Fourier transform Infrared (FTIR) spectroscopy is a versatile technique for the characterization of materials belonging to the carbon family. Based on the interaction of the IR radiation with matter this technique may be used for the identification and characterization of chemical structures. Most important features of this method are: non-destructive, real-time measurement and relatively easy to use. Carbon basis for all living systems has found numerous industrial applications from carbon coatings (i.e. amorphous and nanocrystalline carbon films: diamond-like carbon (DLC) films) to nanostructured materials (fullerenes, nanotubes, graphene) and carbon materials at nanoscale or carbon dots (CDots). In this paper, we present the FTIR vibrational spectroscopy for the characterization of diamond, amorphous carbon, graphite, graphene, carbon nanotubes (CNTs), fullerene and carbon quantum dots (CQDs), without claiming to cover entire field.

The introduction of inorganic nanomaterials into polymer matrix has resulted in polymer nanostructured materials exhibiting multi-functional, high performance polymer characteristics beyond what traditional polymer composites possess. Multi-functional features attributable to polymer nanocomposites consist of improved moisture resistance, antibacterial and fungal properties. Zinc oxide powders was prepared via coprecipitation and used as inorganic materials; polyvinylalcohole was used as polymer matrix. The technical approach involves the introduction of nanoparticles into polymer matrix whereby nanoparticles has antibacterial characteristics and enhanced inclusion into the polymer matrix. The objectives of this paper are to summarize our research activities in: (a) developing processes to disperse nanomaterials (undoped and doped zinc oxide powders) in the polymers matrix, (b) using optical microscopy and scanning electron microscopy (SEM) techniques to characterize polymer matrix structures, (c) studying structure-property relationship of these types of new materials, and (d) evaluating the antibacterial performance of these materials for different applications. The results also show that the ZnO nanoparticles were uniformly dispersed in the polymer matrix and the particles remained their original size (20 -150 nm) before incorporation into the polymer matrix.

Metastasis is the main cause of death in cancer patients worldwide. During metastasis, cancer cells detach from the primary tumor and invade distant tissue. The cells that undergo this process are called circulating tumor cells (CTCs). Studies show that the number of CTCs in the peripheral blood can predict progression-free survival and overall survival and can be informative concerning the efficacy of treatment. Research is now concentrated on developing devices that can detect CTCs in the blood of cancer patients with improved sensitivity and specificity that can lead to improved clinical evaluation. This review focuses on devices that detect and capture CTCs using different cell properties (surface markers, size, deformability, electrical properties, etc.). We also discuss the process of tumor cell dissemination, the biology of CTCs, epithelial-mesenchymal transition (EMT), and several challenges and clinical applications of CTC detection.

Worldwide commercial interest in the production of cerium doped yttrium aluminium garnet (YAG:Ce) phosphors is reflected in the widespread use of white light emitting devices. Despite of the fact that YAG:Ce is considered a “cool phosphor” it is the most important in white LED technology. This article reviews the developed techniques for producing phosphors with superior photoluminescence efficiency, including solid-state reaction, sol-gel and (co)precipitation methods. Also, by co-doping with rare earth elements, a red/blue shift is reached in the spectrum. The characteristics of YAG:Ce phosphors are investigated because the properties of the phosphors are strongly influenced by the synthesis routes and the sintering temperature treatment. After the phase analysis, morphology and emission studies of the phosphors there may be seen the conditions when the transition from the amorphous phase to the crystalline phase appears, when luminescent properties are influenced by the crystalline form, purity, average size of the particles, co-doping and so on.

A sol-gel method was developed to obtain cerium-, gadolinium-(co)activated yttrium aluminum garnet (YAG:Ce,Gd) phosphor. The composite was obtained by incorporating YAG:Ce,Gd powder in poly(methyl methacrylate) (PMMA) matrix in the presence of tetrahydrofuran (THF). Sample characterization was performed using Fourier transform infrared spectrometry, X-ray diffraction, energy dispersive X-ray spectroscopy, field emission scanning electron microscopy, and fluorescence spectroscopy. Results showed a garnet pure phase at 1000 C, a nanoscale phosphor with spherical morphology and a good dispersion in PMMA matrix without structural modification of YAG:Ce,Gd in the composite. This type of phosphor can be used for all commercial blue chips and YAG:Ce,Gd/PMMA composite is a good candidate for white light-emitting devices.

No abstract

No abstract

No abstract