<p>Stabilizatori na bazi biopolimera postaju posebno povoljna prirodna re&scaron;enja za primenu u kompleksnim sistemima, kao &scaron;to su emulzije tipa ulja u vodi. U ovoj disertaciji je ispitan individualni i kombinovani uticaj tri stabilizatora na bazi polisaharida (vlakna &scaron;ećerne repe, pektin &scaron;ećerne repe i OSA maltodekstrin) na formiranje i stabilnost emulzija kukuruznog ulja u vodi. Ispitan je uticaj četiri različite tehnike emulgovanja (ultrazvučna homogenizacija, visokopritisna homogenizacija, membransko emulgovanje i rotor-stator homogenizacija). Sveobuhvatna karakterizacija koja je obuhvatala ispitivanje fizičko-hemijskih, strukturnih, tenziometrijskih, konduktometrijskih, viskozimetrijskih osobina ispitivanih polisaharida je prikazana u ovoj disertaciji. Dobijeni rezultati veličine kapi emulzija i njihove fizičke stabilnosti ukazuju na dobra stabilizaciona svojstva ispitivanih polisaharida. Interakcije između primenjenih stabilizatora na bazi polisaharida rezultovale su značajnim promenama veličine kapi, zeta potencijala, kriming indeksa i strukture emulzije.</p> / <p>Biopolymer based stabilizers become particularly favorable natural solutions for use in complex systems, such as oil-in-water emulsions. In following dissertation, the individual and combined effects of three polysaccharide based stabilizers (sugar beet fibers, sugar beet pectin and OSA maltodextrin) on the formation and stability of corn oil emulsions in water were tested. The influence of four different emulsion techniques (ultrasonic homogenization, high-pressure homogenization, membrane emulsification and rotor-stator homogenization) were examined. A comprehensive characterization that included the examination of physico-chemical, structural, tensiometric, conductometric, viscometric characteristics of the polysaccharides examined is presented in this dissertation. The obtained results of the emulsion droplet size and their physical stability indicate good stabilization properties of the polysaccharides examined. The interactions between the applied polysaccharide-based stabilizers resulted in significant changes in the droplet size, zeta potential, creaming index and the structure of the emulsion.</p>

Scientific development requires profound understandings of micromechanical and nanomechanical systems (MEMS/NEMS) due to their applications not only in the technological world, but also for scientific understanding. At the micro- or nano-scale, when two objects are brought close together, the existence of stiction or adhesion is inevitable and plays an important role in the behavior operation of these systems. Such effects are due to surface dispersion forces, such as the van der Waals or Casimir interactions. The scientific understanding of these forces is particularly important for low-dimensional materials. In addition, the discovery of materials, such as graphitic systems has provided opportunities for new classes of devices and challenging fundermental problems. Therefore, invesigations of the van der Waals or Caismir forces in graphene-based systems, in particular, and the solution generating non-touching systems are needed. In this study, the Casimir force involving 2D graphene is investigated under various conditions. The Casimir interaction is usually studied in the framework of the Lifshitz theory. According to this theory, it is essential to know the frequency-dependent reflection coefficients of materials. Here, it is found that the graphene reflection coefficients strongly depend on the optical conductivity of graphene, which is described by the Kubo formalism. When objects are placed in vacuum, the Casimir force is attractive and leads to adhesion on the surface. We find that the Casimir repulsion can be obtained by replacing vacuum with a suitable liquid. Our studies show that bromobenzene is the liquid providing this effect. We also find that this long-range force is temperature dependent and graphene/bromobenzene/metal substrate configuration can be used to demonstrate merely thermal Casimir interaction at room temperature and micrometer distances. These findings would provide good guidance and predictions for practical studies.