The area of colloidal photonic crystal research has attracted enormous attention in recent years as a result of the potential of such materials to provide the means of fabricating new or improved photonic devices. As an area where chemistry still predominates over engineering the field is still in its infancy in terms of finding real applications being limited by ease of fabrication, reproducibility and 'quality'- for example the extent to which ordered structures may be prepared over large areas. It is our contention that the Langmuir-Blodgett assembly method when applied to colloidal particles of silica and perhaps other materials, offers a way of overcoming these issues. To this end the assembly of silica and other particles into colloidal photonic crystals using the Langmuir-Blodgett (LB) method is described and some of the numerous papers on this topic, which have been published, are reviewed. It is shown that the layer-by-layer control of photonic crystal growth afforded by the LB method allows for the fabrication of a range of novel, layered photonic crystals that may not be easily assembled using any other approach. Some of the more interesting of these structures, including so-called heterostructured photonic crystals comprising of layers of spheres having different diameters are presented and their optical properties described. Finally, we offer our comments as to future applications of this interesting technology.

A simple, versatile method for non‐covalent functionalization of graphene based on solution‐phase assembly of alkane‐amine layers is presented. Second‐order Møller–Plesset (MP2) perturbation theory on a cluster model (methylamine on pyrene) yields a binding energy of ≈220 meV for the amine–graphene interaction, which is strong enough to enable formation of a stable aminodecane layer at room temperature. Atomistic molecular dynamics simulations on an assembly of 1‐aminodecane molecules indicate that a self‐assembled monolayer can form, with the alkane chains oriented perpendicular to the graphene basal plane. The calculated monolayer height (≈1.7 nm) is in good agreement with atomic force microscopy data acquired for graphene functionalized with 1‐aminodecane, which yield a continuous layer with mean thickness ≈1.7 nm, albeit with some island defects. Raman data also confirm that self‐assembly of alkane‐amines is a non‐covalent process, i.e., it does not perturb the sp2 hybridization of the graphene. Passivation and adsorbate n‐doping of graphene field‐effect devices using 1‐aminodecane, as well as high‐density binding of plasmonic metal nanoparticles and seeded atomic layer deposition of inorganic dielectrics using 1,10‐diaminodecane are also reported.

Abstract. This paper describes a broadband cavity ringdown spectrometer and its deployment during the 2002 North Atlantic Marine Boundary Layer Experiment (NAMBLEX) to measure ambient concentrations of NO 3 , N 2 O 5 , I 2 and OIO at the Mace Head Atmospheric Research Station, Co. Galway, Ireland. The effective absorption path lengths accessible with the spectrometer generally exceeded 10 km, enabling sensitive localised "point" measurements of atmospheric absorbers to be made adjacent to the other instruments monitoring chemically related species at the same site. For the majority of observations, the spectrometer was used in an open path configuration thereby avoiding surface losses of reactive species. A subset of observations targeted the N 2 O 5 molecule by detecting the additional NO 3 formed by the thermal dissociation of N 2 O 5 . In all cases the concentrations of the atmospheric absorbers were retrieved by fitting the differential structure in the broadband cavity ringdown spectra using a methodology adapted from long path differential optical absorption spectroscopy. The uncertainty of the retrieval depends crucially on the correct treatment and fitting of the absorption bands due to water vapour, a topic that is discussed in the context of analysing broadband cavity ringdown spectra. The quality of the measurements and the retrieval method are illustrated with representative spectra acquired during NAMBLEX in spectral regions around 660 nm (NO 3 and N 2 O 5 ) and 570 nm (I 2 and OIO). Typical detection limits were 1 pptv for NO 3 in an integration time of 100 s, 4 pptv for OIO and 20 pptv for I 2 in an integration time of 10 min. Additionally, the concentrations of atmospheric water vapour and the aerosol optical extinction were retrieved in both spectral regions. A companion paper in this issue presents the time series of the measurements and discusses their significance for understanding the variability of short lived nitrogen and iodine compounds in the marine boundary layer.

Brammertz, G.; Heyns, M.; Newcomb, Simon B.; Afanas'ev, V. V.;Hurley, Paul K.

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