The stabilities and transferabilities of monolayers for the two kinds
of polyamic acid alkylamine salts (PAAS) were investigated. The stabil
ity of monolayer increases as the chain length of salts increases. At
well-balanced condition, the Langmuir film is transferred as a Y-type
on various substrates, and the thickness of one layer of PAAS was foun
d to be about 16.7 Angstrom.