Search results for "fabrication"

Reactive nanorods based on activated esterpolymers: a versatile template-assisted approach for the fabrication of functional nanorods

2011

A new route for the fabrication of polymeric nanorods with functional moieties via post-modification of reactive nanorods is described. To this end reactive nanorods with a homogenous and narrow size distribution were fabricated by utilizing an anodic aluminium oxide (AAO) template-assisted approach. The nanorods are based on activated pentafluorophenyl esters, to enable quantitative post-modification with amines under very mild reaction conditions yielding the corresponding functionalized amide. Post-modification with fluorescent dyes as well as the conversion into well-dispersed rod-shaped poly(N-isopropylacrylamide) (PNIPAM) hydrogels that exhibit a thermal-responsive phase transition wa…

Fabrication of Robust High-Quality ORMOCER® Inverse Opals

2006

The nanostructuring of ORMOCER® to form inverse opals is described. For this purpose a polymer opal is used as a template and infiltrated with liquid ORMOCER®. After photopolymerization of the resin the host opal is dissolved in tetrahydrofuran and an ORMOCER® inverse opal is obtained. It shows excellent periodicity (by SEM) and optical properties to reveal a high degree of face centered cubic order. This replication process leads to a nanostructured photonic crystal with the outstanding mechanical properties of ORMOCER® and high temperature stability up to 350 °C.

Hybrid silicon on insulator/polymer electro-optical intensity modulator operating at 780  nm

2014

Currently inorganic materials prevail as the nonlinear active medium for light modulation in electro-optical (EO) device technology. A recent promising trend is to consider organic nonlinear optical materials for application in EO modulators due to their multiple advantages including low costs and high EO coefficients. In this paper, we proposed a new type of polymer EO modulator whose fabrication is compatible with the currently used silicon on insulator technology. Our numerical optimization of the proposed structure demonstrates that it is theoretically possible to achieve a half-wave voltage as low as 1.56 V for a 1 cm long modulator structure operating at 780 nm. Based on the results o…

Preparation and processing of nanocomposites of all-inorganic lead halide perovskite nanocrystals

2021

Abstract Solution processed all-inorganic trihalide perovskite nanocrystals are potential materials for the fabrication of future generation optoelectronic devices. However, the surface of the perovskite nanocrystals should be encapsulated to prevent degradation. Because of their stability under ambient conditions, nanocomposites of perovskite nanocrystals have been intensively researched for display applications. Perovskite nanocrystals dispersion or growth in a polymer matrix imparts structural stability and influences the optical properties, preventing effects such as halide migration. Developing flexible, high-performance lighting devices through perovskite nanocomposites will need to b…

Metal-polymer nanocomposite resist: a step towards in-situ nanopatterns metallization

2013

In this work we propose an alternative method for the fabrication of metal micro/nanostructures from metal-polymer nanocomposite resists and their subsequent electroless metallization. The process consists of three simple steps: 1. Fabrication of micro or nanopatterns by lithography or any other direct printing technologies (inkjet or microplotter printing...), 2. In-situ synthesis of metal nanoparticle during a post-bake step and 3. Non-electrochemical metallization of nanocomposite patterns. The novelty of our approach is that both Ag and Au nanoparticles are embedded into the polymer pattern and act as seeds for the reduction of Ag(I) when immersed into a solution of the corresponding pr…

Metal nanoparticle/polymer superlattice films: Fabrication and control of layer structure

1997

Trapping and Immobilization of DNA Molecules Between Nanoelectrodes

2011

DNA is one of the most promising molecules for nanoscale bottom-up fabrication. For both scientific studies and fabrication of devices, it is desirable to be able to manipulate DNA molecules, or self--assembled DNA constructions, at the single unit level. Efficient methods are needed for precisely attaching the single unit to the external measurement setup or the device structure. So far, this has often been too cumbersome to achieve, and consequently most of the scientific studies are based on a statistical analysis or measurements done for a sample containing numerous molecules in liquid or in a dry state. Here, we explain a method for trapping and attaching nanoscale double-stranded DNA …

Assembly of iron oxide nanosheets at the air-water interface by leucine-histidine peptides

2021

The fabrication of inorganic nanomaterials is important for a wide range of disciplines. While many purely inorganic synthetic routes have enabled a manifold of nanostructures under well-controlled conditions, organisms have the ability to synthesize structures under ambient conditions. For example, magnetotactic bacteria, can synthesize tiny ‘compass needles’ of magnetite (Fe3O4). Here, we demonstrate the bio-inspired synthesis of extended, self-supporting, nanometer-thin sheets of iron oxide at the water–air interface through self-assembly using small histidine-rich peptides.

Architetture del divenire. Innovazioni contemporanee/Emerging Architecture. Contemporary Innovations (presentazione di Giuseppe Pellitteri) - Quadern…

2014

La posizione assunta dall'architettura all'inizio del ventunesimo secolo è ambigua e così la forma degli edifici che ambiscono a convogliare significati. Il processo di radicale trasformazione dell’architettura, avvenuto sin dal primo Novecento, quale conseguenza della graduale sostituzione delle tecniche edilizie tradizionali con le tecniche “moderne”, ha subito un notevole slancio nell'ultimo ventennio, per effetto del crescente mutamento tecnologico. I materiali, le tecniche costruttive e l’innovazione tecnologica hanno condizionato sensibilmente ed irreversibilmente il pensiero architettonico, producendo in questi ultimi anni nuove espressività linguistiche del tutto “insolite” rispetto…

"C'est pas pour nous normalement". La médiation culturelle et les non-publics

2014

International audience; L'article porte sur les non-publics, ces personnes en situation à l'instant t de non-pratique culturelle, de non-contact avec un objet culturel précis. A travers une étude de cas (la réception d'une pièce de théâtre participatif par un groupe de migrants), il montre comment des dispositifs institutionnels de médiation produisent, dans des contextes précis, la distance à la culture que les institutions en charge des politiques culturelles tentent d'abolir.