COATING OF TiO2 RUTILE NANOPARTICLES IN A SUSPENSION WITH HYDRATED SiO2 AND Al2O3

The invention refers to a rapid, adaptable, manageable and reproducible approach to a synthesis of coated TiO2 nanoparticles with hydrated silicon and aluminium oxides with the use of harmless chemicals. The proposed method is based on a preparation of a well dispersed system of TiO2 nanoparticles and a controlled hydrolysis of Si02 from an alkaline precursor Na2Si03 in the presence of the mineral acid H2S04 or a hydrolysis of Al203 from an alkaline precursor of NaAlO2 in the presence of the mineral acid H2S04. The analyses have proved that the longer the coating times, the higher the SiO2 quantity and consequently the thickness of the coating. Controlled synthesis conditions were used to coat individual TiO2 nanoparticles. The mechanism of inorganic coating of TiO2 nanoparticles can be categorised as precipitation of hydrated oxides in the form of a thin layer onto already present particles (heterogeneous nucleation). The advantage of the method is its simplicity and the fact that a stable suspension of TiO2 nanoparticles is present in the whole method from the beginning to the end, which provides for healthy work conditions of industrial workers and users and also prevents negative effects on the environment (emission of nanoparticles). Izum se nanaša razvoj hitrega prilagodljivega obvladljivega in ponovljivega pristopa k sintetiziranju oplaščenih nanodelcev TiO s hidratiziranimi silicijevimi in aluminijevimi oksidi ob rabi nenevarnih kemikalij Predlagani postopek temelji na pripravi dobro dispergiranega sistema nanodelcevTiO in kontrolirani hidrolizi SiO iz alkalnega prekurzorja Na SiO ob prisotnosti mineralne kisline H SO oz na hidrolizi Al O iz alkalnega prekurzorja NaAlO ob prisotnosti mineralne kisline H SO Na podlagianaliz smo ugotovili da daljši časi oplaščevanja vplivajo na povečanje količine SiO in debeline nanosa S kontroliranimi sinteznimi pogoji sobili oplaščeni posamezni nanodelci TiO Mehanizem anorganskega oplaščevanja nanodelcev TiO lahko kategoriziramo kot izobarjanje hidratiziranih oksidov v obliki tankih plasti na že prisotne delce heterogena nukleacija Prednost postopka je vnjegovi enostavnosti in v tem da je v celotnem postopku od začetka do konca prisotna stabilna suspenzija nanodelcev TiOkar omogoča zdrave pogoje dela zaposlenih pri proizvodnji in uporabi ter preprečuje negativne vplive na okolje emisija nano delcev