CEMENT MORTARS WITH NANOSTRUCTURED ZINC OXIDE/TITANIUM OXIDE POWDERS WITH ANTIBACTERIAL AND SELF-CLEANING PROPERTIES

The invention relates to a process for preparing a cement mortar additivated with nanostructured powders based on zinc oxide/titanium oxide with self-cleaning and antibacterial properties to be used inside public buildings, such as schools, hospitals, public organizations for inhibiting the development of bacteria and molds. According to the invention, the process for preparing the mortar has the following steps: a. preparation of a zinc oxide/titanium oxide powder by hydrothermal synthesis, at a pressure ranging between 100...120 at, at a temperature of 200°C, for 2 h, using aqueous solutions of zinc nitrate hexahydrate Zn(NO3)2*6H2O and titanium oxychloride TiO2Cl2 as reaction precursors, which precipitate with ammonia solution NH3 25% up to a pH=9, the precursor amounts being calculated depending on the desired final ratio ZnO:TiO2 which can be 95 : 5, 90 : 10 or 85 : 15, as well as depending on the amount of powder desired to be obtained from the synthesis, namely 40 g or 50 g; b. preparation of the cement mortar with nanostructured powder of zinc oxide/titanium oxide by mixing the cement CEM I with sand and superplasticizer (CONPAC 149 per 100 g of cement) and nanomaterial powder in a mass percent ratio of 25 : 75 : 0.05 : 5 (or 10), the amount of nanomaterial powder being expressed in relation with the cement mass. Invenţia se referă la un procedeu de obţinere a unui mortar de ciment aditivat cu pulberi nanostructurate pe bază de oxid de zinc/oxid de titan cu proprietăţi de autocurăţare şi antibacteriene care poate fi utilizat la interiorul unor clădiri publice precum şcoli, spitale, instituţii publice cu rol de inhibare a dezvoltarii bacteriilor şi a mucegaiurilor. Procedeul de obţinere a mortarului conform invenţiei are următoarele etape:a) obţinerea pulberii de oxid de zinc/oxid de titan prin sinteză hidrotermală la o presiune cuprinsă între 100...120 atm., la o temperatură de 200°C, timp de 2 h, utilizându-se ca precursori de reacţie soluţii apoase de azotat de zinc hexahidratat Zn(NO3)2*6H2O şi oxiclorură de titan TiO2Cl2, care se precipită cu soluţie de amoniac NH3 25%, până la un pH = 9, cantităţile de precursori calculându-se în funcţie de raportul ZnO : TiO2 final dorit care poate fi 95 : 5, 90 : 10 sau 85 : 15, precum şi funcţie de cantitatea de pulbere pe care dorim săo obţinem în urma sintezei, respectiv 40 g. sau 50 g.,b) obţinerea mortarului de ciment cu pulbere nanostructurată de oxid de zinc/oxid de titan se face prin amestecarea cime