RESUMO
The transport of intensity equation (TIE) technique is used to investigate the effect of stretching and annealing conditions on the optical features and antimicrobial activity of polyethylene terephthalate (PET) fibers treated with TiO2 nanoparticles. The main core of this paper gets the most preferable optical and mechanical properties for PET/TiO2 fiber which maintains its antibacterial activity. The variation of the refractive index of untreated PET/TiO2 fiber along its axis is studied. The computed tomography technique is used to investigate the morphology of the tested fiber and the distribution of TiO2 nanoparticles inside the fiber. The effect of stretching on the refractive index and the density of TiO2 nanoparticles of drawn PET/TiO2 fibers are carried out. The antimicrobial activity of the PET/TiO2 fibers are evaluated before and after stretching. The PET/TiO2 fibers are annealed at different temperatures and durations. The influence of annealing on the variation of the refractive index of PET/TiO2 fiber along its axis and the distribution of TiO2 is investigated.
RESUMO
A modified method was suggested to improve the performance of the Pluta microscope in its nonduplicated mode in the calculation of the areal craze density especially, for relatively low draw ratio (low areal craze density). This method decreases the error that is resulted from the similarity between the formed crazes and the dark fringes of the interference pattern. Furthermore, an accurate method to calculate the birefringence and the orientation function of the drawn fibers via nonduplicated Pluta polarizing interference microscope for high areal craze density (high draw ratio) was suggested. The advantage of the suggested method is to relate the optomechanical properties of the tested fiber with the areal craze density, for the same region of the fiber material.
