InterNano Nanomanufacturing Repository
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Polymer-Mediated Clustering of Charged Anisotropic Colloids
No full textFormation of stable, dense nanoparticle clusters is interesting due to both the underlying physics and use of nanoclusters in applications such as digital printing, imaging and biosensing, and energy storage. Here, we explore formation of nanoparticle clusters in dispersions of the model disk-shaped colloid Laponite. Under basic conditions, the model disk-shaped colloid Laponite forms a repulsive glass in water due to strong electrostatic interactions. Addition of a nonadsorbing polymer, the sodium salt of poly(acrylic acid) (PAA), induces a depletion attraction between particles. Through dynamic light scattering (DLS) and rheology, we see that the polymer initially causes a transition from the glassy phase to an ergodic fluid. Samples at higher particle concentration age to a weak nonergodic state, while samples at lower Laponite remain as fluids. As the strength of attraction between particles is increased, we find an increase in the fast relaxation time measured via dynamic light scattering (e.g., slowing of the short-time diffusion of a single particle). While this may in part be attributed to an increase in the ionic strength, the aging behavior and glass-fluid transition we observe appear to be unique to the presence of polymer, suggesting that depletion plays an important role. DLS data on the fluid samples were consistent with two widely spaced diffusive relaxation modes, corresponding to motion of single particles and motion of large clusters, although other slow dynamic processes may be present. On the basis of the estimated volume fraction and depletion attraction, we believe the Laponite-PAA suspensions to be either fluids of stable dusters or glasses of clusters, although it is possible that the nonergodic state we observe is instead a gel of clusters. Additionally, the cluster size was found to be stable for at least 120 days and was directly related to the polymer concentration. This may serve as an important means of tuning cluster size in products and processes based on dense nanoparticle assemblies
Replenishable dendrimer-nanoparticle hybrid membranes for sustained release of therapeutics
No full textWe report a versatile hybrid membrane for sustained release therapeutic delivery systems. Chemically-directed assembly of a hybrid membrane of nanoparticles and dendrimers was integrated with a fluidic delivery device and a refillable drug reservoir, providing continuous sustained release
Symposium on Assessing the Economic Impact of Nanotechnology: Synthesis Report
No full textThe Organisation for Economic Co-operation and Development (OECD) and the United States National Nanotechnology Initiative (NNI) held an international symposium, Assessing the Economic Impact of Nanotechnology, in March 2012. Hosted by the American Association for the Advancement of Science (AAAS) in Washington DC, it brought together participants from the public and private sectors with expertise all along the nanotechnology value chain - scientists, engineers, policy analysts, private investors, technology leaders, and the general public - from both OECD and emerging economies.
The symposium was organised around expert talks and discussions on issues, such as the role of research funding portfolios; intellectual property frameworks; private-sector and industry investments;
patents and publications; venture capital; public-private partnerships; state and local initiatives;
international co-operation; and development metrics for nanotechnology. In addition to plenary talks,
sector-specific breakout sessions were organised in transport and aerospace, nanomedicine, electronics,
energy, materials, and food and food packaging.
This synthesis report aims to summarise the discussions and key messages from the symposium. It
also draws on four background reports that were developed for the symposium:
- Challenges for Governments in Evaluating Return on Investment from Nanotechnology and its Broader Economic Impact, by Eleanor O'Rourke and Mark Morrison, Institute of Nanotechnology, United Kingdom
- Finance and Investor Models in Nanotechnology, by Tom Crawley, Pekka Koponen, Lauri Tolvas and Terhi Marttila, Spinverse, Finland
- The Economic Contributions of Nanotechnology to Green and Sustainable Growth, by Philip Shapira and Jan Youtie; University of Manchester, UK; Arizona State University, USA; and Georgia Institute of Technology, USA
- Models, Tools and Metrics Available to Assess the Economic Impact of Nanotechnology,by Katherine Bojczcuk and Ben Walsh, Oakdene Hollins, United Kingdom
The report was developed by Marie-Ange Baucher and Richard Scott from the OECD and Chris Cannizzaro, Stacey Standridge, Elizabeth Nesbitt, and Tarek Fadel from the NNI. The OECD and NNI are grateful to those who gave their time to review this report.
The report does not necessarily represent the views of the NNI, the OECD, the AAAS; a consensus among participants; or the views of the sponsoring organisation, the National Science Foundation
EU's Graphene Flagship Initiative: A Public-Private Partnership of Unprecedented Scale
No full textGraphene has been the subject of an explosion of technical research in recent years as a result of its unique combination of superior properties. It has become the starting point for disruptive technologies in a wide range of fields including high performance computing, transparent conductors, printed electronics, displays, solar photovoltaics, and sensors. Pathways to large area, high throughput production of graphene materials have been established, and key cases emerging from research labs around the globe have demonstrated the advantages of graphene for the applications noted above. The European Commission recently announced graphene as one of the EU's first 10-year, 1 Billion euro Future $amp; Emerging Technology (FET) flagships. The goal of the Graphene Flagship is to accelerate the path of graphene and related layered materials from academic laboratory research to scaled commercialization. The resulting societal benefit and subsequent revolutionizing of multiple industry sectors should create substantial economic growth and new jobs in the EU. The recent announcement is noteworthy as it is launching a coordinated public-private partnership research initiative of unprecedented scale.
Also included: DNA and Quantum Dots: All That Glitters is Not Gold, The State of Nanoimprinted Polymer Organic Solar Cell Technology, and Flexible Organic Photovoltaic Cells with In-situ Non-thermal Photoreduction of Spin Coated Graphene Oxide Electrode
Regional, State, and Local Initiatives in Nanotechnology: Report of the National Nanotechnology Initiative
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Differentiation of cancer cell type and phenotype using quantum dot-gold nanoparticle sensor arrays
No full textWe demonstrate rapid and efficient sensing of mammalian cell types and states using nanoparticle-based sensor arrays. These arrays are comprised of cationic quantum dots (QDs) and gold nanoparticles (AuNPs) that interact with cell surfaces to generate distinguishable fluorescence responses based on cell surface signatures. The use of QDs as the recognition elements as well as the signal transducers presents the potential for direct visualization of selective cell surface interactions. Notably, this sensor is unbiased, precluding the requirement of pre-knowledge of cell state biomarkers and thus providing a general approach for phenotypic profiling of cell states, with additional potential for imaging applications. (C) 2012 Elsevier Ireland Ltd. All rights reserved
