الفهرس 
NanomaterialsOnly 14 pages are availabe for public view
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Abstract
Summary and conclusions
The thesis aims to prepare some simple and mixed metal oxides using auto combustion method and the prepared nanoparticles were investigated by using different tools. The prepared simple and mixed oxides were also used as adsorbents for the removal of sunset dye from water.
This thesis consists of three main chapters:
Chapter 1: Introduction
This chapter includes a brief introduction about water pollution, sources of pollution and its harms on living things, as well as the different methods used to purify polluted water. It also includes the definition of nanomaterials and the different methods used in their preparation, as well as the different applications of nanomaterials. This chapter also contains literature survey on pervious work for simple oxides and their nano composites. Finaly, it contains the applications of the metal oxide nanoparticles in various fields such as water treatment.
Chapter 2: Experimental
This chapter contains the experimental part of the thesis. It involves complete description of the chemicals and reagents used in the synthesis of magnesium oxide, manganese oxide, and silicon dioxide using auto-combustion and sol-gel methods using organic fuels (oxalic and citric acid). The auto-combustion method was used for the preparation of MgO, Mn2O3 and SiO2. The synthesized MgO/SiO2 and Mn2O3/SiO2 nanoparticles were fabricated from the synthesized simple oxides. The obtained simple oxides were mixed in bidistilled water and ultrasonicated for 15 minutes followed by the calcination at 400˚C for 15 min. This chapter includes also the description of the instrumental tools such as TG-DTA, XRD, FTIR, HR-TEM, FE-SEM and UV-Vis spectrophotometer which were used for the characterization of the synthesized simple and mixed oxides. It also contains the batch method which was used the removal of sunset dye from water using the fabricated adsorbents. It finaly includes the description of the various factors affecting on the removal efficiency.
Chapter 3: Results and discussion
This chapter contains the results and discussion of the extracted data. It can be categorized into two main parts.
The first part
The first part describes the characterization of the obtained simple and mixed metal oxides nanocomposites by different tools such as thermal analysis (TG-DTA), powder X-ray (XRD), infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and UV-Vis spectrophotometer. The results showed that the prepared magnesium oxide (MgO) using auto-combustion method was in the nanometer range. The crystallite sizes were determined using x-ray powder diffraction and they were found to be 20.6, 40.15, and 22.85 nm for the M-O, M-C and M-CO samples, respectively. TEM images for M-CO sample showed that the spherical shape with agglomeration and the average particle size was 11 nm. FT-IR spectra showed a band at 400 cm-1, related to the magnesium oxide nanoparticles.
XRD results revealed that the obtained manganese oxide (Mn2O3) using auto-combustion method was in the nanometer range. The determined crystallite sizes using x-ray powder diffraction were found to be 55.18, 50.7 and 62.6 nm for the Mn-O, Mn-C and Mn-CO samples, respectively. TEM micrographs for Mn-CO sample showed the particles have spherical shapes with agglomeration and average particle size of 24 nm. FT-IR spectra revealed peaks in the range 400-800 cm-1, corresponding to manganese oxide nanoparticles.
The results indicated that silicon oxide nanoparticles (SiO2) synthesized via sol-gel and auto-combustion methods were in the nanometer range. The crystallite sizes of the SiO2 nanoparticles obtained from the x-ray diffraction were found to be amorphous for S-O sample but crystalline for S-C and S-CO samples. The transmission electron microscopy for S-CO sample showed that the prepared SiO2 nanoparticles are composed of complete and incomplete spherical particles and the average particle size was determined to be 16 nm. FT-IR spectra exhibited bands at 450, 800, and 1090 cm-1 for SiO2 nanoparticles.
The results indicated that MgO/SiO2 nanocomposites were in the range of nanometer. The x-ray diffraction patterns confirmed the presence of the obtained nanocomposites without any impurities, as well as the crystallite sizes were found to be 37.8, 37.85, and 30.1 nm for all the synthesized nanocomposites MS11, MS12, MS21, respectively. The transmission electron microscopy of MS11 sample showed that the particles have spherical and tube shapes and the average particle size is 33 nm. The absorption peaks appeared at 1000-1100 cm-1 and 400-500 cm-1 are related to Si-O and Mg-O vibrational mode inside SiO2 and MgO composites lattice, respectively.
The results from that the x-ray diffraction confirmed the presence of the obtained Mn2O3/SiO2 nanocomposite without any impurities and the crystallite sizes were found to be 51.8, 50.29, and 39.6 nm for all the synthesized nanocomposites MnS11, MnS12, MnS21, respectively. The transmission electron microscopy of MnS11 sample showed the presence of the prepared nanocomposites in a spherical shape and the average particle size was determined to be 20 nm. FT-IR spectra exhibited bands in the range 700-400 cm-1 related to Mn2O3 and SiO2 nanocomposites.
The second part
The second part includes the adsorption data for the removal of sunset dye using the fabricated M-CO, Mn-CO, S-CO, MS11 and MnS11 adsorbents. This part contains the results and discussion of the factors affecting the removal of sunset dye from aqueous solutions such as pH, contact time, initial dye concentration, adsorbent dose, temperature and ionic strength. The optimum conditions and the results for the adsorption process can be outlined as follows:
1. The optimum pH for the adsorption of sunset dye was found to be 2 for Mn-CO, S-CO, and MnS11 samples and 3 for M-CO and MS11 samples.
2. The contact times for the adsorption of sunset dye using M-CO, Mn-CO, S-CO, MS11, and MnS11 samples were found to be 35, 8, 100, 35 and 9 min, respectively.
3. The dye removal decreased with increasing the amount of KCl using the synthesized simple and mixed oxides.
4. The dye removal decreased with raising the temperature for all the synthesized materials.
5. The adsorption data followed well the Langmuir isotherm model for all the prepared nano materials. The adsorption of the sunset dye fitted the pseudo second order model using M-CO, Mn-CO, S-CO, MS11 and MnS11 samples.
6. The adsorption of sunset dye was spontaneous, physiorption and exothermic process for the all adsorbents.
7. The adsorption capacities of M-CO, Mn-CO, S-CO, MS11 and MnS11 samples for the removal of sunset dye were found to be 40, 154.40, 6.90, 14.11 and 119.04 mg/g, respectively.