The study of the properties of the hydroxyapatite/electrolyte interface
A physicochemical property of hydroxyapatite (HAP) [Ca10(OH)2(PO4)6] surface was studied and parameters of electrical double layer of the hydroxyapatite/NaCl solution system were described. The study sample of hydroxyapatite was synthesized. The structure of the hydroxyapatite was confirmed using X-ray diffraction (XRD), its particle size by PCS (photon correlation spectroscopy) AFM and SCM microscope and its surface properties by means of adsorption-desorption of nitrogen (ASAP), Raman spectra,. Then the point of zero charge and the isoelectirc point were measured.
J. Reszczyńska, A. Jurek, I. Łącka, E. Skwarek and A. Zaleska
Preparation of Silver Nanoparticles in Reverse Micelles and Antibacterial Activity of Silver Modified-Paints
Silver particles having fine or ultrafine sizes are one of the fastest growing research interests with wide applications. Here we report the preparation method of silver modified paints which revealed antimicrobial activity against gram-negative bacteria Escherichia coli, gram-positive Staphylococcus aureus, yeast Saccharomyces cerevisiae and pathogenic fungi belonging to Candida family. In this work, we choose heptane and cyclohexane, as the oil phase for preparation nanometer sized metallic particles. We have also studied the effect of different silver precursors - silver nitrate, silver citrate and different surfactants: anionic AOT, non-ionic Triton X100, Span 80 and Tween 85 for stabilization of obtained silver colloids. UV-VIS spectrum contained a strong plasmon band near 410 nm, which confirmed silver ions reduction to Ag○ in microemulsion system or aqueous phases. Prepared samples contained from 500 to 2000 ppm of silver. The diameter size of silver nanoparticles was in the range from 16 nm to 82 nm and were stable for 3 months without precipitation.