Volume 6, Issue 9, September 2015

 Research Trends In “Biomaterials” Under Advanced Materials From Last Five Years

Lokman Uzun

Advanced Materials Letters, 2015, Volume 6, Issue 9, Pages 756-759
DOI: 10.5185/amlett.2015.9001

In this issue, we continue to publish the data collected from Scopus in accordance to Biomaterials under “Advanced Materials” research from last five years. We elucidated the data for top-ten countries, affiliations and authors in respective biomaterials field. The most producing countries in last five years were USA, China, Germany, South Korea, Japan, United Kingdom, India, Australia, Italy and Spain ranked in respect to last five years performances. In addition to country ranking, we also extracted the citation variation through years besides the total numbers of citation and h-indexes. As clearly seen in citation variation through last five years, the trends in the biomaterials has still exponentially grown up meanwhile it has also seen in the distribution/number of patents approved mainly by US patent office. In addition, one third of the all patents belong to private company as well as top-twenty patents mostly belong to academic research institutes. Besides including top-ten researchers in top-ten countries, we want to guide the attentions on who/what leads these researches: institute-driven, collaborative and senior researcher leading works.

In-situ Electrochemical Synthesis Of Prussian Blue Composite With Gold Nanoparticles And Its Application In Hydrogen Peroxide Biosensor

Suman Singh; D. V. S. Jain; M. L. Singla

Advanced Materials Letters, 2015, Volume 6, Issue 9, Pages 760-767
DOI: 10.5185/amlett.2015.5796

This manuscript presents in-situ electrochemical synthesis of Prussian Blue-gold nanoparticles (PB- AuNPs) composite for application in hydrogen peroxide (H2O2) biosensor. The SEM image clearly showed the presence of AuNPs of size in range of 50 to 200 nm spread on PB matrix. UV-Visible spectra showed absorbance peak at 530 nm corresponding to AuNPs and a hump in 690-740 nm region for PB, confirming the synthesis of composite. The cyclic voltammetry (CV) showed the surface coverage of 3.65 x 10 -9 mol/cm 2 for pure PB film and 4.33 x 10 -9 mol/cm 2 for PB-AuNPs film, with diffusion coefficient of 1.19 x 10 -9 cm 2 /s, and 5.64 x 10 -9 cm 2 /s respectively. The film thickness is found to be 2.4 x 10 -12 cm for PB and 2.9 x 10 -12 cm for PB-AuNPs composite. The concentration of redox active centers (Fe +3/+2 ) is 3.5 moles/cm 3 for ITO/PB and 4.1 moles/cm 3 for ITO/PB-AuNPs respectively. The CV of ITO/PB showed one redox couple at 0.118 V and 0.215 V, whereas with ITO/PB-AuNPs electrode, two sets of well-defined redox peaks; (i) 0.095 V & 0.135 V and (ii) 0.74 V & 0.78 V were obtained. The faradic current obtained with ITO/PB was 3.6 x 10 -3 A and 7.3 x 10 -3 A for ITO/PB-AuNPs composite film, respectively. The faradic current was almost double in presence of gold nanoparticles, as compared to pure PB. For H2O2 biosensor, the horse radish peroxidase (HRP) was immobilized on composite film and was used for H2O2 detection. The linearity was obtained from 10 to 90 nM, with sensitivity of 0.73µA/nM and the apparent Km value was 45 nM. The response time of reported biosensor is 20 sec and is stable for about three months.

A Comparative Study Of Polyurethane Nanofibers With Different Patterns And Its Analogous Nanofibers Containing MWCNTs

Javier Macossay; Faheem A Sheikh; Hassan Ahmad; Hern Kim; Gary L Bowlin

Advanced Materials Letters, 2015, Volume 6, Issue 9, Pages 768-773
DOI: 10.5185/amlett.2015.5888

Tissue engineering is a multidisciplinary field that has evolved in various dimensions in recent years. One of the main aspects in this field is the proper adjustment and final compatibility of implants at the target site of surgery. For this purpose, it is desired to have the materials fabricated at the nanometer scale, since these dimensions will ultimately accelerate the fixation of implants at the cellular level. In this study, electrospun polyurethane nanofibers and their analogous nanofibers containing MWCNTs are introduced for tissue engineering applications. Since MWCNTs agglomerate to form bundles, a high intensity sonication procedure was used to disperse them, followed by electrospinning the polymer solutions that contained these previously dispersed MWCNTs. Characterization of the produced nanofibers has confirmed production of different non-woven mats, which include random, semi-aligned and mostly aligned patterns. A simultaneous and comparative study was conducted on the nanofibers with respect to their thermal stability, mechanical properties and biocompatibility. Results indicate that the mostly aligned nanofibers pattern presents higher thermal stability, mechanical properties, and biocompatibility. Furthermore, incorporation of MWCNTs among the different arrangements significantly improved the mechanical properties and cell alignment along the nanofibers.

Effects Of Infrared And Ultraviolet Radiation On The Viability Of Cells Immobilized In Porous TiNi-based Alloy Scaffold

Sergey Gunther; Oleg Kokorev; Timofey Chekalkin; Valentina Hodorenko; Georgiy Dambaev; Ji-Hoon Kang; Victor Gunther

Advanced Materials Letters, 2015, Volume 6, Issue 9, Pages 774-778
DOI: 10.5185/amlett.2015.5882

Cell responses to electromagnetic radiation are due to many factors including the cellular microenvironment. The aim of the present study was to explore the effects of ultraviolet (UV) and infrared (IR) irradiation of low intensity on cultured cells derived from different biological tissues (spleen, bone marrow, and Ehrlich's adenocarcinoma), which were immobilized in a porous TiNi-based alloy scaffold. Accordingly, the following objectives were set: i) to evaluate the impact of low-intensity radiation on cell suspensions, and ii) to carry out a comparative analysis of the viability of cells immobilized in porous TiNi-based alloy and IR- and UV-irradiated. The data show that the extracellular environment of bone marrow, tumor and spleen cell populations affects their viability and proliferative potency in porous TiNi-based scaffolds. IR- and UV irradiation of cell cultures immobilized in the scaffold affects the cell viability in populations of bone marrow, tumor, and spleen cells. In case of IR irradiation, cell viability was significantly improved, at the same time UV irradiation suppressed cell proliferation activity. The effect of IR irradiation can be used to resuscitate the cell area. The effect of UV irradiation can be used to destroy residual tumor lesions or other pathological cell populations. Effects of low-intensity infrared (IR) and ultraviolet (UV) radiation on the number of viable cells were evaluated against the control group in which cells were exposed to natural daylight. The results showed that IR irradiation led to a 4.6-, 2.5-, and 1.3-fold increase in viable Ehrlich tumor, bone marrow, and spleen cells, respectively, while UV exposure led to a 3.9-, 1.5-, and 1.2-fold increase, respectively.

Dielectric Properties Of Pr6O11 Nanorods Grown Chemically At Low Temperature And Atmospheric Pressure

Lalit Sharma; Partheepan Ganesan; Ranjit Kumar; T.D. Senguttuvan; Vidya N. Singh

Advanced Materials Letters, 2015, Volume 6, Issue 9, Pages 779-782
DOI: 10.5185/amlett.2015.5848

Due to high dielectric constant, Pr6O11 is viewed as a prospective gate dielectric material in decanano metal-oxide-semiconductor devices. In this study, structural, optical and dielectric properties of Pr6O11 nanorods have been investigated for its possible application as gate dielectric materials for the future generation optoelectronic devices. Pr(OH)3  nanorod structure was synthesized in an alkaline medium (KOH and NaOH) at a moderate temperature (~188°C) and atmospheric pressure. The Pr(OH)3 nanorods were converted to Pr6O11 nanorods by annealing them at 400°C. XRD studies showed that both Pr(OH)3, as well as Pr6O11, were highly crystalline. TEM studied showed that the diameter and length of nanorods were ~30 nm and 100 nm, respectively. Optical studies showed that the band gap of these nanorods is 5.31eV. Dielectric studies showed that dielectric constant at 1 kHz is ~ 4000.

Predicted Growth Of Through-thickness Stress Corrosion Cracks In Anhydrous Ammonia Nurse Tanks 

Andrew T. Becker; Alan M. Russell; L. Scott Chumbley

Advanced Materials Letters, 2015, Volume 6, Issue 9, Pages 783-789
DOI: 10.5185/amlett.2015.5838

Anhydrous ammonia is a toxic material that is transported from distribution centers to farm fields in steel pressure vessels called nurse tanks. Numerous accidents have occurred in which nurse tanks failed and ammonia was released, often with explosive force. The majority of such accidents are caused by stress corrosion cracking of the tank steel. Stress corrosion cracking is caused by the combination of stress in the tank's steel and the corrosive effect of ammonia. Neutron diffraction analysis was used to map the residual stress state in and near circumferential welds from two used anhydrous ammonia nurse tanks, one manufactured in 1966 and the other manufactured in 1986. Notched SA455 steel test specimens were held under tensile load (stress concentration factors of 40 to 80 MPa·√m) while immersed in NH3 for seven months to generate crack propagation rate data. The results from these measurements were then used to predict stress corrosion crack growth rates for various pre-existing crack sizes at various temperatures. These data may be useful for estimating safe service lifetimes of nurse tanks that contain cracks.

Synthesis And Characterization Of Semi-interpenetrating Polymer Network Based On Single-walled Carbon Nanotubes

A. Jayakumar; N. Malarvizhi; B. Rajeswari; A. Murali; Debasis Samanta; P. Saravanan; C. Muralidharan; Sellamuthu N. Jaisankar

Advanced Materials Letters, 2015, Volume 6, Issue 9, Pages 790-794
DOI: 10.5185/amlett.2015.5895

Semi-interpenetrating polymer networks (semi-IPNs) based polyurethane (PU), polyvinyl alcohol (PVA) and functionalized single–walled carbon nanotubes (f-SWCNTs), films were prepared using sequential polymerization technique. Carboxyl functionalized SWCNTs in semi-IPNs matrixes were confirmed by Raman spectroscopy and  hydrogen bond interactions were studied using attenuated total reflectance fourier transform infrared spectroscopy. The soft segments of the PU with nanotubes interact much stronger than hard segments, this was observed by Differential Scanning Calorimeter. The activation energy and thermal degradation temperatures were calculated from thermogravimetric analysis. The tensile strength and Young’s modulus was increases with increase f-SWCNTs loadings. The AFM micrographs clearly shows f-SWCNTs were located in semi-IPNs matrix. Further, SWCNTs are attached in PU and spherical structures were dispersed in polymer matrix. The surface activation energy of the composites were increases up to 29 kJ/mole with increasing SWCNTs content on PU networks.

Effect Of Xe Dilution On Structural, Electrical And Optical Properties Of Nanocrystalline Si Films Deposited By HW-CVD Method

Vaishali S. Waman; Azam H. Mayabadi; Mahesh M. Kamble; Bharat B. Gabhale; Adinath M. Funde; Vasant G. Sathe; Habib M. Pathan; Sandesh R. Jadkar

Advanced Materials Letters, 2015, Volume 6, Issue 9, Pages 795-802
DOI: 10.5185/amlett.2015.5902

We investigated the effect of Xe dilution of silane on structural, optical and electrical properties of nanocrystalline Si films deposited by HW-CVD. With increase in Xe dilution of silane nanocrystalline-to-amorphous transition or amorphization has been observed in nanocrystalline Si films. The amorphization has been confirmed from dark and photoconductivity measurement, Raman spectroscopy, low angle XRD and atomic force microscopy analysis. The FTIR spectroscopy analysis showed that with increase in Xe dilution of silane, in addition to di-hydrogen [Si-H2] and poly-hydrogen [(Si-H2)n] complexes, hydrogen incorporated in these films in mono-hydrogen [Si-H] bonded species. The hydrogen content was found < 5 at. % over the entire range of Xe dilution of silane studied and it increases with increase in Xe dilution of silane. On the other hand, ETauc and E04 show decreasing trend with increasing Xe dilution of silane. The ETauc decreases from 2.4eV to 1.9eV whereas E04 decreases from 2.9eV to 2.3eV. The optical band gap values estimated from E04 method are found higher than ETauc values calculated from Tauc’s method. Finally, it has been concluded that Xe dilution of silane in HW-CVD enhances the deposition rate but has adverse effect on the crystallinity of nanocrystalline Si films.

Poly(o-anisidine) Carbon Fiber Based Composites As An Introductory Material For EMI Shielding      

Rakesh Kumar; Seema Joon; Avanish P. Singh; Brij P. Singh; S. K. Dhawan

Advanced Materials Letters, 2015, Volume 6, Issue 9, Pages 803-809
DOI: 10.5185/amlett.2015.5915

In response to the striking research activity and publications in fabrication of multifunctional materials, the present work is an attempt to fabricate processible composite sheets of poly (o-anisidine)-carbon fiber (PoACF) by a facile, low cost method and find their use in electromagnetic interference (EMI) shielding in X-band (8.2-12.4 GHz).  PoACF composite is synthesized by in-Situ oxidative emulsion polymerization and transformed into thin sheets by compression molding technique using different ratio of phenolic novolac resin as a binder. The prepared PoACF composites and sheets are characterized by SEM, TGA, UV-vis, & FT-IR techniques. PoACF sheets have conductivity of the order of 10 -3 to 10 -1 S/cm and maximum shielding effectiveness of 32.57 dB at 4 mm thickness. These sheets have flexural strength between 18.82 to 41.28 MPa. The sheets of PoACF composite have sufficient thermal as well as mechanical stability and may be accepted as an economical material for EMI shielding application.

Influence Of Al3+ Substitution On Impedance Spectroscopy Studies Of Ni0.27Cu0.10Zn0.63AlxFe2-xO4 

M. Belal Hossen; A.K.M. Akther Hossain

Advanced Materials Letters, 2015, Volume 6, Issue 9, Pages 810-815
DOI: 10.5185/amlett.2015.5854

The influence of Al 3+ substitution on the microstructure and impedance spectroscopy of Ni0.27Cu0.10Zn0.63AlxFe2-xO4 has been studied by scanning electron microscopy and impedance analyzer where the formation of the material in the spinel crystal structure was initially confirmed by X-ray structural analysis with room temperature data. The surface morphology indicates well defined grains separated by grain boundaries and with Al substitution average grain size decrease from 17 μm to 12 μm and zinc losses as well. The complex-plane impedance spectra indicate that the material can be represented by two semicircular arcs (its tendency) which corresponds to the bulk and the grain boundary resistance at high and low frequencies respectively. With Al substitution both grain and grain boundary resistance increases from 7.48 kΩ to 15.62 kΩ and 92.34 kΩ to 192.46 k respectively. Electric modulus spectra reflect the contributions from grain and grain boundary effects: the large resolved semicircle arc caused by the grain effect and the small poorly resolved semicircle arc was attributed to the grain boundary.

Synthesis And Characterization Of SnO2 Nanoparticles: Effect Of Hydrolysis Rate On The Optical Properties

R. Bargougui; K. Omri; A. Mhemdi; S. Ammar

Advanced Materials Letters, 2015, Volume 6, Issue 9, Pages 816-819
DOI: 10.5185/amlett.2015.5844

Nanocrystalline SnO2 oxides particles have been successfully synthesized via polyol process using diethylene glycol (DEG) as a solvent, followed by powder thermal treatment. The general applicability of the process is shown and the advantages in terms of properties and processability are described. The powders thus prepared were investigated using X-ray diffractometry. (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and photoluminescence spectra (PL). The X-ray diffraction patterns of the samples were indexed to the rutile phase for SnO2.The TEM images show uniform isotropic morphologies with average sizes close to10 nm. This decrease in particle size is accompanied with a decrease in the band-gap value from 3.55 eV for SnO2 down to 3.27 eV as shown by UV-visible spectra. It is demonstrated that the crystallite size less than 10 nm can be controlled by changing the quantity of added water (rate hydrolysis h=n H2O/n Metal).

Swift Heavy Ion Induced Functionality In Nanocrystalline CdS Thin Films: Role Of Growth Temperature

Pragati Kumar; Nupur Saxena; Avinash Agarwal; Vinay Gupta

Advanced Materials Letters, 2015, Volume 6, Issue 9, Pages 820-827
DOI: 10.5185/amlett.2015.5921

Influence of growth temperature on swift heavy ion (SHI) induced structural and optical functionality in CdS thin films is explored for photonic applications. Intense green emission is observed in nanocrystalline CdS thin films grown by pulsed laser deposition (PLD) at two different substrate temperatures (Ts): room temperature (RT) and 200 ºC. The role of Ts and its implications on the effect of dense electronic excitation provoked by swift heavy ion irradiation (SHII) on various optical and structural properties of CdS films is investigated under the influence of 70 MeV 58 Ni +6 ion beam. It reveals from the present studies that Ts may crucially affect the crystalline structure, vibrational and electronic states of the film and thereafter the functionality induced by ion beam. It is found that ion beam is capable to transform structural phase from mixed phase of cubic and hexagonal structure to either pure cubic or pure hexagonal phase of CdS depending upon the pre-existing preferred orientation in pristine film. The modification in crystallite size and band gap due to impact of ion beam is found to be strongly dependent on pre-existing structural phase, as determined by Ts. The studies presented here confirm that initial growth conditions play a key role even after post deposition SHII treatment in selecting precisely the functional behavior of the films.

Estimation Of Magnetic Interactions In Substituted Mg-Mn Ferrites Synthesized Via Citrate Precursor Technique

Gagan Kumar; Virender Pratap Singh; Arun Kumar; Jyoti Shah; Shalendra Kumar; B.S. Chauhan; R.K. Kotnala; M. Singh

Advanced Materials Letters, 2015, Volume 6, Issue 9, Pages 828-833
DOI: 10.5185/amlett.2015.5958

We investigated the effects of In 3+ and Co 2+ substitutions on the structural and magnetic properties of Mg-Mn ferrites. The cation distribution technique was taken into account to estimate the magnetic interactions. Cation distribution was also used to investigate the ionic radii of tetrahedral and octahedral sites, oxygen positional parameter, site bond as well as edge lengths, bond lengths and bond angles. The ionic radius of tetrahedral site and octahedral site was observed to increase with the incorporation of In 3+ and Co 2+ ions respectively. Theoretical lattice parameter was observed to increase with the substitution of In 3+ and Co 2+ ions. In 3+ substitution resulted in weakening of super-exchange interactions while in Co 2+ substituted Mg-Mn ferrites, anisotropy was observed to play a decisive role in addition to bond lengths and bond angles.

Structural, Electrical and Optical Properties Of Molybdenum Doped Zinc Oxide Films Formed By Magnetron Sputtering

R. Subba Reddy; K. Radhamma; A. Sivasankar Reddy; S. Uthanna

Advanced Materials Letters, 2015, Volume 6, Issue 9, Pages 834-839
DOI: 10.5185/amlett.2015.5920

Thin films of molybdenum doped (2.7 at.%) zinc oxide (MZO) were deposited on glass substrates held at room temperature by RF magnetron sputtering of mosaic target of Mo-Zn at different substrate bias voltages. The influence of substrate bias voltage on the structural, electrical and optical properties was investigated. The MZO films deposited on unbiased substrate were of amorphous, while those formed at substrate bias voltage of -40 V and above were of nanocrystalline. The crystallite size of the films improved with the applied bias voltage. At higher substrate bias voltage of -120 V the ion bombardment induced the high defect density in the films hence decrease in the crystallinity. The films formed at substrate bias voltage of -80 V exhibited low electrical resistivity of 1.2x10 -2 Ωcm and optical transmittance of about 79 %. These films showed optical band gap of 3.29 eV and figure of merit of 19 Ω -1 cm -1 .

Structural And Electrical Properties Of Self-standing Polyaniline Films Modified With Gold Nanoparticles 

Sonika Thakur; Anupinder Singh; Lakhwant Singh

Advanced Materials Letters, 2015, Volume 6, Issue 9, Pages 840-846
DOI: 10.5185/amlett.2015.5917

Self-standing polyaniline (Pani) films modified with gold nanoparticles (Au NP’s), where Au NP’s are added in different successive weight percents, have been synthesized by conventional chemical polymerization technique. An in-depth investigation of the structural and electrical characteristics of prepared films has been conducted using various characterizations. The X-ray diffraction (XRD) validates the presence of Au NP’s in Pani and the results are supported well by energy dispersive X-ray analyzer (EDX). The field emission scanning electron microscopy (FESEM) clearly shows thorough dispersion of Au NP’s in the amorphous host matrix with minor aggregation. The Fourier transform infrared red (FTIR) studies give the information of possible chemical interaction between the nanoparticles and polymer which is in good agreement with charge transfer mechanism proposed in the manuscript. The temperature dependent dc electrical conductivity has been observed to depend strongly on the nanoparticle loading and follows Mott’s three-dimensional variable range hopping (3D VRH) conduction mechanism. Parameters obtained from Hall Effect measurements are of same order as is calculated by dc measurements which indicates a very good corroboration of results. Higher ac conductivity, dielectric constant and dielectric loss of nanocomposites have also been observed as compared to that of pure Pani.