20.500.12556/RUL-161289 Metode za merjenje površinske napetosti tekočin Methods of measuring surface tension of liquids Diplomsko delo opisuje principe najpogosteje uporabljenih metod za določanje površinske napetosti tekočin. Najbolj neposredna metoda je tenziometrična metoda, kjer se meri sila, ki je potrebna, da se s fazne meje tekočina-zrak odtrga na fazni meji ležeč in geometrijsko dobro definiran testni element (du Noüyev obroček, Wilhelmyjeva ploščica ali platinska paličica). Instrumenti, ki uporabljajo to metodo, se med seboj ločijo po stopnji avtomatizacije meritve (ročni instrumenti ali samodejni instrumenti) in po kriteriju, kdaj je izmerjena sila merodajna za meritev. Pri tej metodi smo med seboj primerjali meritve na ročnem tenziometru K6, starejšem samodejnem tenziometru K10 ST ter sodobnem samodejnem tenziometru Tensíío. Drugi in tretji instrument se med seboj razlikujeta po hitrosti in natančnosti opravljenih meritev, ter po kriteriju, kdaj je izmerjena sila merodajna za meritev, pri tem pa novejši instrument daje bolj točne in natančne rezultate. Površinsko napetost smo izmerili vodi iz destilatorja, 2 M mešanicam vodnih raztopin soli NaBr in KF ter nekaterim hidrofobnim globoko evtektičnim topilom. Ugotovili smo, da na izmerjeno površinsko napetost vplivajo različni dejavniki, kot so temperatura (višja kot je temperatura, nižja je površinska napetost), mehanski vplivi (hoja oziroma tresljaji v okolici instrumenta), zakrivljenost in siceršnja poškodovanost testnih elementov, uspešnost kalibracije in natančnost instrumentov, uporabljen volumen tekočine, kontaminacija testnih elementov ter seveda lastnosti merjene tekočine. This thesis describes the principles of the most commonly used methods for determining the surface tension of liquids. The most direct method is the tensiometric method, which measures the force required to detach a geometrically well-defined test element (du Noüy ring, Wilhelmy plate or platinum rod) from a liquid-air phase boundary. The instruments using this method are distinguished by the degree of automation of the measurement (manual instruments or automatic instruments) and by the criteria for when the measured force is relevant to the measurement. In this method, measurements on a manual tensiometer K6, an older automatic tensiometer K10 ST and a modern automatic tensiometer Tensíío were compared with each other. The second and third instruments differ by the speed and accuracy of the measurements made and by the criteria for when the measured force is relevant to the measurement, with the newer instrument giving more accurate and precise results. Surface tension was measured on distilled water, 2 M aqueous mixtures of NaBr and KF salt solutions and some hydrophobic deep eutectic solvents. We found that the measured surface tension is affected by various factors such as temperature (the higher the temperature, the lower the surface tension), mechanical effects (walking or vibrations around the instrument), mechanical deformation and other damage of the test elements, calibration efficiency and accuracy of the instruments, the volume of liquid used, contamination of the test elements and finally the properties of the liquid being measured. površinska napetost tenziometrične meritve vplivi dejavnikov surface tension tensiometer measurements factor influence true false false Slovenski jezik Angleški jezik Diplomsko delo/naloga 2024-09-09 11:00:00 2024-09-09 11:00:14 2024-11-07 12:37:27 0000-00-00 00:00:00 2024 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 23097 214057475 Saje_Urska_-_Metode_za_merjenje_povrsinske_napetosti_tekocin.pdf Saje_Urska_-_Metode_za_merjenje_povrsinske_napetosti_tekocin.pdf 1 F0577F145A0555F2FD50846DCC662C45 c15718ee4d1048e864d8dfffb978116c4f03f3a8bc2daa1b9ba56ef4139bc42a e64f1a50-6e89-11ef-b232-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=190186 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0