In this study, tannin-derived porous carbon (TAC) with different microstructures was prepared via a microwave hydrothermal method, followed by KOH activation. Subsequently, the sea urchin–like NiCo-LDH/Tannin-derived carbon-based microsphere composite materials were rationally synthesized through a single-step microwave hydrothermal co-assembly process. The physicochemical characteristics and supercapacitive performance were systematically analyzed. TAC with a microspherical structure promoted and controlled the growth of LDHs, resulting in a more regular sea urchin–like structure, improved dispersibility, reduced resistance, and increased active sites. NiCo-LDH@TAC600-0 (without KOH activation) as an electrode material delivered a specific capacitance (Cs) of 1250 F g−1 at 1 A g−1 and 1035 F g−1 at 10 A g−1, with a rate performance of 82.8%. The asymmetric supercapacitor device using NiCo-LDH@TAC600-0 and TAC provided an energy density of 30.8 Wh kg−1 at 800 W kg−1 and a capacitance retention rate of 72.5% after 5000 cycles. This study offers a novel approach to enhancing NiCo-LDH properties for efficient energy storage.
20 January 2024 in Journal of Colloid and Interface Science
By focusing on the disadvantages of weak water resistance and high formaldehyde emission of urea–formaldehyde resin (UF), this research provides a new method to overcome these shortages of UF resin by using tannin for partial substitution of urea. Furthermore, plasma pretreatment of wood was introduced to strengthen the bonding performance of plywood. The investigation of the chemical structure of UF resin and tannin–urea–formaldehyde resin (TUF) were performed with Fourier transform infrared spectroscopy (FT-IR) and solid-state 13C nuclear magnetic resonance (13C NMR). The results of investigations confirmed the joining of tannin into the resin structure, which may enhance structural rigidity of TUF adhesives and improve hydrolysis stability. Then, thermal performance of UF resin and TUF resins were tested by differential scanning calorimetry (DSC) and thermogravimetric (TG) analysis. The DSC results indicated that the curing temperature did not change significantly. However, the TG analysis showed that the thermal stability of TUF resin was considerably improved. In bonding performance test, tannin–urea–formaldehyde resin (TUF) revealed an excellent water resistance, comparable to UF resin and can fulfill the standard requirement for plywood (Type II according to the Norm GB/T 17657-2013). It is interesting that the shear strength of wood specimens, bonded with TUF6 resin, after low-pressure cold plasma equipment (CLP plasma) and jet type atmospheric low-temperature plasma (JTLP plasma) treatment, reached 0.80 MPa and 0.85 MPa, respectively, after being soaked in boiling water for 3 h. In addition, most of the bonded plywood samples with TUF resin exhibited a lower formaldehyde emission, especially those prepared at 70 °C and 1.5 h, in which the formaldehyde emission amount could be reduced by approximately 39%.
The current work explores the potential use of commercial Chinese bayberry tannin (BT) to develop antioxidant PVA-based films using solvent casting process for packaging applications. The effect of BT concentration on opacity, water resistance and antioxidant capacity of resulting films was investigated. Properties like tensile strength, thermal behavior, and morphological aspects were also characterized. The experimental results showed that PVA/BT films formed with uniformly brown color and generally good transparency, offering good antioxidant ability. The PVA film containing BT presented slightly higher water resistance according to the results of moisture content and water vapor permeability, especially at low BT content (
Wood plastic composites (WPCs) is one of crucial and potential engineering wood products that has been extensively employed in the fields of landscape, transportation, municipal engineering and building construction. It has gradually been used to replace the conventional wood-based composites. This chapter aims to introduce the properties and development of WPCs and illustrate how defects in their mechanical properties, biological and aging resistance, and flame retardance affect their global development. Herein, the effects on the biological durability of WPCs against algae, mold, fungi, and termites made with various wood species with different chemical extractive compositions, the natural weathering performance of WPCs and the mechanisms of protection against ultraviolet light and moisture, the effectiveness and mechanism of reinforcement of WPCs by novel alloy modification of linear and aromatic polyamides are reviewed. Additionally, the flame retardance properties, common testing methods as well as the performances of novel flame retardants for WPCs, are comparatively described. Lastly, the limitations and prospects of WPCs in future construction applications are also discussed.
The possibility of using commercial bayberry tannin (BT) from a Chinese source as a cross-linker and functional additive to develop soybean protein isolate (SPI)-based films was explored in this study by using the solvent casting method. In particular, the impacts of BT loading on the tensile strength, microstructure, thermal stability, water resistance and antioxidant capacity were fully investigated. The results reveal that SPI incorporated with BT yielded a phenolic–protein hybrid whose relevant films exhibited an improvement in tensile strength of around two times greater compared with native SPI as a result of the formed interactions and covalent cross-links, which could be proven using FTIR spectroscopy. The introduction of BT also led to the compact microstructure of SPI–BT films and enhanced the thermal stability, while the water vapor permeability was reduced compared with the control SPI film, especially at high loading content of tannin. Additionally, the use of BT significantly promoted the antioxidant capacity of the SPI-based films according to DPPH radical scavenging assay results. On this basis, Chinese bayberry tannin is considered a promising natural cross-linker and multifunctional additive that can be dedicated to developing protein-derived films with antioxidant activity for food packaging applications.
About Me
Prof. Du has published more than 100 peer-reviewed journal articles.
Prof. Du has published more than 100 peer-reviewed journal articles.