An etching solution contains a quaternary ammonium compound as a main component, by which an etching rate for silicon is improved, no adhered substances are formed on an etching surface during etching, and the etching rate does not decrease even after continuous use for a long time. The silicon etching solution contains a phenol compound represented by the following Formula (1), a quaternary ammonium compound, and water, and has a pH of 12.5 or more.

##STR00001## wherein R.sup.1 is a hydrogen atom, a hydroxy group, an alkyl group, an alkoxy group, or an amino group. R.sup.2 is a hydrogen atom, a hydroxy group, an alkoxy group, or an amino group. R.sup.1 and R.sup.2 are not hydrogen atoms at the same time. When R.sup.1 is a hydrogen atom, R.sup.2 is not a hydroxy group. When R.sup.1 is an alkyl group or a hydroxy group, R.sup.2 is not a hydrogen atom.

An aqueous solution for surface treatment, for treating a surface of an alloy, the aqueous solution comprising: a copper compound at a copper ion concentration of 20000 ppm or more and 50000 ppm or less; a heterocyclic nitrogen compound at a concentration of 200 ppm or more and 3000 ppm or less; and a halide ion at a concentration of 2000 ppm or more and 70000 ppm or less.

A method for reducing adhesion between a maskant and a substrate, wherein the maskant is adhered to a surface of the substrate, the method comprising applying a composition to the maskant.

A method for reducing adhesion between a maskant and a substrate, wherein the maskant is adhered to a surface of the substrate, the method comprising applying a composition to the maskant.

A method for chemical processing an internal cavity of an additive manufactured (AM) metal workpiece is disclosed in which a connector is provided in fluid connection with the internal cavity and a chemical polishing solution is flowed through the connector and the internal cavity to process the internal cavity to a desired finish.

An anti-coking nanomaterial based on a stainless steel surface. In percentage by weight, the nanomaterial comprises: 0 to 3% of carbon, 23% to 38% of oxygen, 38% to 53% of chromium, 10% to 35% of ferrum, 0 to 2% of molybdenum, 0 to 4% of nickel, 3.5 to 5% of silicon, 0 to 1% of calcium, and the balance of impurity elements. Also disclosed are a preparation method for the anti-coking nanomaterial, the anti-coking nanomaterial that is based on a stainless steel surface and that is prepared by using the preparation method, and a stainless steel substrate comprising the anti-coking nanocrystalline material.

An anti-coking nanomaterial based on a stainless steel surface. In percentage by weight, the nanomaterial comprises: 0 to 3% of carbon, 23% to 38% of oxygen, 38% to 53% of chromium, 10% to 35% of ferrum, 0 to 2% of molybdenum, 0 to 4% of nickel, 3.5 to 5% of silicon, 0 to 1% of calcium, and the balance of impurity elements. Also disclosed are a preparation method for the anti-coking nanomaterial, the anti-coking nanomaterial that is based on a stainless steel surface and that is prepared by using the preparation method, and a stainless steel substrate comprising the anti-coking nanocrystalline material.

A patterning sheet, or the like, is suitable when a complex etching target is to be etched in a simple manner to produce an etched structure. This patterning sheet comprises a base sheet formed from an etching-solution permeable first polymer, and particles dispersed in the base sheet and formed from a second polymer, which absorbs and holds the etching solution.

A patterning sheet, or the like, is suitable when a complex etching target is to be etched in a simple manner to produce an etched structure. This patterning sheet comprises a base sheet formed from an etching-solution permeable first polymer, and particles dispersed in the base sheet and formed from a second polymer, which absorbs and holds the etching solution.

The present invention is directed to methods for inhibiting growth of bacteria and to nanometer scale surfaces having antibacterial properties.