الفهرس 
Chapter I: Introduction and Literature ReviewOnly 14 pages are availabe for public view
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Abstract
Title: Preparation and characterization of Superabsorbent Hydrogel Based on Carboxymethyl Cellulose and Its application for Improvement of some sandy soil Properties.
Chapter I (Introduction):
This chapter introduces the subject matter problem and the importance of the superabsorbent polymer hydrogels (SAH), as a synthesized soil conditioner, in the sandy soil properties improvement. And focusing on some literature review about SAH’s as a water management resource for agricultural development, as well as, SAH synthesis methods, characterizations and its classifications, and polymers applications in agriculture which used widely in amelioration of the hydro-physical and chemical soil properties, especially sandy soils.
Chapter II (Experimental):
This chapter represents the experiments and techniques that were used in preparation and characterization of the two synthesized hydrogel, (IPNSH and IPNCB). It, also, gives details of a laboratory experiment on the studied sandy soil. characterization of the two synthesized hydrogel, (IPNSH and IPNCB), was achieved by different spectroscopic methods and Thermal gravimetric analysis. Two pot experiments were carried out, on a sandy soil, to study the effect of the two synthesized hydrogel, (IPNSH and IPNCB), on some physical and chemical properties of the sandy soil. The experimental treatments were: Non conditioned soil (the control) and conditioned soil with different rates (0.02, 0.03, 0.04, and 0.05% IPNSH), and were (1% and 2% of the IPNCB). Barley and wheat plants were used as indicator plants for reflection of such treatments upon plant growth.
Chapter III (Results and discussions):
The results can be summarized as follows:
Synthesis of the two hydrogel, IPNSH and IPNCB
Two hydrogel (IPNSH and IPNCB) were synthesized. The synthesis of CMC-g-TerPolymers superabsorbent hydrogel (IPNSH) was achieved using a free radical polymerization technique. The IPNCB was synthesized by grafting of biochar based on copolymerization of AA, Am and AMPS monomers along the chains of CMC, through conventional and microwave methods. The new IPNCB was manufactured to improve swilling properties and nutrient enrichment which means it can be used as a potential candidate for agriculture applications.
Characterization of the CMC-g-TerPols (IPNSH) and IPNCB
The structure features of IPNSH and IPNCB were examined by FTIR and Scanning Electron Microscope (SEM). Thermal gravimetric analysis TGA was also carried out. The microwave route improved the time of the polymerization reaction and shows high swelling behavior when compared with the conventional technique with optimized monomer, crosslinker, and initiator concentration.
The addition of the 2% biochar (BC) to the polymer matrix results in an improvement in swelling behavior in different media. TGA showed better thermal stability of the IPNCB composite as compared to the blank CMC. The porous structure of the IPNCB shown by SEM proves the incorporation of biochar into the polymer network. IPNCB shows good degradation rate in the soil, which helps to decrease environmental contamination.
Effect of IPNSH and IPNCB Composites on some Physical Properties of the sandy soil and plant growth.
The effect of the two synthesized hydrogel was studied on a sandy soil, characterized by low fertility, insufficient water for plant growth and had a high hydraulic conductivity leading to rapid infiltration rate and fast loss of water, and had a high bulk density reflecting a low porosity, consequently faible soil moisture retention. The selected properties were: soil water retention (WR), water holding capacity (WHC), permanent wilting point (PWP), The Available water content (AW), Bulk density (Bd), Saturated hydraulic conductivity (Ks), Soil pH, Soil salinity, soil organic matter (OM) and the available macronutrient N, P, and K. The results showed that additions of IPNSH and IPNCB improved all the studied hydro physical and chemical properties of the sandy soil which improves plant growth conditions. Values of Bd, Ks and pH decreased, while that of WHC, WR, AW, OM, and the available N, P, and K, increased with increasing the application rates of the IPNSH and IPNCB composites. The EC values increased but don’t reach salting level (4.0 ds/m). The increase values of both WHC and WR upon the addition of IPNSH and IPNCB, indicate that the soil can hold much water and retains it for a longer period of time which reduces the number of irrigation times. Thus saving the irrigation water and decrease water consuming.
All the plant growth parameters of barley and wheat plants: seedling emergence, plant height, and the fresh and dry weights were also improved. The two composites, IPNSH and IPNCB, therefore shows promise in sustainable agriculture.