Journal of Nanomaterials The latest articles from Hindawi © 2017 , Hindawi Limited . All rights reserved. Physical Properties Investigation of Reduced Graphene Oxide Thin Films Prepared by Material Inkjet Printing Wed, 23 Aug 2017 00:00:00 +0000 The article is focused on the study of the optical properties of inkjet-printed graphene oxide (GO) layers by spectroscopic ellipsometry. Due to its unique optical and electrical properties, GO can be used as, for example, a transparent and flexible electrode material in organic and printed electronics. Spectroscopic ellipsometry was used to characterize the optical response of the GO layer and its reduced form (rGO, obtainable, for example, by reduction of prepared layers by either annealing, UV radiation, or chemical reduction) in the visible range. The thicknesses of the layers were determined by a mechanical profilometer and used as an input parameter for optical modeling. Ellipsometric spectra were analyzed according to the dispersion model and the influence of the reduction of GO on optical constants is discussed. Thus, detailed analysis of the ellipsometric data provides a unique tool for qualitative and also quantitative description of the optical properties of GO thin films for electronic applications. Veronika Schmiedova, Jan Pospisil, Alexander Kovalenko, Petr Ashcheulov, Ladislav Fekete, Tomas Cubon, Peter Kotrusz, Oldrich Zmeskal, and Martin Weiter Copyright © 2017 Veronika Schmiedova et al. All rights reserved. Influence of Irradiation Time on Structural, Morphological Properties of ZnO-NRs Films Deposited by MW-CBD and Their Photodiode Applications Tue, 22 Aug 2017 06:44:20 +0000 Microwave-assisted chemical bath deposition (MW-CBD) was used to deposit zinc oxide nanorods (ZnO-NRs) films by using different microwave irradiation time. The films exhibit a good crystallinity having a hexagonal wurtzite phase formation. Although the dominant preferred orientation was not observed for the ZnO-5 and ZnO-10, ZnO-8 showed (002) preferred orientation. The emission scanning electron microscope (FESEM) showed almost randomly oriented hexagonal nanorods on the surface. A slight decrease in the length of the observed hexagonal nanorods due to the increase in the irradiation time was observed, changing from 550 nm to 300 nm. The p-Si/n-ZnO-NRs heterojunction photodiodes were fabricated. The current-voltage characteristics of these photodiodes were investigated under dark and different illumination intensity. An increase in the reverse current with increasing illumination intensity confirmed that the fabricated photodiodes exhibited a photoconducting behavior. In addition, the barrier height and series resistance values of the photodiodes were determined from capacitance-voltage measurements. Saliha Ilican, Kamuran Gorgun, Yasemin Caglar, and Mujdat Caglar Copyright © 2017 Saliha Ilican et al. All rights reserved. Efficient Absorption of Antibiotic from Aqueous Solutions over MnO2@SA/Mn Beads and Their In Situ Regeneration by Heterogeneous Fenton-Like Reaction Mon, 21 Aug 2017 06:20:33 +0000 Alginate has been extensively used as absorbents due to its excellent properties. However, the practical application of pure alginate has been restricted since the saturated adsorbent has weak physical structure and could not be regenerated easily. In this study, a low-cost and renewable composite MnO2@alginate/Mn adsorbent has been prepared facilely for the absorptive removal of antibiotic wastewater. FE-SEM, FTIR, and XRD analyses were used to characterize the samples. The norfloxacin (NOR) was used as an index of antibiotics. More specifically, the batch absorption efficiency of the adsorbents was evaluated by pH, contact time with different NOR concentration, and the temperature. Thus, the performance of absorption kinetic dynamics and isotherm equations were estimated for the adsorptive removal process. Parameters including , , and were utilized to describe the feasible adsorption process. To regenerate the saturated absorptive sites of the adsorbent, the heterogeneous Fenton-like reactions were trigged by introduction of H2O2. The results showed that the in situ regenerating has exhibited an excellent recycling stability. The high activity and the simple fabrication of the adsorbents make them attractive for the treatment of wastewater containing refractory organic compound and also provide fundamental basis and technology for further practical application. Yu Luo, Bo Bai, Honglun Wang, Yourui Suo, and Yiliang Yao Copyright © 2017 Yu Luo et al. All rights reserved. Influence of the Distance between Nanoparticles in Clusters on the Magnetization Reversal Process Sun, 20 Aug 2017 00:00:00 +0000 Fourfold magnetic nanoparticles, created from nanowires or in the form of an open square, offer the possibility of creating quaternary memory devices with four unambiguously distinguishable stable states at remanence. This feature, however, has been simulated for single magnetic nanoparticles or clusters with interparticle distances similar to the nanoparticle dimensions. For the possible use in bit-patterned media, it is important to understand the scaling behavior of the stability of the additional intermediate states with the interparticle distance. The paper investigates exemplarily nanoparticles of two shapes which were found to be optimum to gain four states at remanence. For clusters of these particles, the probability of reaching the additional intermediate states in all particles in the same field region is strongly reduced with decreased interparticle distance. The differences between both shapes indicate possible solutions for this problem in the form of new nanoparticle shapes. Andrea Ehrmann and Tomasz Blachowicz Copyright © 2017 Andrea Ehrmann and Tomasz Blachowicz. All rights reserved. Preparation and Characterisation of Nobiletin-Loaded Nanostructured Lipid Carriers Thu, 17 Aug 2017 00:00:00 +0000 The objective of this manuscript was to investigate and optimise the potential of nanostructured lipid carriers (NLCs) as a carrier system for nobiletin (NOB), which was prepared by high-pressure homogenisation method. Additionally, this study was focused on the application of NOB-loaded NLC (NOB-NLC) in functional food. Response surface method with a three-level Box–Behnken design was validated through analysis of variance, and the robustness of the design was confirmed through the correspondence between the values measured in the experiments and the predicted ones. Properties of the prepared NOB-NLC, such as -average, polydispersity, entrapment efficiency, zeta potential, morphology, and crystallinity, were investigated. NOB-NLC exhibited a spherical shape with a diameter of 112.27 ± 5.33 nm, zeta potential of −35.1 ± 2.94 mV, a polydispersity index of 0.251 ± 0.058, and an EE of 81.06%±6.02%. Results from X-ray diffraction and differential scanning calorimetry of NOB-NLC reviewed that the NOB crystal might be converted to an amorphous state. Fourier transform infrared spectroscopic analysis demonstrated that chemical interaction was absent between the compound and lipid mixture in NOB-NLC. Wei Huang, Huating Dou, Houjiu Wu, Zhigao Sun, Hua Wang, and Linhua Huang Copyright © 2017 Wei Huang et al. All rights reserved. Synthesis and Characterization of the Optical Properties of Pt-TiO2 Nanotubes Sun, 13 Aug 2017 08:21:48 +0000 Composite Pt-doped TiO2 nanotubes (Pt-TNTs) were synthesized via alkaline fusion-hydrothermal method (AFHM) under ambient atmosphere pressure. Further systematic characterization of Pt-TNTs was performed by using XPS, surface photovoltage spectroscopy (SPS), electric field-induced surface photovoltage spectroscopy (FISPS), UV-Vis diffuse reflectance spectrophotometry (UV-Vis), TEM, and XRD. XPS spectrum showed double peaks which accounted for the presence of platinum dioxide and platinum oxide (PtO2 and PtO, ). Composition analysis showed that the particulate matters on surface of Pt-TNTs were composed of and TiO2. The results of SPS and FISPS demonstrated that the bound exciton showed sub-band gap transition characteristics with the asymmetric changes of photoelectric property corresponding to changes in polarity and strength of the external electric field. Furthermore, the influence of the changed microstructure morphology of Pt-doped TNTs on both the photovoltage spectroscopy and the lifetime of photogenerated carriers which occurred at the interfaces of Pt-TNTs was observed. Result of XRD indicated that a mixture of anatase and rutile phases prevailed in Pt-TNTs. Contact potential barriers consisting of , anatase, rutile, and are presumed to form upon particle that deposited on the surface of Pt-TNTs. Zhuwu Jiang, Jingling Li, Wei Liao, Gongduan Fan, Hualiang Yu, Lihong Chen, and Zhaoyue Su Copyright © 2017 Zhuwu Jiang et al. All rights reserved. Structural and Optical Properties of Spray Coated Carbon Hybrid Materials Applied to Transparent and Flexible Electrodes Sun, 13 Aug 2017 00:00:00 +0000 Transparent and flexible electrodes were fabricated with cost-effective spray coating technique on polyethylene terephthalate foil substrates. Particularly designed paint compositions contained mixtures of multiwalled carbon nanotubes and graphene platelets to achieve their desired rheology and electrooptical layers parameters. Electrodes were prepared in standard technological conditions without the need of clean rooms or high temperature processing. The sheet resistance and optical transmittance of fabricated layers were tuned with the number of coatings; then the most suitable relation of these parameters was designated through the figure of merit. Optical measurements were performed in the range of wavelengths from 250 to 2500 nm with a spectrophotometer with the integration sphere. Spectral dependence of total and diffusive optical transmission for thin films with graphene platelet covered by multiwalled carbon nanotubes was designated which allowed determining the relative absorbance. Layer parameters such as thickness, refractive index, energy gap, and effective reflectance coefficient show the correlation of electrooptical properties with the technological conditions. Moreover the structural properties of fabricated layers were examined by means of the X-ray diffraction. Grzegorz Wroblewski, Barbara Swatowska, Wieslaw Powroznik, Malgorzata Jakubowska, and Tomasz Stapinski Copyright © 2017 Grzegorz Wroblewski et al. All rights reserved. The Advances of Carbon Nanotubes in Cancer Diagnostics and Therapeutics Wed, 09 Aug 2017 00:00:00 +0000 Carbon nanotubes (CNTs), one of the unique one-dimensional nanomaterials, have gained great attention because of their specific characters, versatile functionalization chemistry, and biological compatibility in the past few decades. CNTs can be functionalized via different methods to perform their specific functions. CNTs have been used in various areas of biomedicine as nanocarriers, including cancer diagnosis and therapy. Different molecules such as peptide, antigen, and nucleic acid can be delivered to cancer cells by CNTs with high efficiency. In this review, we summarized the properties of CNTs and the method of CNTs functionalization and illustrated their application in cancer diagnosis and therapy. Zhou Chen, Aili Zhang, Xiaobing Wang, Jing Zhu, Yamin Fan, Hongmei Yu, and Zhaogang Yang Copyright © 2017 Zhou Chen et al. All rights reserved. Low-Density Polyethylene/Polyamide/Clay Blend Nanocomposites: Effect of Morphology of Clay on Their Photooxidation Resistance Wed, 09 Aug 2017 00:00:00 +0000 The photooxidation behaviour of low-density polyethylene (LDPE)/polyamide (PA) blends, containing polyamide 11 (PA11) or polyamide 6 (PA6), has been investigated in the absence and presence of a small amount of commercial organomodified clay (OMMT). The polymer blends LDPE/PA11 and LDPE/PA6 at 75/25 wt./wt.%, with and without OMMT, have been prepared by a two-step procedure: extrusion and sheet formulation. The formulated complex systems have been subjected to accurate morphological analysis in order to evaluate the effect of the OMMT presence on the refinement of the blend morphology. Furthermore, the produced sheets have been subjected to arterial UVB exposure and the variations of the mechanical properties and chemical structure of all the investigated samples have been monitored as a function of the exposure time. Finally, the rate of the photodegradation of the complex systems has been related to the morphological changes of these systems upon OMMT addition. N. Tz. Dintcheva, G. Filippone, R. Arrigo, and F. P. La Mantia Copyright © 2017 N. Tz. Dintcheva et al. All rights reserved. Stoichiometry Calculation in BaxSr1−xTiO3 Solid Solution Thin Films, Prepared by RF Cosputtering, Using X-Ray Diffraction Peak Positions and Boltzmann Sigmoidal Modelling Wed, 09 Aug 2017 00:00:00 +0000 A novel procedure based on the use of the Boltzmann equation to model the parameter, the film deposition rate, and the optical band gap of BaxSr1−xTiO3 thin films is proposed. The BaxSr1−xTiO3 films were prepared by RF cosputtering from BaTiO3 and SrTiO3 targets changing the power applied to each magnetron to obtain different Ba/Sr contents. The method to calculate consisted of fitting the angular shift of (110), (111), and (211) diffraction peaks observed as the density of substitutional Ba2+ increases in the solid solution when the applied RF power increases, followed by a scale transformation from applied power to parameter using the Boltzmann equation. The Ba/Sr ratio was obtained from X-ray energy dispersive spectroscopy; the comparison with the X-ray diffraction derived composition shows a remarkable coincidence while the discrepancies offer a valuable diagnosis on the sputtering flux and phase composition. The proposed method allows a quick setup of the RF cosputtering system to control film composition providing a versatile tool to optimization of the process. J. Reséndiz-Muñoz, J. L. Fernández-Muñoz, M. A. Corona-Rivera, M. Zapata-Torres, A. Márquez-Herrera, M. Meléndez-Lira, F. Caballero-Briones, F. Chale-Lara, and O. Zelaya-Ángel Copyright © 2017 J. Reséndiz-Muñoz et al. All rights reserved. Deviation from Regular Shape in the Early Stages of Formation of Strain-Driven 3D InGaAs/GaAs Micro/Nanotubes Tue, 08 Aug 2017 07:11:38 +0000 Single-crystalline InGaAs/GaAs semiconductor micro/nanotubes have been obtained by the strain-driven self-rolling mechanism. This approach combines the advantages of bottom-up (epitaxial growth) and top-down (postgrowth processing) techniques, offering an exceptional opportunity to realize complex three-dimensional nanoarchitectures by using conventional photolithography and wet-etching processes. The method employed to obtain micro/nanotubes with selected orientation and length is described in detail. By means of high-resolution scanning electron microscopy characterization, we show a clear shape difference between single-wall and multiwalls tubes and we discuss it on the basis of strain release, taking into account also possible shape deformations induced during micro/nanotubes drying. We analyse the In-segregation profile in the nominal In0.20Ga0.80As/GaAs bilayer and we show its effect on the actual diameter of the tubes, concluding that a more accurate description of the structure should consider an In0.20Ga0.80As/In0.10Ga0.90As/GaAs trilayer. This work will be useful to set up reliable methodologies for the realization of strain-driven micro/nanotubes with controlled properties, necessary for their implementation in a large number of application fields. Paola Frigeri, Luca Seravalli, Marco Calicchio, Enos Gombia, and Giovanna Trevisi Copyright © 2017 Paola Frigeri et al. All rights reserved. Silica Based Superhydrophobic Nanocoatings for Natural Rubber Surfaces Tue, 08 Aug 2017 00:00:00 +0000 Silica based nonfluorinated superhydrophobic coatings for natural rubber surfaces have been developed. The coating was synthesized using nanosilica dispersion and a polychloroprene type binder as a compatibilizer. This nanocoating of silica was applied on to the surface of finished natural rubber gloves, by spray coating or dipped coating methods. The nanocoating demonstrates a water contact angle of more than 150° and sliding angle of 7°. The morphological features of the coating have been studied using scanning electron microscopy and atomic force microscopy while Fourier transform infrared spectroscopy was used to understand the nature of surface functional groups. Both imaging techniques provided evidence for the presence of nanosized particles in the coating. Coated gloves demonstrated comparable mechanical properties and significantly better alcohol resistivity when compared to those of the uncoated gloves. Veromee Kalpana Wimalasiri, Helapiyumi Uthpala Weerathunga, Nilwala Kottegoda, and Veranja Karunaratne Copyright © 2017 Veromee Kalpana Wimalasiri et al. All rights reserved. Facile Synthesis, Microstructure, and Gas Sensing Properties of NdCoO3 Nanoparticles Thu, 03 Aug 2017 07:46:55 +0000 NdCoO3 nanoparticles were successfully synthesized by a simple, inexpensive, and reproducible solution method for gas sensing applications. Cobalt nitrate, neodymium nitrate, and ethylenediamine were used as precursors and distilled water as solvent. The solvent was evaporated later by means of noncontinuous microwave radiation at 290 W. The obtained precursor powders were calcined at 200, 500, 600, and 700°C in a standard atmosphere. The oxide crystallized in an orthorhombic crystal system with space group Pnma (62) and cell parameters  Å,  Å, and  Å. The nanoparticles showed a diffusional growth to form a network-like structure and porous adsorption configuration. Pellets prepared from NdCoO3 were tested as gas sensors in atmospheres of carbon monoxide and propane at different temperatures. The oxide nanoparticles were clearly sensitive to changes in gas concentrations (0–300 ppm). The sensitivity increased with increasing concentration of the gases and operating temperatures (25, 100, 200, and 300°C). Lorenzo Gildo-Ortiz, Héctor Guillén-Bonilla, Juan Reyes-Gómez, Verónica María Rodríguez-Betancourtt, M. de la L. Olvera-Amador, Sandra Irene Eguía-Eguía, Alex Guillén-Bonilla, and Jaime Santoyo-Salazar Copyright © 2017 Lorenzo Gildo-Ortiz et al. All rights reserved. Natural Transformation of Zinc Oxide Nanoparticles and Their Cytotoxicity and Mutagenicity Wed, 02 Aug 2017 08:52:11 +0000 With rapid development of the nanoindustry, studies focusing on the transformation of nanoparticles (NPs) are required to understand their stability and toxicity after being released into the environment. Here, we characterized the physicochemical properties of ZnO NPs and found that they are naturally alkalized in the presence of air (without the addition of exogenous alkaline substances). Energy dispersive X-ray/X-ray powder diffraction/Fourier transform infrared (EDX/XRD/FTIR)/Raman spectroscopy gave evidence for the formation of hydrozincite (Zn5(CO3)2(OH)6) and zinc hydroxide (Zn(OH)2). Further, we comparatively evaluated the cellular toxicity of pristine and alkalized ZnO NPs. Cell viability testing (colony formation) showed that alkalization time-dependently decreased cytotoxicity. Alkalized NPs exhibited mutagenicity at multiple concentrations, as shown by a CD59 gene loci mutation assay. Variations in toxicity were associated with the chemical transformation of ZnO NPs, and Zn2+ played a key role in the mutagenicity of alkalized NPs. These results indicate that NPs are chemically transformed in the environment. These transformations result in obvious variations in toxicity, suggesting that the NP transformation process should be considered more thoroughly when evaluating toxicity. Mei M. Wang, Juan Wang, Rui Cao, Si Y. Wang, and Hua Du Copyright © 2017 Mei M. Wang et al. All rights reserved. Hybrids of Iron-Filled Multiwall Carbon Nanotubes and Anticancer Agents as Potential Magnetic Drug Delivery Systems: In Vitro Studies against Human Melanoma, Colon Carcinoma, and Colon Adenocarcinoma Mon, 31 Jul 2017 07:22:58 +0000 Cell type, morphology, and functioning are key variables in the construction of efficient “drug-vehicle” hybrids in magnetic drug delivery. Iron-encapsulated multiwall carbon nanotubes (Fe@MWCNTs) appear as promising candidates for theranostics due to in situ chemical catalytic vapor deposition (c-CVD) synthesis, straightforward organic functionalization, and nanoneedle (1D) behavior. Here, model hybrids were synthesized by exploring C-sp2 chemistry ((1+2)-cycloaddition of nitrenes and amidation) of the outer MWCNT walls combined with anticancer agents, that is, 5-fluorouracil (5FU), purpurin (Purp), and 1,8-naphthalimide DNA intercalators (NIDIs), via linkers. Analyses of the Fe@MWCNT vehicles by SEM, TEM, and Raman spectroscopy revealed their morphology while Mössbauer spectroscopy confirmed the presence of encapsulated ferromagnetic iron-based nanodomains. Cytotoxicity of the hybrids was studied using a 24 h MTS assay combined with the apoptosis and life cycle assays against human melanoma (Me45), colon carcinoma (HCT116+), and colon adenocarcinoma (Caco-2). The cells had different sensitivity to the vehicles themselves as well as to the hybrids. MWCNT-based covalent hybrids of 5FU and Purp emerged as the most promising systems against Me45 and HCT116+ cell lines with the highest in vitro cytotoxicity and proapoptotic activity. Furthermore, nanotubes bearing 4-nitro- and 4-(N-morpholinyl)-1,8-naphthalimide DNA intercalators appear as a promising candidate for the treatment of Caco-2. Sławomir Boncel, Anna Pluta, Magdalena Skonieczna, Andrzej Gondela, Barbara Maciejewska, Artur P. Herman, Rafał G. Jędrysiak, Sebastian Budniok, Kamila Komędera, Artur Błachowski, and Krzysztof Z. Walczak Copyright © 2017 Sławomir Boncel et al. All rights reserved. Recent Progress in Synthesis and Application of Low-Dimensional Silicon Based Anode Material for Lithium Ion Battery Mon, 31 Jul 2017 00:00:00 +0000 Silicon is regarded as the next generation anode material for LIBs with its ultra-high theoretical capacity and abundance. Nevertheless, the severe capacity degradation resulting from the huge volume change and accumulative solid-electrolyte interphase (SEI) formation hinders the silicon based anode material for further practical applications. Hence, a variety of methods have been applied to enhance electrochemical performances in terms of the electrochemical stability and rate performance of the silicon anodes such as designing nanostructured Si, combining with carbonaceous material, exploring multifunctional polymer binders, and developing artificial SEI layers. Silicon anodes with low-dimensional structures (0D, 1D, and 2D), compared with bulky silicon anodes, are strongly believed to have several advanced characteristics including larger surface area, fast electron transfer, and shortened lithium diffusion pathway as well as better accommodation with volume changes, which leads to improved electrochemical behaviors. In this review, recent progress of silicon anode synthesis methodologies generating low-dimensional structures for lithium ion batteries (LIBs) applications is listed and discussed. Yuandong Sun, Kewei Liu, and Yu Zhu Copyright © 2017 Yuandong Sun et al. All rights reserved. Molecular Dynamics Simulation of Crack Propagation in Single-Crystal Aluminum Plate with Central Cracks Thu, 27 Jul 2017 09:20:52 +0000 The crack propagation process in single-crystal aluminum plate (SCAP) with central cracks under tensile load was simulated by molecular dynamics method. Further, the effects of model size, crack length, temperature, and strain rate on strength of SCAP and crack growth were comprehensively investigated. The results showed that, with the increase of the model size, crack length, and strain rate, the plastic yield point of SCAP occurred in advance, the limit stress of plastic yield decreased, and the plastic deformability of material increased, but the temperature had less effect and sensitivity on the strength and crack propagation of SCAP. The model size affected the plastic deformation and crack growth of the material. Specifically, at small scale, the plastic deformation and crack propagation in SCAP are mainly affected through dislocation multiplication and slip. However, the plastic deformation and crack propagation are obviously affected by dislocation multiplication and twinning in larger scale. Jun Ding, Lu-sheng Wang, Kun Song, Bo Liu, and Xia Huang Copyright © 2017 Jun Ding et al. All rights reserved. Effect of Nanotube Geometry on the Strength and Dispersion of CNT-Cement Composites Thu, 27 Jul 2017 07:21:41 +0000 This study investigated the effect of multiwalled carbon nanotubes’ geometry on the dispersion and strength of cement composites. Mixes with CNTs contents ranging from 0.03 to 0.25% were prepared and tested using CNTs’ diameters of 10–20, 20–30, and 30–50 nm and lengths of 0.5–2 and 10–30 μm. The samples’ microstructures were then examined using a scanning electron microscope. After that, Response Surface Methodologies techniques were implemented to determine the strength functions’ response to the aspect ratio and weight fraction variables. The results showed that CNTs of smaller diameters and longer lengths resulted in the highest strength values in batches having CNT contents of up to 0.15%. At 0.25% CNTs, the results showed that those CNTs of shorter lengths attained higher strengths than those of longer ones. SEM images showed better dispersion properties at lower CNTs’ contents regardless of their geometry. The analysis also indicated that short CNTs of 0.5–2 μm length have better dispersion properties compared to long ones of 10–30 μm length. The RSM model confirmed this finding. Furthermore, the model showed that the CNTs with the lowest aspect ratio of 83 and highest weight fraction of 0.25% provided the highest strength response among all batches. Mohamed O. Mohsen, Ramzi Taha, Ala Abu Taqa, Nasser Al-Nuaimi, Rashid Abu Al-Rub, and Khaldoon A. Bani-Hani Copyright © 2017 Mohamed O. Mohsen et al. All rights reserved. Effect of Aluminum Incorporation into Mesoporous Aluminosilicate Framework on Drug Release Kinetics Thu, 27 Jul 2017 07:09:49 +0000 Mesoporous silica materials are promising nanocarriers for the development of drug delivery systems. In this study, the influence of pore size, volume, surface area, and doping the silica framework on the release kinetics of a model drug, metoprolol, has been studied. 20% or 50% wt. therapeutic agent was loaded into the carrier mesopores through incipient wetness impregnation. The carriers and drug-loaded samples have been characterized by small- and wide-angle X-ray diffraction, FT-IR spectroscopy, scanning electron microscopy, and nitrogen adsorption-desorption isotherms. The in vitro release profiles have been fitted using a three-parameter kinetic model and they have been explained in terms of the release rate during the burst and sustained release stages and the fraction of drug molecules released during the burst stage. The silica framework doping with aluminum was found to decrease the amount of drug released in the burst stage, without affecting the other kinetic parameters. The therapeutic agent release rates depend mainly on the pore size and volume of the mesoporous carriers and drug-loaded samples. Raul-Augustin Mitran, Daniela Berger, Jeanina Pandele-Cusu, and Cristian Matei Copyright © 2017 Raul-Augustin Mitran et al. All rights reserved. CVD-Graphene-Based Flexible, Thermoelectrochromic Sensor Thu, 27 Jul 2017 00:00:00 +0000 The main idea behind this work was demonstrated in a form of a new thermoelectrochromic sensor on a flexible substrate using graphene as an electrically reconfigurable thermal medium (TEChrom™). Our approach relies on electromodulation of thermal properties of graphene on poly(ethylene terephthalate) (PET) via mechanical destruction of a graphene layer. Graphene applied in this work was obtained by chemical vapor deposition (CVD) technique on copper substrate and characterized by Raman and scanning tunneling spectroscopy. Electrical parameters of graphene were evaluated by the van der Pauw method on the transferred graphene layers onto SiO2 substrates by electrochemical delamination method. Two configurations of architecture of sensors, without and with the thermochromic layer, were investigated, taking into account the increase of voltage from 0 to 50 V and were observed by thermographic camera to define heat energy. Current-voltage characteristics obtained for the sensor with damaged graphene layer are linear, and the resistivity is independent from the current applied. The device investigated under 1000 W/m2 exhibited rise of resistivity along with increased temperature. Flexible thermoelectrochromic device with graphene presented here can be widely used as a sensor for both the military and civil monitoring. Adam Januszko, Agnieszka Iwan, Stanislaw Maleczek, Wojciech Przybyl, Iwona Pasternak, Aleksandra Krajewska, and Wlodzimierz Strupinski Copyright © 2017 Adam Januszko et al. All rights reserved. Surface Modification of Carbon Nanofibers and Graphene Platelets Mixtures by Plasma Polymerization of Propylene Tue, 25 Jul 2017 09:43:10 +0000 Carbon nanofibers (CNFs), graphene platelets (GPs), and their mixtures were treated by plasma polymerization of propylene. The carbon nanoparticles (CNPs) were previously sonicated in order to deagglomerate and increase the surface area. Untreated and plasma treated CNPs were analyzed by dynamic light scattering (DLS), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and thermogravimetric analysis (TGA). DLS analysis showed a significant reduction of average particle size, due to the sonication pretreatment. Plasma polymerized propylene was deposited on the CNPs surface; the total amount of polymerized propylene was from 4.68 to 6.58 wt-%. Raman spectroscopy indicates an increase in the sp3 hybridization of the treated samples, which suggest that the polymerized propylene is grafted onto the CNPs. Carlos Andrés Covarrubias-Gordillo, Florentino Soriano-Corral, Carlos Alberto Ávila-Orta, Victor Javier Cruz-Delgado, María Guadalupe Neira-Velázquez, Ernesto Hernández-Hernández, José Francisco Hernández-Gámez, and Patricia Adriana De León-Martínez Copyright © 2017 Carlos Andrés Covarrubias-Gordillo et al. All rights reserved. TiO2 Nanotubes with Different Ag Loading to Enhance Visible-Light Photocatalytic Activity Tue, 25 Jul 2017 00:00:00 +0000 An improved photocatalytic activity of semiconductor materials using incorporation of the noble metals such as Ag, Au, and Pt is a promising technology. In this study, Ag nanoparticle-TiO2 nanotube structures (Ag-TNTs) have been investigated as a photocatalyst in different irradiation conditions using different characterization techniques. The results indicate that Ag nanoparticles dispersed uniformly on the TNTs’ surface without any change in TNTs’ morphology. In addition, Ag-TNTs exhibited lower photoactivity than the TNTs under UV irradiation. In contrast, Ag-TNTs increased the photoactivity in comparison with TNTs and the photocatalytic performance under sunlight irradiation. These phenomena could be contributed to the appearance of Ag nanoparticles on the nanotube surface. Thi Ngoc Tu Le, Nu Quynh Trang Ton, Van Man Tran, Nguyen Dang Nam, and Thi Hanh Thu Vu Copyright © 2017 Thi Ngoc Tu Le et al. All rights reserved. Interaction of Solid Lipid Nanoparticles and Specific Proteins of the Corona Studied by Surface Plasmon Resonance Tue, 25 Jul 2017 00:00:00 +0000 The applications of pharmaceutical and medical nanosystems are among the most intensively investigated fields in nanotechnology. A relevant point to be considered in the design and development of nanovehicles intended for medical use is the formation of the “protein corona” around the nanoparticle, that is, a complex biomolecular layer formed when the nanovehicle is exposed to biological fluids. The chemical nature of the protein corona determines the biological identity of the nanoparticle and influences, among others, the recognition of the nanocarrier by the mononuclear phagocytic system and, thus, its clearance from the blood. Recent works suggest that Surface Plasmon Resonance (SPR), extensively employed for the analysis of biomolecular interactions, can shed light on the formation of the protein corona and its interaction with the surroundings. The synthesis and characterization of solid lipid nanoparticles (SLN) coated with polymers of different chemical nature (e.g., polyvinyl alcohol, chitosans) are reported. The proof-of-concept for the use of SPR technique in characterizing protein-nanoparticle interactions of surface-immobilized proteins (immunoglobulin G and bovine serum albumin, both involved in the formation of the corona) subjected to flowing SLN is demonstrated for non-chitosan-coated nanoparticles. All assayed nanosystems show more preference for IgG than for BSA, such preference being more pronounced in the case of polyvinyl-alcohol-coated SLN. Mauricio E. Di Ianni, Germán A. Islan, Cecilia Y. Chain, Guillermo R. Castro, Alan Talevi, and María E. Vela Copyright © 2017 Mauricio E. Di Ianni et al. All rights reserved. One-Step Synthesis of Hierarchical Micro-Mesoporous SiO2/Reduced Graphene Oxide Nanocomposites for Adsorption of Aqueous Cr(VI) Mon, 24 Jul 2017 08:21:03 +0000 A novel micro-mesostructured SiO2/reduced graphene oxide (RGO) nanocomposite was successfully synthesized by means of simple one-step hydrothermal method under acidic conditions using tetraethoxysilane (TEOS) and graphene oxide (GO) as the raw material. The nanocomposites were characterized by TEM, XRD, FT-IR, TG-DSC, and N2 adsorption-desorption. The results showed that GO was partially reduced to RGO without adding any reducing agent and SiO2 nanoparticles (ca. 10 nm) were uniformly anchored on the surface of RGO. The optimized composite contained 75 wt.% SiO2 and possessed hierarchical micro-mesoporous structure with surface area of 676 m2/g. The adsorption performance of synthesized SiO2/RGO samples was investigated by removal efficiency of Cr(VI) ions in wastewater. The Cr(VI) adsorption reached equilibrium in 30 min and 98.8% Cr(VI) adsorption efficiency was achieved at pH = 2 at 35°C. Stability tests showed that SiO2 nanoparticles effectively prevented RGO from the restacking. The mechanisms of composite formation and for Cr(VI) adsorption were suggested. Guiyun Yi, Baolin Xing, Huihui Zeng, Xiaodong Wang, Chuanxiang Zhang, Jianliang Cao, and Lunjian Chen Copyright © 2017 Guiyun Yi et al. All rights reserved. Fast and Straightforward Synthesis of Luminescent Titanium(IV) Dioxide Quantum Dots Thu, 20 Jul 2017 07:21:59 +0000 The nucleus of titania was prepared by reaction of solution titanium oxosulphate with hydrazine hydrate. These titania nuclei were used for titania quantum dots synthesis by a simple and fast method. The prepared titanium(IV) dioxide quantum dots were characterized by measurement of X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), high-resolution electron microscopy (HRTEM), and selected area electron diffraction (SAED). The optical properties were determined by photoluminescence (PL) spectra. The prepared titanium(IV) dioxide quantum dots have the narrow range of UV excitation (365–400 nm) and also a close range of emission maxima (450–500 nm). Václav Štengl, Jiří Henych, Martin Šťastný, and Martin Kormunda Copyright © 2017 Václav Štengl et al. All rights reserved. The Influence of Spherical Nano-SiO2 Content on the Thermal Protection Performance of Thermal Insulation Ablation Resistant Coated Fabrics Thu, 20 Jul 2017 00:00:00 +0000 In the high temperatures experienced in fire, radiant heat accounts for 80% of the total heat flow; therefore, improving the radiation protection is the best way to enhance the thermal protective performance of thermal insulation ablation resistant coated fabrics. To achieve this goal, the coating process and the ingredients used were optimized, spherical nano-SiO2 and other particles were added, and thermal insulation ablation resistant coated fabrics with high radiant heat reflectivity were prepared. The influence of the spherical nano-SiO2 content on the thermal protection performance of the prepared coated fabrics was investigated. Research showed that (1) the radiant heat reflectivity of the prepared coated fabrics improves significantly with increasing content of spherical nano-SiO2; when the mass fraction of spherical nano-SiO2 is 15%, the reflectivity of coated fabrics is at its largest, and its average value was 74.30%. At present, the average size of grains in samples increased 1.9 times; (2) after adding the spherical nano-SiO2, the thermal stability of the thermal insulation ablation resistant coated fabrics is significantly improved; the residual mass is as high as 88.49% at 1200°C, which is 18.77% higher than the residual mass of the coated fabrics with no spherical nano-SiO2 added at the same temperature. Guoyi Liu, Yuanjun Liu, and Xiaoming Zhao Copyright © 2017 Guoyi Liu et al. All rights reserved. Writing Field Analysis for Shingled Bit-Patterned Magnetic Recording Thu, 20 Jul 2017 00:00:00 +0000 A novel method utilizing response surface methodology (RSM) is proposed for effective analysis of the combined influence of writing head geometry and media properties on writing field performance. The method comprises two main modules: () a parametric writing head model based on finite element electromagnetic field analysis and () an effective writing field gradient model based on RSM. Using the method proposed, the writing performance of an asymmetrically shielded writing head for shingled magnetic recording on bit-patterned media (SMR-BPM) is analyzed. The results show that the shielding trailing gap and medium coercivity primarily impact the effective writing field (EWF) gradient and that the shielding side gap has a secondary impact. More importantly, the analysis shows a strong interaction effect between the influences of writing head geometry and medium coercivity on the EWF gradient, which indicates the need for inclusive design. X. G. Li, Z. J. Liu, A. G. Kang, and X. Y. Xie Copyright © 2017 X. G. Li et al. All rights reserved. Evaluation of Mechanical Properties of Σ5(210)/[001] Tilt Grain Boundary with Self-Interstitial Atoms by Molecular Dynamics Simulation Thu, 20 Jul 2017 00:00:00 +0000 Grain boundary (GB) can serve as an efficient sink for radiation-induced defects, and therefore nanocrystalline materials containing a large fraction of grain boundaries have been shown to have improved radiation resistance compared with their polycrystalline counterparts. However, the mechanical properties of grain boundaries containing radiation-induced defects such as interstitials and vacancies are not well understood. In this study, we carried out molecular dynamics simulations with embedded-atom method (EAM) potential to investigate the interaction of Σ5(210)/[] symmetric tilt GB in Cu with various amounts of self-interstitial atoms. The mechanical properties of the grain boundary were evaluated using a bicrystal model by applying shear deformation and uniaxial tension. Simulation results showed that GB migration and GB sliding were observed under shear deformation depending on the number of interstitial atoms that segregated on the boundary plane. Under uniaxial tension, the grain boundary became a weak place after absorbing self-interstitial atoms where dislocations and cracks were prone to nucleate. Liang Zhang, Cheng Lu, Linqing Pei, Xing Zhao, Jie Zhang, and Kiet Tieu Copyright © 2017 Liang Zhang et al. All rights reserved. Nanoparticles Decorated on Resin Particles and Their Flame Retardancy Behavior for Polymer Composites Wed, 19 Jul 2017 06:13:02 +0000 New nanocomposites have been developed by doping of amberlite IR120 resin with spherical TiO2 nanoparticles in the presence of maleate diphosphate. Polystyrene composites of resin, maleate diphosphate, and resin-maleate diphosphate were prepared individually. This is in addition to preparation of polymer nanocomposites of polystyrene-resin doped TiO2 nanoparticles-maleate diphosphate. The flame retardancy and thermal stability properties of these developed polymer composites were evaluated. The inclusion of resin and resin doped nanoparticles improved the fire retardant behavior of polystyrene composites and enhanced their thermal stability. Synergistic behavior between flame retardant, resin, and nanoparticles was detected. The rate of burning of the polymer nanocomposites was recorded as 10.7 mm/min achieving 77% reduction compared to pure polystyrene (46.5 mm/min). The peak heat release rate (PHRR) of the new polymer composites has reduced achieving 46% reduction compared to blank polymer. The morphology and dispersion of nanoparticles on resin and in polymer nanocomposites were characterized using transmission and scanning electron microscopy, respectively. The flame retardancy and thermal properties were evaluated using UL94 flame chamber, cone tests, and thermogravimetric analysis, respectively. Nour F. Attia and Mohamed Zayed Copyright © 2017 Nour F. Attia and Mohamed Zayed. All rights reserved. Plasma Treated Active Carbon for Capacitive Deionization of Saline Water Wed, 19 Jul 2017 00:00:00 +0000 The plasma treatment on commercial active carbon (AC) was carried out in a capacitively coupled plasma system using Ar + 10% O2 at pressure of 4.0 Torr. The RF plasma power ranged from 50 W to 100 W and the processing time was 10 min. The carbon film electrode was fabricated by electrophoretic deposition. Micro-Raman spectroscopy revealed the highly increased disorder of sp2 C lattice for the AC treated at 75 W. An electrosorption capacity of 6.15 mg/g was recorded for the carbon treated at 75 W in a 0.1 mM NaCl solution when 1.5 V was applied for 5 hours, while the capacity of the untreated AC was 1.01 mg/g. The plasma treatment led to 5.09 times increase in the absorption capacity. The jump of electrosorption capacity by plasma treatment was consistent with the Raman spectra and electrochemical double layer capacitance. This work demonstrated that plasma treatment was a potentially efficient approach to activating biochar to serve as electrode material for capacitive deionization (CDI). Aiping Zeng, Maheshwar Shrestha, Keliang Wang, Victor F. Neto, Bárbara Gabriel, and Qi Hua Fan Copyright © 2017 Aiping Zeng et al. 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