Hierarchical Nanoporous Glass with Antireflectivity and Superhydrophilicity by One-Pot Etching

Abstract

We have developed a hierarchical nanoporous layer (HNL) on silicate glass by a simple one-pot etching method. The HNL has a three-dimensionally continuous spongelike structure with a pore size of a few tens of nanometers on its apparent surface. The pore size gradually decreases from the apparent surface to the HNL-bulk interface. This HNL bestows significant properties to glass: low optical reflectivity that reflects 7% less visible light than nontreated glass and long-persistence superhydrophilicity that keeps its water contact angle at about 5° for more than 1 year. The superhydrophilicity also realizes antifogging and antifouling functionalities.

Fingerprint Blurring on a Hierarchical Nanoporous Layer Glass

“…The HNL glass samples were prepared by following the method described in our previous work [10]. We used a soda-lime glass (Matsunami Glass) as a base material.…”

“…We have realized a new antifouling material with a hierarchically nanoporous layer (HNL) on a silicate glass in recent years [10,11]. The HNL has a three-dimensionally continuous porous structure like a sponge, with its porous size decreasing from the apparent surface toward the buried region.…”

Mapping the transition to superwetting state for nanotextured surfaces templated from block-copolymer self-assembly

“…Young contact angles below 30, 47 we and many other groups find an unexpected increase in the apparent contact angle with increasing roughness 48,49 owing to the pinning effect. 22,[50][51][52][53][54] Strong pinning can even cause droplets to spread along the underlying lattice directions creating polygonal droplet shapes.…”

Role of the surface chemistry of plasma polymer layers on their long‐term antifogging behavior

“…[12] One of the more stable superhydrophilic inorganic surfaces is the hierarchical nanoporous layer of silicate glass etched by an alkaline solution with a WCA at about 5°f or more than 1 year. [14] In the case of the superhydrophilic organic thin coating, the polydiethylene glycol bis(allyl carbonate) treated by Ar ions implantation under dioxygen partial pressure can retain its antifogging property over only the first 2,000 hr to attain a WCA ≅ 40°. [8] On the other hand, to preserve hydrophilicity of the surface from organic contamination, oil-repellent or oleophobic properties are required.…”