In Situ Generation of Plasma-Polymer Standards by Plasma Assisted Free Radical Polymerization

Abstract

The use of reliable reference compounds was recently shown as a powerful strategy for a thorough characterization of plasma‐polymers, but their elaboration remains a topical issue since wet chemistry leads to linear structures with specific chain ends which poorly mimic the notorious disorder found in plasma‐polymers. Here is proposed the elaboration of standards directly using aerosol assisted plasma polymerization. Exaggerating the phenomenon observed in a so‐called ante plasma zone where no discharge is ignited but thick organic coatings are deposited brought the concept of discharge overfeeding to decrease the energy per particle and produce intermediate polymeric materials between conventional polymers and plasma‐polymers, synthesized through a plasma‐assisted free radical polymerization.

The Definitive Evidence of a Plasma Copolymerization of Alkyl and Perfluorinated Acrylates Using High Resolution Mass Spectrometry and Mass Defect Analysis

“…In spite of the soluble oligomers only are desorbed and ionized using a soft ionization such as MALDI, the species found in the soluble part of plasma polymers have been found to be sufficiently representative of the whole deposits when dealing with the molecular composition . MS spectra of complex samples such as plasma polymers nevertheless rapidly turn very tedious to interpret and discuss . As proposed by Sato et al mass defect analysis could be advantageously used for a user‐friendly visualization of MS spectra of complex polymers mixtures, copolymers as well as tandem mass spectra (MS/MS) of polymer ions .…”

“…The present communication reports on the use of high resolution mass spectrometry combined with mass defect analysis for the analysis of plasma (co)polymers deposited at atmospheric pressure from the co‐injection of two long alkyl and perfluorinated acrylates. The plasma homopolymers deposited from those two precursors have been thoroughly characterized in previous studies and exhibited drastically different properties in terms of wettability and thermal behavior . Copolymerizing these antagonist acrylates is expected to produce interesting new materials with tailored properties readily monitored by the composition of the mixture fed through the plasma discharge and constitutes a right‐thinking example of application of an original analytical procedure which brings a definitive evidence of a plasma copolymerization route.…”

Challenges in the characterization of plasma polymers using XPS

“…Another route, proposed by Fouquet et al, consists in building more realistic references, deposited under very specific plasma conditions, which could be classified somewhere between conventional and plasma polymers [118]. While the authors did not consider XPS characterizations of such samples, it could be of great interest to study their core-level and valence band spectra and evaluate their potential use as new references.…”

“… Helpful to determine the evolution of C=C in pp as a function of plasma deposition conditions, with relatively well resolved peaks [17,118].…”

Unraveling the architecture of plasma polymers by electrospray tandem mass spectrometry

“…From an analytical point of view, alternative activation processes such as electron transfer 393 dissociation (ETD) [48], electron capture dissociation (ECD) [49], electron detachment 394 dissociation (EDD) [50] or activated-electron photo-detachment dissociation (activated-EPD) 395 [51][52][53] could also be of high added values for structural analysis of polysiloxanes prepared by 396 either conventional or plasma polymerization. Off-line or on-line couplings of mass spectrometry 397 with chromatographic techniques such as size exclusion chromatography (SEC) can be 398 implemented to decrease the complexity of mass spectra, as recently proposed by our group for 399 the specific case of plasma-polymers [54]. Ion mobility coupled to MS would provide an 400 additional separation dimension to tentatively distinguish branched isomers from linear ones.…”