Search Results - h+winter

Graphene sheets are prized for their unusual but exciting properties, including extremely high mechanical strength and ability to efficiently conduct heat and electricity. These properties open up a myriad of applications in medicine, electronics, energy, and sensors. However, the production of graphene, which is derived from the exfoliation of graphite, is currently challenged by low efficiency and long exfoliation times.

This invention uniquely combines two techniques, flow and sonication, to overcome these challenges. A graphite suspension is first subjected to a flow process, where it is mixed with zirconium oxide pebbles. Collisions between the graphite and the pebbles modify the graphite’s surface, making it easier for the solvent molecules to “wedge” in between layers during subsequent sonication, significantly increasing graphene exfoliation time-efficiency.

Zeolites have found wide application in catalysis and separation processes due to their tunable pore structure and active sites, and they show remarkable stability in commercial use. Recently, ultra-thin two-dimensional (2D) zeolite nanosheets have been synthesized from zeolite precursors. These ultra-thin nanosheets show promise for high throughput separations and catalytic reactions involving bulky molecules. A commercially feasible synthesis method, however, has yet to be developed. State-of-the-art methods require high energy input and multiple processing steps, and give low yield and small nanosheet size.

 

Professors Winter and Fan have developed a simpler, lower energy method to synthesize ultra-thin 2D zeolite nanosheets from precursor zeolite materials, such as MCM-22 and ml-MFI. In the method, zeolite precusors can be subjected to either a short sonication or chaotic flow treatment in the presence of commercially available telechelic polymers, resulting in exfoliated zeolite nanosheets. While demonstrated in batch, this process can potentially be scaled and made continuous.