A Time-of-Flight Secondary Ion Mass Spectrometry/Multivariate Analysis (ToF-SIMS/MVA) Approach To Identify Phase Segregation in Blends of Incompatible but Extremely Similar Resins

Abstract

This work presents a data analysis extension to a well-established methodology for the assessment of organic coatings using imaging time-of-flight secondary ion mass spectrometry (ToF-SIMS). Such an approach produced results that can be analyzed using a multivariate analysis (MVA) procedure that performs the simultaneous processing of spatially and chemically related datasets. The coatings consist of two commercial resins that yield extremely similar spectra, and there are no peaks of sufficient intensity that are uniquely diagnostic of either material to provide an unambiguous identification of each. In order to resolve the problem, in addition to microtome-based sample preparation steps of tapers for the analysis through sample thickness, standard samples in cured and uncured conditions are introduced and measured in the same fashion as the specimens under investigation. The resulting ToF-SIMS imaging datasets have been processed using non-negative matrix factorization (NMF), which enabled identification of phase separation in the cured coatings.

A study of the interfacial chemistry between polymeric methylene diphenyl di‐isocyanate and a Fe–Cr alloy

“…MVA methods were used to process the large and complex data sets generated in this work, in order to reduce the data processing time and make data interpretation significantly quicker and more assertive 8,9 . Firstly, ToF‐SIMS depth profile data sets were preprocessed using the SurfaceLab software (ION‐TOF GmbH).…”

Controlling orientation, conformation, and biorecognition of proteins on silane monolayers, conjugate polymers, and thermo-responsive polymer brushes: investigations using TOF-SIMS and principal component analysis

“…PCA could also be applied to an analysis of TOF-SIMS 2D images [33,[58][59][60] and even 3D TOF-SIMS sputtering data [50]. Other multivariate methods already applied for TOF-SIMS data analysis are non-negative matrix factorization (NMF) [61,62], the k-means cluster method [63], discriminant analysis [64,65], and artificial neuronal networks [55,66] involving self-organizing maps [67][68][69][70][71].…”

A methodology to investigate heterogeneous oxidation of thermally aged cross‐linked polyethylene by ToF‐SIMS

“…Additionally, to achieve a better understanding of the high amount of information present in ToF-SIMS mass spectra, a data analysis method related to multivariate analysis was proposed to obtain information about the spatial distribution of oxidized compounds. 11,12 2 | EXPERIMENTAL 2.1 | Sample preparation XLPE was produced at the University of Bologna and provided in the form of sheets. XLPE sheets were cut to a practical size (approximately 10 × 20 mm) with a thickness of 2 mm.…”

“…A methodology to produce cross sections of XLPE in order to study the ageing effects with depth was developed, and the generated specimens were studied using a chemical analysis technique capable to resolve chemistry at the microscale such as ToF‐SIMS. Additionally, to achieve a better understanding of the high amount of information present in ToF‐SIMS mass spectra, a data analysis method related to multivariate analysis was proposed to obtain information about the spatial distribution of oxidized compounds 11,12 …”