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Investigation of the Dependence of Thickness and Roughness of TiO2 Thin Films Fabricated Using Pulsed Laser Deposition on the Laser Energy
Ahmed Mohamed Salih,
Nafie Abdallatief Almuslet,
Abdelmoneim Mohamed Awadelgied
Issue:
Volume 5, Issue 2, June 2019
Pages:
35-39
Received:
2 March 2019
Accepted:
8 April 2019
Published:
15 May 2019
Abstract: In this work Titanium Dioxide thin films were successfully deposited on glass substrates at room temperature by pulsed laser deposition technique (PLD) using a Q-switch Nd: YAG laser to fabricate thin films. The target was an Anatase TiO2 powder that converted to solid disks by compressing it. The disks were irradiated with different laser pulse energies (100, 150 and 200 mJ) with the same number of laser pulses (10 pulses) and the same laser repetition rate to fabricate three groups of thin film (I, II and III). An atomic force microscopy (AFM) was used for the characterization of the thickness and topography of these thin films. The results showed that the thickness of the films was in the range of hundreds nanometers and it is increased exponentially with the laser energy. The dependence of the root means squire roughness (RMS) on laser pulse energy also was investigated and the results showed that the (RMS) increase exponentially as laser pulse energy to specific value, and then decrease exponentially that the whole curve looks like Gaussian shape.
Abstract: In this work Titanium Dioxide thin films were successfully deposited on glass substrates at room temperature by pulsed laser deposition technique (PLD) using a Q-switch Nd: YAG laser to fabricate thin films. The target was an Anatase TiO2 powder that converted to solid disks by compressing it. The disks were irradiated with different laser pulse en...
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Release Behavior of Bovine Serum Albumin Loaded on Hydrogels of Natural Polymer Blend Poly (Vinyl Alcohol) and Analyze Their Compositions
Roua'a Kassim Al-Ojar,
Fawzi Habeeb Jabrail
Issue:
Volume 5, Issue 2, June 2019
Pages:
40-54
Received:
16 March 2019
Accepted:
26 April 2019
Published:
4 June 2019
Abstract: Amylopectin AP, shellac SH, starch ST and ethyl cellulose EC, the natural polymers of multi functional groups have been blended with poly (vinyl alcohol). The new hydrogels were cross-linked chemically and physically using glutaraldehyde and sodium hexametaphosphate respectively. The prepared hydrogels and according to their different functional groups were studied for their degree of swelling in (pH4, pH7 and pH9) swelling medium and in saline solution of 0.1 N NaCl. The wt% of blend composite of the final hydrogels beside their degree of cross-link was manipulated for maximum loading and suitable release of BSA protein. FT-IR studies were used to improve blending of the mixed polymers in prepared hydrogels from their distinctive functional groups in the final hydrogels structures, as well as the emphasis on BSA protein loaded on prepared hydrogel. The XRD patterns have shown low crystalline structure of the prepared hydrogels after blending, with some elevation in degree of crystallinity for hydrogels cross-linked physically in comparison with hydrogels chemically cross-linked. The DTA thermograms have shown blending of polymers would change the thermal stability of the final hydrogels, and according to their Tg, Tcr and ∆Hf the hydrogels were thermally more stable in chemically cross-linked structures than cross-linked physically which because of their ionic interactions and their competition with hydrogen bonds. SEM micrographs have shown the homogeneous structures of the hydrogels after blending beside the irregular and fold surface for chemical cross-linked hydrogels which increase the surface area and increase the loading efficiency of some prepared hydrogels. Whereas physical cross-linked hydrogels have shown surface of smooth and uniform character with high porosity which increase the loading percentage too. The BSA protein model was depended for loading on prepared hydrogels, where the pH, time of loading and BSA concentrations have been shown a significant effects on maximum loading percentages. Finally, the cumulative release percentages Rcum of BSA protein from the prepared hydrogels were examined in different pH and temperatures of the release medium. The hydrogels after release the protein have shown morphological surface from SEM images filled with holes and remain stable where they can be used again.
Abstract: Amylopectin AP, shellac SH, starch ST and ethyl cellulose EC, the natural polymers of multi functional groups have been blended with poly (vinyl alcohol). The new hydrogels were cross-linked chemically and physically using glutaraldehyde and sodium hexametaphosphate respectively. The prepared hydrogels and according to their different functional gr...
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Synthesis of Poly(Acrylamide-Graft-Chitosan) Hydrogel: Optimization of The Grafting Parameters and Swelling Studies
Ahmed Galal Ibrahim,
Ahmed Zaky Sayed,
Hamada Abd El-Wahab,
Mahmoud Mohamed Sayah
Issue:
Volume 5, Issue 2, June 2019
Pages:
55-62
Received:
4 April 2019
Accepted:
30 May 2019
Published:
18 June 2019
Abstract: Hydrogel polymers were prepared via graft polymerization of acrylamide (AAm) onto chitosan (CTS) backbone in the presence of methylene bisacrylamide (MBA) as cross-linker and ammonium persulfate (APS) as an initiator. Optimizing the crosslinking graft reaction of AAm onto CTS was studied by varying the concentration of CTS and MBA cross-linker and discussing the effect of these conditions on the gel fraction and the grafting parameters. The grafting parameters; grafting percentage (%GP), grafting efficiency (%GE), Add-on (%A) and homopolymer (%H) were studied as a function of the chitosan and the cross-linker concentrations. Also the swelling properties of the prepared hydrogel were examined. In this research, the simple second order kinetic model proposed by Schott has been carried out to describe the swelling mechanism. The effect of the grafting reaction on the thermal properties of the chitosan was also investigated by the thermal gravimetric analysis (TGA). The structure of the prepared hydrogel polymer was confirmed by FT-IR spectra. The porous structure of the hydrogel was observed by the Scanning Electron Microscope (SEM) and also the elemental composition of the prepared hydrogel was identified by using the energy dispersive X-ray (EDX).
Abstract: Hydrogel polymers were prepared via graft polymerization of acrylamide (AAm) onto chitosan (CTS) backbone in the presence of methylene bisacrylamide (MBA) as cross-linker and ammonium persulfate (APS) as an initiator. Optimizing the crosslinking graft reaction of AAm onto CTS was studied by varying the concentration of CTS and MBA cross-linker and ...
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Preparation and Research of Hydrophilic Polyurethane Modified by Folate-Lactose
Liudmyla Kulyk,
Iryna Gladyr,
Rita Rozhnova,
Dmytro Kuliesh,
Nataliia Galatenko,
Larisa Narazhaiko
Issue:
Volume 5, Issue 2, June 2019
Pages:
63-72
Received:
21 May 2019
Accepted:
26 June 2019
Published:
9 July 2019
Abstract: The biological active polyurethane (PU) based on diisocyanate prepolymer and folate-lactose (FL) was synthesized. Physical, mechanical and thermophysical properties of polymeric films were investigated. It was found that the value of the strength at break and elongation of PU with FL are higher by 83% and 22% than the corresponding physical and mechanical properties of the PU with D-lactose. According to the obtained results, the characteristic viscosity and water absorption of PU with FL are higher by 44% and 34% for the parameters of PU containing D-lactose. It has been established that prepeared PU are single-phase. The glass transition temperature is 247 K for PU with FL and 245 K for PU with D-lactose. At the same time, FL introduction into the polymer matrix causes decreasion of the heat jump value (ΔСр) to 0,1551 J/g(°C) for PU with FL sample and 0,2911 J/g(°C) for PU with D-lactose sample. Biodegradation of synthesized materials was investigated after incubation in physiological solution (0.9% NaCl) and biological medium 199 for 180 days. According to research results, polyurethane, modified by folate-lactose, retains sufficient performance for use within 6 months in conditions close to the human body. Biological activity and biocompatibility of synthesized polyurethane modified with FL were confirmed by tissue culture and histological methods.
Abstract: The biological active polyurethane (PU) based on diisocyanate prepolymer and folate-lactose (FL) was synthesized. Physical, mechanical and thermophysical properties of polymeric films were investigated. It was found that the value of the strength at break and elongation of PU with FL are higher by 83% and 22% than the corresponding physical and mec...
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