As the focus of architecture, furniture, and other fields, wood has attracted extensive attention for its many advantages, such as environmental friendliness and excellent mechanical properties. Inspired by the wetting model of natural lotus leaves, researchers prepared superhydrophobic coatings with strong mechanical properties and good durability on the modified wood surface. The prepared superhydrophobic coating has achieved functions such as oil-water separation and self-cleaning. At present, some methods such as the sol-gel method, the etching method, graft copolymerization, and the layer-by-layer self-assembly method can be used to prepare superhydrophobic surfaces, which are widely used in biology, the textile industry, national defense, the military industry, and many other fields. However, most methods for preparing superhydrophobic coatings on wood surfaces are limited by reaction conditions and process control, with low coating preparation efficiency and insufficiently fine nanostructures. The sol-gel process is suitable for large-scale industrial production due to its simple preparation method, easy process control, and low cost. In this paper, the research progress on wood superhydrophobic coatings is summarized. Taking the sol-gel method with silicide as an example, the preparation methods of superhydrophobic coatings on wood surfaces under different acid-base catalysis processes are discussed in detail. The latest progress in the preparation of superhydrophobic coatings by the sol-gel method at home and abroad is reviewed, and the future development of superhydrophobic surfaces is prospected.
Transparent films with excellent antibacterial properties and strong mechanical properties are highly sought after in packaging applications. In this study, Ag/SiO2 nanoparticles were introduced into a mixed solution of chitosan (CS) and polyvinyl alcohol (PVA) and a Ag/SiO2-CS-PVA transparent film was developed. The excellent properties of the film were confirmed by light transmittance, water contact angle tests and tensile tests. In addition, for the antibacterial test, the antibacterial properties of the sample against Gram-negative bacteria (Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus) were explored, and the average size of the bacteriostatic circle was measured by the cross method. The final results show that Ag/SiO2-CS-PVA transparent film has the advantages of good antibacterial properties, high transparency and high mechanical strength.
Carbon quantum dots (CQDs), a distinctive class of fluorescent carbon nanomaterials, exhibit considerable potential for widespread application across several industries due to their safety, environmental sustainability, excellent water solubility, and tunable yet stable fluorescence properties. Nevertheless, the mass field is limited, and the cost of production is higher for the majority of methods. This study examines a cost-effective approach for the hydrothermal synthesis of nitrogen-doped carbon quantum dots (N-CQDs) from wood using NH3·H2O as the nitrogen precursor, facilitated by H2O2 and ultraviolet light. The produced N-CQDs demonstrate superior crystallinity and solubility in water, with the average particle size of 5.02 nm. After 10 experiments under the same conditions, a significant and stable yield of 5.04 g (42 wt%) was finally obtained by hydrothermal synthesis. The N-CQDs solution exhibits green fluorescence when exposed to ultraviolet light, and its fluorescence performance is influenced by concentration and excitation wavelength. Furthermore, it explores their application in identifying Fe (III) in water. The surface of N-CQDs is abundant in hydrophilic hydroxyl groups, distinctive nitrogen-containing groups, and various oxygen-containing functional groups. Fe (III) can extinguish fluorescence in water. The ratio of fluorescence intensity before and after to the addition of Fe (III) solution to the N-CQDs solution (F0/F) exhibits the effective linear correlation within the concentration range of 0.1 to 100 μmol/L. Within the concentration range of 100 to 1000 μmol/L, the increase in Fe (III) concentration results in substantial aggregation of Fe (III) and N-CQDs, along with a blue shift in the fluorescence wavelength. This discovery possesses significant potential for the synthesis and application of environmentally friendly, high-yield N-CQDs.
A superhydrophobic wood surface was produced by employing the solvothermal method to form shuttle-like, well-crystallized MIL-88(Fe) on the surface of wood and assembling a Octadecylphosphonic acid (OPA) reagent. The nanosized MIL-88(Fe) molecule caused the wood’s surface to take on a nano mastoid shape. In addition, MIL-88(Fe) provides metal sites to capture OPA molecules, preventing the long-chain alkane hydrophobic group from contacting the surface of the wood. They both make a considerable difference in the growth of a hydrophobic wood surface. The results of the experiment indicate that the water contact angle (WCA) increases with reactant concentration. The WCA of the samples prepared with 5.0 × 10−2 M FeCl3 was 140.57°. When the reactant concentration was 10.0 × 10−2 M, the greatest WCA = 153.69° reading was obtained. The research’s findings present a novel technique for producing superhydrophobic wood surfaces.