BEIJING, April 23 (Xinhua) -- Imagine a future where a pile of straw on a farm after harvest is transformed into ultra-strong, lightweight materials for smartwatches, medical devices or eco-friendly packaging. That future may not be far away.
Researchers at the Ningbo Institute of Materials Technology and Engineering (NIMTE) under the Chinese Academy of Sciences have successfully extracted a new two-dimensional (2D) nanomaterial directly from ordinary plant straw, proving that a "hidden treasure" has been sitting in plain sight in fields across the country.
The breakthrough, published in the journal SusMat, opens a low-cost, environmentally friendly path to turning agricultural waste into high-value green materials, according to a NIMTE press release on Wednesday.
This achievement holds great significance for promoting the development of green new materials, improving the efficient utilization of biomass resources, and supporting sustainable development, according to the research team.
Plant straw is widely available. Its cell walls contain cellulose, the most abundant natural polymer on Earth, which provides plants with their structural rigidity. Its global production reaches hundreds of billions of tonnes every year, making it a virtually inexhaustible green resource.
For years, scientists could only break cellulose down into one-dimensional nanofibers. But plant cell walls are built like layers of carefully stacked building blocks, raising an important question: could cellulose also exist as flat, sheet-like 2D nanostructures?
The challenge has always been the issue of how to extract them. Traditional chemical methods, such as strong acids, or mechanical grinding often destroy the fragile 2D structure before it can be recovered.
The NIMTE researchers solved this problem by designing a pair of "precision scissors" -- a novel solid catalyst made of carefully arranged ions, to unlock this structure.
The new technique uses ionic liquids to slide between the molecular layers. With the help of phosphotungstic acid, the catalyst gently severs the hydrogen bonds that hold the cellulose layers together, releasing intact 2D nanosheets without damaging their internal structure.
"This technology has two core advantages," said Na Haining, a NIMTE researcher of the study. "First, it works under mild conditions. No high temperature or high pressure is needed. Second, it has high conversion efficiency and makes full use of the biomass material."
More importantly, the method is also widely applicable in numerous scenarios, working with cotton cellulose, wood cellulose, bacterial cellulose, and more, added Na.
In addition to the practical benefits, the study provides fundamental proof that natural cellulose does contain native 2D structures.
"This deepens our understanding of cellulose's multi-level architecture and opens a completely new direction for turning biomass into high-performance materials and expanding its new applications," said Zhu Jin, the team leader at NIMTE. ■
