Abstract
In order to examine the distribution of a polyacrylamide (PAM) on exact fiber surface, the latest imaging
with a scanning ESCA microprobe, which analytical depth is up to 10 nm, was adapted to papers containing a cationic
PAM dry strength resin. The exact surface PAM contents were significantly higher than the total PAM content, which
indicates that the PAM added would be concentrated nearby the surface of fibers. And the degree of the concentration
decreased with increasing in beating degree. C1s and O1s images apparently showed unevenness due to the surface
roughness of paper irrespective of beating degree of the fibers, although these images derived from cellulosic fibers
may be expected to show their uniform distributions. On the other hand N1s image derived from the PAM gave isolated
and scattered signals. This characteristic distribution of the PAM on fiber surface differed from the generally uniform
in-plane distribution of the PAM within a fiber wall as shown in the imaging with a microscopic ATR/FT-IR in which
the analytical depth is about 1 µm.
