Detection of suspended nanoparticles with near-ambient pressure x-ray photoelectron spectroscopy

Abstract

Two systems of suspended nanoparticles have been studied with near-ambient pressure x-ray photoelectron spectroscopy: silver nanoparticles in water and strontium fluoride-calcium fluoride core-shell nanoparticles in ethylene glycol. The corresponding dry samples were measured under ultra high vacuum for comparison. The results obtained under near-ambient pressure were overall comparable to those obtained under ultra high vacuum, although measuring silver nanoparticles in water requires a high pass energy and a long acquisition time. A shift towards higher binding energies was found for the silver nanoparticles in aqueous suspension compared to the corresponding dry sample, which can be assigned to a change of surface potential at the water-nanoparticle interface. The shell-thickness of the core-shell nanoparticles was estimated based on simulated spectra from the National Institute of Standards and Technology database for simulation of electron spectra for surface analysis. With the instrumental set-up presented in this paper, nanoparticle suspensions in a suitable container can be directly inserted into the analysis chamber and measured without prior sample preparation.

Analysis of nanoparticles and nanomaterials using X-ray photoelectron spectroscopy

“…Результаты методов измерения физикохимических параметров нанообъектов существенно влияют на прогноз использования этих материалов в коммерческих целях. В настоящее время перед научным сообществом стоят задачи по дальнейшему повышению точности и разрешающей способности многих методов анализа наночастиц и наноматериалов [49,51,[162][163][164][165]. Однако существуют значительные проблемы при анализе наноматериалов из-за отсутствия подходящих стандартных материалов для калибровки аналитических инструментов, трудности, связанные с пробоподготовкой для анализа и интерпретации данных in situ и operando, особенно в крупномасштабном производстве, а также их анализе в сложных матрицах [49,164].…”

Spiers Memorial Lecture: prospects for photoelectron spectroscopy

“…78 These instruments are suitable for the routine and fast measurement of a wide range of materials that are insulating and/or outgas in UHV, such as zeolites and polymers, biological and other liquid and wet samples (including nanoparticle suspensions) and consumer goods, such as foods and cosmetics. 76,80 This approach has made XPS easy and accessible to new communities. It has been possible, for example, to use NAP-XPS to study Escherichia coli in the hydrated state, 81 and to show that freeze drying (which has been commonly used to study biological systems by XPS 82 ) alters the composition of carbon species at the surface.…”

Effects of background gas composition and pressure on 1,4-polymyrcene (and polytetrafluoroethylene) spectra in near-ambient pressure XPS

“…Data were collected with the SPECS EnviroESCA instrument (Refs. [12][13][14][15]. The spectra of 1,4-polymyrcene are important references for NAP-XPS because of its use as a replacement for petro-based analogues, i.e., it is a bio-based liquid rubber/elastomer (Ref.…”