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Exfoliation of Hexagonal Boron Nitride via Ferric Chloride IntercalationSodium fluoride (NaF) was used as an activation agent to successfully intercalate ferric chloride (FeCl3) into hexagonal boron nitride (hBN). This reaction caused the hBN mass to increase by approx.100 percent, the lattice parameter c to decrease from 6.6585 to between 6.6565 and 6.6569 Ǻ, the x-ray diffraction (XRD) (002) peak to widen from 0.01deg to 0.05deg of the full width half maximum value, the Fourier transform infrared (FTIR) spectrum's broad band (1277/cm peak) to change shape, and new FTIR bands to emerge at 3700 to 2700 and 1600/cm. This indicates hBN's structural and chemical properties are significantly changed. The intercalated product was hygroscopic and interacted with moisture in the air to cause further structural and chemical changes (from XRD and FTIR). During a 24-h hold at room temperature in air with 100 percent relative humidity, the mass increased another 141 percent. The intercalated product, hydrated or not, can be heated to 750 C in air to cause exfoliation. Exfoliation becomes significant after two intercalation-air heating cycles, when 20-nm nanosheets are commonly found. Structural and chemical changes indicated by XRD and FTIR data were nearly reversed after the product was placed in hydrochloric acid (HCl), resulting in purified, exfoliated, thin hBN products.
Document ID
Document Type
Technical Memorandum (TM)
Hung, Ching-cheh
(NASA Glenn Research Center Cleveland, OH, United States)
Hurst, Janet
(NASA Glenn Research Center Cleveland, OH, United States)
Santiago, Diana
(NASA Glenn Research Center Cleveland, OH, United States)
Rogers, Richard B.
(NASA Glenn Research Center Cleveland, OH, United States)
Date Acquired
May 9, 2014
Publication Date
April 1, 2014
Subject Category
Inorganic, Organic And Physical Chemistry
Nonmetallic Materials
Chemistry And Materials (General)
Report/Patent Number
Funding Number(s)
WBS: WBS 794072.
Distribution Limits
Work of the US Gov. Public Use Permitted.

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NameType 20140005373.pdf STI