Lanthanide-based luminescent hybrid materials.

Organic–inorganic hybrid materials do not represent only a creative alternative to design new materials and compounds for academic research, but their improved or unusual features allow the development of innovative industrial applications. Nowadays, most of the hybrid materials that have already entered the market are synthesised and processed by using conventional soft chemistry based routes developed in the eighties. These processes are based on: a) the copolymerisation of functional organosilanes, macromonomers, and metal alkoxides, b) the encapsulation of organic components within sol–gel derived silica or metallic oxides, c) the organic functionalisation of nanofillers, nanoclays or other compounds with lamellar structures, etc. The chemical strategies (self-assembly, nanobuilding block approaches, hybrid MOF (Metal Organic Frameworks), integrative synthesis, coupled processes, bio-inspired strategies, etc.) offered nowadays by academic research allow, through an intelligent tuned coding, the development of a new vectorial chemistry, able to direct the assembling of a large variety of structurally well defined nano-objects into complex hybrid architectures hierarchically organised in terms of structure and functions. Looking to the future, there is no doubt that these new generations of hybrid materials, born from the very fruitful activities in this research field, will open a land of promising applications in many areas: optics, electronics, ionics, mechanics, energy, environment, biology, medicine for example as membranes and separation devices, functional smart coatings, fuel and solar cells, catalysts, sensors, etc.

Applications of hybrid organic–inorganic nanocomposites

A surface science perspective on TiO2 photocatalysis

Controlled release of food ingredients at the right place and the right time is a key functionality that can be provided by microencapsulation A timely and targeted release improves the effectiveness of food additives, broadens the application range of food ingredients and ensures optimal dosage, thereby improving cost-effectiveness for the food manufacturer Reactive, sensitive or volatile additives (vitamins, cultures, flavors, etc) can be turned into stable ingredients through microencapsulation With carefully fine-tuned controlled release properties, microencapsulation is no longer just an added value technique, but the source of totally new ingredients with matchless properties

Microencapsulation: industrial appraisal of existing technologies and trends

Platinum-based nanostructured materials: synthesis, properties, and applications.

Samples of red mud, by-products of alumina production from bauxite, are studied in the 120–1400°C interval. An extensive characterization was performed by thermal and X-ray diffraction analyses. The identification of gaseous species released upon heating was carried out by coupling the thermal analizer with a gas-chromatographic/mass spectrometer. Density evolution was also determined as a function of the heat treatment. Results indicate primary H2O release from aluminium hydroxides, followed by carbonate decomposition with CO2 evolution below 900°C. Alkaline oxides, mainly CaO and Na2O, lead to the formation of Ca3Al2O6 and NaAlSiO4 between 900 and 1100°C. At the highest temperatures, reduction of Fe3+ to Fe2+, involving O2 release, promotes the formation of Fe2TiO4, with the disappearance of the rutile-TiO2 phase. The various solid state reactions, ascertained at different stages of the heating process, and possible mass balances are discussed with reference to the state diagrams of principal red mud components.

Bauxite ‘red mud’ in the ceramic industry. Part 1: thermal behaviour

Some potential uses of red mud as a raw component in clay mixtures for ceramic bodies production are presented. The influence of increasing amounts of red mud on the forming procedure, sintering and final properties was analyzed. Samples were produced by uniaxial pressing and slip casting. Two different clays are used as basic materials, the former being currently employed for the production of bricks by extrusion, the second — almost pure Kaolin — for high quality ceramic manufacturing. In both cases the addition of red mud led to more deflocculated solid–water systems and an increase of the critical moisture content. Mixtures prepared with the first clay and red mud loads up to 50% were fired at 850°C. The red mud content did not influence the sample porosity while determining a strength decrease attributed to the inertness of red mud at the working temperature. Samples produced using the second clay and red mud (0 – 20%) were fired at 950 and 1050°C. The addition of red mud determined increases of density and flexural strength which can be accounted for by the formation of a larger amount of glassy phase at higher red mud contents. The results of this work indicate excellent perspectives for using ‘red mud’ as raw material in mixtures with clay for the production of ceramic bodies.

Bauxite ‘red mud’ in the ceramic industry. Part 2: production of clay-based ceramics

A picoscale catalyst for hydrogen generation from NaBH4 for fuel cells

This paper compares the luminescence spectra of Eu3+ in sol-gel derived silica samples heated at different temperatures, following the densification process from wet gel to compact silica glass Lifetimes, linewidths, and Stark splittings of the transitions were used to study the structural evolution of the gel network

Luminescence of Eu3+ ions during thermal densification of SiO2 gel

Inorganic gels for immobilization of biocatalysts: inclusion of invertase-active whole cells of yeast (saccharomyces cerevisiae) into thin layers of SiO2 gel deposited on glass sheets

Giovanni Carturan

Papers

Bauxite ‘red mud’ in the ceramic industry. Part 1: thermal behaviour

Bauxite ‘red mud’ in the ceramic industry. Part 2: production of clay-based ceramics

A picoscale catalyst for hydrogen generation from NaBH4 for fuel cells

Luminescence of Eu3+ ions during thermal densification of SiO2 gel

Inorganic gels for immobilization of biocatalysts: inclusion of invertase-active whole cells of yeast (saccharomyces cerevisiae) into thin layers of SiO2 gel deposited on glass sheets