تخليق مركبات السليكا المسامية المعتمدة والمشتقة من قشور الارز وتطبيقاتها التحليلة

Synthesis of Mesoporous Silica-based materials derivatised from Rice Husk and their Analytical Applications

Abstract
Rice husk (RH) is regarded as one of the most common agricultural residues worldwide. RH can itself be transformed to sodium silicate. Mobil Composition of Matter No. 41 (MCM-41) is prepared from sodium silicate. This thesis includes three steps, the first of which involves extraction of silica from RH, generation of RH-SiO2, MCM-41 and functionalized compounds from the extracted silica; The second and third steps involve characterization of the synthesized compounds can be successfully achieved via the use of various techniques and then some analytical applications.
MCM-41 was functionalized with 3-aminopropyltriethoxysilane (APTES) to obtain MCM-41@APTES.In the next step, 5-bromosalicylaldehyde(BSAL) was refluxed with MCM-41@APTES in toluene to obtain the Schiff base-functionalized mesoporous silica material,MCM-41@APTES-BSAL.Additionally, MCM-41 was functionalized with N-[3-(trimethoxysilyl)propyl]ethylenediamine(NTPE)to obtain MCM-41@NTPE,In the following step, 5-bromosalicylaldehyde(BSAL)was refluxed with MCM-41@NTPE in toluene to obtain a Schiff-base functionalized mesoporous silica material (MCM-41@NTPE-BSAL).
The amount of carbon , hydrogen and nitrogen present in compounds were improved through elemental analysis.The FT-IR spectra of prepared compounds shows several distincit peaks related to compounds.The XRD and TEM investigation demonstrated that MCM-41 and functionalized compounds with an extremely ordered hexagonal arrangement was generated.The N2 adsorption–desorption analysis revealed that the average pore diameter, total pore volume, and specific surface area.Thermogravimetric analysis (TGA/DSC) of RH-SiO2 and MCM-41 revealed two mass reduction steps while for functionalize compounds , revealed three mass reduction steps.The surface topographies for RH-SiO2 and MCM-41 were demonstrated via AFM analysis which shows the presence of blocks of different shapes in RH-SiO2, For MCM-41, it is clear from result that the roughness factor is low. The increase in the AFM parameter for MCM-41@APTES compare with MCM-41,The average roughness of MCM-41@APTES-BSAL was decreased upon functionalization of MCM-41@APTES with 5-Bromosalicylaldehyde(BSAL).The increase in the AFM parameter for MCM-41@NTPE compared with MCM-41,While for MCM-41@NTPE-BSAL the results demonstrated that the functionalization of MCM-41@NTPE led to a decreased in the surface roughness material upon functionalization. FESEM images shows that RH-SiO2 is composed of amorphous silica, while for MCM-41and functionalized compounds, it is clear from the images that the particles are smooth with spherical agglomerations. According to EDX analysis, the existence of elements in the solid ligands was proven.
Mesoporous materials (organic-inorganic materials) derived from rice husk as low-cost adsorbents and applied them in the removal of metal ions (Co (II) and Cu (II)) from their aqueous solutions after prepared column from solid ligands and attempt to activate the column. Removal experiments were performed after optimize the concentration of Co(II) and Cu(II) ions, pH, exposure time, and mass of prepared compounds. The amount of Co (II) in pharmaceuticals was determined using the prepared compounds. Investigation Langmuir and Freundlich models showed that the data was best fitted with the Freundlich adsorption isotherm model in multilayer fashion.