University of Science and Technology of China invented a high-performance degradable transparent film

Plastic products have brought great convenience to people's lives, but discarded plastic garbage has caused unimaginable harm to the ecological environme.
Hard-to-degrade plastic waste causes the death of hundreds of thousands of marine animals every year, and the microplastics produced are spread all over the earth, even into the bodies of animals and plants or other environments, posing a huge threat to human heal.
In order to better prevent and control plastic pollution, it is urgent to develop a new generation of sustainable plastic alternative materia.
? Recently, the team of Academician Yu Shuhong of the University of Science and Technology of China has successfully developed a super-strong, super-tough, transparent and high-performance sustainable shell-like composite film based on the microbial fermentation proce.
The film is based on sustainable biological materials and is prepared by an aerosol-assisted biosynthesis meth.
This new preparation method perfectly combines the advantages of nanomaterial deposition and microbial fermentation process, and successfully realizes the in-situ composite of microbial products and nanomaterials, greatly improving the optical and mechanical properties of the materi.
At the same time, through the two natural components of nano-clay flakes and bacterial cellulose, a "brick-fiber" shell-like layered structure was successfully constructed, which made the film exhibit mechanical properties far exceeding that of traditional plasti.
Thanks to this biomimetic structure design and the in-situ composite process of nanomaterials in the process of microbial fermentation, the film integrates a variety of excellent macro characteristics, showing more outstanding comprehensive performance than plastic films, and is used in new displays, photoelectric conversion, and flexibili.
Competitive in fields such as electronic devic.
The results were published in Matter under the title "Ultra-Strong, Ultra-Tough, Transparent, and Sustainable Nanocomposite Films for Plastic Substitut.
? figureSchematic diagram of the preparation process and structure of a high-performance sustainable shell-like transparent fi.
(AB) The process of microbial-assisted synthesis of composite hydrogel under normal temperature and pressu.
(C) A composite hydrogel with a three-dimensional nanofiber network structu.
(D) High-performance and sustainable "brick-fiber" structure inside the transparent shell-like fi.
? The film has excellent light management characteristics, and has a high optical haze on the basis of high transparency, which can efficiently scatter the transmitted light, so as to achieve an ideal uniform light effe.
Because of its homogeneous structure, the traditional polymer plastic film makes it easy to transmit light and difficult to scatter, so it is difficult to possess such optical characteristi.
This high-transparent and high-haze film benefits from the dense shell-like "brick-fiber" structu.

The pores inside the film are filled to ensure the light transmission effect, and the optical haze is ensured by the interface scattering of the nanosheet-cellulo.

In the visible spectrum wavelength range of 370-780 nm, high transparency of more than 73% and high optical haze of more than 80% are simultaneously achiev.

For optoelectronic devices, this combination of high transparency and high optical haze optical characteristics can effectively increase the proportion of transmitted light, extend the light transmission path, and significantly improve the light capture efficien.

? figureAshby diagrams of the film and a variety of traditional plastics in terms of strength, modulus, maximum service temperature and thermal expansion coefficie.

(A) Ashby diagram of strength and modulus, indicating that the film has superior strength and modulus than traditional plasti.

(B) Ashby diagram of the highest service temperature and thermal expansion coefficient, indicating that the film has the highest service temperature and thermal expansion coefficient superior to traditional plasti.

(C) A large sample of the fi.

(DE) The film can be folded into various shapes, and unfolded without obvious damage after many times of foldi.

(F) In the case of unfolding and bending, the circuit on the film can be kept open to make the LED light brig.

? At the same time, the film also has excellent properties of high strength and toughne.

Its strength and modulus can reach 482 MPa and 15 GPa, which are 6 times and 3 times higher than commercial PET plastic film respective.

In addition, the film also exhibits good flexibility, can be folded into various shapes, and there is no obvious damage after multiple folding and unfoldi.

This excellent mechanical property can ensure that the film material is better suitable for various Scen.

The three-dimensional network of nanofibers and the "brick-fiber" shell-like structure design help uniform stress distribution, avoid stress concentration, and effectively inhibit crack propagati.

At the same time, the fiber thinning effect can increase the hydrogen bond density between fibers in the material and promote film stretchi.

The fiber slips during the process, so that the material has both high strength and high toughne.

? As a bio-based sustainable material, the biomimetic film also has excellent thermal stability, with a coefficient of thermal expansion as low as 3 ppm K-1, that is, for every 100°C change in temperature, the dimensional change is only three ten thousandt.

It is commercially available A few tenths of plastic fi.

Moreover, compared with the plastic film that is very easy to soften and deform at high temperatures, the film can still maintain stable structure and performance at 250°C, so it has better service performance than plastic film under extreme environmen.

? This kind of bionic film material integrates excellent optical, mechanical and thermal properties, and can be completely biodegradable under natural conditions, overcomes the problem of difficult degradation of waste plastics, and avoids the production of microplastics and their threat to human heal.

While meeting the requirements of optical transparency, flexibility, low cost, and dimensional stability at high and low temperatures of flexible electronic device substrate materials, the film is green and pollution-free throughout its life cycle, and will have a wide range of application prospects in the field of flexible electronic devices in the futu.

? This research was funded by the National Natural Science Foundation of China's Innovative Research Group, the National Natural Science Foundation of China's key projects, the Chinese Academy of Sciences' Frontier Science Key Research Projects, the Chinese Academy of Sciences' Nanoscience Excellence and Innovation Center, and the Hefei Comprehensive National Science Cent.