Comparisons of Analytical Approaches for Determining Shell Thicknesses of Core–Shell Nanoparticles by X-ray Photoelectron Spectroscopy

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

Artyushkova

Brundle³

et al. 2019

159

Over the past three decades, the widespread utility and applicability of X-ray photoelectron spectroscopy (XPS) in research and applications has made it the most popular and widely used method of surface analysis. Associated with this increased use has been an increase in the number of new or inexperienced users which has led to erroneous uses and misapplications of the method. This article is the first in a series of guides assembled by a committee of experienced XPS practitioners that are intended to assist inexperienced users by providing information about good practices in the use of XPS. This first guide outlines steps appropriate for determining whether XPS is capable of obtaining the desired information, identifies issues relevant to planning, conducting and reporting an XPS measurement, and identifies sources of practical information for conducting XPS measurements. Many of the topics and questions addressed in this article also apply to other surface-analysis techniques.

Section: Where Can I Find the Information I Need About Xps?mentioning

confidence: 99%

Practical guides for x-ray photoelectron spectroscopy: First steps in planning, conducting, and reporting XPS measurements

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

Artyushkova

Brundle³

et al. 2019

159

“…◦ SESSA and other computational methods allow XPS to be used in a quantitative manner to extract important information about particle coatings and layer thicknesses (Powell et al, 2018 ).…”

Section: Minimizing Reproducibility Issuesmentioning

confidence: 99%

“…The full range of surface analysis tools can be useful to understanding NP surfaces (Baer et al, 2010 ; ISO/TR-14187, 2011 ), but XPS has proven highly valuable for understanding the presence of contaminants and the uniformity of surface functionalization (Baer et al, 2013 ; Mireles et al, 2016 ), the chemical state of elements on NP surfaces including surface oxidation (Guascito et al, 2013 ), as well as the nature and thicknesses of surface and layered NP coatings (Techane et al, 2011 ; Shard, 2012 ; Belsey et al, 2015 ; Wang et al, 2016 ). Appropriate application of surface analysis methods requires careful and thoughtful sample preparation (ISO-20579-4, 2018 ), often involving extraction of samples for complex solution environments (Pourrahimi et al, 2014 ; La Spina et al, 2017 ) to be followed by appropriate data collection and spectral analysis (Guascito et al, 2013 ) that should include consideration of the potential impacts NP size and shape on the analysis (Baer and Engelhard, 2010 ; Powell et al, 2018 ).…”

Section: Minimizing Reproducibility Issuesmentioning

confidence: 99%

The Chameleon Effect: Characterization Challenges Due to the Variability of Nanoparticles and Their Surfaces

2018

Front. Chem.

Nanoparticles in a variety of forms are increasing important in fundamental research, technological and medical applications, and environmental or toxicology studies. Physical and chemical drivers that lead to multiple types of particle instabilities complicate both the ability to produce, appropriately characterize, and consistently deliver well-defined particles, frequently leading to inconsistencies, and conflicts in the published literature. This perspective suggests that provenance information, beyond that often recorded or reported, and application of a set of core characterization methods, including a surface sensitive technique, consistently applied at critical times can serve as tools in the effort minimize reproducibility issues.

“…The presence of unplanned or unexpected chemical elements or compounds on a nano‐object surface, and challenges in reproducible surface functionalization highlight the importance of the analysis of nano‐object surfaces . Such issues make it important to obtain consistent, reproducible, and accurate information about nanoparticle coatings and multi‐layered structures, eg, core‐shell nanoparticles . The high importance of surface energy for nano‐objects produces a variety of behaviors that impact stability, reproducible synthesis, and accurate surface analysis.…”

Section: Introductionmentioning

confidence: 99%

“…8,10 Such issues make it important to obtain consistent, reproducible, and accurate information about nanoparticle coatings and multi-layered structures, eg, core-shell nanoparticles. [11][12][13][14][15][16] The high importance of surface energy for nano-objects produces a variety of behaviors that impact stability, reproducible synthesis, and accurate surface analysis.…”

mentioning

confidence: 99%

Importance of sample preparation on reliable surface characterisation of nano‐objects: ISO standard 20579‐4

Surface & Interface Analysis

Karakoti

Clifford

et al. 2018

The international ISO Standard 20579‐4, dealing with the history and preparation of nano‐objects for surface analysis, has been developed to help address some of the replication and reproducibility issues caused by the fundamental nature of nano‐objects. Although all types of samples requiring surface analysis need thoughtful preparation, nano‐objects, for which many properties are controlled by their surfaces, present additional challenges in order to avoid variations and artefacts due to the handling and preparation of materials prior to analysis. This international standard is part of a series of standards related to preparation of samples for surface chemical analysis. Parts 1 and 2 of ISO Standard series 20579 address general issues that apply to many samples. Part 3, which is still in development, will focus on biomaterials. Part 4 specifically considers issues that arise due to the inherent nature of nano‐objects. Because of sensitivity to their environment, the standard indicates the minimum information that needs to be reported about the handling and preparation of nano‐objects prior to surface analysis. This information should become part of sample provenance information that helps assure the reliability and usefulness of data obtained from surface‐analysis in the context of the synthesis, processing, and analysis history of a batch of material. Application of this standard can help address reproducibility and traceability issues associated with synthesis, processing, and characterization of nano‐objects in research and commercial applications.