Periodic structures were imprinted on a soda lime glass surface below its glass transition temperature (T g ) using a carbon-coated SiO 2 mold under application of DC voltage. The structure height increased with the applied DC voltage, although no significant increase with pressure was found. At a temperature around T g , the height reached saturation. Chemical etching using 55% KOH solution at 70 C increased the structure height to eight times the height before etching. Noticeable alternating depression patterns and rapid chemical etching are closely related with the selective decrease in sodium concentration, which occurred only in the surface areas that were pressurized by the mold. V C 2013 AIP Publishing LLC. [http://dx

Formation mechanisms of alkali-free and high-proton concentration surfaces were investigated for a soda lime glass using a corona discharge treatment under an atmospheric pressure. Protons produced by high DC voltage around an anode needle electrode were incorporated into a sodium ion site in the anode side glass. The sodium ion was swept away to the cathode side as a charge carrier. Then it was discharged. The precipitated sodium was transformed to a Na 2 CO 3 powder when the surface contacted with air. The sodium ion in the glass surface layer of the anode side was replaced completely by protons. The concentration of OH groups in the layer was balanced with the amount of excluded sodium ions. The substitution reaction of sodium ions with protons tends to be saturated according to a square root function of time. The alkali depletion layer formation rate was affected by the large difference in mobility between sodium ions and protons in the glass. V C 2013 AIP Publishing LLC. [http://dx

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Selective deposition of SiO2 nanoparticles was demonstrated on a soda-lime glass surface with a periodic sodium deficient pattern formed using the electrical nanoimprint. Positively charged SiO2 particles generated using corona discharge in a cyclic siloxane vapor, were selectively deposited depending on the sodium pattern. For such phenomena to occur, the sodium ion migration to the cathode side was indispensable to the electrical charge compensation on the glass surface. Therefore, the deposition proceeded preferentially outside the alkali-deficient area. Periodic SiO2 structures with 424 nm and 180 nm heights were obtained using one-dimensional (6 μm period) and two-dimensional (500 nm period) imprinted patterns.

Surface relief grating of azobenzene polymer formed on a soda-lime-silica glass plate was treated by corona discharge for the formation of a hologram on the glass plate. The Na concentration distribution near the glass surface was investigated using a time-of-flight secondary ion mass spectrometry (TOF-SIMS) depth analysis with buckminsterfullerene (C 60) ion sputtering and an image processing. The periodical Na deficient region identical to the azobenzene grating pattern existed near the glass surface, which suggested that the Na ions below the grating groove preferentially migrated to the cathode side during the corona discharge treatment. Generally, the refractive index of the Na poor region becomes lower than that of the pristine soda-lime silica glass. Therefore, the origin of the hologram on the glass surface should be the three-dimensional distribution of refractive index at the glass surface.