/pdf/self-assembled-monolayers-of-thiolates-on-metals-as-a-form-1neb0hj3k4.pdf

Self-assembled monolayers of thiolates on metals as a form of nanotechnology.

Fundamentals of Plasmonics.- Electromagnetics of Metals.- Surface Plasmon Polaritons at Metal / Insulator Interfaces.- Excitation of Surface Plasmon Polaritons at Planar Interfaces.- Imaging Surface Plasmon Polariton Propagation.- Localized Surface Plasmons.- Electromagnetic Surface Modes at Low Frequencies.- Applications.- Plasmon Waveguides.- Transmission of Radiation Through Apertures and Films.- Enhancement of Emissive Processes and Nonlinearities.- Spectroscopy and Sensing.- Metamaterials and Imaging with Surface Plasmon Polaritons.- Concluding Remarks.

/pdf/plasmonics-fundamentals-and-applications-4syb9877sr.pdf

Plasmonics: Fundamentals and Applications

The surface science of titanium dioxide

Self-assembly is the autonomous organization of components into patterns or structures without human intervention. Self-assembling processes are common throughout nature and technology. They involve components from the molecular (crystals) to the planetary (weather systems) scale and many different kinds of interactions. The concept of self-assembly is used increasingly in many disciplines, with a different flavor and emphasis in each.

http://science.sciencemag.org/content/sci/295/5564/2418.full.pdf

Self-assembly at all scales.

Recent developments have greatly improved the sensitivity of optical sensors based on metal nanoparticle arrays and single nanoparticles. We introduce the localized surface plasmon resonance (LSPR) sensor and describe how its exquisite sensitivity to size, shape and environment can be harnessed to detect molecular binding events and changes in molecular conformation. We then describe recent progress in three areas representing the most significant challenges: pushing sensitivity towards the single-molecule detection limit, combining LSPR with complementary molecular identification techniques such as surface-enhanced Raman spectroscopy, and practical development of sensors and instrumentation for routine use and high-throughput detection. This review highlights several exceptionally promising research directions and discusses how diverse applications of plasmonic nanoparticles can be integrated in the near future.

Biosensing with plasmonic nanosensors

Theory of penning ionization of adsorbed Co by metastable helium (21S, 23S) beams

Surface spectroscopic techniques may provide rather detailed information on the atomic processes occurring at solid surfaces. Some examples for applications of this ‘surface science’ approach to well-defined model systems and their implications on ‘real’ catalysis are presented. These comprise the characterization of catalyst surfaces (bimetallic Cu/Ru systems and ammonia synthesis catalysts) as well as studies on the elementary steps of catalytic reactions (synthesis of ammonia and oxidation of carbon monoxide).

Surface Science and Catalysis

Cs and CO coadsorbed on Ru(0001): low-energy electron diffraction analysis

Imaging surface reactions with light

The development of a large variety of surface spectroscopic methods enables microscopic characterisation of the species adsorbed on well-defined single crystal surfaces which supplements measurements of macroscopic thermodynamic properties of as solid equilibria. A series of examples with chemisorbed and physisorbe) systems serves to illustrate the underlying principles. The equilibrium between gaseous particles and a solid surface can be described by a function O(p,T), where 0 is the surface concentration or coverage of the adsorbed species, p the partial pressure and T the temperature. This equilibrium is governed by the interactions of the adparticles with the surface and by the interactions between the adsorbed species. Traditionally, one distinguishes between weak ( = physisorption) and strong (= chemisorption) adsorption, whereby an adsorption energy of 40 kJ/mol can be considered as a rough borderline. 'Real' surfaces are polycrystalline and are hence a riori energetically heterogeneous. Fundamental processes are therefore preferably (UHV) conditions and characterizedlby a variety of modern surface spectroscopic methods (ref. 1). This contribution will be restricted to model systems of this type. The possibility of atomic-scale characterisation of these systems enables also the investigation of microscopic properties and provides direct access to concepts of statistical thermodynamics. Phenomenological thermodynamic quantities such as heats or entropies of adsorption may be derived experimentally either from calorimetric measurements or through analysis of the recorded function O(p,T). Calorimetric techniques require a minimum surface area in order to achieve a sufficiently high signal to noise ratio and can therefore not routinely be applied to single crystal samples with surface areas t pically < 1 cm2. No such restriction holds for analysis of adsorption isotherms or isosteres, provided &at a sensitive enough probe for the coverage is available. This can be realized in various ways as will become evident from some of the examplesto be presented below. It is customary in single crystal studies to define the absolute coverage 0 as the ratio of density of adsorbed particles over the density of substrate atomwtopmost layer. Saturation of the (first) adlayer occurs at Omax which will generally be unequal to 1. The relative covera e 9. =@/Omax, on the other hand, runs up to unity at monolayer saturation and corresponds to tfe commonly used notation, defined as the fraction of the surface area covered by the adsorbate (ref. 2). studied wit +' well defined single ' cr stal surfaces which can be prepared under ultra high vacuum CHEMISORPTION The termination of the bulk lattice of the surface of a solid can be considered as a source of unsaturated valencies which are able to form regular chemical bonds with suitable partners arriving from the gas phase. The simplest form of the interaction potential along the surface normal (disregarding possible dissociation or the presence of an 'intrinsic' precursor state) is illustrated schematicall by fi . la, while fi . 1 b represents the periodic variation of the potential in a direction parallel to tKe su8ace due to tfe periodic arrangements of atoms in a single crystal surface. This situation resembles close1 the model underlying the derivation of the famous Langmuir adsorption isotherm: "The surface otcrystals resembles to some extent a checkerboard. When molecules of gas are adsorbed by such a surface these molecules take up definite positions with respect to the surface lattice and thus tend to form a new lattice above the old" (ref. 3).

/pdf/thermodynamics-of-gas-surface-interactions-5aunmay9wv.pdf

Gerhard Ertl

Papers

Theory of penning ionization of adsorbed Co by metastable helium (21S, 23S) beams

Surface Science and Catalysis

Cs and CO coadsorbed on Ru(0001): low-energy electron diffraction analysis

Imaging surface reactions with light

Thermodynamics of gas-surface interactions