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Crystal faces of aragonite in various orientations were dissolved in water or in a dilute aqueous acetic acid. Facet formation processes were observed in situ using atomic force microscopy (AFM). At the polar (001) surface, which gave atom-resolved AFM images in air, less polar {112} facets were developed in water. At two other polar faces (110) and (010), which are frequently seen in natural forms, electrically neutral facets such as (130) and (100) were developed in the acidic solution. No facet formation was observed at the neutral (130) and (100) faces. Atom-resolved AFM images observed in air at the latter nearly corresponded to the arrangement of H atoms binding to the carbonate ions. The relative stabilities of polar and neutral surfaces strongly depend on pH, since protonation of the carbonate ions changes distributions of positive and negative electric charges at the surfaces. The equilibrium crystal form of aragonite in acidic conditions most probably consists of {100}, {130} and {112} faces, which is in strong contrast to the cases of alkaline conditions. The (001) face having carbonate ions fully exposed to the solution will not be stabilized without a specific adsorbate.

Vertical alignment (VA) and in‐plane switching modes have been widely used for liquid crystal displays (LCDs). They require a polyimide (PI) alignment layer in the pixel structure. PI‐free LCDs have been proposed to exploit the VA of liquid crystals (LCs) obtained by dissolving dendrimers without PI. In this paper, we report a new PI‐free VA mode with a pixel structure that has in‐plane electrodes. The PI‐free VA is achieved by dissolving an LC dendrimer in a positive LC mixture. We measured the test cell properties and obtained a lower voltage and a higher brightness in the voltage–brightness curve. In addition, we analyzed the alignment surface of LC dendrimer by time‐of‐flight secondary ion mass spectrometry and scanning electron microscopy observations. We found that dendrimer molecules are uniformly adsorbed on the glass surface and that the layer was generally one molecule thick. These properties are responsible for the lower voltage and higher brightness of the PI‐free VA mode. The use of dendrimers allows the PI process to be omitted and reduces the power consumption of the VA mode. It is thus possible to reduce the high manufacturing costs and improve the performance of the VA mode.