Speaker
Description
APT analysis of polymers has been relatively limited compared to many other material systems due to sample preparation, data collection and data analysis challenges. Polymers are often beam sensitive and Focused Ion Beam (FIB) sample preparation is often avoided, leading to approaches based on spray deposition of polymer films [1] or self assembling monolayers [2] onto pre-fabricated sharpened supports. Mass spectra collected from polymers can consist of carbon compound ions, and halogens used in polymers such as chlorine or fluorine are difficult to ionise and so compositional analysis can also be challenging [3].
Boron nitride 2D nanoparticles (NP) within a thermoplastic semi-crystalline polymer matrix (polyvinylidene fluoride (PVDF)), so called polymer nanocomposites (PNC) – are systems considered as promising material candidates for gas barrier applications. PNC samples were prepared using a melt-compounding process at different NP loadings, injection moulded into discs and characterised using thermogravimetric analysis, differential scanning calorimetry and scanning electron microscopy, alongside gas permeation studies at the macroscopic level.
Laser pulsed analysis using a LEAP 5000XR of these samples by the authors produced a mass spectra that contains various compound ions linked to fragments of the polymer chain. In the samples predicted to contain nanoparticles (visible through secondary electron imaging during Focused Ion Beam sample preparation), localised regions that contained boron species were observed along with various compound ions of carbon, boron and fluorine. Hydrogen species were found in many locations within the reconstruction and so in order to determine their origin, gas phase deuteration is required.
In this presentation we discuss the workflows and challenges for deuterium charging and APT analysis of polymer nanocomposites and initial results collected using the Reacthub facilties at Max-Planck-Institut für Eisenforschung.
[1] Journal of Microscopy, 2010, 237,2 pp. 155–167
[2] Langmuir 2010, 26, 8, 5291–5294.
[3] Langmuir 2012, 28, 1, 56–59.
