Inventi Impact: Nanotech & Bionic Engg

Inventi:enb/68/13

ASSEMBLED NANOSTRUCTURED ARCHITECTURES STUDIED BY GRAZING INCIDENCE X-RAY SCATTERING

Inthischapter,wewillfocusonaspecificXray\r\nbased technique among those employed in surface\r\nscience andwhich is especially suitable for the study of\r\nselfassemblednanocrystals:GrazingIncidenceSmallAngle\r\nXray Scattering (GISAXS). We will first introduce the\r\nmainfield of investigation considered herein, with basic\r\nnotions of Xray scattering from surfaces, and then\r\naddress basic concepts about GISAXS. Finally, we will\r\ndescribe a few relevant examples of studies, of\r\nnanostructured architectures, through ex situ and in situ\r\nexperiments of grazing incidence Xray scattering. This\r\nmanuscript is focused on the former, showing that they\r\ncanbeperformedbyusinglaboratoryinstruments.Insitu\r\ninvestigationsstillneedsynchrotronradiationsourcesin\r\nmostcases;therefore,onlyafewexamplesselectedfrom\r\nthe literature are reported here, for the sake of\r\ncompleteness. The experiments described are mainly\r\nperformed in the small angle range, providing\r\ninformation on the size and shape of nanocrystals,\r\ntogetherwiththeirspatialarrangement.Both2Dand3D\r\narchitectures are considered. In particular, GISAXS\r\nmeasurements of 2D superlattices of nanooctapods,\r\nperformed both at a third generation synchrotron\r\nbeamlineand with a tabletop setup, arecompared;the\r\nemployed tabletop setup is described in a dedicated\r\nparagraph.Furtherexamplesofgrazingincidencestudies\r\nas performed by the authors with a tabletop setup are\r\nreported: a GISAXS study of 3D iron oxide nanocrystal\r\nsuperlattices, showing the importance of modelling in\r\norder to obtain structural information from data; a\r\ncombined small/wide angle scattering(GISAXS/GIWAXS)\r\nstudyof3DPbSnanocrystalsuperlattices;andaGIWAXS\r\nstudy of P3HT nanofibres, showing how the ordering at\r\nthemolecularandatomiclengthscalescanbeobtainedby\r\nexploring different angular ranges in the same grazing\r\nincidence geometry. Finally, selected examples of in situ\r\nGISAXS studies, performed with synchrotron radiation\r\nsources,aredescribed.