Eco-friendly versatile shielding revolution: Tannin tailored bamboo waste composite with wave-absorbing, flame retardancy, and antibacterial abilities.

The swift evolution of fifth-generation technology has intensified the need for lightweight, high-efficiency, and low-reflection multifunctional electromagnetic interference shielding materials, crucial in combating escalating electromagnetic pollution in complex application environments. To tackle these challenges, an innovative solution has emerged: a biocomposite crafted from discarded bamboo materials. This innovation incorporates a meticulously engineered functional coating composed of tannic acid, boric acid, and polyvinyl alcohol. Additionally, the integration of highly conductive Ti3C2Tx (MXene) nanosheets onto the surface of bamboo powders enhances the EMI shielding efficiency of composites, achieving an impressive ∼40.9 dB. Meanwhile, significant improvements in mechanical reinforcement have been achieved, along with increases in the relative values of key performance indicators: tensile strength (89.8 %), tensile modulus (79.6 %), flexural strength (51.6 %), flexural modulus (35.1 %), and impact strength (45.4 %). Furthermore, the introduction of functional components grants the composite exceptional flame retardancy and antibacterial properties against both Gram-negative and Gram-positive bacteria. Beyond these strides, the utilization of bamboo waste as a composite pioneer a paradigm shift in waste utilization, converting refuse into invaluable resources.

Polydopamine-treated hierarchical cellulosic fibers as versatile reinforcement of polybutylene succinate biocomposites for electromagnetic shielding.

There is a need for scalable technologies to reduce electromagnetic pollution with materials of low density and low carbon footprint. Unfortunately, environmental adaptability, economic feasibility and lightweight are factors that are still far from optimal in most electromagnetic shielding materials. Herein, we address these challenges with polybutylene succinate (PBS) reinforced with bamboo fibers functionalized with Fe3O4 nanoparticles (Fe3O4-NPs) and polypyrrole (PPy). Such hybrid system was compatibilized via polydopamine (PDA) coupling, demonstrating magnetic, dielectric and interfacial polarization losses as well as distributed reflection, yielding a shielding effectiveness of ~36.9 dB. Simultaneously, the composite displayed gains in tensile strength and modulus (by 18 and 38%, respectively) combined with improved flexural strength and modulus (by 33% and 15%, respectively). Overall, this work demonstrates a new pathway toward low cost and lightweight bio-based materials for high-performance electromagnetic shielding.

The Effect of Alkali Treatment on Properties of Dopamine Modification of Bamboo Fiber/Polylactic Acid Composites.

In this study, a synergistic treatment including dopamine (DA) modification and alkali pretreatment on bamboo fiber (BF) was used as reinforcement in a polylactic acid (PLA) matrix to improve the mechanical and thermal properties of BF/PLA composites. The effects of the sodium hydroxide loading rate on the performance of mussel-inspired dopamine-modified bamboo fiber and the BF/PLA composites were evaluated using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), mechanical testing (examining flexural, tensile, and impact properties), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). Analysis of the composites suggested that the optimal condition was treatment with a 4 wt % solution of NaOH and a 1 wt % concentration of dopamine. Compared with the untreated bamboo fiber/polylactic acid composites, the synergistic treatment improved the thermal properties and mechanical properties; flexural, tensile, and impact strengths increased by 16.1%, 34.4%, and 3.7%, respectively. It was further verified that appropriate alkali treatment was a promising approach in promoting the effect of dopamine-modified coating while maintaining the crystal structure of the cellulose.

Mussel-Inspired Polydopamine as a Green, Efficient, and Stable Platform to Functionalize Bamboo Fiber with Amino-Terminated Alkyl for High Performance Poly(butylene succinate) Composites.

A new and eco-friendly mussel-inspired surface modification pathway for bamboo fiber (BF) is presented in this study. The self-assembly polydopamine (PDA) coating can firmly adhere on BF surface, which also serves as a bridge to graft octadecylamine (ODA) for hydrophobic surface preparation. The as-formed PDA/ODA hybrid layer could supply abundant hydrophobic long-chain alkyls groups and generated a marked increase in BF surface roughness and a marked decrease in surface free energy. These changes provided advantages to improve fiber⁻matrix interfacial adhesion and wettability. Consequently, high performance was achieved by incorporating the hybrid modified BF into the polybutylene succinate (PBS) matrix. The resultant composite exhibited excellent mechanical properties, particularly tensile strength, which markedly increased by 77.2%. Meanwhile, considerable high water resistance with an absorption rate as low as 5.63% was also achieved. The gratifying macro-performance was primarily attributed to the excellent interfacial adhesion attained by hydrogen bonding and physical intertwining between the PDA/ODA coating on the BF and the PBS matrix, which was further determined by fracture morphology observations and dynamic mechanical analysis. Owing to the superior adhesive capacity of PDA, this mussel-inspired surface modification method may result in wide-ranging applications in polymer composites and be adapted to all natural fibers.