Elena Celia

Recent advances in designing superhydrophobic surfaces.

The interest in superhydrophobic surfaces has grown exponentially over recent decades. Since the lotus leaf dual hierarchical structure was discovered, researchers have investigated the foundations of self-cleaning behavior. Generally, surface micro/nanostructuring combined with low surface energy of materials leads to extreme anti-wetting properties. The great number of papers on this subject attests the efforts of scientists in mimicking nature to generate superhydrophobicity. Besides the thirst for knowledge, scientists have been driven by the many possible industrial applications of superhydrophobic materials in several fields. Many methods and techniques have been developed to fabricate superhydrophobic surfaces, and the aim of this paper is to review the recent progresses in preparing manmade superhydrophobic surfaces.

The design of superhydrophobic stainless steel surfaces by controlling nanostructures: A key parameter to reduce the implantation of pathogenic bacteria

Reducing bacterial adhesion on substrates is fundamental for various industries. In this work, new superhydrophobic surfaces are created by electrodeposition of hydrophobic polymers (PEDOT-F4 or PEDOT-H8) on stainless steel with controlled topographical features, especially at a nano-scale. Results show that anti-bioadhesive and anti-biofilm properties require the control of the surface topographical features, and should be associated with a low adhesion of water onto the surface (Cassie-Baxter state) with limited crevice features at the scale of bacterial cells (nano-scale structures).

Three steps to organic–inorganic hybrid films showing superhydrophilic properties

The concept of surface polymerisation to obtain dendritic functionalised surfaces is combined with the grafting of nanoparticles to realise hyperbranched functionalised PE surfaces for the control of wettability and surface adhesion. First, plasma induced polymerisation of acrylic acid allows highly reactive PE surfaces to be obtained. The further covalent grafting of amine functionalised silica nanoparticles (NPs) of 20 nm diameter was realised in one step with specific coupling agents for the creation of amide bonds between the NPs and the polyacrylic acid (pAA) surface. This reaction can be conducted in dichloromethane as well as in water depending on the coupling agents. This procedure afforded in three steps (plasma activation, polymerisation of acrylic acid and grafting of silica nanoparticles) highly functionalised hybrid organic–inorganic films. IR analysis as well as microscopic observations (AFM and SEM) and wettability measurements attest the PE surface modifications. Depending on the conditions used to link the NPs to the surface, superhydrophilic material can be reached.