Exploratory Materials Science Research

Articles in Press

Kaolin and Bentonite  Supported Metallic Catalysts forSelective Semi-Hydrogenation Reaction of Phenylacetylene

Rokhsana Ismail1,   WaelQasem Almaqtri2, Mohammed Hassan3,4

1Chemistry Department, Faculty of Science, Aden University, Aden, Yemen.
2Faculty of Medical Lab. (Department of Chemistry) , Jibla University for Medical and Health Sciences, Ibb, Yemen.
3Chemistry department, Faculty of Science, Ibb University, Ibb, Yemen.
4Department of Basic Sciences and Mathematics, Faculty of Science, Philadelphia University, Jordan
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Abstract

Kaolin and Bentonite clays supported metal ions Ce, Pd and Pt, have been used to catalyze hydrogenation reaction of phenylacetylene. The purpose was to fabricate natural clay-based catalysts for selective hydrogenation of phenylacetylene to styrene. The reaction was performed into hydrogenation reactor connected to gas chromatography.Chemical composition of both clays was analyzed by atomic absorption spectroscopy and their particle size and BET surface area were measured. Both clays were found to be with high Si/Al ratios with Bentonite more Iron rich than Kaolin. Kaolin based catalysts showed higher catalytic activity and semi-hydrogenation selectivity compared to bentonite-based. Particularly, Pd/Kaolin exhibited a high conversion rate and styrene selectivity close to those reported for Lindlar catalysts.

 

Nanorod Hierarchical Structures of 3D Flower-like ZnO Nanoparticlesand TheirStructurally-Influenced Superhydrophobicities

Tayirjan T. Isimjan1,2, Quan Ge1, Edward Sacher3, De-Quan Yang1*
1Solmont Technology Wuxi Co., Ltd. 228 Linghu Blvd.,Tianan Tech Park, A1-602, Xinwu District, Wuxi, Jiangsu 214135, China
2Division of Physical Sciences and Engineering, Solar and Photovoltaics Engineering Center, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia.
3Regroupement Québécois de Matériaux de Pointe, Départementde Génie Physique,Polytechnique Montréal, Case Postale 6079, Succursale Centre-Ville, Montréal, Québec H3C 3A7, Canada
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Abstract
A simple aqueous solution process,employingtriethyleneglycol (TEG) and sodium hydroxide (NaOH),was used to synthesize zinc oxide (ZnO) powder,whose 3D flower-like structure self-assembled intolarger scalenanorod hierarchical nanostructures. Theinfluences of various reaction parameters on thecrystalstructuresand morphologies of the resulting productswereinvestigated. Thesampleswerecharacterized by X-ray diffraction (XRD), fieldemission scanning electron microscopy (FESEM), andhigh-resolutiontransmissionelectron microscopy (HRTEM).Wefound that the hierarchical ZnOnano/microstructures could be precisely controlled by adjusting the experimental parameters. Further, coatings prepared fromtwo typical hierarchical ZnO flower-like structures showed high levels of superhydrophobicity ontreatment with stearic acid.Superhydrophobicity values differedfordifferent morphologies,attributed to the synergistic effects of the ratios of thedualstructures formed. This leads to a simple, scalable, low-temperature aqueous solutionsynthesis route for flower-like zinc oxide,which is then self-assembled into nanorod blocks, intended for superhydrophobic coating applications.

 

Physical Properties Of Materials That Determine Reversible And Irreversible Deformations

Yu. A. Alyushin
National University of Science and Technology MISIS, Moscow, 119991, Russia
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Abstract
The mechanisms of reversible and irreversible deformations are considered using a model of mechanics based on the concepts of space, time and energy. Local energy, as a generalized scalar function, is represented as a linear combination of independent invariants of the equations of motion in the form of Lagrange with the addition of terms that characterize the processes of dissipation and hardening. The use of material density as a General factor of physical properties involved in the mathematical formulation of the concept of "energy", which determines the scale of the energy scale for all types of energy manifested in the movement of solids, is justified. Arguments are given in favor of switching to a new scale of average stresses, including on the basis of comparing changes in potential and elastic energy during deformation under the influence of its own weight. A variant of experimental determinationcharacteristics of the elastic properties is proposed. The possibilities of spontaneous processes of energy transfer from one form to another within one invariant for elastic deformation and with simultaneous change of several invariants for irreversible deformation are noted. An interpretation of the coefficients associated with the physical properties of the material in the field of irreversible deformations is proposed using the unified curve hypothesis and the theory of plastic flow. The determining role of density, heat capacity and coefficient of linear expansion of the material in the processes of deformation and the energy state of particles is proved.

 

Composites Of Zinc And Cis-Dinitroglycoluril Isomers - A DFT Treatment

Lemi Türker
Middle East Technical University, Department of Chemistry, Üniversiteler, Eskişehir Yolu No:1, 06800
Çankaya/Ankara TURKEY

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Abstract
An insensitive explosive, cis-1,4-Dinitroglycoluril also known as DINGU, is considered to investigate the compatibility of it and its nitramine isomers with zinc in 1:1 composites. The model composites of them have been subjected to density functional treatment at the level of B3LYP/6-31++G(d,p). Within the restrictions of the theory and the level of calculations performed, it has been found that two of the model composites considered are unstable and undergo N-NO2 bond rupture. Only the third one, in which N-NO2 bonds exist in different rings but nearby of each other is stable. Some physical and molecular orbital properties of the systems are obtained and discussed.

 

Hydrothermal Synthesis Of TitanateNanostructures As A High Surface Area Adsorbent

MohdHasmizamRazali*, NurArifah Ismail, KhairulAnuar Mat Amin

Advanced Nanomaterials Research Group, Faculty of Science and Marine Environment,
Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia.

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Abstract
In this research, titanate nanostructures were prepared via a simply hydrothermal method with different hydrothermal temperature which are 100, 150, 200, 250 °C for 24 hours. Commercial TiO2 powder (merck) was used as a precursor and the synthesized samples were characterized using FT-IR, XRD, FESEM, nitrogen gas adsorption and TG analyses. The results revealed that the structure, texture and morphology of samples strongly depend on the temperature of hydrothermal treatment. Hydrogen trititanatenanofibrous was produced at 150 °C, meanwhile, sodium trititanatenanorods were obtained at 200 and 250 °C. At low hydrothermal treatment (100 °C), no reaction was happening. The diameter of nanofibrous and nanorods were found to be (25-30) nm and (250-300) nm, respectively. Hydrogen trititanatenanofibrous possessed the highest surface area due to their small elongated fiber structures thus offers a great potential as adsorbent.

 

Radiation Damage in Ceria

Jean-Marc COSTANTINI

Université Paris-Saclay, CEA, Service de Recherches Métallurgiques Appliquées, 91191, Gif-sur-Yvette, France
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Abstract
The damage induced in cerium dioxide or ceria by charged particle irradiations was investigated by various spectroscopic techniques, such as Raman spectroscopy, electron paramagnetic resonance (EPR) spectroscopy, and UV-visible absorption/reflection spectroscopy. These results confirmed the radiation resistance of this material which is not amorphised by heavy ion irradiations even for high fluence and high stopping power.  However, clear evidence of cerium reduction from the 4+ to 3+ oxidation state was provided by EPR and optical spectroscopy data after electron or heavy ion irradiations.

 

Design of Eco-Friendly Poly Lactic Acid (PLA) Film loaded with bio-additives for Possible Food Packaging Applications

Swathi S1, Keerthana P1, Rajiv G1, Ananda Kumar S1*#, Nirmala JP2, Neelakantan R3

1Department of Chemistry, College of Engineering Guindy, Anna University, Chennai 600025, Tamil Nadu, India.
2Department of Textile Technology, A.C. Tech Campus, Guindy, Anna University, Chennai 600 025, Tamil Nadu, India
3Department of Printing Technology, College of Engineering, Guindy, Anna University, Chennai 600 025, Tamil Nadu, India
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# Dr. S. Ananda Kumar, Associate Professor, Department of Chemistry, CEG, Anna University, Chennai- 600025, Tamil Nadu, India.

Abstract
An active packaging film for food applications based on PLA with Spirulina and guava leaf extract was constructed. The effect of different levels of biocide incorporation on physical properties (contact angle, water absorption, and oxygen permeability), mechanical properties (tensile strength) and thermal properties (degradation behavior, glass transition and melting characteristics) of PLA films was investigated. Incorporation of Spirulina into PLA films showed more improvement in mechanical properties than incorporation of guava leaves. However, guava leaf extract loaded PLA films had better barrier properties towards water and oxygen. The agar disc diffusion method was employed to determine the antibacterial activities of PLA films with biological additives against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. The results revealed the maximum zone of inhibition observed for E. coli (the common foodborne pathogen responsible for food spoilage) was 15±0.44. This work clearly confirms the dual scope of PLA as suitable and sustainable material for active food packaging applications to replace the existing non-biodegradable petroleum-based counterparts.