A multifunctional nanoporous layer created on glass through a simple alkali corrosion process

Transparency of the glass substrate plays an important role in the performance of many optical and electronic devices. Herein, the authors have demonstrated a simple method to create a high performance wide-range anti-reflection layer on a glass surface by "carving" it with a hot alkali solution (95 °C). Morphology, composition, surface and optical properties were controlled by changing both the original composition of the glass substrates and etching time. Enhanced transparency (up to 97.7%) was achieved in a wide wavelength range. Superhydrophilic and antifogging properties were also demonstrated, which provide an advantage for optical and opto-electrical devices operating outdoors, in high humidity environments or underwater. In addition, the etched glass surfaces were modified to become hydrophobic (even superhydrophobic) by n-octadecyltrichlorosilane treatment. The glass etching mechanism was investigated and verified using energy dispersive spectra (EDS) and Fourier transform infrared (FTIR) absorption spectra analyses.