Structure of polyaniline formed in different inorganic porous materials: A spectroscopic study

In this work, the electronic and structural characterization of polyaniline (PANI) formed in cavities of zeolites Y (ZY) and Mordenite (MOR) and montmorillonite (MMT) clay having Cu(II) as oxidant agent are presented. The formation of PANI and its structure is analyzed by Resonance Raman, UV-Vis-NIR, FT-IR and N K XANES techniques. In all cases the structure of PANT formed is different from the ""free"" polymer. The presence of azo bonds linked to phenazine-like rings are observed only for PANI-MMT composites, independent of the kind of oxidant agent employed in the synthesis. The presence of Cu(II) ions leads to the formation of Phenosafranine-like rings. The presence of these phenazine-like rings in the structure of confined PANT chains can also contribute to the enhancement of the thermal stability observed for all composites. (C) 2008 Elsevier Ltd. All rights reserved.

Supramolecular Approach to Gold Nanoparticle/Triruthenium Cluster Hybrid Materials and Interfaces

A systematic and comprehensive study of the interaction of citrate-stabilized gold nanoparticles with triruthenium cluster complexes of general formula [Ru(3)(CH(3)COO)(6)(L)](+) [L = 4-cyanopyridine (4-CNpy), 4,4`-bipyridine (4,4`-bpy) or 4,4`-bis(pyridyl)ethylene (bpe)] has been carried out. The cluster-nanoparticle interaction in solution and the construction of thin films of the hybrid materials were investigated in detail by electronic and surface plasmon resonance (SPR) spectroscopy, Raman scattering spectroscopy and scanning electron microscopy (SEM). Citrate-stabilized gold nanoparticles readily interacted with [Ru(3)O(CH(3)COO)(6)(L)(3)](+) complexes to generate functionalized nanoparticles that tend to aggregate according to rates and extents that depend on the bond strength defined by the characteristics of the cluster L ligands following the sequence bpe > 4,4`-bpy >> 4-CNpy. The formation of compact thin films of hybrid AuNP/[Ru(3)O(CH(3)COO)(6)(L)(3)](+) derivatives with L = bpe and 4,4`-bpy indicated that the stability/lability of AuNP-cluster bonds as well as their solubility are important parameters that influence the film contruction process. Fluorine-doped tin oxide electrodes modified with thin films of these nanomaterials exhibited similar electrocatalytic activity but much higher sensitivity than a conventional gold electrode in the oxidation of nitrite ion to nitrate depending on the bridging cluster complex, demonstrating the high potential for the development of amperometric sensors.

Automatic devices for monitoring environmentally induced auto-oxidative degradation of artistic materials in conservation sites

This paper describes an automatic device for in situ and continuous monitoring of the ageing process occurring in natural and synthetic resins widely used in art and in the conservation and restoration of cultural artefacts. The results of tests carried out under accelerated ageing conditions are also presented. This easy-to-assemble palm-top device, essentially consists of oscillators based on quartz crystal resonators coated with films of the organic materials whose response to environmental stress is to be addressed. The device contains a microcontroller which selects at pre-defined time intervals the oscillators and records and stores their oscillation frequency. The ageing of the coatings, caused by the environmental stress and resulting in a shift in the oscillation frequency of the modified crystals, can be straightforwardly monitored in this way. The kinetics of this process reflects the level of risk damage associated with a specific microenvironment. In this case, natural and artificial resins, broadly employed in art and restoration of artistic and archaeological artefacts (dammar and Paraloid B72), were applied onto the crystals. The environmental stress was represented by visible and UV radiation, since the chosen materials are known to be photochemically active, to different extents. In the case of dammar, the results obtained are consistent with previous data obtained using a bench-top equipment by impedance analysis through discrete measurements and confirm that the ageing of this material is reflected in the gravimetric response of the modified quartz crystals. As for Paraloid B72, the outcome of the assays indicates that the resin is resistant to visible light, but is very sensitive to UV irradiation. The use of a continuous monitoring system, apart from being obviously more practical, is essential to identify short-term (i.e. reversible) events, like water vapour adsorption/desorption processes, and to highlight ageing trends or sudden changes of such trends. (C) 2007 Elsevier B.V. All rights reserved.

Self-reinforced composites obtained by the partial oxypropylation of cellulose fibers. 1. Characterization of the materials obtained with different types of fibers

The in-depth oxypropylation of different types of cellulose fibers, namely Avicel, Rayon, Kraft, and Filter Paper, was investigated. New biphasic mono-component materials were obtained, which could be hot-pressed to form films of cellulose fibers dispersed into a thermoplastic matrix. The success of this chemical modification was assessed by FTIR spectroscopy, X-ray diffraction, scanning electron microscopy. differential scanning calorimetry, thermogravimetric analysis and contact angle measurements. The optimization of this process led to the establishment of the optimal molar ratio between the cellulose CH groups and propylene oxide, which varied as a function of the specific morphology of the fibers. (C) 2008 Elsevier Ltd. All rights reserved.

SnO(2)-based materials for pesticide degradation

This study presents the results of the degradation of the pesticide atrazine using electrochemical and photo-assisted electrochemical degradation techniques using SnO(2)-containing electrode of nominal composition electrodes of composition Ti/Ru(x)Sni-(x)O(2) (where X = 0.10, 0.15, 0.20, 0.25 and 0.30). The materials were characterized ex situ and in situ in order to correlate the observed atrazine removal rates with electrode morphology/composition. The results obtained demonstrate the effectiveness of the photo-assisted electrochemical degradation. Using purely electrochemical methods the rate of atrazine removal is almost zero at all the electrodes studied. However, the application of photo-assisted degradation results in almost complete atrazine removal in 1 h of electrolysis. The efficiency of atrazine degradation does not seem to be greatly affected by the electrode material or by SnO(2) content, but the overall COD removal is dependent on the SnO(2) content. Overall, the SnO(2)-containing electrodes do not reach the level of COD removal (maximum similar to 21%) seen for the Ti/Ru(0.3)Ti(0.2)O(2) electrode. An interesting correlation between the morphology factor (phi) and chemical oxygen demand removal is observed. (C) 2010 Elsevier B.V. All rights reserved.

Evaluation of galling resistance for some selected combinations of tool steels/stainless steel sheet materials/lubricants using pin-on-disc testing

Stainless steels are well known to be prone to cold welding and material transfer in sliding contacts and therefore difficult to cold form unless certain precautions as discussed in this paper are taken. In the present study different combinations of tool steels/stainless steels/lubricants has been evaluated with respect to their galling resistance using pin-on-disc testing. The results show that a high galling resistance is favored by a high stainless steel sheet hardness and a blasted stainless steel sheet surface topography. The effect of type of lubricant was found to be more complex. For example, the chlorinated lubricants failed to prevent metal-to-metal contact on a brushed sheet surface but succeeded on a blasted sheet surface of the same stainless steel material. This is believed to be due to a protective tribofilm which is able to form on the blasted surface, but not on the brushed surface.

An investigation of worn work roll materials used in the finishing stands of the hot strip mill for steel rolling

The surface failure characteristics of different work roll materials, i.e. High Speed Steel, High Chromium Iron and Indefinite Chill Iron, used in the finishing stands of a hot strip mill have been investigated using stereo microscopy, 3D optical profilometry, scanning electron microscopy and energy dispersive X-ray spectroscopy. The results show that the surface failure mechanisms of work rolls for hot rolling are very complex, involving plastic deformation, abrasive wear, adhesive wear, mechanical and thermal induced cracking, material transfer and oxidation. Despite the differences in chemical composition and microstructure, the tribological response of the different work roll materials was found to be strongly dependent on the material microstructure and especially the presence and distribution of microstructural constituents, such as the different carbide phases and graphite (in the case of Indefinite Chill Iron). Cracking and chipping of the work roll surfaces, both having a negative impact on work roll wear, are strongly influenced by the presence of carbides, carbide networks and graphite in the work roll surface. Consequently, the amount of carbide forming elements as well as the manufacturing process must be controlled in order to obtain an optimised microstructure and a predictable wear rate.

Final report on heat pump developments in WP 4 - MacSheep Deliverable 4.4 : MacSheep -New Materials and Control for a next generation of compact combined Solar and heat pump systems with boosted energetic and exergetic performance

FP7- MacSheep

Perceptions of Sustainability and Functional Aspects on Liquid Carton Board Packaging Materials versus Competing Materials for Juice Applications in Sweden

This research explores the downstream perceptions of liquid carton board versus competing materials in packaging applications for juice. The methodology used is focus groups. The context is sustainability and functional performance, and related potential implications for the beverage industry value chain. The purpose is to get a deeper insight and understanding of functionality in relation to juice beverage packaging. The results confirm that there is no optimal packaging for every juice product, but a multitude, depending on the distribution channel, retail outlet, customer preferences, and context of consumption. There are some general packaging preferences, but the main deciding criteria for purchase seem to be the product characteristics in terms of quality, taste, brand, price and shelf life. For marketing reasons, packaging has to be adopted to the product and its positioning, liquid carton board packaging seem to have some functional advantages in distribution and is considered as sustainable and functional among many consumers. Major drawbacks seem to be shape limitations, lack of transparency, and lack of a “premium look”. To improve packaging performance and avoid sub-optimization, actors in the beverage industry value chain need to be integrated in development processes.

Materials Collection Creation and Administration: A New Role for Libraries (White Paper)

The Problem/Opportunity: To define, identify, and guide design-based materials collections in academic settings and foster community among those with existing collections and/or those considering creating and supporting one. Contents and topics: What is a materials collection? Why have a materials collection? Acquisition strategies Organizational approaches Programming possibilities Symposium summary Resources