Tobacco is one of China's key economic crops, known for its wide distribution, high yield, and renewability. Tobacco stalk fibers (TSFs) share a similar chemical composition to wood fibers, making them a potential reinforcement for plant fiber composites. However, the waste tobacco stalk fibers raw material utilization rate is very low, and wasteful phenomenon is very serious. In this study, we prepared biodegradable TSF/PBAT composites using waste tobacco stalk fibers and polybutylene adipate-co-terephthalate (PBAT) through melt blending and injection molding techniques. The effects of different modifiers on the performance of the composites were systematically investigated, with a particular focus on their influence on the degradation behavior. The results showed that the waste tobacco straw fiber can be used as a reinforcing fiber for PBAT. The addition of modifiers significantly improved the mechanical properties of the composites and effectively slowed down the degradation rate in the soil environment. Among the modifiers, the combined use of maleic anhydride (MA) and hydroxylated multi-walled carbon nanotubes (OM) produced the best results, with the tensile strength and flexural strength of the composite reaching 17.3 MPa and 28.0 MPa, respectively-representing increases of 74.7% and 57.3% compared to the untreated composite. After 16 weeks of soil degradation, the mass loss rate of the MA/OM-modified composite decreased from 10.50 to 6.34%. This study provides a comprehensive exploration of the entire lifecycle of TSF-reinforced PBAT composites and offers important theoretical support for the resource utilization and value-added application of waste tobacco stalks in the field of green composite materials.

Bamboo charcoal (BC) was utilized as a modifier to functionalize poly (L-lactide-co-epsilon-caprolactone) (PLCL) in this research. Five types of BC/PLCL composite films with varying BC content (0.5 wt%, 1.0 wt%, 1.5 wt%, 2.0 wt%, and 2.5 wt%) were fabricated and subjected to degradation studies in soil. The degradation performance of these composite films was assessed by analyzing changes in apparent morphology, micromorphology, mass loss, molecular weight, and mechanical properties after 20, 40, 60, and 80 days of degradation. Results indicated a gradual increase in the degradation level of PLCL over time, accompanied by a decrease in elongation at break from 273.5 % to 12.01 %. The incorporation of BC was found to decelerate the degradation of PLCL, leading to a delayed degradation process as the proportion of BC increased.

This study explores the feasibility and benefits of utilizing plastic waste in the production of construction materials, specifically composite bricks. The escalating accumulation of plastic waste poses significant environmental challenges, which necessitates innovative approaches for recycling and re-utilization to mitigate pollution and reduce landfill use. Our research focuses on the synthesis of bricks by incorporating high-density polyethylene (HDPE) and polystyrene (PS) with sand brick powder, utilizing a compatibilizer (SBS-g-MA) to enhance interfacial adhesion and mechanical integrity. The experimental methodology involved the preparation of composite materials through melt mixing, followed by molding to form brick specimens. These were analyzed for their mechanical properties, including tensile strength, Young's modulus, and elongation at break, as well as thermal properties such as degradation temperature and crystallization behavior. Results showed that the inclusion of sand brick powder significantly enhances the thermal stability of the composites, as evidenced by the higher degradation temperatures observed. Specifically, the degradation temperature increased from 300.59 degrees C in pure HDPE/PS blends to 420.39 degrees C in composites with 7% brick powder, suggesting the formation of a protective barrier against thermal decomposition. Moreover, mechanical testing revealed that composites with up to 7% brick powder exhibited improved tensile strength and Young's modulus compared to pure polymer blends.

Traditional robotic grippers encounter significant challenges when handling small objects in confined spaces, underscoring the need for innovative instruments with enhanced space efficiency and adaptability. Erodium cicutarium awns have evolved hygroresponsive helical deformation, efficiently driving seeds into soil crevices with limited space utilization. Drawing inspiration from this natural mechanism, we developed a biomimetic thin-walled actuator with water-responsive helical capabilities. It features a composite material structure comprising common engineering materials with low toxicity. Leveraging fused deposition modeling 3D printing technology and the composite impregnation process, the actuator's manufacturing process is streamlined and cost-effective, suitable for real-world applications. Then, a mathematical model is built to delineate the relationship between the biomimetic actuator's key structural parameters and deformation characteristics. The experimental results emphasize the actuator's compact dimension (0.26 mm thickness) and its capability to form a helical tube under 5 mm diameter within 60 s, demonstrating outstanding space efficiency. Moreover, helical characteristics and stiffness of the biomimetic actuators are configurable through precise modifications to the composite material structure. Consequently, it is capable of effectively grasping an object smaller than 3 mm. The innovative mechanism and design principles hold promise for advancing robotic technology, particularly in fields requiring high space efficiency and adaptability, such as fine tubing decongestion, underwater sampling, and medical endoscopic surgery.

Concrete is widely used in civil engineering applications and the natural aggregates which used in concrete are scarce, but its demand is increasing. The disposal of rubber tyres poses a significant environmental challenge, as their decomposition releases harmful chemicals into the soil and water bodies over many years. Decomposition of tyres should be done in a smart way and hence came the emergence of mixing recycled rubber crumbs into concrete as Rubberised Concrete (RC). This paper provides an in-depth analysis of the mechanical properties of concrete such as Compressive Strength (fck), Tensile Strength (ft), Flexural Strength (fcr) of 7, 14, 28 days in replacement of fine aggregate with fine rubber (FR), and Coarse Aggregate with Coarse Rubber (CR). The results indicate that RC is more suitable for structural applications, including Reinforced Concrete columns, beams, slabs, than conventional concrete. The primary objective of the article is to explore the potential use of recycled rubber crumbs in concrete, referred to as Rubberised Concrete (RC), and to analyze its mechanical properties such as compressive strength, tensile strength, and flexural strength over different curing periods. Additionally, machine learning (ML) based prediction model has been developed for various strength characteristics of concrete mixtures at 28 days. The hyperparameter optimization using Grid Search CV with fivefold cross-validation have been performed to obtain the best hyperparameters. The model's performance is evaluated using metrics like MAE, MSE, RMSE, and R-squared values. Results reveal varying performances among different ML algorithms for predicting flexural, tensile, and compressive strengths.

Utilizing MSC composite materials (M-Metakaolin(MK)), S-Slag, C-Calcium carbide residue (CCR)), the waste engineering mud produced through the drilling and grouting pile construction method was solidified.Through the analysis of unconfined compressive strength (UCS), X-ray diffraction (XRD), and scanning electron microscope (SEM) on solidified engineering mud test blocks, the influence of complex factors such as slag content, CCR content, and curing time on the solidification efficiency of engineering mud was investigated, and the microscopic mechanism was analyzed.Concurrently, supplementary tests were carried out to ascertain the pH and water content of the cured mud.The results indicated that the 7-day unconfined compressive strength of cured mud specimens could achieve 3 MPa when incorporating 12 % MK, 8 % slag, and 6 % CCR.The optimal pH for the curing mud is determined to be 11.25, correlating with a water content of 84 %.The destructive strains corresponding to the peak stresses of the cured mud at different curing times ranged from 1.6 % to 2.5 % and generally decreased with increasing peak stresses.The XRD and SEM analyses have demonstrated that the enhancement in the strength of the cured mud can be attributed to the processes of hydration and polymerization, resulting in the generation of gel products such as calcium silicate hydrate (CSH) and aluminosilicate-Na hydrate (NASH). These products are responsible for the adsorption of clay and bentonite particles, thereby efficiently occupying the structural voids.The research findings have the potential to provide theoretical support for the development of environmentally friendly and low-carbon MSC gelling materials, as well as their application in soil reinforcement, notably in the context of engineered mud solidification.