Synthesis of nanowalled polymer microtubes using glass fiber templates

Covalently crosslinked flexible polymer microtubes with wall thicknesses of 1-3 nm, diameters of 2-10 mum, and lengths of 0.1-0.5 mm have been fabricated using glass wool and silica wool as templates. Fluorescent-dye-tagged polyamines were adsorbed onto the glass and silica templates and crosslinked by reductive amination with glutaraldehyde and sodium cyanoborohydride, then the templates were dissolved with hydrofluoric acid. Microtubes were prepared from polyallylamine (PAA), polyethyleneimine (PEI), and poly(iminohexamethylene) (PIH) labeled with sulforhodamine B. These flexible hollow structures were characterized by bright-field and fluorescent optical microscopy and confocal laser scanning microscopy; they adopt open tubular conformations when suspended in water, and dry to give flat ribbons.