Susanna Laurenzi

Advanced Composite Materials by Resin Transfer Molding for Aerospace Applications

© 2012 Laurenzi and Marchetti, licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Advanced Composite Materials by Resin Transfer Molding for Aerospace Applications

Surface-enhanced Raman spectroscopy characterisation of functionalised multi-walled carbon nanotubes

Multi-walled nanotube (MWNT) functionalisation was investigated by surface-enhanced Raman spectroscopy (SERS). The MWNTs were deposited as dilute dispersions on SERS-active substrates. We used nano-structured gold surfaces with various morphologies for our measurements. The surface enhancement effect was used to amplify the Raman signal from functional molecules bound to the nanotube walls. The recorded spectral features allowed for discrimination between the differently functionalised MWNTs. Although the present study is limited to a few examples, our measurements indicate the higher specificity obtained by the SERS approach and its possible use for a systematic study of functionalisation effects on MWNT structures.

Dynamic and structural performances of a new sailcraft concept for interplanetary missions

Typical square solar-sail design is characterised by a central hub with four-quadrant sails, conferring to the spacecraft the classical X-configuration. One of the critical aspects related to this architecture is due to the large deformations of both membrane and booms, which leads to a reduction of the performance of the sailcraft in terms of thrust efficiency. As a consequence, stiffer sail architecture would be desirable, taking into account that the rigidity of the system strongly affects the orbital dynamics. In this paper, we propose a new solar-sail architecture, which is more rigid than the classical X-configuration. Among the main pros and cons that the proposed configuration presents, this paper aims to show the general concept, investigating the performances from the perspectives of both structural response and attitude control. Membrane deformations, structural offset, and sail vibration frequencies are determined through finite element method, adopting a variable pretensioning scheme. In order to evaluate the manoeuvring performances of this new solar-sail concept, a 35-degree manoeuvre is studied using a feedforward and feedback controller.

Nanomaterial-based biosensors for a real-time detection of biological damage by UV light.

In this work, the design and fabrication of a miniaturized and light-weight biosensor that can be used to monitor the biological effects of hostile ultraviolet radiation in earth and space are presented. The biosensor is generated by embedding a sensitive element to UV radiation, DNA, in a hybrid carbon-based nanomaterial. In particular, we present results on the fabrication and characterization of hybrid nanostructured films containing graphene nanoplatelets (GNPs) and double-stranded DNA for the in situ and real-time detection of UV radiation damaging effects from the changes of the film electrical properties induced by exposure to UV-C radiation. The biosensor is realized by the deposition of the sensitive unit GNP/DNA on a supporting substrate made of flexible polymers or glass.

Steady-shear rheological properties of graphene-reinforced epoxy resin for manufacturing of aerospace composite films

The aim of this work is to analyze the steady-shear rheological behavior and the absolute viscosity of epoxy matrix reinforced with graphene nanoplatelets (xGnP) before cure. Three different grades of xGnP (grades C, M and H) were dispersed homogenously at different weight percentages (wt%) into the epoxy matrix, ranging from 0.5 to 5 wt%. It is found that nanocomposite fluids with xGnP-C exhibit a Newtonian behavior at shear rate in the range 0.1–100 s−1, conversely, nanocomposite fluids with xGnP of grade M and H exhibit a shear-thinning behavior with the increase of nanoplatelet loading. Results from this analysis indicate how the steady shear rheological properties of the nano-reinforced polymer fluids depend on the geometrical characteristics of the graphene nanoplatelets.