In a hydrothermal preparation of crystalline magnetite (Fe3O4) nanoparticles, the influence of the experimental parameters (initial molar ratio of ferrous/ferric ions, initial concentration of ferrous ions, and heating time), and their interactions, on the particle formation was studied using response surface methodology (RSM), based on a statistical design of experiments (DOE). As indices indi...

Bamboo materials with improved antibacterial performance based on ZnO and graphene oxide (GO) were fabricated by vacuum impregnation and hydrothermal strategies. The Zn2+ ions and GO nanosheets were firstly infiltrated into the bamboo structure, followed by dehydration and crystallization upon hydrothermal treatment, leading to the formation of ZnO/GO nanocomposites anchored in the bulk bamboo....

Polypropylene (PP) has been one of the most widely used polymers due to the versatility and cost benefits obtained with this material. In this work, composites of PP modified with nanostructured ZSM-5 zeolite were prepared and their thermal and mechanical properties were evaluated. Zeolites were synthetized by hydrothermal method and the crystallization time was modified to evaluate the effect ...

Clay minerals may be si<j'nifieant indieatoi's of earth processes. They form throufrh a range which involves at one extreme the action of compressed water vapor at a temperature of several hundred degrees centigrade, and at the other extreme, the action of atmospheric agencies at an ordinary temperature. Not recognized as original products of magmatic crystallization, clay minerals are prima fa...

A continuous microwave equipment (CME) has been successfully developed in order to achieve an extremely rapid and mass production for ZSM-5 and NaY zeolite. A precursor mixture for synthesis of ZSM-5 was prepared by mixing aluminosilicate gel with a nanoseed solution obtained under microwave irradiation, and pumped continuously into the CME. Duration time in the CME was 5 min to accomplish the ...

Nanopore silicalite type membranes were prepared on the outer surface of a porous-mullite tube by in situ liquid phase hydrothermal synthesis. The hydrothermal crystallization was carried out under an autogenously pressure, at a static condition and temperature of 180 °C with tetrapropylammonium bromide (TPABr) as a template agent. The molar composition of the starting gel of silicalite zeolite...

Vanadium silicates such as V-Al-analcime, V-analcime, V-magediite and V-ZSM-11 were synthesized using vanadium pentoxide or vanadyl sulfates. Vanadium silicates with analcime structure with and without aluminum (V-Al-analcime, V-analcime) were prepared as pure phase by hydrothermal crystallization from a gel with molar composition of (1 SiO2; 0.2 V2O5; 1 Na2O; 0.034 Al2O3; 35.7 H2O) and (1 SiO2...

Molecular sieves and zeolites are materials whose crystalline frameworks form nanometer or subnanometer pores. A variety of different crystal structures are known having a range of pore sizes. Because the pore sizes are usually smaller than 2 nm, they are classified as microporous materials. Synthesis of microporous materials is usually conducted by the high temperature treatment (80-200 °C) of...

Molecular sieves and zeolites are materials whose crystalline frameworks form nanometer or subnanometer pores. A variety of different crystal structures are known having a range of pore sizes. Because the pore sizes are usually smaller than 2 nm, they are classified as microporous materials. Synthesis of microporous materials is usually conducted by the high temperature treatment (80-200 °C) of...