Advances in Fingerprint Technology.pdf

O
R C
O
R C O C
OH + R' N C N R"
R C
NHR"
NR' + R''' NH 2
Figure 6.17 Carbodiimide-mediated amidation reaction.
CH 2
CH 2
[
O -
R C
NHR'''
O
NHR"
C
NHR'
+
Figure 6.18 Structure of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride.
of chemical fingerprint labeling. Results with polyethylene, paper, and
cyanoacrylate ester-fumed fingerprints suggest an additional contribution by
preferential physical adherence of the nanocomposite to fingerprint material.
In general, chemical reaction rates increase with increasing temperature.
Accordingly, the diimide pretreatment was examined at 60°C in comparison
with room temperature. At the elevated temperature, severe chemical attack
on the aluminum foil substrate of samples occurred for heating times longer
than about 1 hr. For shorter heating times, no fingerprint development
enhancement was observed. If there is chemical binding of the generation 4
nanocomposite to fingerprint constituents in the absence of diimide, one
might expect an enhancement of fingerprint development with temperature
upon direct application of the CdS/dendrimer solution. Such enhancement
was indeed observed.
O
R C
N (CH2 ) 3 N C N
[
[
NHR"
O C NR'
OH NHR"
O
NHR'''
R'NHCNHR" +
O
O
C NR'
R C N
H
R'''
CH 2 CH 3 HCI
[