Irina Dumitriu

The miscibility estimation of some nanocomposites based on starch

Abstract Based on the FTIR spectral changes, the miscibility of some nanocomposites based on starch, polyvinyl alcohol and treated multilayered silicate, was qualitatively estimated. The FTIR spectroscopy provide evident gross/small spectral changes as well as appreciable spectral shifts mainly in those spectral range that defines hydroxyl O-H vibrations (3600- 3000 cm-1 ), water absorbtion (1800 - 1500 cm-1) , the morphological order degree and the interaction with multilayered silicate and (1192 - 950 cm-1). Based on the observed spectral modifications it can be estimate that high miscibility do exist between the components of the studied nanocomposites.

Nanotechnology applied in archaeometry: restoration and conservation

The preservation of the cultural heritage is important for all countries, as this is a reminder of what they were once, being the most important element of identity in these modern days. The different directions and ways in which these processes are realized depend on the particular stage of development of science and technology, welfare of society, and encountered dangers of this identity. Very important objects of cultural heritage are material objects and objects of art produced by all communities. The study of nanostructured materials is considered an emerging field for the next years. To advance the field of preservation of cultural heritage science and nanostructured materials there is a continuous interdisciplinary collaboration between material science specialists and preservationists. In this work we present a complex study on the synthesis and the application of nanomaterials for the restoration and conservation of different artifacts.

Influence of the morphology of thermoplastic elastomers on the properties of bitumen composites

Bitumen properties may be successfully modified if the polymeric modifiers have the ability to control the elastic and plastic properties within wide temperature ranges of −30/−40°C to +45/+60°C. The article presents a study on the ability of two thermoplastic elastomers, thermoplastic block co-polymer styrene–styrene butadiene (SBS) and the co-polymer ethylene–vinyl acetate (EVA), to be used in obtaining polymer bitumen composites with controlled properties. The elastic and plastic properties of the bitumen composites can be more easily controlled if these composites are modified with SBS. This thermoplastic elastomer is characterized by an optimum ratio between soft domains of amorphous polybutadiene and rigid ones of those represented by the thermoplastic blocks of polystyrene.

Nano-engineered materials based on fullerenes: synthesis and biomedical applications

The nanoengineering of various materials for biomedical application has became in the last decade one of the most important research areas, due to the continuous struggle to find new and more efficient instruments for the therapy of cancer and other diseases. Attempts to obtain functionalized derivatives of fullerene seek the synthesis of watersoluble materials, in order to investigate their effects in physiological conditions. International studies on the biological properties of fullerenes and their derivatives, are now targeted towards anti-tumor effects, pharmacology and their involvement in oxidative stress. Their toxicity, demonstrated both in vitro and in vivo is important for characterization and selection of applications. Phototoxicity of some molecules of fullerenes has been identified as future therapeutic tool. The present paper describes the synthesis, characterization and some biomedical applications of some nanomaterials based on fullerenes.

New materials for water ozonization.

Application of ozone is known to yield favorable results in purification of phosphate plant water from elemental phosphorus, in treatment of water of alkali aluminate solutions of aluminum plants, in decontamination of cyanide-containing waste water of enrichment plants, and so on. It has been proved that halogen-containing compounds, most of which have mutagenic properties, and some of which are carcinogenic to humans, are formed when water is treated with chlorine. Conclusions made in a majority of studies into toxicity of ozonized natural water suggest that ozone does not increase or produce toxic effect. In some studies toxic effect is noted and attributed to ozone dose and treatment time. Increase in ozone doses reduces mutagenic activity of the treated water. In this context, of special importance is to look for and scientifically substantiate new technological solutions that would make possible more thorough purification of drinking and waste waters.

Photonic metallic nanostructures in photodynamic therapy

Plasmons are resonant modes that involve the interaction between free charges and light. Nanoparticle-based photonic explorers have been developed for photodynamic therapy (PDT). PDT has been widely used in both oncological (e.g., tumors) and nononcological (e.g., age-related macular degeneration, localized infection, and nonmalignant skin conditions) applications. Three primary components are involved in PDT: light, a photosensitizing drug, and oxygen. The photosensitizer adsorbs light energy, which it then transfers to molecular oxygen to create an activated form of oxygen called singlet oxygen. The singlet oxygen is a cytotoxic agent and reacts rapidly with cellular components to cause damage that ultimately leads to cell death and tumor destruction. The changed topography of the film surface after deposition is caused by a local material transport and a material separation between formed particles (probably AgNO3) and an embedding polymer matrix as chitosan. This paper focuses on the current use of injectable in situ Au/(Ag)/chitosan hydrogels in cancer photodynamic treatment. Formulation protocols for their cytotoxic properties, their effect on cell growth in vitro and inhibition of tumor growth in vivo using mouse models, are discussed.