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High-angle misorientations can significantly influence material properties. In this study, optical microscopy, Scanning Electron Microscope-Electron Backscatter Diffraction (SEM-EBSD), and Atomic Force Microscopy (AFM) have been used to investigate high-angle misorientations in quartz-bearing crustal rocks. Thin sections of high-grade quartzofeldspathic rocks were subjected to chemical mechanical polishing (CMP) with colloidal silica. In quartz, high-angle misorientations like random high angle grain boundaries (RHAGBs) and Dauphiné twin boundaries (DTBs) could be discriminated using EBSD techniques but not optical microscopy. In nanoscale AFM images, indented channels are observed along RHAGBs but not DTBs; these result from material removal during CMP, indicating lower compactness of RHAGBs compared to DTBs. Along any RHAGB, EBSD reveals different misorientations across segments between consecutive RHAGB-DTB intersections. Grains adjacent to these RHAGB segments have angles between their c-axes varying from 61-66° with parallel { 10 1 ‾ 2 } planes, and 81–84° with parallel { 11 2 ‾ 2 } planes, respectively. These symmetries represent the Japan and Sardinian twin laws of quartz, indicating that the RHAGB segments become low-energy twin boundaries, thereby reducing the overall surface energy of the aggregate. Finally, these results suggest that apart from surface topography quantification and high-resolution nanoscale imaging, AFM in conjunction with SEM-EBSD can be used for precisely locating sites for TEM study. • High-angle grain boundaries (HAGBs) in quartz aggregates vary in compactness. • Random HAGBs show indented channels in Atomic Force Microscopy (AFM) scans. • Dauphiné twin boundaries (DTBs) have greater compactness than random HAGBs. • DTB formation creates twinned random HAGB segments reducing overall surface energy. • AFM can be used for site selection before Transmission Electron Microscopy analysis. [ABSTRACT FROM AUTHOR]

Aerosol particles can trigger various environmental issues, not only when they are airborne but even after their deposition. For example, highly corrosive sea spray aerosols (SSA) can be deposited on surfaces and cause damage to steel- or concrete-based infrastructure, especially in coastal areas. However, the extent to which the adhesive behavior of SSA is affected by different degrees of organic mixing has not been sufficiently studied. The goal of this study was to evaluate the adhesion forces of both laboratory-generated and ambient SSA with a variety of organic contents on an individual particle basis using atomic force microscopy. Aerosols were also generated using a bulk sea foam sample collected from the coast of Noto Peninsula, Japan to simulate SSA enriched in a complex mixture of marine organics. The adhesion force of the sea foam particles was compared with that of two types of standard monosaccharides (glucose and fucose), artificial inorganic sea salt (ASS), glucose and ASS mixtures at different mass ratios, and ambient sea salt (SS) particles. Pure monosaccharide or its mixtures showed substantially larger adhesion forces than predominantly inorganic particles such as ASS and SS. In addition, it was found that a fraction of sea foam particles showed similarly large adhesion forces, suggesting that organic (e.g., monosaccharides)-enriched SSA can be considerably more adhesive than inorganic salts. Furthermore, a few but surprisingly adhesive particles were also identified among ambient aerosols. Therefore, it is necessary to consider the abundance of organics such as saccharides to correctly evaluate the adhesivity of SSA. [Display omitted] • Atomic force microscopy was used to evaluate the adhesion forces of the sea spray aerosols on an individual particle basis. • Organic-rich particles have been shown to exhibit substantially larger adhesion forces than inorganic particles. • The presence of such highly adhesive particles was confirmed in the ambient atmosphere. [ABSTRACT FROM AUTHOR]

A new method, namely, force–distance curve mapping, was developed to directly measure the adhesion force of individual aerosol particles by atomic force microscopy. The proposed method collects adhesion force from multiple points on a single particle. It also takes into account the spatial distribution of the adhesion force affected by topography (e.g., the variation in the tip angle relative to the surface, as well as the force imposed upon contact), thereby enabling the direct and quantitative measurement of the adhesion force representing each particle. The topographic effect was first evaluated by measuring Polystyrene latex (PSL) standard particles, and the optimized method was then applied on atmospherically relevant model dust particles (quartz, ATD, and CJ-1) and inorganic particles (ammonium sulfate and artificial sea salt) to inter-compare the adhesion forces among different aerosol types. The method was further applied on the actual ambient aerosol particles collected on the western coast of Japan, when the region was under the influence of Asian dust plume. The ambient particles were classified into sea salt (SS), silicate dust, and Ca-rich dust particles based on individual particle analysis (micro-Raman or Scanning Electron Microscope/Energy Dispersive X-ray Spectroscopy (SEM-EDX)). Comparable adhesion forces were obtained from the model and ambient particles for both SS and silicate dust. Although dust particles tended to show smaller adhesion forces, the adhesion force of Ca-rich dust particles was larger than the majority of silicate dust particles and was comparable with the inorganic salt particles. These results highlight that the original chemical composition, as well as the aging process in the atmosphere, can create significant variation in the adhesion force among individual particles. This study demonstrates that force–distance curve mapping can be used as a new tool to quantitatively characterize the physical properties of aerosol particles on an individual basis. [ABSTRACT FROM AUTHOR]

This article reviews recent progress in Japan in the techniques and applications of dynamic mode atomic force microscopy (AFM), specifically focusing on three topics: (1) mechanical discrimination of intermixed two-atom species and their manipulation by frequency modulation (FM) AFM under ultrahigh vacuum; (2) sub-molecular and atomic-resolution imaging in liquids by FM-AFM; and (3) high-speed imaging of biological macromolecules in solution by amplitude modulation (AM) AFM. After reviewing the state of the art of these high-performance AFMs and various techniques that have enabled them, we present future prospects for these AFMs and for technological innovations that will be led by them. These prospects are given from the viewpoint of Japanese groups that have been involved in these three topics. [ABSTRACT FROM AUTHOR]