Functional Materials and Application

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Authors: Wei Liang Zhao
Abstract: A novel two-step sequential deposition method is proposed for the preparation of CH3NH3PbI3 for perovskite solar cell. In order to increase the crystallinity of the PbI2 film, rapidly drop the anhydrous chlorobenzene to the center of the substrate at 6 seconds of spin coating. Ultimately, the quality of the CH3NH3PbI3 film is improved. Through the transmission spectrum of CH3NH3PbI3 thin films, it is clear to see the use of the additive reduces the transmittance of the film. The PL spectroscopy of CH3NH3PbI3 thin films dropping with different additives shows that CH3NH3PbI3 thin films all have an emission peak at 768nm. The J-V test curve of the perovskite solar cell shows that the use of the additive improves the power conversion efficiency.
Authors: Xing Hui Hou, Jing Kun Yu, Xin Yang, Zhao Yang Liu
Abstract: One kind of Al2O3 ceramic-lined steel pipe was prepared with the gravitational separation SHS method by using the reaction system of Al-Fe2O3-Cr2O3. The element line scans of transition structure and the element plane scans of ceramic coating far away from transition layer were analyzed by Scanning Electron Microscopy and Energy Dispersive Spectroscopy, and then they were used to discuss the coating structure and interface bonding mechanism, and investigate the element composition distribution of coating. All of these were closely related to improving the properties of ceramic-lined steel pipe. The results showed that a transition layer was formed between metal pipe and ceramic coating, it was due to the gravitational separation and molecular diffusion motion of the reaction products in molten state; in the transition structure the amount of the reaction elements was gradually transitional from the direction of the coating-transition layer-steel pipe, which could reduce the stress difference between the layers; in the coating far away from the transition layer, only small amount of Fe embedded in the ceramic was left in the form of Fe-Cr alloy, while Cr was uniformly enriched in the Al2O3 ceramic, these all have great influence on the anti-corrosion ability of coating.
Authors: Mykhaylo Paszeczko, Klaudiusz Lenik, Krzysztof Dziedzic, Marcin Barszcz
Abstract: The paper presents the results of a SEM/EDS and XPS study of changing of chemical and phase composition of the friction surfaces Fe-Mn-C-B-Si-Ni-Cr hardfacing coatings depend on depth. The tribological examination was conducted in a pin-on disc system with unitary pressure of 10 MPa under dry friction conditions. A scanning electron microscope SEM/EDS as well as X-Ray photoelectron spectroscopy (XPS) were used to examine the structures on the friction surface and depend on depth 5, 10, 15, 20, 50, 100, 200, 6000 nm. The presence of compounds such as oxides (B2O3, SiO2, Cr2O3), carbides (Fe3C, Cr7C3), borides (FeB, Fe2B).
Authors: Peter L. Bishay, Bhavin Sampat, Jan Sladek, Ernian Pan, Vladimir Sladek
Abstract: A fully coupled thermo-electro-mechanical models of cylindrical and truncated conical GaN/AlN Functionally Graded Quantum Dot (FGQD) systems with and without WL are analyzed in this study to determine the effect of lattice mismatch strain grading on the electromechanical behavior of the FGQD system. This has a technological and fundamental importance because the production methodology adopted for manufacturing QDs enables the composition of the QD material to be graded in the growth direction, so the material properties as well as the induced mismatch strain between the QD and the carrier matrix are accordingly graded. The power law is used to describe the grading function. Based on the obtained results, grading of material properties and lattice mismatch strain have significant effect on the distribution of the electromechanical quantities inside the QD and can be used as another tuning parameter in the design of QD systems.
Authors: Thankaraj Salammal Shyju, Manidurai Paulraj
Abstract: The vertically aligned TiO2 Nanotubes (TiNTs) extracts electrons from an absorber and also helps in its transport in perovskite and dye sensitized solar cells (DSSCs) solar cells. Thus electron transporting layer plays a very important role in photon to electron conversion. Electrochemical anodization is been used widely to grow TiNTs for solar cell applications; due to its low cost, flexibility to vary pore diameter and tube length. We observed that, TiNTs maintained its tubular array only for a set time period. On increasing the growth time they begin to take the form of nanocrystals with {001} facets. Formation of these titanium nanocrystals (TiNcs) was clearly observed through field emission scanning electron microscope (FESEM) and Transmission electron microscopy (TEM). Thus TiO2 nanostructures can be tuned by varying anodization time. More importantly, optimization of the reaction process led to the growth of more orderly, crystalline anatase TiNTs/TiNcs over Ti metal foil substrate. The crystal structure and surface morphology of the prepared thin film samples were studied using X-ray diffraction (XRD) technique and scanning and transmission electron microscopes (TEM). XRD confirmed the anatase phase of as grown TiO2 with (101) as major intensity preferred orientation. Lattice parameters calculated were found to be a= 3.77-to-3.82 and c= 9.42-to-9.58 for grown TiO2.
Authors: Tongsai Jamnongkan, Supranee Kaewpirom, Amnuay Wattanakornsiri, Rattanaphol Mongkholrattanasit
Abstract: Recently, the composited nanofiber attraction has been growing from researchers across the world due to its exciting opportunities for use in biomedical applications. In this study, we fabricated electrospun fibers from poly (vinyl alcohol) (PVA) composited with Zinc Oxide (ZnO) nanoparticle for potential use in biomedical applications. From the experimental results, there was not any chemical bonding between the ZnO nanoparticles and the PVA molecules. The effect of concentration of ZnO nanoparticles in PVA solution on the diameter of electrospun fibers was found that the diameter of electrospun fibers increased with raising the concentration of suspended ZnO nanoparticles in solution. This is probably because the effect of nanoparticles on the diameter of electrospun fibers was through their effect on the viscosity of solution. In addition, we found that the diameter of electrospun fibers depended on the solution and processing parameters.
Authors: Jiang Tao Hou, Wen Bo Du, Zhao Hui Wang, Xian Du, Chao Xu
Abstract: A wet powder metallurgy (WPM) process was developed to disperse carbon nanotubes (CNTs), and to fabricate the CNTs reinforced Mg matrix (CNTs/Mg) composite. The dispersion effect of CNTs were evaluated by field emission scanning electron microscopy (FE-SEM), dynamic light scattering (DLS) and high-resolution transmission electron microscopy (HR-TEM), respectively. Results showed that the CNTs were homogeneously dispersed on the surface of Mg powder. Adequate bonding and good interfacial interaction between the CNTs and Mg matrix contributed to the efficient load transferring from the CNTs to Mg matrix under a mechanical force. Furthermore, no brittle MgO was formed on the surface and it was beneficial to improving the adhesion of the CNTs to Mg matrix. With 0.5 wt.% CNTs addition, the CNTs/Mg composite experienced remarkable enhancements in tensile stress of 28% and Young’s modulus of 24%. The reasons responsible for these enhancements are suggested as the effective dispersion of the CNTs and the good interface bonding between the CNTs and Mg matrix.
Authors: Hassan M. Ibrahim, Omar A. Farid, Amany Samir, Rehab M. Mosaad
Abstract: Chemotherapy is a major therapeutic approach for the treatment of localized and metastasized cancers. Although Doxorubicin (DOX) possesses abroad spectrum of anticancer activity, its clinical use is limited because of it cause heart failure. Chitosan nanoparticles was prepared by using ionic gelation method. These nanoaparticles were used as polyload of anticancer DOX to form safer and non-toxic anticancer drug. infrared spectroscopy (FTIR) and transmission electron microscope (TEM) were used to characterize the prepared nanoparticles. The cancer animals’ experiments using Ehrlich static cancer, (EAC) cells using six groups of experimental animals were performed to evaluate the efficiency of Doxorubicin and Doxorubicin loaded chitosan nanoparticles as anticancer drug especially from its toxicity towards heart. Tumor volume was calculated as to monitor the response to treatment. Cytotoxicity of Doxorubicin and Doxorubicin loaded chitosan nanoparticles were evaluated. Biochemical parameters were be estimated to illustrate the cytotoxicity of these drugs on heart.
Authors: Vimolvan Pimpan, Thanawan Ritthichai
Abstract: Silver nanoparticles were synthesized using silver nitrate as a silver precursor in the presence of tannic acid under UV radiation for 60 minutes. Various pH conditions were employed in the synthesis in order to study its effect on characteristics and ammonia sensing of the synthesized nanoparticles. The images obtained from transmission electron microscope revealed the formation of the spherical particles with average diameters in the range of 10-40 nm depending on pH conditions. It was found that using acidic condition resulted in yellow silver nanoparticles colloids with bigger particles and exhibiting a UV-visible absorbance peak at around 435 nm whereas using other conditions yielded greenish-yellow colloids with smaller particles and having two absorbance peaks at around 370 and 430 nm. After adding 100 ppm of ammonia, TEM images revealed the aggregation and the changes in size and shape of the silver nanoparticles. The color of the silver nanoparticles colloids synthesized using acidic condition changed to orange-yellow color. However, other pH conditions caused the color of the colloids became darker. These color changes were observed by the naked eyes.

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