Search Results (6,770)

The mounting global concern regarding the accumulation of plastic waste underscores the necessity for the development of innovative solutions, with particular emphasis on the incorporation of plant-based biofillers into polymer composites as a sustainable alternative to conventional materials. This review provides a comprehensive and structured overview of the recent progress (2020–2025) in the integration of plant-based biofillers into both thermoplastic and thermosetting polymer matrices, with a focus on surface modification techniques, physicochemical characterization, and emerging industrial applications. Unlike the prior literature, this work highlights the dual environmental and material benefits of using plant-derived fillers, particularly in the context of waste valorization and circular material design. By clearly identifying a current research gap—the limited scalability and processing efficiency of biofillers—this review proposes a strategy in which plant-derived materials function as key enablers for sustainable composite development. Special attention is given to extraction methods of lignocellulosic fillers from renewable agricultural waste streams and their subsequent functionalization to improve matrix compatibility. Additionally, it delineates the principal approaches for biofiller modification, demonstrating how their properties can be tailored to meet specific needs in biocomposite production. This critical synthesis of the state-of-the-art literature not only reinforces the role of biofillers in reducing dependence on non-renewable fillers but also outlines future directions in scaling up their use, improving durability, and expanding performance capabilities of sustainable composites. Overall, the presented analysis contributes novel insights into the material design, processing strategies, and potential of plant biofillers as central elements in next-generation green composites. Full article

Negative air ions (NAI) represent an important ecological value indicator for green tree species. Flow of sap is a crucial indicator for water utilization and physiological state of trees. Although there have been some advancements in studies on the correlation between the release of NAI by plants and sap flow in recent years, it is still unclear how the release of NAI by plants changes during drought stress and recovery processes, as well as the coupling effect between the release of NAI by plants and sap flow under drought stress. In this context, four typical green tree species, Robinia pseudoacacia, Quercus variabilis, Pinus tabulaeformis, and Platycladus orientalis, were selected as experimental materials. A drought stress and recovery control experiment was conducted based on OTC. The dynamic data of negative air ion concentration (NAIC) and sap flow rate during the process of drought stress and recovery were monitored to clarify the characteristics and correlations of NAI and sap flow changes in the experimental tree species under drought stress and recovery. The main research results are as follows: (1) At the end of the drought period, the NAI and sap flow in the drought treatment group significantly decreased (p < 0.01), compared with the control group (CK), and the reduction rate of sap flow (77.73 ± 4.96%) for each tree species was higher than that of NAI (47.78% ± 4.96%). (2) At 1 day after rehydration, the recovery amplitudes of NAI and sap flow for all tree species were the greatest; at 7 days after rehydration, the NAI and sap flow of the drought treatment group recovered to the levels of the control group (p > 0.05). (3) During different stages of drought rehydration, the response degree of NAI to sap flow varied. The study found that in the drought-rehydration stage, the correlation between the NAI released by each tree species and sap flow was the lowest at the drought endpoint. In conclusion, this research clarifies the changing patterns of plant NAI release and sap flow during drought-rehydration, as well as the response changes of NAI to sap flow. It provides a theoretical basis for selecting drought-tolerant tree species in arid regions. Full article

Molecularly imprinted polymer nanoparticles (MIP NPs) are synthetic receptors with selective recognition sites for target molecules. They are employed instead of biorecognition elements in many applications due to their high affinity and selectivity, stability, easy preparation, and low cost. Their nanoscale size provides enhanced surface interactions, faster response times, improved biocompatibility, and effective cellular penetration, particularly in complex biological environments. MIP NPs provide high selectivity and structural versatility in the sample preparation, sensor-based detection, and controlled drug delivery, serving as promising alternatives to conventional methods. This review highlights the recent advancements in the synthesis and application of MIP NPs in three critical areas: sample preparation, sensor-based detection, and controlled drug release. Additionally, recent developments in green synthesis approaches, biocompatible materials, and surface functionalization strategies that are effective in the performance of MIP NPs are mentioned. Full article

Petrochemicals currently represent the predominant global source of energy and consumer products, including the starting materials used in the platform chemical, plastic polymer, and pharmaceutical industries. However, in recent years, the world’s approaches have shifted towards green chemistry and bio-based chemical production in an effort to reduce CO₂ emissions and mitigate climate change. Over the past few decades, researchers have discovered that marine metabolites, primarily sourced from invertebrates, can be utilized to create sustainable and renewable chemicals. This review highlights the significance of advancing marine microorganism-based biotechnology and biochemistry in developing effective conversion systems to enhance the biological production of key platform chemicals, including those utilized as biomaterials and for energy. A background in marine metabolite biochemistry lays the groundwork for potential strategies to mitigate dependence on petroleum for consumer products. This is followed by a discussion of petroleum product replacement technologies, green chemistry alternatives, and CO₂ mitigation efforts for the production of sustainable and renewable key platform chemicals. Full article

Lotus stems contain cellulose, which can be utilized as a base material for producing green products, specifically degradable plastics. This research investigates the effect of polylactic acid (PLA) blends on cellulose degradable plastics from the lotus stem (Nelumbo nucifera). The mechanical characteristics are as follows: tensile strength of 0.7703–3.3212 MPa, elongation of 0.58–1.16%, Young’s modulus of 78.7894–364.6118 MPa. Compound analysis showed the presence of O-H, C-C, and C=O groups, and the presence of microbial activity in the soil can also lead to the degradation of these groups due to their hydrophilic nature, which allows them to bind water. Thermal analysis within a temperature range of 413.24 °C to 519.80 °C, shows that significant weight loss begins with the formation of crystalline structures. The degradable plastic exhibiting the lowest degree of swelling consists of 1 g of cellulose and 8 g of PLA, resulting in a swelling value of 6.25%. The degradable plastic is anticipated to decompose most rapidly after 52 days, utilizing 2 g of PLA and 7 g of cellulose. This complies with standard requirement, which sets a maximum degradation period of 180 days for polymers. Full article

The study employed a green, template-free ball milling method to construct a series of Ni-Al mixed oxide catalysts modulated by different nickel precursors (nitrate, acetate, carbonate, sulfate, and chlorate). Through multiscale characterization techniques (XRD, TEM, XPS, H₂-TPR, etc.) and catalytic performance evaluations, we systematically elucidated the regulatory mechanism of precursor types on the structure-performance relationship. The NiAlO_x-CO₃²⁻ catalyst derived from nickel carbonate exhibited a unique structure, an optimal Ni/Al ratio, and well-tuned active oxygen species, thereby demonstrating exceptional catalytic performance in the oxidative dehydrogenation of ethane (ODHE) at 475 °C with 53.2% ethane conversion, 72.6% ethylene selectivity, and maintained stability over 40 h of continuous operation. Beyond developing high-performance ODHE catalysts, this work establishes a “precursor chemistry–material structure–catalytic performance” relationship model, offering new insights for the rational design of efficient catalysts for light alkane conversion. Full article

In recent years, the green and low-carbon agenda has gained importance across various economic sectors, including the construction sector, which encompasses both the development of infrastructure and buildings, as well as the production of construction materials. The purpose of this study is to demonstrate that the effectiveness of green integration is achieved by balancing the collective capital of all participants in forming green value chains. The authors propose a methodology for evaluating the integration capital, which enables the assessment of both joint capital accumulation and the resulting added green value. A system of indicators is proposed to evaluate participants in green integration and determine the maturity levels of their integration capital. The methodology is tested using a case study reflecting green integration in the construction sector covering the erection of buildings and the production of building materials. The authors introduce a three-dimensional model (triangular prisms) to visualize the potential and the integration capital of the involved actors. The study’s findings are applicable to scenario modeling, particularly in developing strategic trajectories for participants in green integration. Full article

Permian shale gas is a kind of energy resource with commercial development potential. The characteristics of its organic source and enrichment have received extensive attention in recent years. This study systematically analyzed the variations in types and assemblages of hydrocarbon-forming organisms across different stratigraphic layers of Permian shale in western Hubei through scanning electron microscopy (SEM) and microscopic observations. Moreover, the source characteristics and enrichment mechanisms of organic matter in Permian shale were identified. Hydrocarbon generation in Permian shale is primarily attributed to planktonic algae-derived acritarchs, supplemented by higher plants and green algae, based on the observation under the SEM and microscope. The hydrocarbon-forming microorganisms in the Gufeng Formation are predominantly characterized by acritarchs. A notable decrease in acritarch content is observed at the bottom of the Wujiaping Formation, accompanied by a significant increase in higher plant constituents and a slight rise in green algae abundance. Subsequently, from the middle-upper members of the Wujiaping Formation through the Dalong Formation, acritarch concentrations rebound while higher plants and green algae contributions diminish. The organic matter in the studied layer is predominantly generated from planktonic algae (acritarchs and green algae), with subordinate contributions from terrestrial higher plants. During the sedimentary stage of the Gufeng Formation, rising sea levels sustained a deep siliceous shelf environment in the E’xi Trough, where organic matter was primarily sourced from acritarchs, with limited terrigenous input. The regressive phase at the bottom of the Wujiaping Formation resulted in coastal marsh throughout the E’xi Trough, creating a mixed organic matter assemblage of aquatic planktonic algae and enhanced terrestrial higher plant material. As sedimentation progressed into the middle-upper Wujiaping Formation and Dalong Formation, the E’xi Trough evolved into a deep siliceous shelf and platform-margin slope environment. During this stage, organic matter was again predominantly supplied by planktonic algae (mainly acritarchs), with reduced terrestrial organic input. These findings provide valuable theoretical insights for guiding Permian shale gas exploration and development strategies. Full article

Fruit pomace, generated as a by-product of juice processing, is a valuable source of bioactive compounds but requires sustainable extraction approaches to enable its valorisation. Supercritical CO₂ extraction (SFE-CO₂) represents a promising green technology due to its efficiency, solvent-free character, and tuneable selectivity. In this study, the response surface methodology (RSM) was applied to evaluate the effects of pressure, temperature, and time on the recovery of fat, protein, and total phenolic compounds (TPCs) from blackcurrant (Ribes nigrum) and redcurrant (Ribes rubrum) pomace subjected to conventional- and freeze-drying. The highest protein content (14.5%) was obtained in freeze-dried blackcurrant at 400 bar, 60 min, and 30 °C, while the maximum TPCs (24.60 mg GAE/g d.w.) was reached at 500 bar, 60 min, and 40 °C. The redcurrant samples consistently showed lower extractable values across all the responses. Pressure and time were identified as the most influential process variables, enhancing the solvent density and mass transfer during extraction. These results demonstrate that both the drying pre-treatment and raw material type significantly affect the SFE efficiency and confirm the potential of optimised SFE-CO₂ as a viable strategy for converting fruit pomace into functional ingredients for food, nutraceutical, and cosmetic applications. Full article

Graphene, a two-dimensional material with remarkable electrical, thermal, and mechanical properties, has revolutionized the fields of electronics, energy storage, and nanotechnology. This review presents a comprehensive analysis of graphene synthesis techniques, which can be classified into two primary approaches: top-down and bottom-up. Top-down methods, such as mechanical exfoliation, oxidation-reduction, unzipping carbon nanotubes, and liquid-phase exfoliation, are highlighted for their scalability and cost-effectiveness, albeit with challenges in controlling defects and uniformity. In contrast, bottom-up methods, including chemical vapor deposition (CVD), arc discharge, and epitaxial growth on silicon carbide, offer superior structural control and quality but are often constrained by high costs and limited scalability. The interplay between synthesis parameters, material properties, and application requirements is critically examined to provide insights into optimizing graphene production. This review also emphasizes the growing demand for sustainable and environmentally friendly approaches, aligning with the global push for green nanotechnology. By synthesizing current advancements and identifying critical research gaps, this work offers a roadmap for selecting the most suitable synthesis techniques and fostering innovations in scalable and high-quality graphene production. The findings serve as a valuable resource for researchers and industries aiming to harness graphene’s full potential in diverse technological applications. Full article

The manufacture of Portland cement (PC) emits a significant amount of CO₂ into the atmosphere. Therefore, the partial replacement of PC by supplementary cementitious materials (SCMs) possessing pozzolanic properties is considered a viable strategy to reduce its environmental impact. Recently, waste glass (WG) has been explored as a potential SCM. However, due to the wide variety of glass types and their differing physical and chemical properties, not all WG can be universally considered suitable for this purpose; therefore, this study investigates the use of recycled WG as an SCM for the partial replacement of PC. Two types of WG were evaluated: green waste glass from wide bottles (GWG) and laboratory waste glass (LWG), and their performance was compared to that of fly ash (FA). The physical, mechanical, and pozzolanic properties of the materials were assessed. Results show that both types of WG exhibit particle size distributions comparable to PC and have contents of SiO₂, Al₂O₃, and Fe₂O₃ exceeding 70%. Chemical, mineralogical, and pozzolanic analyses revealed that both GWG and LWG presented higher pozzolanic activity than FA, particularly at later ages. Notably, LWG demonstrated the most significant contribution to mechanical strength development. These findings suggest that recycled waste glass, especially LWG, can serve as a viable and sustainable SCM, contributing to the reduction of the environmental footprint associated with Portland cement production. Full article

Green and low-carbon filling materials, primarily composed of dredged waste fills, are commonly used in the foundation of coastal highways. These materials possess high water content and under-consolidation characteristics, which can lead to differential settlement between piles and the surrounding environment. However, mechanical models of negative friction in piles within recycled dredged waste fills are insufficiently developed and presented. A mechanical model for the negative friction of a single pile in a composite foundation, consisting of dredged waste fills and other materials, is established based on the load transfer method. Through centrifugal model testing and numerical simulations, the development of negative friction and the migration pattern of the neutral point are analyzed and clarified. The results show that the theoretical model based on improved transfer function can effectively predict the neutral point position and negative friction value (average relative error < 6.5%). The theoretical analysis and experimental results indicate that the downward load due to negative friction increases nonlinearly. The loading strength exhibits a clear relationship with the consolidation process. Additionally, the dynamic evolution of the neutral point position is strongly correlated with consolidation of dredged fills. The size of pile foundation significantly influences the distribution of negative friction. Results show that the increment in negative friction for a pile with a 1.05 m diameter is 7.3% higher than that for a pile with a 1.5 m diameter. Smaller-diameter piles are more susceptible to negative friction due to the higher friction strength per unit area. The negative frictional resistance will enter a stable period after 50 months of settlement. The investigation can provide significant references for the design of pile foundations in areas with reclaimed materials, improving the stability and safety of pile foundations in practical engineering. Full article

Electrospun alginate nanofibers are emerging as versatile materials for biomedical, environmental, and packaging applications due to their biocompatibility, biodegradability, and functional tunability. However, the direct electrospinning of alginate remains a significant challenge, mainly due to its polyelectrolytic nature, rigid chain structure, and limited chain entanglement. This review provides a comprehensive analysis of recent strategies developed to overcome these limitations, including polymer blending, chemical modification, the addition of surfactants, multi-fluid techniques, and process optimization. We systematically discuss the integration of nanofibers with functional agents such as microorganisms, bioactive compounds, plant extracts, and nanoparticles, highlighting their potential in wound healing, active packaging, bioremediation, and controlled release systems. This review also examines the scalability of alginate electrospinning, summarizing recent patents, industrial solutions, and challenges related to the standardization of the process. Key knowledge gaps are identified, including the need for long-term stability studies, structure–function correlations, green processing approaches, and expansion into novel application domains beyond healthcare. Addressing these research directions will be crucial to unlocking the full potential of alginate nanofibers as sustainable, high-performance materials for industrial use. Full article

Nickel-catalyzed cyanation of aryl halides has emerged as a powerful and sustainable method for the synthesis of aryl nitriles—valuable motifs widely found in pharmaceuticals, agrochemicals, and functional materials. Compared to traditional cyanation methods that involve harsh conditions and toxic reagents, nickel catalysis enables mild, efficient, and versatile transformations. This review systematically summarizes recent advances in this field, categorized by different cyanide sources, including metal cyanides (NaCN, KCN, Zn(CN)₂, K₄[Fe(CN)₆]) and non-metal or organic cyanide sources (e.g., MeCN, nitriles, BrCN, CO₂/NH₃). Key developments in catalyst systems, ligand design, mechanistic insights, and green chemistry aspects are highlighted. Remaining challenges and future directions are also discussed. Full article

Urban green spaces (UGSs) are a vital component of urban landscapes nowadays, with an impact on energy distribution in cities and local climate regulation. This study aims to quantify the thermal and optical behavior of various materials in a small-scale Mediterranean UGS and provide insights into the use of green and artificial materials in urban parks. The analysis also includes the changes in the UGS’s optical and thermal properties following its restoration in 2024. The thermal comfort in the UGS is assessed for the 2020–2024 period, along with the reflectivity and surface temperatures of the different materials pre- (in 2022) and post-restoration (in 2024), using in situ measurements. The results show notable seasonal and interannual variability in the thermal comfort of the site. The impact of vegetation on the UGS was critical. The vegetation-covered surfaces exhibited surface temperatures close to ambient air temperature, highlighting their effective thermal regulation. During summer mornings, the average temperatures of the vegetation-covered surfaces were around 30.5 °C, lower compared to artificial or non-green materials, like asphalt, concrete, gravel, and dry bare soil, which were above 42 °C. The vegetation albedo was relatively lower (around 0.19), while artificial covers showed a greater reflectance (up to 0.35), thus boosting the heat retention. These results highlight the essential importance of green infrastructure incorporation to boost the thermal dynamics of urban open spaces and mitigate climate change effects. Full article