Department of Materials Science, University of Patras, 26504 Rio Patras, Greece, Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vass. Constantinou Avenue, 116 35 Athens, Greece, Institut de Biologie Moleculaire et Cellulaire, UPR9021 CNRS, Immunologie et Chimie Therapeutiques, 67084 Strasbourg, France, and Dipartimento di Scienze Farmaceutiche, Universita di Trieste, Piazzale Europa 1, 34127 Trieste, Italy

Chemistry of Carbon Nanotubes

Polydopamine and Its Derivative Materials: Synthesis and Promising Applications in Energy, Environmental, and Biomedical Fields

Carbon nanotube–polymer composites: Chemistry, processing, mechanical and electrical properties

The widespread use of controlled molecular-level motion in key natural processes suggests that great rewards could come from bridging the gap between the present generation of synthetic molecular systems, which by and large rely upon electronic and chemical effects to carry out their functions, and the machines of the macroscopic world, which utilize the synchronized movements of smaller parts to perform specific tasks. This is a scientific area of great contemporary interest and extraordinary recent growth, yet the notion of molecular-level machines dates back to a time when the ideas surrounding the statistical nature of matter and the laws of thermodynamics were first being formulated. Here we outline the exciting successes in taming molecular-level movement thus far, the underlying principles that all experimental designs must follow, and the early progress made towards utilizing synthetic molecular structures to perform tasks using mechanical motion. We also highlight some of the issues and challenges that still need to be overcome.

Synthetic molecular motors and mechanical machines.

The major strategies for designing surfaces that prevent fouling due to proteins, bacteria, and marine organisms are reviewed. Biofouling is of great concern in numerous applications ranging from biosensors to biomedical implants and devices, and from food packaging to industrial and marine equipment. The two major approaches to combat surface fouling are based on either preventing biofoulants from attaching or degrading them. One of the key strategies for imparting adhesion resistance involves the functionalization of surfaces with poly(ethylene glycol) (PEG) or oligo(ethylene glycol). Several alternatives to PEG-based coatings have also been designed over the past decade. While protein-resistant coatings may also resist bacterial attachment and subsequent biofilm formation, in order to overcome the fouling-mediated risk of bacterial infection it is highly desirable to design coatings that are bactericidal. Traditional techniques involve the design of coatings that release biocidal agents, including antibiotics, quaternary ammonium salts (QAS), and silver, into the surrounding aqueous environment. However, the emergence of antibiotic- and silver-resistant pathogenic strains has necessitated the development of alternative strategies. Therefore, other techniques based on the use of polycations, enzymes, nanomaterials, and photoactive agents are being investigated. With regard to marine antifouling coatings, restrictions on the use of biocide-releasing coatings have made the generation of nontoxic antifouling surfaces more important. While considerable progress has been made in the design of antifouling coatings, ongoing research in this area should result in the development of even better antifouling materials in the future.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/adma.201001215

Antifouling coatings: recent developments in the design of surfaces that prevent fouling by proteins, bacteria, and marine organisms.

Biomimetic research indicates that many phenomena regarding wettability in nature, such as the self-cleaning effect on a lotus leaf and cicada wing, the anisotropic dewetting behavior on a rice leaf, and striking superhydrophobic force provided by a water strider's leg, are all related to the unique micro- and nanostructures on the surfaces. It gives us much inspiration to realize special wettability on functional surfaces through the cooperation between the chemical composition and the surface micro- and nanostructures, which may bring great advantages in a wide variety of applications in daily life, industry, and agriculture. This Account reviews recent progress in these aspects.

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Bioinspired surfaces with special wettability

Wettability is a very important property that is governed by both chemical composition and surface structure. Recently, the control of surface wettability has aroused great interest because of its wide variety of applications. In general, superhydrophobic surfaces with a water contact angle (CA) greater than 1508 can be obtained by controlling the topography of hydrophobic surfaces, while superhydrophilic surfaces with a CA about 08 can be realized through a 3D or 2D capillary effect on hydrophilic surfaces. Stimuli-responsive surfaces make it possible to reversibly control the wettability of the surface and has been demonstrated by various methods, including light-irradiation, 12] use of an electric field, 14] thermal treatment and treatment with solvent. However, reversible switching between superhydrophilicity and superhydrophobicity has never been reported. Herein we show the roughness-enhanced thermally responsive wettability of a poly(N-isopropylacrylamide) (PNIPAAm)-modified surface. 18] Reversible switching between superhydrophilicity and superhydrophobicity can be achieved in a narrow temperature range of about 10 8C, which is considered to result from the combined effect of the chemical variation of the surface, and surface roughness. Such switchable surfaces may have wide applications in functional textiles, intelligent microfluidic switching, controllable drug release, and thermally responsive filters. Surface-initiated atom-transfer radical polymerization 20] was used to fabricate thermally responsive PNIPAAm thin films on both a flat and a rough silicon substrate. Results from atomic force microscopy (AFM) and scanning electron microscopy (SEM) showed that the thickness of the PNIPAAm thin film could be well controlled by the polymerization time. Figure 1a (left) shows a typical SEM image of a rough substrate that has been modified with a PNIPAAm thin film. Compared with the smooth surface (Figure 1a right) of the flat substrate, the rough substrate exhibits a regular array of square silicon microconvexes (bright squares). The dark lines are microgrooves that are about 6 mm in width and about 5 mm in depth. These microgrooves were generated by a laser cutter (see Experimental Section) on a silicon wafer in a region of about 1 : 1 cm. The surface roughness can be adjusted by controlling the spacing between the grooves. In our experiments, different groove spacings of about 31 mm, 18 mm, 8 mm, and 6 mm were selected. The magnified image of the rough surface shows that both microconvexes and microgrooves were also rather rough (Figure 1b). Further magnified SEM images of the silicon microconvexes before (Figure 1c) and after (Figure 1d) PNIPAAm polymerization show that these

/pdf/reversible-switching-between-superhydrophilicity-and-299eahb4uf.pdf

Reversible Switching between Superhydrophilicity and Superhydrophobicity

Superhydrophobic Aligned Polystyrene Nanotube Films with High Adhesive Force

Aromatic Carbonyl Derivative Polymers as High-Performance Li-Ion Storage Materials†

To the best of our knowledge, a dual-re-sponsive surface that switches between hydrophilic andhydrophobic has never been reported, to say nothing of adual-responsive surface that switches between superhydro-philic and superhydrophobic.In this communication, a dual-stimuli-responsive surfacewith tunable wettability, reversible switching between super-hydrophilicity and superhydrophobicity, and responsivity toboth temperature (

Taolei Sun

Papers

Bioinspired surfaces with special wettability

Reversible Switching between Superhydrophilicity and Superhydrophobicity

Superhydrophobic Aligned Polystyrene Nanotube Films with High Adhesive Force

Aromatic Carbonyl Derivative Polymers as High-Performance Li-Ion Storage Materials†

Dual‐Responsive Surfaces That Switch between Superhydrophilicity and Superhydrophobicity