Puranity tu 3 uv uf system

Magnesium(II) nitrate hexahydrate (Mg(NO₃)₂·6H₂O), aluminum(III) nitrate nonahydrate (Al(NO₃)₃·9H₂O), ellagic acid (EA), 4 M sodium hydroxide solution (NaOH), 1 M hydrochloric acid (HCl), ammonium acetate (NH₄OAc), 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), copper(II) chloride dihydrate (CuCl₂·2H₂O), neocuproine (Nc), Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid), methanol (MeOH), ethanol (EtOH), acetone (AC), acetonitrile (ACN), formamide (FA), N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) were all purchased from VWR International (Radnor, Pennsylvania, USA) in analytical purity and were used as received. Purified water was produced by reverse osmosis and UV irradiation (VWR Puranity TU 3+ UV/UF system from VWR International).

All samples were made by using deionized water, which was produced by reverse osmosis and was further purified by UV irradiation, using a Puranity TU3 UV/UF+ system (VWR). Furthermore, samples were always freshly prepared before tensiometric and dynamic light scattering (DLS) measurements, since long-term aggregation of micelles or particle cohesion may alter the samples properties significantly.
First, solution with an appropriate concentration of Ca²⁺-ion (0.01–5.00 g L^–1) was prepared from CaCl_2∙2H₂O. This solution was then filled into a volumetric flask containing the necessary amount of solid NaLAS. The thus-obtained aqueous mixtures (c_NaLAS = 0.05–5.00 g L^–1) were stirred for 24 h at room temperature. To avoid the incidental adsorption of either Na⁺, Ca²⁺, Cl^–, or LAS^– ions onto the glass surface of the flask, plastic vessels were used to store all colloidal solutions and filtrates. In case of precipitate formation, the samples were filtered, washed with 20 mL water, and dried. In addition, several precipitates were calcined at 900 °C for 24 h or at 1000 °C for 16 h under air in a Nabertherm L9 furnace (Lilienthal, Germany).