Louis, MO, USA), sodium silicate solution (8% Na2O, 27% SiO2; Merck & Co., Inc., Whitehouse Station, NJ, USA), H2SO4 (97%; Merck & Co., Inc., Whitehouse Station, NJ, USA), and distilled water. Typically, CTABr (5.772 g) was first dissolved in a 125-mL polypropylene bottle containing distilled water (79.916 g) under stirring (Figure  1). Sodium silicate (21.206 g) was then introduced into the mixture before H2SO4 (1.679 g) was added dropwise to give a solution with a pH of 11.0 and a composition molar ratio of 1 CTABr/1.76 Na2O/6.14 SiO2/335.23 H2O. The mixture was allowed to heat in an oven at 100°C for 24 h. Figure SBI-0206965 in vivo 1 Flow diagram of multi-cycle

synthesis of MCM-41 materials. The mother liquor was separated via filtration, and the water from the filtrate was partially evaporated at 55°C for 16 h to enable compensation analysis. For the MCM-41 wet filter cake on clay filter, the mass of water in it was estimated by measuring the mass of the solid before and after drying at 60°C selleck products for 14 h. The dried solid was then allowed to redisperse

again in water, and the solid product was purified by washing with distilled water until the pH of the solid became 7.0. The purified solid was dried at 80°C overnight, and the mass of purified solid was measured again. Prior to the second and third synthesis cycles, the chemical composition of the non-reacted solutions was analyzed (please refer to the ‘Characterization’ subsection) and was adjusted to the original one by adding the required amount of CTABr, sodium silicate, and water. The H2SO4 was then added slowly under stirring until a pH of approximately 11.0 was reached using a pH meter (Ohaus Starter 3000, Parsippany, NJ, USA)

to monitor the pH of the solution. The MCM-41 nanoporous materials prepared from the first, second, and third synthesis cycles will be denoted as M-1, M-2, and M-3, respectively. The organic template in the as-synthesized MCM-41 was removed and recovered through extraction by refluxing the solid (1.5 g) in 1 M hydrobromic acid ethanolic selleck compound solution (500 mL) at 75°C for 24 h. The template-free MCM-41 was filtered, washed with ethanol, and dried for 10 h at 100°C in vacuum [19]. On the other hand, the ethanol in the filtrate solution was distilled out at 80°C, and the surfactant was recrystallized in a mixture solution of acetone/ethanol (95:5 in volume) after the acid in the solution was neutralized [20]. The recrystallized CTABr white solid was purified with ethanol and dried at 70°C overnight. Characterization X-ray powder diffraction patterns were recorded using a Siemens D5000 Kristalloflex diffractometer (Munich, Germany) with a monochromated Cu Kα radiation in the angular range from 1.7° to 10° (2θ) with a scanning speed of 0.02°·s−1. TEM was performed using a Philips CM-12 microscope (Amsterdam, The Netherlands) with an accelerating voltage of 300 kV.