Molecular Surface Analysis and Depth-Profiling of Polyethylene Modified by an Atmospheric Ar-D₂O Post-Discharge

Abstract

The injection of water vapor into ambient “open air” plasmas for the treatment of polymers represents a promising functionalization route for industrial and medical applications. The present study reports a scientist‐independent methodology, based on the ToF‐SIMS (time‐of‐flight secondary ion mass spectrometry) technique coupled with PCA/Wavelet‐PCA (principal component analysis), to probe the (sub) surface chemical/structural modifications induced by an atmospheric Ar‐D2O post‐discharge on low density polyethylene (LDPE) films as a function of two external plasma parameters, namely sample‐torch distance and treatment time. The SIMS characterization identifies two different families of samples (type I and II) as a function of time and distance. The highest reactivity of the D2O vapors with the LDPE films is achieved for times of few tens of seconds at a distance of 5 mm from the plasma source.

Residual polymer stabiliser causes anisotropic conductivity in metal nanoparticle 2D and 3D printed electronics

“…Organic molecules are used in MNPs inks as stabilisers or capping agents to enable particle dispersion in low viscosity solvents, however, their residues are likely to hinder device performance, 34 even when present in very small amounts. Surface sensitive chemical analysis techniques of time-of-flight secondary ion mass spectrometry (ToF-SIMS) and X-ray photoelectron spectroscopy (XPS), in combination with gas cluster ion beams (GCIBs), are a powerful toolset for depth profiling organic materials with high chemical specificity, sensitivity, and nanometre depth resolution, [35][36][37][38][39][40][41][42] chemical imaging of buried hybrid organic/inorganic interfaces 43,44 and characterisation of core-shell structures. [45][46][47][48][49][50][51] Here, we present a comprehensive study of the effect of the organic residues, such as stabilisers, and their localised distribution at the interface between printed layers on the functional performance of the printed devices before and after low-temperature sintering.…”

A quantitative determination of the polymerization of benzoxazine thin coatings by time‐of‐flight secondary ion mass spectrometry

“…Combined with principal component analysis (PCA), secondary ion mass spectrometry (SIMS) has proven to be a powerful method to determine the structure of plasma polymers and, in particular, to determine their crosslinking degree . Plasma polymers form very thin layers (<1 μm) with a complex crosslinked structure, and therefore, SIMS is one of the few tools able to access the chemical information …”

Spectroscopic study of excited molecular nitrogen generation due to interactions of metastable noble gas atoms

“…Plasma interaction with sample surfaces can cause surface modification, functionalization, sputtering, and etching. Examples include atomic etching of circuits or deposition of oxygen species onto polymers . Furthermore, when used on organic samples, the introduction of oxygen or nitrogen containing radicals can sterilize surfaces due to an increase of reactive oxygen and nitrogen species that cause stresses within organic matter, which leads to degeneration.…”