Page 32 - Handbook of Adhesion Promoters

2.8 Interphase formation 25

Figure 2.24. Overview of the coating/fabrication process. [Adapted, by permission, from Chatterjee, S; Major,
GH; Lunt, BM; Kaykhaii, M; Linford, MR, Micros. Microanal., 22, 964-70, 2016.]

of wüstite into magnetite during the plasma coating, heteroepitaxy between superficial
44
magnetite and alumina deposit.
2.8 INTERPHASE FORMATION

Adhesion of poly(3,4-ethylenedioxythiophene) to various substrates is insufficient which
45
limits its applications in electronics. Nanostructured Pt was found to be an excellent
adhesion promoter providing 10-fold adhesion improvement compared to the smooth Pt
45
substrates due to altering the morphology of Pt. Also, iridium oxide gives exceptional
stability to PEDOT coatings, resulting in polymer survival of over 10,000 redox cycles
and 110 days under accelerated
45
aging conditions at 60°C. In both
cases, the adhesion promoters
were sputtered on the surface of
polyimide creating interphase hav-
ing a form of brush which
improved adhesion of PEDOT to
45
polyimide (Figure 2.23). The
average roughness of the two sub-
strate materials was 177±18 nm
for IrO and 130±8 nm for nano-
x
45
structured Pt.
To reduce the weight of auto-
mobiles and retain required
strength and stability, fiber-rein-
forced plastics-metal hybrid com-
46
ponents are used. They
overcome weaknesses of fiber-
reinforced plastics, such as low
formability, low hardness, and
high sensibility during drilling, but
special technology has to be used
Figure 2.25. Schematics of A-174 promoting adhesion between to increase adhesion of both com-
Ta 2 O 5 and Parylene C. (a) Chemical structure of A-174; (b) chemi-
46
cal structure of dimer, monomer and polymer Parylene-C; (c) ponents. Aluminum alloy and
bonding process of Ta 2 O 5 and Parylene-C. [Adapted, by permis- polyamide-6 were connected by
sion, from Gao, J; Chen, T; Dong, C; Jia, Y; Mak, P-I; Vai, M-I; interphase obtained by twin
Martins, RP, RSC Adv., 5, 48626-30, 2015.]