Chemical Vapor Deposition of Silver on Plasma-Modified Polyurethane Surfaces

Abstract

The surface chemistry of [(1,1,1,2,2,3,3-heptafluoro-7,7-dimethyl-4,6-octanedionato)(trimethylphosphine)silver(I)], [(fod)AgP(CH 3 ) 3 ], a silver precursor for chemical vapor deposition (CVD), has been investigated on plasma-modified polyurethane surfaces by means of reflection−absorption infrared spectroscopy (RAIRS) and X-ray photoelectron spectroscopy (XPS). On the unmodified polyurethane surface, the RAIRS and XPS data show that [(fod)Ag(P(CH 3 ) 3 )] reacts with polyurethane CO, N−H, and C−O−C groups present at the surface by displacing the Lewis base P(CH 3 ) 3 ; these acid−base reactions yield the formation of surface Ag−O and Ag−N bonds. Air plasma treament of the polyurethane surface leads to the incorporation of CO and C−O−O functional groups, as well as the conversion of C−N(H)− into CN− functional groups by the abstraction of hydrogen. RAIRS data obtained following O2 and air plasma treatment showed that, in addition to grafting of functional groups, polyurethane chains change their conformation in the polyurethane film. The increase of silver concentration resulting from CVD is proportional to the increase of oxygen incorporated on the polymer surface. This study shows that CVD on soft polymers can be performed at room temperature.

The chemistry involved in the loading of silver(I) into poly(amic acid) via ion exchange: A metal-ion-induced crosslinking behavior

“…It contains not only the formation of silver carboxylate but also the strong covalently bonding interactions between silver ions and the functional groups in PAA molecules. Scheme 4 shows what we believe (based on our FTIR, XPS data and literatures [31,[36][37][38][39]) are the most probable chemical entities formed during the ion exchange of PAA in silver ion solutions. Some of them might promote the formation of inter-or intra-molecular hydrogen-bonding [40] or might function as crosslinking points joining the macromolecules together to form the extended network and therefore make the silver-ion-doped PAA film undissolved in its original good solvent.…”

“…3A. The peak at 533.6 eV is pertaining to the COOH species; the peak at 532.7 eV is associated with the oxygen atoms in the C-O bonds; and the peak at 531.4 eV is corresponding to the oxygen atoms in all carbonyl groups (C]O, COOH and CONH) [31][32][33]. However, following ion exchange, it can be clearly observed that an additional peak at 529.0 eV was present in the O 1s core-level spectra, as illustrated in Fig.…”

Functionally modified, melt‐electrospun thermoplastic polyurethane mats for wound‐dressing applications

“…The maximum peak of nitrogen shifted to 400.3 from 400.5 eV after plasma treatment. This behavior could be explained as the new bond formation on the melt‐electrospun TPU surface by dissociation of the NH bond …”

Molecular structure of a random copolymer film by plasma‐enhanced CVD from a mixture of cyclohexa hydrocarbons

“…For estimating this parameter for different samples, we need to measure the film thickness t . Table II shows the cross section due to the stretching vibration of CH from the literature [13,14]. In the table, the peaks at 3085 and 3010 cm −1 and the related vibrations are assigned to CH or CH 2 sp 2 bonding of olefin.…”