<Emphasis Type="Italic">In situ</Emphasis> grazing-incidence small-angle X-ray scattering observation of block-copolymer templated formation of magnetic nanodot arrays and their magnetic properties

The fabrication of bit-patterned media (BPM) is crucial for new types of hard disk drives.The development of methods for the production of BPM is progressing rapidly.Conventional lithography reaches the limit regarding lateral resolution,and new routes are needed.In this study,we mainly focus on the dependence of the size and shape of magnetic nanodots on the Ar+-ion etching duration,using silica dots as masks.Two-dimensional (2D) arrays of magnetic nanostructures are created using silica-filled diblock-copolymer micelles as templates.After the self-assembly of the micelles into 2D hexagonal arrays,the polymer shell is removed,and the SiO2 cores are utilized to transform the morphology into a (Co/Pt)2-multilayer via ion etching under normal incidence.The number of preparation steps is kept as low as possible to simplify the formation of the nanostructure arrays.High-resolution in situ grazing-incidence small-angle X-ray scattering (GISAXS) investigations are performed during the Ar+-ion etching to monitor and control the fabrication process.The in situ investigation provides information on how the etching conditions can be improved for further ex situ experiments.The GISAXS patterns are compared with simulations.We observe that the dots change in shape from cylindrical to conical during the etching process.The magnetic behavior is studied by utilizing the magneto-optic Kerr effect.The Co/Pt dots exhibit different magnetic behaviors depending on their size,interparticle distance,and etching time.They show ferromagnetism with an easy axis of magnetization perpendicular to the film.A systematic dependence of the coercivity on the dot size is observed.     

Controlled release mechanisms of sodium benzoate from a biodegradable polymer and halloysite nanotube composite

Multiscale polymeric composites combining a biodegradable matrix with low cost and biocompatible hybrid nanocarriers promise to supply a new generation of multipurpose devices for drug delivery. The aim of this work was to investigate the release mechanisms of sodium benzoate (NaBz ) from halloysite nanotubes (HNTs ) embedded in a biodegradable polymer matrix (poly(?‐caprolactone)). To that purpose, different amounts of NaBz molecules were successfully incorporated into HNTs using a simple environmentally friendly procedure. The resulting HNT‐NaBz nano‐hybrids were then incorporated into a poly(?‐caprolactone) matrix by high energy ball milling at ambient temperature and in dry conditions. Analysis of the resulting composites showed important effects of the HNT‐NaBz nano‐hybrids on the thermal and mechanical properties. Controlled drug release, followed by UV spectrophotometry, was also found to be dependent on the HNT‐NaBz relative fractions. Experimental data were thus analyzed using a modified Gallagher ? Corrigan model and correlated with the nano‐hybrid morphologies. © 2016 Society of Chemical Industry     

Increments of dietary linoleate raise liver arachidonate,but markedly reduce heart n−6 and n−3 fatty acids in the rat

Four diets containing 20% of energy (en%) as fat and with linoleic acid contents of 1.9, 3.1, 7.7 and 10.1 en%, respectively, were fed to one-month-old male rats for three months. The fatty acid profiles and the levels of the major n−6 and n−3 fatty acids in the lipids of plasma, liver, heart and kidney were measured. We found that with increasing concentrations of 18∶2n−6 in the diet, linoleic acid rose in plasma and in all organs, but long-chain n−6 and n−3 fatty acids responded differently. In liver, arachidonic acid increased and n−3 fatty acids were not significantly affected; in heart, both arachidonic and docosahexaenoic acids were progressively reduced; and in kidney, there was no change of n−6 and n−3. The results indicate that incremental changes in dietary, linoleate affect the levels of polyunsaturated fatty acids in liver and extrahepatic organs differently.