Manufacturing-friendly and scalable methods for the production of silicon micro- and nanostructures, including silicon nanotubes, are described. The integrated air filter frame-connecting means are adapted to connect a plurality of identical air filter sub-assemblies into an air filter assembly with sufficient structural strength in at least one direction such that the air filter sub-assemblies resists separation when the air filter assembly is extracted from the filter track of a filter bank. Subsequently, anhydrous ethanol is added to the solution to initiate copolymer gel precipitation, after which the solution is separated to obtain the gel precipitate, which is subsequently washed and dried.