Volume 2, Issue 5, November 2011

Editorial Of AM 2011, China Special Issue

Advanced Materials Letters, 2011, Volume 2, Issue 5, Pages 318-318
DOI: 10.5185/amlett.100am2011

This special issue of Advanced Materials Letters contains selected peer-reviewed papers presented in the '1st International Congress on Advanced Materials 2011' which was held during May 13-16, 2011 at Jinan Nanjiao Hotel, Jinan, Shandong, China. This congress was jointly organized by the International Association of Advanced Materials (IAAM), University of Jinan (UJN, Shandong, China), the Advanced Materials Letters (AML, www.amlett.com, www.vbripress.com), Journal of Inorganic and Organometallic Polymers and Materials (JIOPM)-Springer, the Chinese Ceramic Society and Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Shandong University), Ministry of Education, China. The congress was also supported by Polymers & Polymer Composites (PPC), Advanced Materials Research (AMR) and Journal of Materials Chemistry (JMC)-RSC Publishing. The purpose of congress was to provide a forum for the rapidly expanding field of Advanced Materials across the world, focusing on specific aspects of Polymers, Composite materials, Magnetic materials, Structured materials, Constructional materials, Biomaterials, Energy harvesting materials and energy transfer-materials, Optical and electronic materials, Environmental and green materials etc. at macro and nano levels.

From metal ions to biospecies: template-assisted synthesis as a strategy to generate artificial receptor materials

Peter A. Lieberzeit; Sadia Bajwa; Ghulam Mustafa; Thipvaree Wangchareansak; Franz L. Dickert

Advanced Materials Letters, 2011, Volume 2, Issue 5, Pages 319-321
DOI: 10.5185/amlett.2011.1024am2011

Materials science increasingly focuses on generating “smart”, i.e. highly functional, advanced matrices. Selective recognition can be implemented into man-made polymers by template-assisted synthesis. The method covers a surprising size range: it is possible to generate sensitivity and selectivity towards bivalent metal cations, such as Cu 2+ , in polyacrylate matrices. Despite the template being substantially smaller in size than the monomers, recognition can be achieved. Furthermore, acrylates can be templated with much larger species, such as influenza viruses. This leads to a nanostructured polymer surface that selectively re-binds the respective virion. Additional enhancement of sensitivity can be achieved by composite materials. Silver sulphide nanoparticles for instance show very appreciable affinity towards butanol vapors. When blending into butanol-imprinted polyurethane, the material incorporates three times more of the alcohol.

Eu, Dy codoped Y2Zr2O7 powders with white light luminescence

Aiyu Zhang; Ping Yang; Yongqiang Cao; Yuanna Zhu

Advanced Materials Letters, 2011, Volume 2, Issue 5, Pages 322-326
DOI: 10.5185/amlett.2011.3042am2011

Eu, Dy codoped Y2Zr2O7 crystalline powders have been prepared by a simple sol-gel-combustion method. The lumincescence excitation and emission spectra of the products were measured, and the CIE chromaticity was introduced to characterize the color of the phosphor. It was found that the emission color of the Eu, Dy codoped Y2Zr2O7 powders depends on the doping concentration of Eu, Dy ions and the excitation wavelength. White light emission has been observed for Y2Zr2O7: 1.5%Eu 3+ , 2.0%Dy 3+ under 350nm excitation, for which the calculated chromaticity coordinate is (0.37, 0.32).

Combustion synthesis of X3.5Mg0.5Si3O8Cl4 (X3.5 = Sr,Ba):Eu2+ blue emitting phosphors

N.S. Dhoble; V.B. Pawade; S.J. Dhoble

Advanced Materials Letters, 2011, Volume 2, Issue 5, Pages 327-330
DOI: 10.5185/amlett.2011.3070am2011

Eu 2+ luminescence in novel Sr3.5Mg0.5Si3O8Cl4 and Ba3.5Mg0.5Si3O8Cl4 phosphors is reported in this paper. These were synthesized by combustion method at 550 o C furnace temperature. The prepared phosphors shows PL emission spectra at 445 nm, due to 4f 6 5d 1 → 4f 7 transition of Eu 2+ ions by monitoring excitation at 358 nm for Sr and Ba host lattice. Phase purity was checked by using XRD-pattern. The prepared phosphors have potential applications for solid-state lighting purpose.

One step synthesis and X-ray induced luminescence in RGB PDP phosphors

J.G. Mahakhode; S.J. Dhoble; S.V. Moharil

Advanced Materials Letters, 2011, Volume 2, Issue 5, Pages 331-335
DOI: 10.5185/amlett.2011.3074am2011

One step combustion synthesis of preparation of plasma display panel (PDP) phosphors for X-ray induced luminescence is reported. The prepared phosphors were characterized by XRD, PL and X-ray excited luminescence (XEL) techniques. Phosphors emitting three primary colors have been be prepared by using the combustion synthesis. These may be used for X-ray imaging phosphors.

Semi-circular surface cracks and flaking failures in silicon nitride bearings

Katsuyuki Kida; Takashi Honda; Edson Costa Santos

Advanced Materials Letters, 2011, Volume 2, Issue 5, Pages 336-340
DOI: 10.5185/amlett.2011.5042am2011

There is a well-known pattern of flaking failure under spherical ball-on-plate contact, i.e., the network between multiple Hertzian cracks causes the surface layer’s separations. Based on this pattern previous researchers studied the failures of silicon nitride bearings. However, contrary to their explanation, we found that the surface cracks did not explain the process of the flaking failure of bearing plates. In the present work we calculate the stress concentration of surface crack in order to find out which crack is more dominant in the process of the flaking failure.

Eu3+ and Dy3+ activated Sr2V2O7 phosphor for solid-state lighting

Roshani Singh; S.J. Dhoble

Advanced Materials Letters, 2011, Volume 2, Issue 5, Pages 341-344
DOI: 10.5185/amlett.2011.3071am2011

Eu 3+ and Dy 3+ doped strontium vanadium oxide (Sr2V2O7) phosphor has been successfully synthesized using solid state diffusion method and characterized by XRD as well as photoluminescence (PL) measurements. The PL emission of Eu 3+ ion was observed in Sr2V2O7 phosphor at 593 nm and 618 nm in orange and red region of the spectrum, which corresponds to 5 D0→ 7 F1,  5 D0→ 7 F2 transitions, at the excitation wavelength of 393 nm. The PL emission of Dy 3+ ion was observed in Sr2V2O7 phosphor at 484 nm and 575 nm in blue and yellow region of the spectrum, which corresponds to 4 F9/2→ 6 H15/2 and 4 F9/2 → 6 H13/2 transitions, at the excitation wavelength of 349 nm. The 300 – 400 nm is Hg free excitation, which is characteristic of solid state lighting. Hence, Sr2V2O7 :RE [RE = Eu 3+ and Dy 3+ ] phosphors may be efficient materials for solid state lighting.

Formation process of two-dimensional crystalline film of vacuum-evaporated n-alkane: a molecular dynamics simulation

Hong-zhen Li; Zhao-xiang Wang; Dong-hua Jing; Xiang-he Kong; Ke-zhu Yan

Advanced Materials Letters, 2011, Volume 2, Issue 5, Pages 345-348
DOI: 10.5185/amlett.2011.9101am2011

The formation of two-dimensional crystalline film of n-pentadecane (C15H32) on a flat substrate with attractive forces similar to that of the metals or graphite substrate is investigated with molecular dynamics simulation. By controlling the deposition rate of the molecules, we observed the behavior in adsorption and conformational change of single molecule and the growing process of the n-pentadecane film. Two distinct sub-processes are recognized in the formation of the crystalline film, the formation of the molecular clusters and the coalescence of the molecular clusters. It is found that the conformational changes are gentle when only or few molecules are deposited on the substrate. However, this change becomes drastic as more molecules are gathered together. The accelerated conformational variation is attributed to the no-bonding molecular interaction.

Ce3+ and Eu3+ activtated Na2Sr2Al2PO4F9 nanophosphor

S.J. Dhoble; K.N. Shinde

Advanced Materials Letters, 2011, Volume 2, Issue 5, Pages 349-353
DOI: 10.5185/amlett.2011.3072am2011

A halophosphate based nanophosphor has been synthesized by wet chemical method. XRD confirms the preparation of nanophosphor and this article presents the luminescence properties of Ce 3+ and Eu 3+ activated Na2Sr2Al2PO4F9 under UV/NUV excitation. The photoluminescence spectrum comprises of a main peak in the range 270–350 nm with a shoulder in the range 350–370 nm, which may be ascribed to transitions from 5d–4f levels of cerium in the mixed host lattice (Na2Sr2Al2PO4F9). In Na2Sr2Al2PO4F9: Eu 3+ nanophosphor, orange/red luminescence under the near ultraviolet excitation of 393 nm, attributed to the transitions from 5D0 excited states to 7FJ (J=0–4) ground states of Eu 3+ ions.

Lasing characteristics of ZnO nanosheet excited by ultraviolet laser beam

Kota Okazaki; Kazuki Kubo; Tetsuya Shimogaki; Daisuke Nakamura; Mitsuhiro Higashihata; Tatsuo Okada

Advanced Materials Letters, 2011, Volume 2, Issue 5, Pages 354-357
DOI: 10.5185/amlett.2011.9093am2011

The lasing characteristics of ZnO nanosheets were investigated for an application to ultraviolet laser diode. ZnO nanosheets were synthesized on a silicon substrate by a CVD method, and then those ZnO nanosheets were examined by a photoluminescence method with a third-harmonic Nd:YAG laser (355 nm, 5 ns). The observed emission spectra showed the obvious lasing characteristics having mode structure and a threshold for lasing. The threshold power density of a ZnO nanosheet was measured to be 40 kW/cm2, and it would be low enough to be oscillated by an electrical pumping for ultraviolet laser diode.

Novel phosphors of ALaLiWO6:Dy3+ (A = Sr2+ And Ba2+) for white light applications

Parag Nimishe; S.J. Dhoble

Advanced Materials Letters, 2011, Volume 2, Issue 5, Pages 358-361
DOI: 10.5185/amlett.2011.3073am2011

In this paper we report the synthesis and luminescence of Dy 3+ activated tungstates of the type ALaLiWO6 (where A = alkaline earth metals Sr and Ba), prepared by solid state diffusion reaction method. These novel luminescent tungstate materials were characterized by X-ray diffraction, scanning electron microscope (SEM) and photoluminescence (PL) techniques. The Dy 3+ activated ALaLiWO6 (where A = Sr and Ba) phosphors are effectively excited around 350 nm which is mercury free excitation in near UV and give a broad emission band peaking around 470 nm(blue region) along with a sharp characteristic peak at 577 nm (yellow region). Thus, the Dy 3+ activated ALaLiWO6 phosphors may be used in white light applications.

Microwave assisted hydrothermally synthesized nanostructure zinc oxide reinforced polyaniline nanocomposites

Subhash B. Kondawar; Smita A. Acharya; Sanjay R. Dhakate

Advanced Materials Letters, 2011, Volume 2, Issue 5, Pages 362-367
DOI: 10.5185/amlett.2011.9107am2011

ZnO in different nanostructures were synthesized by microwave assisted hydrothermal route. Different experimental conditions such as microwave irradiation power, exposure time have been investigated to reveal the process of formation of the ZnO nanostructures. It was revealed that the microwave exposure time plays a vital role in determining the diameter of the rods. The interaction of microwaves with the growth units of ZnO was systematically investigated to explain formation of different structural geometry of ZnO on nanoscale. ZnO nanostructures consisted of flower-like, sword-like, needle-like and rods-like structures were prepared by microwave assisted hydrothermal process at different conditions of microwave power and irradiation time. The ZnO nanostructures are in hexagonal phase. It is considered that microwave can interact with growth units of ZnO to generate active centers on the surface of ZnO nuclei so that needle-like ZnO rods are created on those sites, resulting in the formation of the flower-like ZnO nanostructures. Polyaniline - ZnO nanocomposites (PZ) in various weight % of nanostructure ZnO were synthesized by the chemical oxidation method in sulphuric acid medium using ammonium persulphate as oxidant at 276K. The synthesized polymer nanocomposites were characterized by XRD, FTIR and UV-VIS spectroscopy.

Intermetallic Al2Cu orientation and deviation angle measured by the rotating directional test during directional solidification

K. Gao; S.M. Li; H.Z. Fu

Advanced Materials Letters, 2011, Volume 2, Issue 5, Pages 368-372
DOI: 10.5185/amlett.2011.5013am2011

The orientation and deviation angle of intermetallic Al2Cu phase in directionally solidified Al-40wt. %Cu hypereutectic alloy were investigated using a rotating orientation X-ray diffraction (RO-XRD) method. Experimental results show that preferred planes (110) and (310) of the Al2Cu phase occur at 10 μm/s and the growth directions of the two planes are not well aligned with the heat flux direction. The growth direction of the preferred plane (110) has a 7.24 º~11.43 º angle with the heat flux direction. For the direction of the plane (310), its deviation angle attains 2.68 º ~ 20.82 º. Besides, the measured data agree well with the previously reported results, indicating that the RO-XRD method is an effective method for measuring the orientation and deviation angle of the phase in polycrystalline materials.

Photoluminescence studies of trichloro-DPQ organic phosphor

S.B. Raut; S.J. Dhoble; R.G. Atram

Advanced Materials Letters, 2011, Volume 2, Issue 5, Pages 373-376
DOI: 10.5185/amlett.2011.3075am2011

A new blue emitting material containing quinoline is designed, synthesized and characterized. The material has been prepared by well-known reaction such as Friedlander condensation reaction at 140 °C. The blended thin films of Trichloro-DPQ with poly (methyl methacrylate) (PMMA) at different weight % concentrations such as 10, 5, 1 and 0.1 weight % have been prepared. The structural characterization has been done by FTIR spectra. The synthesized polymeric compound demonstrates emission in blue region at 460 nm in powder form. At different weight % concentrations, there is emission at 444 nm with varying intensity. The light emitting and optoelectronic property of polymeric compound may find application in electroluminescence, OLED and sensors.