No abstract

-The aim of research is to develop an area of nanoporous ceramics of ternary systems. Nanoporous ceramic system SiO2-TiO2-ZrO2 has been synthesized via sol-gel technology by hydrolysis of tetraethylorthosilicate (TEOS), zirconia and titanium alcoxides solutions. The sols have been polymerized at room temperature to obtain gels and dried at 100 o C, then milled for 1 or 6 hours for particle homogenization, pressed into samples, and then sintered at 800 o C or 1000 o C in air. The samples have been characterized by XRD, particle size distribution, crystallite size distribution, compressive strength. Porosity of ceramic samples has been determined by nitrogen adsorption-desorption isotherms.

Būvniecībā kopš seniem laikiem izmanto neorganiskās saistvielas. Materiāli kultūrvēsturiskajos un mākslas pieminekļos pastāvīgi tiek pakļauti struktūras sairšanas procesiem, kurus paātrina arvien pieaugošais vides piesārņojums. Autotransporta dūmgāzes gaisā izdala NxOy, SO2, CO un CO2, kas saistās ar gaisa mitrumu un veido skābos lietus. Tie kopā ar putekļiem un sodrējiem nonāk uz mūrējumu virsmas, veidojot blīvu slāni. Rezultātā sākas ķīmiski korozijas procesi, veidojoties ūdenī šķīstošiem sāļiem (visbiežāk – nātrija, kālija, kalcija un magnija sulfāti). Atmosfēras mitruma svārstību un žūšanas procesu rezultātā šie sāļi kristalizējas un izraisa mūrējuma sairšanu, ko veicina bioloģiskā un fizikālā korozija.Pirmie pētījumi par mūrējumu un dabīgo akmens materiālu  koroziju  Latvijā  sākti 1984. g. RTU Silikātu tehnoloģijas katedrā. 1995. g. RTU Silikātu materiālu institūtā tika nodibināts Akmens materiālu konservācijas un restaurācijas centrs (AMKRC). Tā darbības pamatā ir kultūrvēsturisko pieminekļu zinātniskā analīze – korodējošo materiālu sastāva, struktūras, fizikālo un mehānisko īpašību izpēte.In restoration of the masonry, it is important to maintain its original composition and appearance by matching historical materials with appropriate material which is consistent both visually and in accordance with physical and chemical properties. Materials of historic-cultural and artistic monuments are constantly exposed to disintegration processes which are accelerated by ever- increasing environmental pollution (NxOy, SO2, CO and CO2). This environmental pollution reacts with moisture from air and causes acid rain. As a result, water- soluble salts (most commonly sodium, potassium and magnesium sulphates, and gypsum) are formed, causing the chemical corrosion of the masonry, which can cause its disintegration.The earliest research on corrosion of  masonry and  of  natural stone  materials  in Latvia was conducted in 1984 at the Department of Silicate Technologies, Riga Technical University. In 1995 the Center for Conservation and Restoration of Stone Materials was established at the Institute of Silicate Materials, Riga Technical University. Research by the Center includes scientific analyses of cultural-historical monuments – the study of the composition, structure, physical, and mechanical properties of corroding materials.