In-situ fabrication of polyelectrolyte-CSH superhydrophilic coatings via layer-by-layer assembly

Superhydrophilic and antireflective coatings were fabricated via the layer-by-layer (LbL) assembly method with in situ precipitation of sodium silicate and calcium acetate on quartz or glass slide substrate. The influences of assembly conditions on the growth behavior, surface topologies, zeta potentials, wettability, antifogging behavior and transmittances of the multilayer coatings have been investigated in details. The results indicated that more than three deposition cycles with 3.27 g/L calcium silicate hydrates (CSH) solution were optimal condition for the fabrication of a superhydrophilic and antireflective coating structure of poly(ethyleneimine)/poly(sodium 4-styrenesulfonate) (PEI/PSS-CSH)(3) with 98.0% of transmittance, and even 99.4% of (PEI/PSS-CSH)(4) multilayer film. Additionally, the 3.0 bilayers of PEI-PSS/CSH coatings exhibited superior antifogging characteristics. This in situ formation of CSH nanoparticles in the LbL film offers a potential strategy to fabricate multifunctional films for a variety of technological applications. (C) 2014 Elsevier B.V. All rights reserved.