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Insect eyes have an anti-reflective coating, owing to nanostructures on the corneal surface creating a gradient of refractive index between that of air and that of the lens material.sup.1,2. These nanocoatings have also been shown to provide anti-adhesive functionality.sup.3. The morphology of corneal nanocoatings are very diverse in arthropods, with nipple-like structures that can be organized into arrays or fused into ridge-like structures.sup.4. This diversity can be attributed to a reaction-diffusion mechanism.sup.4 and patterning principles developed by Alan Turing.sup.5, which have applications in numerous biological settings.sup.6. The nanocoatings on insect corneas are one example of such Turing patterns, and the first known example of nanoscale Turing patterns.sup.4. Here we demonstrate a clear link between the morphology and function of the nanocoatings on Drosophila corneas. We find that nanocoatings that consist of individual protrusions have better anti-reflective properties, whereas partially merged structures have better anti-adhesion properties. We use biochemical analysis and genetic modification techniques to reverse engineer the protein Retinin and corneal waxes as the building blocks of the nanostructures. In the context of Turing patterns, these building blocks fulfil the roles of activator and inhibitor, respectively. We then establish low-cost production of Retinin, and mix this synthetic protein with waxes to forward engineer various artificial nanocoatings with insect-like morphology and anti-adhesive or anti-reflective function. Our combined reverse- and forward-engineering approach thus provides a way to economically produce functional nanostructured coatings from biodegradable materials. The building blocks of the nanostructures observed on Drosophila corneas are determined, and then used to create artificial nanostructures with anti-reflective and anti-adhesive properties., Author(s): Mikhail Kryuchkov [sup.1] [sup.2] , Oleksii Bilousov [sup.2] , Jannis Lehmann [sup.3] , Manfred Fiebig [sup.3] , Vladimir L. Katanaev [sup.1] [sup.2] [sup.4] Author Affiliations: (1) Department of Cell [...]

The objective of the present work is to investigate the electro-activated shape memory behavior of a polycyclooctene (PCO) based nanocomposite device. At this aim, carbon black (CB) and exfoliated graphite nanoplatelets (xGnP) were melt compounded with a PCO matrix crosslinked with a dicumylperoxide content of 2 wt% and a total filler amount of 4 wt%. Electrical resistivity measurements on bulk materials evidenced a noticeable decrease of the electrical resistivity upon CB addition, while no synergistic effects were detected mixing CB and xGnP. Nanocomposite with a CB amount of 4 wt% revealed also a noticeable heating capability through Joule effect for voltage levels higher than 100 V. The subsequent characterization of an electro active shape memory device based on this composition demonstrated how it is possible to prepare a shape memory nanocomposite material able to completely recover its original shape after 100 s with a voltage of 90 V. The retention of the shape memory behavior after several (50) programming cycles was also demonstrated., INTRODUCTION It is well known that the addition of metal and carbon based nanofillers, such as metal nanopowders, graphite nanoplatelets (GnPs), carbon black (CB), and carbon nanofibers (NFs) could significantly [...]

Surface morphology development for SBM triblock copolymer thin films has been studied by atomic force microscopy. The effect of copolymer composition and solvent on the final morphology has been investigated. Obtained results indicated that depending on the block ratio (symmetric or asymmetric with minority middle block) and solvent, lamellar, hexagonal, cylindrical, or spheres in lamellae (/s)-type morphologies can be achieved at film surfaces. The influence of the interaction parameters among blocks and solvents and cohesive energy values of block pairs on the final morphology has been proved., INTRODUCTION Among the applications of di- or triblock copolymers based on polystyrene and elastomeric blocks, their use for preparing solvent-based highly elastic coatings that provide outstanding crack-free adhesion to polar [...]

To broaden the applications of the electrospinning technique, high throughput is one of the primary goals of many researchers. To overcome the throughput limitation, we have introduced coaxial grooved nozzles. By using a coaxial grooved nozzle and two fluids, including polyethylene oxide (PEO), we are able to achieve stable multi-jet operation and relatively high throughput. The multi-jets are initiated by the multi-jet mode of the inner fluid, and share the total flow rate of the polymer solution. We have investigated the operating conditions for various flow rate combinations of two fluids. The morphology of the resulting nanofibers is uniform without bead formation. The fibers have an average diameter of about 350 nm. POLYM. ENG. SCI., 58:416-421, 2018. [C] 2017 Society of Plastics Engineers, INTRODUCTION Electrospinning is a simple and versatile technique for fabricating nanofibers and fibrous mats, capable of producing continuous nanofibers with various types of surface morphology [1-5]. Because of its numerous [...]

A nanocomposite system based on coumarin derivative and graphene sheet was used to prepare a new electrochemical sensor. The objective of the mentioned nanocomposite was to investigate novel electrochemical properties enabling the quantification of epinephrine (Ep). Cyclic voltammetry was used to study the redox properties of the mentioned modified electrode at different scan rates. Henceforward, the electrocatalytic oxidation of Ep at the surface of the modified electrode was considered. The data has shown excellent catalytic activity of the modified electrode for the electrooxidation of Ep, which leads to a reduction of overpotential for more than 238 mV. According to differential pulse voltammetry (DPV), the oxidation of Ep showed a dynamic range between 0.1 and 1000.0 [micro]M and the detection limit (3s) of 0.011 [micro]M. Besides, DPV was used for the determination of Ep at the mentioned modified electrode in the presence of serotonin. Keywords: nanocomposite, electrochemistry, graphene sheet, epinephrine, serotonin, Nanotechnology is helping to notably improve many technologies. Nanomaterials depict materials of which (in at least one dimension) a single unit is sized between 1 and 1000 nm (usually 1 [...]

Polypyrrole-sepiolite (PPy/SPL) nanofibers were prepared by in situ chemical oxidation polymerization in the presence of sepiolite. A PPy/SPL composite modified glassy carbon electrode (PPy/SPL/GCE) was prepared and characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and electrochemical methods. Differential pulse anodic stripping voltammetry for the simultaneous determination of trace Pb(II) and Cd(II) was carried out at the PPy/SPL/GCE. Operational parameters such as the deposition potential and time, the amount of modified suspension, and the pH values were optimized for the purpose of determination of trace metal ions in 0.10 M acetate buffer solution. Under the optimal conditions, the stripping peak currents showed good linear relationships with Pb(II) and Cd(II) at concentration ranges of 5.0 x [10.sup.-9] - 1.2 x [10.sup.-6] M and 5.0 x [10.sup.-9] - 1.2 x [10.sup.-7] M, and the detection limits were 1.2 and 1.5 nM, respectively. The proposed method is applicable to the simultaneous determination of trace Pb(II) and Cd(II) in real water samples with the relative standard deviations of less than 4.4% and the recovery rates of 97.9-102.2%. Keywords: polypyrrole, sepiolite, differential pulse anodic stripping voltammetry, Pb(II), Cd(II), Lead and cadmium have long been recognized as harmful environmental pollutants, which can cause a variety of adverse health impacts even at lower levels [1-3]. Therefore, the selective and sensitive [...]

3D MAGNETIC NANOSTRUCTURES COULD TRANSFORM COMPUTING A team led by scientists at Cardiff University, U.K., and including researchers at Los Alamos National Laboratory, N.M., created the first 3D replica of [...]

In 2006, the National Institute of Standards and Technology conducted an assessment of the U.S. measurement system (USMS), which encompasses all private and public organizations that develop, supply, use, or […]

Polymeric micro- and nanoparticles play a central role in varied applications such as drug delivery, medical imaging, and advanced materials, as well as in fundamental studies in fields such as microfluidics and nanotechnology. Functional behavior of polymeric particles in these fields is strongly influenced by their shape. However, the availability of precisely shaped polymeric particles has been a major bottleneck in understanding and capitalizing on the role of shape in particle function. Here we report a method that directly addresses this need. Our method uses routine laboratory chemicals and equipment to make particles with >20 distinct shapes and characteristic features ranging in size from 60 nm to 30 [micro]m. This method offers independent control over important particle properties such as size and shape, which is crucial to the development of nonspherical particles both as tools and products for a variety of fields. morphology | nanotechnology | geometry | drug delivery | nonspherical