Synthesis of carbon nitride in a school lab

Does somebody remember an educative video from the Open University, in
the United Kingdom, about Organic Synthesis, where a thin film of
carbon nitride was synthesised from the separation surface of two not
mixable liquids in a simple school-type laboratory?.
Does somebody remember what those liquids were?.
The thin film obtained had metalic bright, and it was told that carbon
nitride is hardest than diamond. I'm talking about a very flexible
material more resistent than diamond, able to be synthesised in a school lab.
-- 
Paul J. Franklin(moderator - sci.chem.organic.synthesis) 
http://organicworldwide.net/sci.chem.organic.synthesis
Georgia State University <[EMAIL PROTECTED]>
Atlanta, GA