The uniquely oriented pore structure of natural wood gives it its light weight and high strength. The research on imitation wood structure is one of the hotspots in the field of biomimetic materials research in the world. However, the traditional imitation wood structure material is “in its own shape”. Previous studies have realized the imitation of oriented pore structure, but its mechanical properties are far from satisfactory. For example, ceramic-based wood-like structural materials currently developed have high density, low strength, and many defects, and the preparation process requires high-temperature sintering (usually >1500 ° C). Therefore, how to prepare imitation wood structural materials that are truly lightweight and high-strength is a challenge in the field of biomimetic materials research.

Recently, the research team led by Yu Shuhong, a professor at the University of Science and Technology of China , developed a new technology combining ice crystal-induced self-assembly and thermal curing. Based on traditional phenolic resin and melamine resin, a series of similar natural products have been developed. A new type of bionic artificial wood with a wood-oriented tunnel structure. This series of bionic artificial wood has the advantages of light weight, high strength, corrosion resistance and fire insulation.

On August 10th, the relevant research results were published in "Progress in Science" under the title of Bioinspired polymeric woods. Science magazine Science News is based on This synthetic wood is as strong as the real thing-and won't catch fire. The results were reported. The co-first author of the thesis is postdoctoral Yu Zhilong and master student Yang Ning.

Paper link

Http://advances.sciencemag.org/content/4/8/eaat7223

A series of resin-based biomimetic artificial woods developed by researchers have oriented pore structures similar to natural wood, and have good controllability in wall thickness and pore size (Fig. 1). This method can be combined with a variety of nanomaterials to prepare multifunctional composite artificial wood, and is simple and efficient, and easy to scale up production. The artificial wood of this oriented tunnel structure has outstanding mechanical properties, and the compression yield strength is superior to that of various wood-like ceramic materials that have been developed and is comparable to that of natural wood (Fig. 2).

Figure 1. Schematic diagram of the preparation process of artificial wood. (A) a mixed solution of a resin polymer; (B) an oriented cell structure after orientation freezing and drying

Figure 2. Photo, structure and mechanical properties of bionic artificial wood. (A) phenolic resin-based artificial wood and microstructure; (B) melamine resin-based artificial wood

The biggest advantage of bionic artificial wood compared to natural wood is its corrosion resistance, thermal insulation and fire resistance. In the research, due to the choice of thermosetting resin material as the matrix material, the prepared bionic artificial wood has good waterproof and acid corrosion resistance. The mechanical strength of the bionic artificial wood is not attenuated after soaking in water and sulfuric acid solution for 30 days. Thanks to its oriented pore structure and composite nanomaterials in the pore walls, the artificial wood compounded with graphene has a good radial (perpendicular to the tunnel direction) insulation effect with a minimum thermal conductivity of up to 20.8 mW/mK (milliwatts). Every meter per Kelvin). Considering the high specific strength (compressive strength/density) of artificial wood, this artificial wood has better utility than other engineering materials and aerogel materials.

Flammability is the biggest problem faced by natural wood in practical applications , and fire retardant is the biggest advantage of artificial wood. It can further improve its fire and heat insulation performance by compounding different nano materials. This artificial wood has good fire resistance and can self-extinguish quickly after the flame is ignited, which is a disadvantage that natural wood cannot overcome (Fig. 3).

Figure 3. Comparison of the fire performance of artificial wood and the flammability of Barkwood. (a) CMF artificial wood; (b) CPF artificial wood; (c) C

As a new type of biomimetic engineering material, its versatility is superior to traditional engineering materials. This kind of artificial wood is expected to replace natural wood and be used under harsh or extreme conditions. In addition, this synthetic method provides a new idea for the preparation and processing of a series of high-performance biomimetic engineering materials, and its functional design and other advantages will help to broaden the application of the method and the prepared materials in various technical fields.

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