cellulosic features of multiple length scales. Particular attention is given to out-of-plane fiber orientations and the persistence of three-dimensional connectivity during sheet formation, features that are not fully captured by idealized two-dimensional network models. The review considers mechanical, rheological, microscopic, and processing-related studies to assess how hydrodynamic conditions, flocculation, consolidation history, and drying influence the formation and effectiveness of interdigitated structures. The collected evidence suggests that interdigitation is an inherent feature of papermaking over a broad range of fiber and fibril dimensions, and that it can be strongly influenced by processing conditions.  In addition to highlighting the topic of interdigitation, this review also reveals a need for more detailed theoretical consideration, as well as focused experimental work.

Nondestructive testing (NDT), also referred to as nondestructive evaluation/examination (NDE), applied to wood studies, has shown steady global growth driven by the development of innovative techniques and technologies that enable the characterization of wood pieces and structures while minimizing damage. The objective of this study was to analyze the development and recent trends of nondestructive testing in wood. To achieve this, a bibliometric analysis (1982-2025) and a systematic review (2020-2025) were conducted to identify the main research lines, commonly used techniques, and emerging approaches and future perspectives. A total of 303 Scopus-indexed scientific articles were analyzed using VOSviewer and Bibliometrix: Biblioshiny, and 137 recent articles were used for the literature review. The results revealed four main research lines: (I) NDE-NDT with computed tomography for defect detection; (II) NDT for the inspection of wooden buildings and structures; (III) ultrasound in forestry for the characterization of mechanical properties; and (IV) moisture content in wood products. Scientific output showed sustained growth, with China as the leading country and Northeast Forestry University as the most productive institution. Traditional NDT techniques prevail, while emerging approaches and artificial intelligence applications demonstrate that wood NDT research is an expanding field with diversified applications and increasing international relevance.

In recent years, the increasing demand for sustainable and renewable materials has intensified interest in biomass resources capable of supporting green processing and circular bioeconomy strategies. Among these, Opuntia spp. (commonly known as nopal or prickly pear cactus) has emerged as a promising biomass resource due to its adaptability to arid environments and its rich and diverse chemical composition. This review aims to provide a comprehensive and integrated analysis of Opuntia spp. biomass, focusing on its chemical composition, extraction and processing technologies, and its potential for the development of bioproducts and biomaterials. One of the key aspects addressed is the comparison between conventional and environmentally friendly extraction approaches, considering their efficiency, limitations, and suitability for recovering important fractions such as mucilage, structural polysaccharides, and bioactive compounds. This review evaluates the utilization of these fractions in food systems, biodegradable materials, hydrogels, composite materials, and environmental remediation, with an emphasis on their functional attributes and technological potential. Sustainability is considered from a biorefinery perspective, focusing on the efficient use of biomass and the mitigation of environmental impacts. This work gives a critical analysis of recent progress and highlights mayor challenges concerning process standardization, scalability and material properties. The findings support the potential of Opuntia spp. as a versatile platform for sustainable materials and point to future research needed for industrial implementation.

Plastic waste is one of the most concerning issues for the environment in the world. Many researchers are seeking sustainable solutions by replacing petroleum-based plastic with bio-based plastic. Bioplastic is synthesized from natural resources, and it can degrade in different ecosystems. Therefore, it could serve as alternative to combat the harmful impacts of conventional plastic. This review explores different bio-based polymers such as polylactic acid (PLA), polyhydroxyalkanoates (PHA), polybutylene succinate (PBS), starch blends (SB), and cellulose-based bioplastics (CB). These polymers can be used for many industrial applications, including agriculture, automobiles, textiles, packaging, and medical. To give insight into the procedure of bioplastic manufacture, various processes are analyzed in this review, including the solvent casting technique, extrusion techniques, injection molding, and 3D printing. The products of bioplastics such as micro-nano plastic, monomers, and oligomers released after degradation are critically analyzed and the toxicity of bioplastic on different ecosystems has been discussed. A research gap was also identified, as most toxicological studies of bioplastic do not include the LC₅₀/LD₅₀ threshold.

Surface inspection plays a critical role in the wood industry, as it helps companies to enhance product quality, improves the utilization of wood resources, and increases the value of final products. In recent years, deep learning has emerged as a promising technique in this domain, offering significant advantages over traditional methods by enabling high-precision, real-time inspection. This paper presents a comprehensive review of advancements in the field from 2021 to 2025. It begins with a brief overview of three foundational aspects: common types of wood defects, publicly available datasets, and evaluation metrics. The core of the review then examines recent deep learning applications, organized according to three computer vision tasks—classification, detection, and segmentation. The paper concludes by discussing key challenges and proposing viable directions for future research, thereby offering a clear technical roadmap.

Heavy metal contamination in agricultural soils poses persistent risks to crop safety and food-chain exposure. Although biochar is widely proposed—and increasingly applied—as a remediation amendment, field performance remains highly variable across soil constraints, metal speciation, and biochar designs. This review addresses this uncertainty by translating immobilization pathways (sorption/ complexation, precipitation, and redox-mediated stabilization) into a decision-oriented “mechanism–lever–endpoint” framework, thus linking mechanistic hypotheses to controllable engineering strategies such as feedstock selection, pyrolysis windows, and mineral/composite design. Beyond established plant–microbe interactions, there is a critical assessment of under-synthesized biochar–soil fauna pathways, with a focus on earthworms, and a reconciliation of conflicting evidence by highlighting boundary conditions that shift biological responses. Agronomic trade-offs and environmental risks are considered, associated with biochar production and application, emphasizing failure modes relevant to long-term soil health and remediation reliability. To support decision-grade deployment under heterogeneous evidence, a bias-aware AI-assisted workflow is outlined, which stresses standardized reporting, interpretability, and leakage-safe validation. Overall, the review integrates engineering options with biological synergies into a practical roadmap for more predictable and site-specific remediation in agricultural soils.