Characterization of polyamic acid/polyimide films in the nanometric thickness range from spin‐deposited polyamic acid

Abstract

A dilute polyamic acid solution was spin-deposited onto gold substrates and XPS analyses were performed after deposition. Evidence of the presence of organic films on the top surface of the substrates was feund. A chemical characterization allowed us to identify these organic films as being polyamic acid after a 125OC curing and polyimide after a 240°C curing. From angledependent data we have shown that the gold substrates were coated quasi-uniformly by ultra-thin films. This conclusion was confirmed by an Auger analysis. The computed thicknesses were found in a range of 1.3 to 2.9 nm depending on the sample preparation conditions. Adsorption was supposed to occur just after the deposition. Some possible mechanisms of the interfacial interaction between the polyamic acid and the surface were proposed. A thermally-activated chain cleavage was supposed to occur at the interface or near the interface.

Low-resistance films of polyimides with impregnated copper sulfide

“…Data from the literature show that polyimide (e.g., PMDA/ODA) cured up to 125°C presents a peak located at 535.0 eV that is attributed to the O(1s) of entrapped H 2 O. 21 Our XPS data from original Kapton are typical of the PMDA/ODA system already described in the literature. 20,[29][30][31] Therefore, when the polyimide was submitted to hydrolysis, we observed the opening of the imide cycle which means that the polyamide salt was formed.…”

“…20,[29][30][31] Therefore, when the polyimide was submitted to hydrolysis, we observed the opening of the imide cycle which means that the polyamide salt was formed. This can be compared to the data from the literature, 21 where PMDA/ODA poly-(amide acid) was completely imidized. In this way, part of the amide and acid functionalities were not imidized, which increased the "partially oxidized" carbon (i.e., the amide-carbonyl and the acid-carbonyl carbon contents) content.…”

Counterions in layer-by-layer films—Influence of the drying process

“…This signifies that water molecules are expected to be present in both types of samples, At the O 1s core level binding energies region, both samples exhibit three components centered at 531.9 ± 0.2, 533.0 ± 0.2 and 534.2 ± 0.2 eV. The first one is assignable to the oxygen in the sulfonic group [33], and the third one to water entrapped in the polymeric film [34]. The second one may be associated oxygen in the sulfonic group bound to isolated water molecules.…”

High refractive index films of polymer nanocomposites

“…Thickness variation upon annealing has also been reported for spin-coated polymer films. 20 Thus, it seems that the spincoating process leads to a "frozen-in" film structure. The driving force for the film shrinking might be a rearrangement of the morphology of gelatin (changing the density and, hence, the refractive index of gelatin) or a disappearance of small holes (increasing the volume fraction of the solid components) upon annealing.…”