Preparation of multi‐level honeycomb‐structured porous films by control of spraying atomized water droplets

Abstract

Honeycomb-structured porous films have been widely applied in various industrial areas such as chemical sensors, tissue engineering, and micro reactors. In this article, one novel self-assembly approach is proposed to fabricate well-ordered polyphenylene oxide honeycomb films by a facile control of spraying ultrasonic humidifier atomized water droplets. Proper spraying retention time is necessary for porous films formation with highly uniform pore size. The effect of atomized water droplets flux on the pore size and the regularity of the hexagonal arrays were experimentally investigated. The pore size became larger with increasing the solution concentration. Especially, honeycomb films with two-level pores were fabricated by spraying atomized water droplets two times and the influence of interval time on the two-level honeycomb films formation was investigated. Apart from analysis of structural characteristics, self-assembly mechanism was also discussed.

Transparent self-cleaning lubricant-infused surfaces made with large-area breath figure patterns

“…In this report, we present a novel method to fabricate large-area BFPs where spraying micro ultrasonic atomized water droplets replace the water vapor in high humidity. In our method [36], spraying time is an important factor that influences the quality of the resulting Page 7 of 27 A c c e p t e d M a n u s c r i p t 7 BFPs. A spraying time that is too long results in an excess amount of water droplets, leading to irregular pores and cracked film.…”

“…The experimental setup and the method used to fabricate BFPs have been described in our previous report [36]. Here, in order to fabricate large-area BFPs, the circular glass substrates were ultrasonicated sequentially in ethanol and Milli-Q water for 10 and 5 min, respectively, and then treated by O 2 plasma after vacuum drying in an oven at 50° for 30 min to facilitate the spread of the solutions.…”

“…Herein, we prepared transparent self-cleaning SLIPS with breath figure patterns (BFPs) formed on the glass substrates based on our previous work regarding BFPs preparation using an enhanced breath figure method (BFM) [36]. BFM is chosen to construct the lubricant holding structures, because it is a fast, facile, easily controllable, and versatile method to fabricate regular porous films [37][38][39][40].…”

Hierarchically Organized Honeycomb Films Based on the Self-Assembly of Fulleromonodendrons

“…They have been prepared by using a sacrificial polymer which can be removed by UV irradiation 29 or hydrolysis 30 or by spraying ultrasonic humidifier-atomized water droplets onto the polymer film. 31 An alternative way to obtain such a film is by using special building blocks, such as polystyrene (PS)-b-poly(ionic liquid) block copolymers 32 or surfactant-encapsulated polyoxometalate. 33 Despite the existence of these pioneering works, investigations on hierarchically organized HCSs are still rare compared to the numerous studies on common HCSs.…”

“…In between the pores, formation of the substructures in angstroms or nanometers has been demonstrated, which typically formed by the nanophase segregation or self-assembly of block polymers. − Nanoparticle deposition combining with the BF method has also been developed to produce hierarchically organized HCSs. − Of special interest are HCSs with hierarchically distributed pores, that is, large pores decorated by smaller ones. They have been prepared by using a sacrificial polymer which can be removed by UV irradiation or hydrolysis or by spraying ultrasonic humidifier-atomized water droplets onto the polymer film . An alternative way to obtain such a film is by using special building blocks, such as polystyrene (PS)- b -poly­(ionic liquid) block copolymers or surfactant-encapsulated polyoxometalate .…”