We propose a new technique suitable for on-line monitoring of gas phase synthesis of nanoparticles. It is based on aerodynamic focusing of nanoparticles followed by Laser-Induced Breakdown Spectroscopy (LIBS) under vacuum. The laser crosses a beam of particles at low pressure so that the plasma-produced photons to be analyzed are emitted only from the particles. Unlike previous experiments, the background from interaction with the gaseous component is totally eliminated from the collected spectra. Vacuum allows also for easier spectra collection in the UV range. Moreover, as the nanoparticle beam is highly collimated, the optical interface windows are not obstructed by particle deposition and the system can be kept running for hours.
Journal: MRS Advances
3 articles found
ON-SITE ANALYSIS; CLOISONNE ENAMELS; 19TH CENTURIES
The focus of this paper is on analysis, comparison and research on the colorful lowtemperature, lead-containing overglazes on glazed porcelain body and on the enamel glazes on the metal body of the Qing Dynasty by adopting several analytical methods. Analysis and tests on the element, boron in overglaze on glazed porcelain body and enamel glaze on metal body, were performed using laser induced breakdown spectroscopy (LIBS), and the results showed that Cloisonn enamel, painted enamel and Falangcai samples contained boron, while Famille Rose (Fencai) samples did not contain boron. Meanwhile, such analysis methods as laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), energy dispersive X-ray spectroscopy (EDXRF), Micro-Raman, stereomicroscope and Confocal laser scanning microscopy (CLSM) were used to test and observe the element composition, crystal composition and microstructure of the samples. The results illustrated that matrix glaze of Cloisonn enamel, painted enamel and Falangcai was the same. The yellow glaze was a lead-alkali glass and other color glazes were boron-lead-alkali glass, while all color glazes of Famille Rose were lead-alkali glass. Colorful low-temperature overglaze on glazed porcelain body and enamel glaze on metal body had a common practice and technology in the use of opacifiers and colorants. Compared to painted enamel, the painting technique of Famille Rose was more complicated, and effect was apparently praised as being superior.
Intermetallic ternary nanoalloys (NA) have increasingly gained prominence as excellent catalysts. But, their size, morphology and chemical compositions affect their catalytic and interfacial activities significantly. In this study, we present laser-induced breakdown spectroscopy (LIBS) for rapid quantitative elemental composition characterization of ternary NAs with different elemental ratios. Specifically, we use a calibration-free approach with LIBS to estimate the elemental ratios of PtCuCo ternary NAs with various stoichiometric ratios synthesized via our in-house laser ablation synthesis in solution-galvanic replacement reactions (LASiS-GRR) technique. The size and morphology of the samples are determined from transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX) measurements. The LIBS quantitative estimations for the NA samples are compared with results from inductively coupled plasma-optical emission spectroscopy (ICP-OES). The elemental ratio results of quantitative LIBS show good agreement with ICP-OES results, while being devoid of any external standard requirements or extensive sample preparations.