Wetting Transition from Hydrophilic to Superhydrophobic over Dendrite Copper Leaves Grown on Steel Meshes

With the development of water purification technologies,the usage of superhydrophobic meshes is increased but the fabrication of durable and cost effective superhydrophobic meshes is still challenging.Here,the formation of hierarchical copper fractals on stainless steel meshes and their superhydrophobicity without any physical or chemical modification were studied.In addition,the improvement of superhydrophobicity of surfaces during storing in a glass bottle for a long time(>one year)is reported.The structures were prepared using electrodeposition method applying cyclic voltammetry and square pulse deposition approaches on stainless steel meshes with 50μm,100μm and 200μm pore sizes.The prepared layers are a composition of copper with varying amounts of cuprite(Cu20)depending on deposition method and mesh pore size.As-prepared cyclic voltammetry layer on 100μm mesh showed the parahydrophobicity with the contact angle of 154°but a large sliding angle.The one-year stored samples in the glass bottle showed superhydrophobicity with the contact angles larger than 150°and sliding angles in the range of 4°-20°.The observed improvement of superhydrophobicity is a great success in the realm of industrial water purification,while most other proposed samples by the others have problems related to the durability of superhydrophobicity.

Formation of Nanotubular Structures with Petal Effect by Soft-Template Electropolymerization of Benzotrithiophene with Hydrophilic Carboxyl Group

The bioinspiration is one of the best ways to make a breakthrough in a field,and particularly in the wetting properties.Bioinspired by natural species,such as rose petals and gecko foot,and previous researches,nanotubular structures are prepared here by soft-template electropolymerization in organic solvent and using an original benzotrithiophene with a hydrophilic carboxyl group,as the monomer.The best results are obtained by cyclic voltammetry because of a much higher amount of gas bubbles released with this deposition method.Both nanoparticles and nanotubes are observed while the water content has an influence on the number of nanotubes.Even if the monomer has hydrophilic carboxyl group,the best films have both high hydrophobicity(apparent water contact angle up to 130.7°)and strong water adhesion(petal effect).These surfaces could be used in future in applications such as water harvesting systems.

Nanoparticles Covered Surfaces for Post-functionalization with Aromatic Groups to Obtain Parahydrophobic Surface with High Water Adhesion （Petal Effect）

Numerous exceptional properties can be observed in nature. Among these properties, parahydrophobic feature is of in- terest. This property describes material with high adhesion with water such as rose petals or gecko foot. Such kind of surface presents a real potential for applications in the field of water harvesting systems. In this work, we report a new synthetic strategy to mimic this property. Here, we combine three strategies in one, First, a monomer is electropolymerized in order to form the starting structured surface. Then, nanoparticles are grafted on the surface to increase the structuration and consequently to create the reactive surface. Finally, the grafted surface is post-functionalized （Huisgen reaction） with various aryl alkynes to control the surface chemistry and energy. This strategy allows to reach surfaces with both very high hydrophobic properties （0= 140~） and high water adhesion. This work also includes the surface wettability, roughness and morphology investigation in order to study the impact of the starting monomer structure and post-functionalization on the surface properties.