Session Chair: Federico Rosei, Institut National de la Recherche Scientifique (INRS) Session Chair: John Wang, National University of Singapore
1:30pm - 2:00pm Invited
Conversion of Light Energy into Heat and Hot Electrons Using Hybrid Nanostructures with Plasmonic Hot Spots
Ohio University, United States
Metal nanocrystals exhibit strong plasmon resonances and have the ability to absorb and scatter solar light very efficiently. This study concerns special designs of plasmonic nanostructures with electromagnetic hot spots, where the energy of incident light concentrates. Overall plasmonic nanostructures with hot spots demonstrate strongly amplified energy-related effects. (1) Using such nanostructures, one can strongly enhance optical generation of heat and also confine high photo-temperatures in small volumes [1,2]. (2) Plasmonic hot spots efficiently generate energetic electrons, which can be used for photochemistry and photodetection [3,4]. (3) Colloidal nanocrystal assemblies with plasmon resonances allow us to strongly enhance chiral optical responses (circular dichroism) of biomolecules and drugs [5,6].
 A. O. Govorov and H. Richardson, Nano Today 2, 20 (2007).
 C. Jack, et al., Nat. Commun. 7,10946 (2016).
 A.O. Govorov, H. Zhang, H.V. Demir and Y. K. Gun’ko, Nano Today 9, 85 (2014).
 H. Harutyunyan, et al., Nature Nanotech. 10, 770 (2015).
 A. O. Govorov, et al., Nano Letters10, 1374–1382 (2010).
 A. Kuzyk, et al., Nature 483, 311 (2012).
2:00pm - 2:30pm Invited
Nanoparticles Interactions with Viruses, from Stabilisation to Virucidal Action
Institute of Materials and Interfaculty Bioengineering Institute, École Polytechnique Fédérale de Lausanne, Switzerland
In this talk, recent progress in investigating and understanding the interactions of nanoparticles with viruses will be presented. In particular the ability of using colloidal properties to stabilize viral vectors for vaccines will be illustrated. Furthermore the possiblity of using nanoparticles as drug against viral infections will be presented.
2:30pm - 3:00pm Invited
Next Generation of Biodegradable Polymer-Ceramic Implants for Bone Regeneration
Iman MANAVITEHRANI1, Yiwei WANG1, Peter K. MAITZ1,2, Farid MIRMOHSENI1,3, Tegan L. CHENG3, Aaron SCHINDELER1,3, Fariba DEHGHANI1
1The University of Sydney, Australia; 2Concord Repatriation General Hospital, Australia; 3Children’s Hospital at Westmead, Australia
The explantation surgery of an implanted orthopaedic prosthesis often causes clinical complications, and the patient suffers from the countless post-surgical symptoms such as infection and the lack of mobility. This issue has been clinically addressed using biodegradable polymers with favourable physical and biological properties. However, the acidic degradation of those polymers causes delays in the bone regeneration process. In this study, we aimed to introduce a biodegradable bone fixation screw based on poly(propylene carbonate) (PPC) with benign degradation by-products, water, and carbon dioxide, with superior characteristics as an alternative implant for metal-based biomaterials. The compressive modulus of the blend increased 2.36 fold after addition of a plasticizer while the surface wettability improved nearly 10 degrees. Furthermore, the microCT analysis confirmed a homogenous distribution of bioglass microparticles that promoted the bioactivity of the composites based on comprehensive in vitro cell studies. The in vivo degradation rate of the samples was investigated, and the 45.82 ± 1.3% volume fraction loss was observed after 6 months post-surgery for the polymer-ceramic blend. In addition, a rat hemiarthroplasty model was used to study the in vivo osseointegration effects of these implants. In summary, these studies emphasize that PPC-based biomaterial developed in this study are superior for orthopaedic fixation implants.
3:00pm - 3:15pm Oral
Atomic Layer Deposition and Thermal Annealing of Al2O3/ZnO Stacking Structures
Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), Singapore
We have synthesized AlO2O3/ZnO stacking structures by atomic layer deposition (ALD) at 150 °C. These stacking structures were annealed under various atmospheres including sulphur vapor, dry nitrogen, forming gas, and air. It has been found that when the individual layer thickness is smaller than ~10 nm, recrystallization or decomposition of ZnO occurred at elevated temperatures depending on the stacking thickness ratios between ZnO and Al2O3. Pores, i.e., surface pits, have also been observed for the nanolaminate structures under certain annealing conditions. On the other hand, when the layer thickness is increased over ~10 nm, surface blistering occurred on Al2O3/ZnO stacks but not on ZnO/Al2O3 ones upon annealing. Detailed optical and structural properties as well as their evolutions upon annealing will be presented during the meeting.
3:15pm - 3:30pm Oral
Fabrication of Titanium Nitride Powder by Nitriding-Heat Treatment of Titanium Hydride
1Korea Institute of Materials Science, South Korea; 2Pukyong National University, South Korea
Titanium nitride (TiN) powders were successfully fabricated by nitriding of titanium hydride (TiH2) powders. It was studied thermodynamically that the de-hydrogenation, "TiH2 = Ti + H2" and nitriding, "Ti + N = TiN" occurred simultaneously at the overall region of reaction temperatures. The fine TiH2 powder, 2 μm, effectively nitrided at the overall reigon of reaction temperatures whereas the coarse powder, 15 μm, did not. Particularly, as the careful study of nitriding kinetics according to initial particle size of TiH2 powder, we found the activation energy for nitriding in 2 μm TiH2 powder to be 17.45 KJ/mol, which was much smaller than in 15 μm TiH2 powder, 42.15 KJ/mol, which confirmed that the nitriding in fine powder is faster than that in coarse powder.