Depth profiling cross‐linked poly(methyl methacrylate) films: a time‐of‐flight secondary ion mass spectrometry approach

Abstract

We demonstrated that the ion intensity ratio of C H to C H detected in TOF-SIMS provides a unique and simple means to assess the degree of cross-linking of the surface of PMMA films cross-linked by the surface sensitive hyperthermal hydrogen projectile bombardment technique. With a C sputter beam, we were able to depth profile the PMMA films and determine cross-linking depths of the cross-linked polymer films at nanometer resolutions. Copyright © 2017 John Wiley & Sons, Ltd.

Self‐assembled monolayers of octadecylphosphonic acid and polymer films: Surface chemistry and chemical structures studied by time‐of‐flight secondary ion mass spectrometry

“…The chemical structures of PE (monomer: C 2 H 4 ), PP (C 3 H 6 ), PIP (C 5 H 8 ), PMMA (C 5 O 2 H 8 ), and PS (C 8 H 8 ) and measured ρ values are illustrated in Figure . As reported in 2 previous publications, their ρ values are 20%, 23%, 27%, 32%, and 53%, respectively. These values were estimated from the ion intensities collected using a 25 keV Bi 3 + primary ion beam.…”

“…For example, although many ions fragmented from octadecylphosphonic acid (OPA) SAMs do not directly render chemical interactions between the organic molecules and the substrate, certain ions bear information about the chemical states of the molecules interacting with the substrate . For polymers, the patterns of ion fragmentation and/or the intensity ratios of certain ions are useful in revealing their chemical structures . In other words, there are ions that have intrinsic relationships, whose intensity ratios cancel the factors determining their measured intensities and are thus capable of revealing their relationships with the chemical structures of polymers.…”

“…Our results in preparing and characterizing OPA SAMs have proven useful in further understanding the surface chemistry of this SAM system and promoting its applications . We also review our more recent results associated with the development of TOF‐SIMS analytical approaches to differentiating the chemical structures of polyethylene (PE), polypropylene (PP), polyisoprene (PIP), and polystyrene (PS), as well as quantifying cross‐linking degrees and depths of poly(methyl methacrylate) (PMMA) using the intensity ratio between hydrocarbon ions C 6 H − and C 4 H − , denoted as ρ . We found that ρ increases with increased “carbon density,” which is largely related to the C/H ratio .…”

“…An ION‐TOF GmbH (Münster, Germany) TOF‐SIMS IV has been used in our laboratory since 1999. The TOF‐SIMS data presented in our publications reviewed in this article were obtained using either a 9 keV 133 Cs + beam or a 25 keV Bi 3 + beam as the primary ion beam.…”

Spatially resolved indiffusion behavior of Cu2+ and Ni2+ in polypropylene

“…ToF-SIMS provides locally resolved depth profiles and also full three-dimensional analysis data by applying, in addition to the analysis beam, a sputter ion beam, which removes the sample layer by layer. [21] Afterward, those depth profiles can be used for calculations of diffusion coefficients of metal ions in PP. This is to our best knowledge the first time, that such an approach is used in this field of research.…”