- ItemEffect of polyamines on low methoxyl pectin-based films(2016-03-23) Sabah, M.Low methoxyl pectin (LMPEC) contains a high amount of free carboxylic acid groups able to interact withCaP2+Poriginating a gel network. LMPEC gelation primarily involves electrostatic forces between the cation and the negative charged cavity formed by the polymer chains where CaP2+Pare inserted. These structures, calledegg-boxes, are stabilized by both Van der Waals interactions and hydrogen bonds. They are of great importance both in the area of fruit and vegetable processing as well as for the use of LMPEC in various food products. Polyamines (PAs) are low mol.wt organic cations known to mimic the action of divalent cations both in vitro and in vivo. The different length of PA aliphatic chains, thus, stimulated us to investigate their effect on the mechanical and barrier properties of LMPEC-based edible films. In fact, LMPEC represents also a suitable polymeric matrix for the preparation of coating films potentially useful for food active packaging for its biodegradability and biocompatibility. One of the main additives of the bio-based edible films is the plasticizer, generally a small molecule of low volatility, like glycerol or sorbitol, able toimprove film extensibility and flexibilityby increasing both free volume and polymer chain mobility. Therefore, our research focused on the specific comparison among calcium, and the two PAs putrescine (PT) and spermidine (SPD) as possible agents influencing the functionality of LMPEC-based films prepared in the presence or absence of glycerol. Zeta potential and particle size were determined on LMPEC aqueous solutions as a function of pH and the effect of calcium ions, PT and SPD on LMPEC-based films were studied. CaP2+ Pand PAs were found to differently influence thickness, as well as mechanical and barrier properties, of films prepared at pH 7.5 either in the presence or absence of the plasticizer glycerol. In particular, CaP2+ Pwas found to increase film tensile strength and elongation to break only in the presence of glycerol and did not affect film thickness and permeability to both water vapor and COR2R. Conversely, increasing PA concentrations progressively reduced film tensile strength and markedly enhanced film thickness, elongation to break and permeability to water vapor and COR2R, both in the presence and absence of glycerol. Our findings suggest that PAs give rise to a LMPEC structural organization different from that determined by calcium ions, previously described as “egg box” model, and that PAs can be used as effective plasticizers to obtain more flexible and less brittle hydrocolloidal films.
- ItemAqua bromo-bis-(propane-1,3-diamine)copper(II) bromide nanocrystal complex(2016-03-23) Abd Al-Ghani, BahaaNanocrystal Cu(II) complex was prepared as in the scheme, characterized by spectroscopic techniques (IR, TOF-MS, UV-Visible, TG/DTA) and finally its three dimensional structure was confirmed by X-ray diffraction studies. The CuPIIP ion is five coordinated by four nitrogen atoms of the base ligand and one bromide ion. In the crystal structure, molecules are connected through intermolecular hydrogen bonds of the type N---H...Br and N---H…O.
- ItemPurification of Groundwater from Heavy Toxic Metals using Suspended Polydentate Supported Ligands(2016-03-23) Khalaf, BayanThis study aims to prepare and develop several vehicles chelation polydentate supported ligands and then installed it using sol-gel or polymerization or to be susceptible to imply conjunction with the highly toxic heavy metal ions in the water and disrupted the underground water used for drinking or agriculture, as the process of interaction between ligands and heavy metals depends on the circumstances surrounding conditions which are treated in this research. Metal ion uptake through complexation or hydrogels can be affected by hydrophilichydrophobic balance, the nature of chelate ligands and the extent of cross-linking of macromolecular supports. Ligand function also dictates reactivity, complexation ability and efficiency of polymer supported ligands in the present case expected to be good solution for such problem. This research involves the synthesis and characterization of new polysiloxane surfaces modified with ortho-, meta-, or para-nitrophenyl moieties. The resulting adsorbents have been characterized by SEM, IR, UV, 13C solid state NMR, BET surface area, B.J.H. pore sizes and TGA. These porous materials showed a very good thermal and chemical stability and hence they can be used as perfect adsorbents to uptake Cd(II), Pb(II) and Ni(II) from groundwater taking from Burqin town in Palestine. In order to investigate the adsorption efficiency for each adsorption process. The effect of solution conditions on each adsorption process were studied. These conditions involve the effect of contact time, pH value, temperature, adsorbent dose and the initial concentration of adsorbate. The maximum extent of adsorption was for (Si-p-NO2) polymer in the presence of lead ions. This adsorption process needed only 1 minute of shaking to have 99.95% as percent of Pb(II) removal at solution conditions of 20°C temperature, pH value equals 8, 5 mg adsorbent dose, 50 ppm of Pb(II) solution as initial concentration and 7 mL solution volume. The best equilibrium isotherm model for each adsorption process was investigated using Langmuir and Freundlich isotherm adsorption models. The kinetics of adsorption were also investigated using pseudo first-order, pseudo second-order and intra-particle diffusion kinetic models. In addition, Van’t Hoff plot for each adsorption was investigated in order to determine the values of enthalpy change and entropy change.
- ItemNew Routes for Synthesis of Environmentally Friendly Superabsorbent Polymers(2016-03-23) Abu Jaber, Firas JaberNew Sucrose – based monomers were prepared. The prepared monomers are Allyl Sucrose (AS) and Epoxy Ally Sucrose (EAS). Allyl sucrose was prepared by reacting sugar with allyl chloride in an alkaline medium. Allyl sucrose was then converted into epoxy allyl sucrose by epoxidation with m-chloroperoxybenzoic acid (m-CPBA). The prepared sucrose-based monomers were characterized by 1H and 13C NMR spectroscopy. Both sucrose-based monomers were then used as cross-linking agents to prepare an entirely new class of special biodegradable superabsorbent polymers. In addition, other cross-linking agent were also used including 1,4-butanediol diglycidyl ether (1,4-BDGE), and ethylene glycol diacrylate (EGDA). Ethylene glycol diacrylate was chosen because it is a well known cross-linking agent that is reported in the literature as a cross-linking agent for superabsorbent polymers. 1,4-Butanediol diglycidyl ether was used for the first time as cross-linking agent for superabsorbent polymer. The absorbency for the prepared SAP’s were evaluated. Free swell for the prepared polymers was measured using the tea bag test, and the absorbency under load was measured using the hanging cell test method. Results showed that the free swells and absorbency under load decrease by increasing percentage of cross-linking agent, lowest absorbency observed at cross-linking about 4%. SAP cross-linked with EAS has the highest absorbent capacity and absorbency under load. This could be because it has the highest polarity and highest number of hydroxyl groups. The advantages of the prepared polymers over the commercial one are that: first; they are biodegradable as shown by the biodegradability test; second, they are prepared in one step process. Since the commercial SAP is prepared in a two-step process, in the first step the acrylic acid is polymerized with the crosslinking agent then the produced SAP is surface cross-linked to enhance it absorbency under load.
- ItemWater Soluble [Cu(dien)(NN)]Br2 complexes and their antibacterial activity(2016-03-23) Abu Saleemh, FatimaWater soluble dicationic copper(II) complexes of general formula [Cu(dien)(NN)]Br2 [dien = diethelenetriamineand NN is diamines] were made available in good yield under ultrasonic mode. The reaction was monitored by both FT-IR and UV-vis spectroscopy. The 3D structure was solved by X-ray single crystal diffraction. The solvatochromism phenomena of such complexes is recorded in several types of solvents. These complexes were spectrally and thermally characterized. The complexes showed higher antibacterial activity against several types of bacteria depending on their structures geometry.