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The development and application of flexible electrodes with extended cycle life have long been a focal point in the field of energy research. In this study, positively charged polyethylene imine (PEI) and conductive polymer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) with negative charge were alternately deposited onto a cellulose nanofiber (CNF) porous material utilizing pressure gradient-assisted layer-by-layer (LbL) self-assembly technology. The flexible substrate, characterized by a three-dimensional porous structure reinforced with stiff CNF, not only facilitated high charge storage but also enhanced the electrode's cycling life by reducing the volume changes of PEDOT:PSS. Furthermore, the exceptional wettability of PEI by the electrolyte could promote efficient charge transport within the electrode. The electrode with 10 PEI/PEDOT:PSS bilayer exhibits a capacitance of 63.71 F g−1 at the scan rate of 5 mV s−1 and a remarkable capacitance retention of 128 % after 3000 charge-discharge cycles. The investigation into the nanoscale layers of the LbL multilayer structure indicated that the exceptional cyclic performance was primarily attributed to the spatial constraints imposed by the rigid porous substrate layered structure on the deformation of PEDOT:PSS. This work is expected to make a significant contribution to the development of electrodes with high charge storage capacity and ultra-long cycling life. [Display omitted] [ABSTRACT FROM AUTHOR]

For the purposes of obtaining poly(3-hydroxylbutyrate) (PHB) matrix composites with high performance, a novel eco-friendly surface modification pathway for bamboo fiber (BF) was demonstrated. Dopamine was first polymerized to poly(dopamine) (PDA) by laccase and then was deposited on the surface of BFs, which would improve interfacial adhesion between PHB and BFs. The replacement of chemical reagents by laccase to catalyze polymerization of dopamine could avoid the environmental damage and the degradation of natural fiber structure under alkaline conditions. The results showed that, when using laccase, the PDA layer was successfully coated on the surface of BFs in an acidic environment without destroying the structure of BFs, while self-polymerization hardly happened in the presence of dopamine alone, according to the X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and X-ray diffraction. When the dosage of dopamine was 1.0 wt% of BFs (1-D-L), the PHB/1-D-L had a higher flexural strength 32.56 MPa and impact strength 16.46 J m−1, meanwhile, the composites had a lower crystallinity index (Xc) 17.08% when the dopamine was added 1.5 wt%. However, the mechanical properties and water resistance of PHB matrix composites could be decreased possibly due to steric hindrance when there was an excess of dopamine during surface modification. [Display omitted] • Dopamine polymerizes into poly(dopamine) by laccase in weak acid environments. • The PDA can be grafted to cellulose because lignin is depolymerized by laccase. • Mechanical performance and water resistance of PHB matrix composites increase. • Interfacial adhesion is improved by modification with dopamine related to laccase. • This surface modification strategy shows great potential in cleaner production. [ABSTRACT FROM AUTHOR]

Natural plant fiber-reinforced biopolymer composites are attractive for their renewable, degradable, and low-carbon, compare to petroleum-based composites. However, the poor interfacial compatibility of bio-composites between fibers and matrix has long been recognized as the biggest challenge. Surface modification of natural fibers or polymers is considered the most common method to address this issue, which is always high energy consumption, and high pollution. Hence, we focus on cleaner and more economical solutions to overcome this difficulty. We pioneered the introduction of a novelty coordination-driven interface system into fibers-filled bio-composites. The chief object of this study is to investigate the iron ions (Fe3+) coordination drives the tannic acid (TA) interface and how to enhance composite interfacial compatibility and promote bio-composite properties. The way of interface formation is cleaner, simpler, more energy efficient, and effective, and the performance of biocomposites has been enhanced, including mechanical (tensile strength, flexural strength, and impact strength increased by 21.65%, 19.41%, and 52.24% respectively. The flexural strength and modulus even reached 59.65 MPa and 6.61 GPa), thermal (T onset and T max increased from 267.39 °C, 377.76 °C–290.13 °C, 389.24 °C, respectively), crystallization (Crystallinity increased by 52.35%) and hydrophobic performance. To summarize, the coordination-driven interfacial system proposes a simple and workable structural model in the field of natural plant fiber-reinforced biopolymer composites interface. [Display omitted] • The Fe3+ coordination-driven tannic acid interfacial system is introduced in fiber-reinforced polymer composites for the first time. • The amount of bamboo fiber filling is raised to 50%. • Better mechanical properties, thermal stability, crystalline properties， and hydrophobic properties are obtained by this strategy. • All the materials are non-toxic, sustainable, low-cost, abundant, and eco-friendly, and the experimental method is simple and mild. • The strategy shows great potential in cleaner production. [ABSTRACT FROM AUTHOR]