AOMatSens 2018 Abstracts


Full Papers
Paper Nr: 1
Title:

Photopolymerizable Nanoparticle-polymer Composite Materials for Light and Neutron Beam Manipulations

Authors:

Yasuo Tomita, Kohta Nagaya, Toshi Aoi, Yuko Iso, Akihisa Kageyama, Naoya Nishimura, Keisuke Odoi, Koichi Umemoto, Jürgen Klepp, Christian Pruner and Martin Fally

Abstract: We report on a recent progress in a new class of photopolymerizable nanostructured materials, the so-called photopolymerizable nanoparticle-polymer composites (NPCs). They consist of photoreactive monomer (photopolymer) dispersed with inorganic or organic nanoparticles at high concentrations. The initially uniform distribution of nanoparticles in a neat monomer host is spatially assembled under holographic exposure, providing the single step formation of large scale and multi-dimensional photonic lattice structures in NPC films. This property can be used for versatile applications in photonics and neutron optics such as holographic data storage, holographic optical elements, nonlinear photonic crystals and slow-neutron beam control. Here we describe applications of NPCs dispersed with new organic and inorganic nanoparticles to holographic data storage and holographic diffractive elements for light and neutron beams.

Paper Nr: 2
Title:

Advances in Optical Sensing of Explosive Vapours

Authors:

Ross N. Gillanders, James M. E. Glackin, Iain A. Campbell, Ifor D. W. Samuel and Graham A. Turnbull

Abstract: Optical techniques for the detection of explosives are receiving increasing interest due to potentially fast-responding, highly-sensitive systems. Conjugated polymers are suitable probe materials for this application since their fluorescence is quenched by electronegative materials including explosives. This can be used to make a sensor for explosive vapour, which can then give chemical information to help identify explosive devices, and complements other approaches such as metal detectors and ground penetrating radar. Whilst the principle has been known for some time, its practical implementation requires considerable development of instrumentation and materials, including preconcentration materials. This paper reports our current efforts to address these challenges, with particular emphasis on humanitarian demining and looking towards application in Improvised Explosive Device (IED) detection.

Paper Nr: 3
Title:

Development of a DNA Biodosimeter for UV Radiation

Authors:

Telma S. Marques, Filipa Pires, Gonçalo Magalhães-Mota, Paulo A. Ribeiro, Maria Raposo and Nigel Mason

Abstract: Ultraviolet (UV) radiation has a strong influence in the damage of deoxyribonucleic acid (DNA). In this work, the possibility of a DNA UV radiation dosimeter is evaluated. For that, calf thymus DNA samples, thin films and aqueous solutions, were irradiated with 254 nm wavelength light during different periods of time, being the damage caused by the irradiation analysed by both UV-visible and infrared spectroscopies. As the DNA is a polyelectrolyte, the pH of the DNA samples was also considered as a variable. Results demonstrated that damage in DNA takes place in both thin films and solutions when irradiated at 254 nm, as revealed by a consistent decay in measured absorbance values. However, DNA solutions were seen to give more reliable as the induced damage is easily measured. For this case, the absorbance at 260 nm was seen to exponentially decrease with the irradiation time as a result of radiation damage with the kinetics damage strongly dependent of pH. Consequently, the lifetime of such dosimeter device can be chosen by changing the pH of aqueous solutions.

Paper Nr: 4
Title:

Photocatalytic Degradation of Rhodamine 6G using TiO2/WO3 Bilayered Films Produced by Reactive Sputtering

Authors:

L. C. Silva, B. Barrocas, M. E. Melo Jorge and S. Sério

Abstract: TiO2/WO3 and WO3/TiO2 bilayered films were deposited onto glass substrates by DC reactive magnetron sputtering and their photocatalytic activity was evaluated on the decolorization of Rhodamine 6G (Rh6G) aqueous solutions. The structures, morphologies and optical properties of TiO2 and WO3 layers and also of the bilayered films were studied by X-ray diffraction, field emission scanning electron microscopy and UV-Vis spectroscopy. It was found that the bilayered films exhibit good adherence to the substrates and high mechanic stability. The structural characterization revealed that in both nanocomposites independently of the above layer, the main phase observed in the X-ray patterns corresponds to WO3 and the optical properties are similar to the WO3 layer. The photocatalytic efficiency of the nanocrystalline bilayered films was further compared with TiO2 and WO3 films also produced by sputtering and the results show that the higher photocatalytic activity was achieved by the bilayered film with WO3 as the upper layer.