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- PublicationStructure-dynamics correlations in composite PF127-PEG-based hydrogels; cohesive/hydrophobic interactions determine phase and rheology and identify the role of micelle concentration in controlling 3D extrusion printability(Elsevier, 2024-04-15)A library of composite polymer networks (CPNs) were formed by combining Pluronic F127, as the primary gelator, with a range of di-acrylate functionalised PEG polymers, which tune the rheological properties and provide UV crosslinkability. A coarse-grained sol–gel room temperature phase diagram was constructed for the CPN library, which identifies PEG-dependent disruption of micelles as leading to liquefication. Small angle X-ray scattering and rheological measurements provide detailed insight into; (i) micelle-micelle ordering; (ii) micelle-micelle disruption, and; (iii) acrylate-micelle disruption; with contributions that depend on composition, including weak PEG chain length and end group effects. The influence of composition on 3D extrusion printability through modulation of the cohesive/hydrophobic interactions was assessed. It was found that only micelle content provides consistent changes in printing fidelity, controlled largely by printing conditions (pressure and feed rate). Finally, the hydrogels were shown to be UV photo-crosslinkable, which further improves fidelity and structural integrity, and usefully reduces the mesh size. Our results provide a guide for design of 3D-printable CPN inks for future biomedical applications.
16 - PublicationUpdate on the status of the Educational Irish Research Satellite (EIRSAT-1)(Iniciativa Digital Politecnica, 2022-04-29)The Educational Irish Research Satellite, EIRSAT-1, is a 2U CubeSat being implemented by a student-led team at University College Dublin, as part of the 2nd round of the European Space Agency’s Fly Your Satellite! programme. In development since 2017, the mission has several scientific, technological and outreach goals. It will fly an in-house developed antenna deployment module, along with three custom payloads, which are integrated with commercial off-the-shelf subsystems. In preparation for the flight model, a full-system engineering qualification model of the spacecraft has undergone an extensive period of test campaigns, including full functional tests, a mission test, and environmental testing at the European Space Agency’s CubeSat Support Facility in Redu, Belgium. Beyond the technical, educational, and capacity-building goals of the mission, EIRSAT-1 aims to inspire wider study of STEM subjects, while highlighting the importance of multidisciplinary teams and creating greater awareness of space in everyday life. A wide range of outreach activities are being undertaken to realise these aims. This paper provides a status update on key aspects of the EIRSAT-1 project and the next steps towards launch.
17 - PublicationDevelopment of a Nanosatellite System Modeling Architecture for EIRSAT-1(IEEE, 2023-07-27)Over the last two decades, CubeSats which are nanosatellites with form factors based on units (U) of 10 x 10 x 10 cm3, have become more common in academia, enabling students to gain hands-on experience with satellite design, testing and deployment [15]. The use of Commercial-Off-TheShelf (COTS) components reduces development cost and time, making CubeSats an accessible and cost effective route to space. CubeSats are increasingly important for in-orbit demonstrations of new technologies. Further, their flexibility allows them to be configured for a wide range of science mission profiles, either as a standalone platform, as a communications relay for lunar and inter-planetary missions, such as NASA's Mars Cube One (MarCO) satellites [14], or as a daughter spacecraft to study a near-Earth object such as LICIACube [2]. Several CubeSats for high energy astrophysics are currently in orbit and in development [9].
12 - PublicationThermally-controlled spherical peptide gel architectures prepared using the pH switch method(Wiley, 2022-03-23)Self-assembling nanostructured peptide gels are promising materials for sensing, drug delivery, and energy harvesting. Of particular interest are short diphenylalanine (FF) peptides modified with 9-fluorenylmethyloxycarbonyl (Fmoc), which promotes the association of the peptide building blocks. Fmoc-FF gels generally form fibrous networks and while other structures have been demonstrated, further control of the gelation and resulting ordered three-dimensional structures potentially offers new possibilities in tissue engineering, sensing, and drug release applications. Herein, we report that the structure tunability of Fmoc-FF gels can be achieved by controlling the water content and the temperature. We further explore the incorporation of metal nanoparticles in the formation of the gel to enable optical sensing applications based on hybrid Fmoc-FF-nanoparticle microspheres. Finally, fluorescence lifetime imaging microscopy reveals a correlation between lifetime and reduced bandgap, in support of a semiconductor-induced charge transfer mechanism that might also increase the stability of an excited state of a probe molecule. The observations potentially further widen the use of these peptide materials in bioimaging and sensing applications.
19Scopus© Citations 1 - PublicationPlasmonic photo-catalysis using a CdS-silver nanowire composite(AIP Publishing, 2022-02-18)We examine the potential of cadmium sulfide when combined with plasmonic nanostructures to support photo-induced catalysis. Super-bandgap irradiation of a silver nanowire and cadmium sulfide composite for the probe molecule p-aminothiophenol (PATP) showed the formation of dimercaptoazobenzene (DMAB) from PATP. Our results demonstrate that cadmium sulfide can be used as an alternative material to semiconductors, such as titanium dioxide, for plasmonic photocatalysis applications.
20Scopus© Citations 3