Search

Quantitative mapping of the mechanical properties of a series of polylactic acid/natural rubber/organoclay bionanocomposites has been accomplished by using nanoindentation with atomic force microscopy. Topography, elastic modulus and adhesion maps were obtained simultaneously revealing nanoscopic mechanical features in the samples associated to the different phases. For polylactic acid and polylactic acid/natural rubber a single distribution of Young's moduli was obtained whose maximum correlates well with the macroscopic measurements. Bionanocomposites with high organoclay loads exhibit a bimodal distribution of elastic moduli whose maxima can be associated to the polylactic acid matrix and to the reinforcing levels provided by the organoclay component. Adhesion maps allow one to obtain mechanical contrast between polylactic acid and organoclay, at high loadings, revealing the good compatibility of the organoclay with the polymer.

Grazing-incidence small-angle X-ray scattering (GISAXS) can be used to characterize the replica quality of polymer gratings prepared by thermal nanoimprint lithography (NIL). Here it is shown using GISAXS experiments that a series of NIL polymer gratings with different line quality present characteristic features that can be associated with the level of defects per line. Both stamps and NIL polymer gratings exhibit characteristic semicircle-like GISAXS patterns. However NIL polymer gratings with defective lines exhibit GISAXS patterns with an excess of diffuse scattering as compared to those of the corresponding stamps. In a first approach, this effect is attributed to a reduction of the effective length of the lines diffracting coherently as the number of defects per line increases. © Blackwell Publishing 2014., The financial support of MICINN through CTQ2010-15680, MAT2011-23455 and MAT2012-33517 is gratefully acknowledged. ER and IMF thank MICINN, Spain, for a `Ramón y Cajal' contract (RYC-2011-08069) and for an FPI fellowship, respectively. MS and DMT thank CSIC for the tenure of JAE fellowships and the Fondo Social Europeo (FSE) for co-financing the JAE program.

6 p.; gráf., In this work, well-defined low aspect ratio nanostructures based on nanogratings on thin films of poly(vinylidene fluoride trifluoroethylene) copolymers were prepared. By using these nanogratings, an improved management of writing and reading information of about 500 Gbit/in.2(0.01 bit/nm2) can be reached as revealed by Piezoresponse Force Microscopy. Structural investigation by means of X-ray diffraction techniques indicates that the physical confinement generated by nanoimprint promotes the development of smaller and edge-on oriented crystals. Our results evidence that one-dimensional nanostructuring can be a straightforward approach to improve the control of the polarization in ferroelectric polymer thin films.© 2013 AIP Publishing LLC., Supported by MINECO MAT2009-07789, MAT2011-23455, and MAT-2012-33517. JAE-Pre fellowship and a JAE-Doc contract of CSIC and the FSE.