Journal of Nanomaterials The latest articles from Hindawi © 2017 , Hindawi Limited . All rights reserved. Linear Optical Properties of Zinc Borotellurite Glass Doped with Lanthanum Oxide Nanoparticles for Optoelectronic and Photonic Application Wed, 29 Mar 2017 00:00:00 +0000 Enhancing the optical properties of glasses for the sake of optical application in various fields is an ongoing challenge in materials science and technology. Thus, the optical properties of zinc borotellurite glass doped with lanthanum oxide nanoparticles (La2O3 NPs) with the chemical composition of {[(TeO2)0.7(B2O3)0.3]0.7(ZnO)0.3}1−x (La2O3 NPs)x, where = 0.01, 0.02, 0.03, 0.04, and 0.05 molar fraction, have been investigated. Characterization techniques such as x-ray diffraction, Fourier Transform Infrared Spectroscopy, and Ultraviolet-Visible Spectroscopy are employed to yield the structural properties and optical parameter of the glass. The amorphous nature of the fabricated glasses is confirmed with the presence of a broad hump via XRD diffraction pattern. The decreasing amount of high polarizable nonbridging oxygen as the concentration of La2O3 NPs increases has contributed to the increasing trend of energy band gap in the range of 2.70 to 3.52 eV and decreasing value of refractive index between 2.34 and 2.48. The fabricated glasses that have a higher refractive index than the widely used fiber material, pure silica glass, indicate that zinc borotellurite glass doped with lanthanum nanoparticles is a promising material to be applied as optical fibers. Faznny Mohd Fudzi, Halimah Mohamed Kamari, Amirah Abd Latif, and Azlan Muhammad Noorazlan Copyright © 2017 Faznny Mohd Fudzi et al. All rights reserved. Nanocomposites of NR/SBR Blend Prepared by Latex Casting Method: Effects of Nano-TiO2 and Polystyrene-Encapsulated Nano-TiO2 on the Cure Characteristics, Physical Properties, and Morphology Wed, 29 Mar 2017 00:00:00 +0000 Nanocomposites of 80/20 (w/w) natural rubber (NR)/styrene butadiene rubber (SBR) blend with four loadings of either nanosized titanium dioxide (nTiO2) or polystyrene-encapsulated nTiO2 (PS-nTiO2), ranging from 3 to 9 parts by weight per hundred of rubber (phr), were prepared by latex casting method. The PS-nTiO2 synthesized via in situ differential microemulsion polymerization displayed a core-shell morphology (nTiO2 core and PS shell) with an average diameter of 42 nm. The cure characteristics (scorch time, cure time, and cure rate index), mechanical properties (tensile properties, tear strength, and hardness), thermal stability, glass transition temperature, and morphology of the prepared nanocomposites were quantified and compared. The results showed that the cure characteristics of all the nanocomposites were not significantly changed compared to those of the neat NR/SBR blend. The inclusion of an appropriate amount of either nTiO2 or PS-nTiO2 into the NR/SBR blend apparently improved the tensile strength, modulus at 300% strain, tear strength, hardness, and thermal stability but deteriorated the elongation at break of the nanocomposites. Based on differential scanning calorimetry, the glass transition temperature of all the nanocomposites was similar to that of the neat NR/SBR blend. Moreover, the morphology of the PS-nTiO2-filled rubber nanocomposites fractured surface analyzed by scanning electron microscopy showed an improvement in the interfacial adhesion between the rubber phase and the nanoparticles. Anyaporn Boonmahitthisud, Peeraphong Pokphat, Phasawat Chaiwutthinan, and Saowaroj Chuayjuljit Copyright © 2017 Anyaporn Boonmahitthisud et al. All rights reserved. Growth of MWCNTs on Flexible Stainless Steels without Additional Catalysts Tue, 28 Mar 2017 10:01:29 +0000 Multiwalled carbon nanotubes (MWCNTs) were synthesized on austenitic stainless steel foils (Type 304) using a home-built thermal chemical vapor deposition (CVD) under atmospheric pressure of hydrogen (H2) and acetylene (C2H2). During the growth, the stainless steel substrates were heated at different temperatures of 600, 700, 800, and 900°C. It was found that MWCNTs were grown on the stainless steel substrates heated at 600, 700, and 800°C while amorphous carbon film was grown at 900°C. The diameters of MWCNTs, as identified by scanning electron microscope (SEM) images together with ImageJ software program, were found to be 67.7, 43.0, and 33.1 nm, respectively. The crystallinity of MWCNTs was investigated by an X-ray diffractometer. The number of graphitic walled layers and the inner diameter of MWCNTs were investigated using a transmission electron microscope (TEM). The occurrence of Fe3O4 nanoparticles associated with carbon element can be used to reveal the behavior of Fe in stainless steel as catalyst. Raman spectroscopy was used to confirm the growth and quality of MWCNTs. The results obtained in this work showed that the optimum heated stainless steel substrate temperature for the growth of effective MWCNTs is 700°C. Chemical states of MWCNTs were investigated by X-ray photoelectron spectroscopy (XPS) using synchrotron light. Udomdej Pakdee, Surasak Chiangga, Suchat Suwannatus, and Pichet Limsuwan Copyright © 2017 Udomdej Pakdee et al. All rights reserved. Synthesis of Nanocrystalline Boron Carbide by Direct Microwave Carbothermal Reduction of Boric Acid Mon, 27 Mar 2017 09:56:28 +0000 The excellent physical and chemical properties of boron carbide make it suitable for many applications. However, its synthesis requires a large amount of energy and is time-consuming. Microwave carbothermal reduction is a fast technique for producing well crystallized equiaxial boron carbide nanoparticles of about 50 nm and very few amounts of elongated nanoparticles were also synthesized. They presented an average length of 82 nm and a high aspect ratio (5.5). The total reaction time was only 20 minutes, which disfavor the growing process, leading to the synthesis of nanoparticles. Microwave-assisted synthesis leaded to producing boron-rich boron carbide. Increasing the forward power increases the boron content and enhances the efficiency of the reaction, resulting in better crystallized boron carbide. Rodolfo F. K. Gunnewiek, Pollyane M. Souto, and Ruth H. G. A. Kiminami Copyright © 2017 Rodolfo F. K. Gunnewiek et al. All rights reserved. Room Temperature Ferromagnetic and Optical Properties of Chrome Doped ZnS Nanorods Prepared by Hydrothermal Method Mon, 27 Mar 2017 00:00:00 +0000 Cr doped S nanorods with different concentration ratio (, 0.01, 0.03, and 0.05) were successfully synthesized by hydrothermal method. The crystal microstructure, morphology, chemical composition, and optical and magnetic properties of the samples were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), X-ray energy dispersive spectrometry (XEDS), diffuse-reflectance spectroscopy (DRS), photoluminescence (PL) spectra, and the vibrating sample magnetometer (VSM). All the samples synthesized by this method exhibited single-phase wurtzite structure with good crystallization as demonstrated by XRD studies, which indicated that all Cr ions successfully substituted for the lattice site of Zn2+ and generated single-phase S. DRS revealed the band gap of doped S underwent blue shift compared to that of the bulk ZnS. PL spectra showed obvious ultraviolet emission peak at 375 nm and two blue emissions appear about 500 and 580 nm. The blue emissions intensity of doped samples improved with the increase of Cr concentration, comparing to pure ZnS. Magnetic measurements indicated that the undoped and doped ZnS nanorods exhibited well-defined ferromagnetic behavior at room temperature. The saturation magnetization weakened significantly with increasing Cr concentration comparing to pure ZnS and reached minimum for 3% Cr. Wenhua Zhao, Zhiqiang Wei, Li Zhang, Xiaojuan Wu, Xuan Wang, and Jinlong Jiang Copyright © 2017 Wenhua Zhao et al. All rights reserved. Antibacterial Efficacy of Gold and Silver Nanoparticles Functionalized with the Ubiquicidin (29–41) Antimicrobial Peptide Sun, 26 Mar 2017 09:33:09 +0000 Recent studies have demonstrated that drug antimicrobial activity is enhanced when metallic nanoparticles are used as an inorganic support, obtaining synergic effects against microorganisms. The cationic antimicrobial peptide ubiquicidin 29–41 (UBI) has demonstrated high affinity and sensitivity towards fungal and bacterial infections. The aim of this research was to prepare and evaluate the antimicrobial efficacy of engineered multivalent nanoparticle systems based on silver or gold nanoparticles functionalized with UBI. Spectroscopy techniques demonstrated that NPs were functionalized with UBI mainly through interactions with the -NH2 groups. A significant increase in the antibacterial activity against Escherichia coli and Pseudomonas aeruginosa was obtained with the conjugate AgNP-UBI with regard to that of AgNP. No inhibition of bacterial growth was observed with AuNP and AuNP-UBI using a nanoparticle concentration of up to 182 μg mL−1. Nonetheless, silver nanoparticles conjugated to the UBI antimicrobial peptide may provide an alternative therapy for topical infections. Enrique Morales-Avila, Guillermina Ferro-Flores, Blanca E. Ocampo-García, Gustavo López-Téllez, Johnny López-Ortega, Diana G. Rogel-Ayala, and Diego Sánchez-Padilla Copyright © 2017 Enrique Morales-Avila et al. All rights reserved. An Efficient Method for Cellulose Nanofibrils Length Shearing via Environmentally Friendly Mixed Cellulase Pretreatment Thu, 23 Mar 2017 09:28:43 +0000 Cellulose nanofibrils (CNFs) have potential applications in the development of innovative materials and enhancement of conventional materials properties. This paper focused on the mixed cellulase hydrolysis with major activity of exoglucanase and endoglucanase on the cellulose length shearing. By the cooperation of two-step production route, including (1) enzymatic pretreatment using cellulase from Trichoderma viride and (2) mechanical grinding twice, a shorter cellulose nanofiber was fabricated. The influence of enzymatic charge and hydrolysis time on cellulose fibers was analyzed by using scanning electron microscopy (SEM), Fourier Transform Infrared Spectrometer (FTIR), and X-ray diffractometer (XRD). SEM images revealed that the surface morphology change, effective diameter sharpening, and length shearing of cellulose fibers are as a result of cellulase hydrolysis. The XRD suggested that the cellulase acted on the amorphous regions more strongly than the crystalline domains during layer-by-layer hydrolysis. The enzymatic charge and hydrolysis time significantly affected the yields and hydrolysis products concentration. The enzymatic pretreatment assisted mechanical grinding could improve the uniformity of CNF and helped to obtain CNF with exact length according to the requirement for special applications. Yuan Chen, Yuchan He, Dongbin Fan, Yanming Han, Gaiyun Li, and Siqun Wang Copyright © 2017 Yuan Chen et al. All rights reserved. Dual Role of a Ricinoleic Acid Derivative in the Aqueous Synthesis of Silver Nanoparticles Thu, 23 Mar 2017 07:56:05 +0000 We show that sodium 9,10-epoxy-12-hydroxytetradecanoate (SEAR), an epoxidized derivative of ricinoleic acid, simultaneously functioned as reducing and stabilizing agents in the synthesis of silver nanoparticles in alkaline aqueous medium. The advantage of using SEAR is its biodegradability and nontoxicity, which are important characteristics for mitigation of environmental impact upon discharge of nanoparticles into terrestrial and aquatic ecosystems. The SEAR concentration was found to impact considerably the size distribution of silver nanoparticles (AgNPs). A concentration below the SEAR critical micelle concentration (CMC) generated 23 nm sized AgNPs with 10 nm standard deviation, while 50 nm sized AgNPs ( nm) were obtained at a concentration above the SEAR CMC. FTIR analysis revealed that the carboxylate that constitutes the SEAR hydrophilic head binds directly to the AgNPs surface promoting stabilization in solution. Finally, AgNPs turned into Ag2S upon contact with wastewater samples from Wastewater Treatment Plant at Federal University of Rio Grande do Norte (UFRN), Brazil, which is an interesting result, since Ag2S is more environmentally friendly than pure AgNPs. Isadora Dantas Costa, Alcides de Oliveira Wanderley Neto, Heloiza Fernanda Oliveira da Silva, Edgar Perin Moraes, Eryka Thamyris Damascena Nóbrega, Celso Sant’Anna, Mateus Eugenio, and Luiz Henrique da Silva Gasparotto Copyright © 2017 Isadora Dantas Costa et al. All rights reserved. Study of the Carbonization and Graphitization of Coal Tar Pitch Modified with SiC Nanoparticles Thu, 23 Mar 2017 06:51:07 +0000 Silicon carbide nanoparticles (nSiC) have been used to modify coal tar pitch (CTP) as a carbon binder. The influence of ceramic nanoparticles on the structure and microstructure was studied. The structure of CTP-based carbon residue with various nSiC contents was analyzed by using SEM with EDAX, Raman spectroscopy, and X-ray diffraction. The effect of ceramic nanofiller on the crystallite sizes (, ) and the -axis spacing () in carbonized samples after heating from 1000 to 2800°C was analyzed. Ceramic nanofillers inhibit structural changes in carbonized samples heated to 1000°C. After heating CTP with nSiC above 2000°C, the carbon samples contained two carbon components differing in structural ordering. Ceramic nanoparticles increase carbon crystallite growth, while their impact on the -axis spacing is low. Maciej Gubernat, Tomasz Lis, Janusz Tomala, Jakub Kawala, Aneta Fraczek-Szczypta, and Stanislaw Blazewicz Copyright © 2017 Maciej Gubernat et al. All rights reserved. Porous Silicon and Indium Doped Zinc Oxide Junctions: Synthesis, Characterization, and Application to Electroluminescent Devices Thu, 23 Mar 2017 00:00:00 +0000 We report the obtaining of electroluminescent devices (ELD) from porous silicon (PS) and indium doped zinc oxide (ZnO:In) junctions. PS presented photoluminescence (PL) in the visible region of the electromagnetic spectrum. ZnO:In thin film was obtained by dip coating technique. SEM images and IR measurements showed the incorporation of the ZnO:In in the PS structure. Once obtained, the device was optically and electrically characterized. The ELD showed emission in the visible (450–850 nm) and infrared region (900–1200 nm) where it was electrically polarized. The visible emission was detected as luminescent spots on the surface. Electrical characterization was carried out by current-voltage (I-V) curves. The I-V curves showed rectifying behavior. It was related to the quenching of the EL with the process that takes place in the PS when it was immersed in the precursor solution of the ZnO:In. F. Severiano, G. García, L. Castañeda, and V. L. Gayou Copyright © 2017 F. Severiano et al. All rights reserved. Preparations, Characterizations, and a Comparative Study on Photovoltaic Performance of Two Different Types of Graphene/TiO2 Nanocomposites Photoelectrodes Tue, 21 Mar 2017 00:00:00 +0000 This research work undertook a comparative study of the promoting effects of graphene in TiO2 photoanodes. The aim of this work was to investigate the effects of the types and concentration of reduced graphene oxides (rGO) on structure properties and the photovoltaic performance of TiO2 based electrodes. Graphene oxide (GO) was prepared by using modified Hammer’s method. Next, GO was reduced by using two different approaches, which were the chemical reduction with vitamin C and thermal reduction. The latter approach was also carried out in situ during the fabrication and heat treatment processes of the dye-sensitized solar cells (DSSCs). From the results, it was found that the photovoltaic performance of the DSSCs containing the GO/TiO2 electrode, in which the GO phase experienced an in situ thermal reduction, was superior to those containing rGO/TiO2. It was also found that the power conversion efficiency of the DSSCs changed with the concentration of graphene in a nonlinear fashion. The optimum concentrations of graphene, corresponding to the highest PCE values of the GO/TiO2 based DSSC (3.69%) and that of the rGO/TiO2 based cell (2.90%), were 0.01 wt% and 0.03 wt%, respectively. Uea-aree Kanta, Voranuch Thongpool, Weradesh Sangkhun, Nutthapon Wongyao, and Jatuphorn Wootthikanokkhan Copyright © 2017 Uea-aree Kanta et al. All rights reserved. Molecular Orientation of Conjugated Polymer Chains in Nanostructures and Thin Films: Review of Processes and Application to Optoelectronics Tue, 21 Mar 2017 00:00:00 +0000 Semiconducting polymers are composed of elongated conjugated polymer backbones and side chains with high solubility and mechanical properties. The combination of these two features results in a high processability and a potential to orient the conjugated backbones in thin films and nanofibers. The thin films and nanofibers are usually composed of highly crystalline (high charge transport) and amorphous parts. Orientation of conjugated polymer can result in enhanced charge transport or optical properties as it induces increased crystallinity or preferential orientation of the crystallites. After summarizing the potential strategies to exploit molecular order in conjugated polymer based optoelectronic devices, we will review some of the fabrication processes to induce molecular orientation. In particular, we will review the cases involving molecular and interfacial interactions, unidirectional deposition processes, electrospinning, and postdeposition mechanical treatments. The studies presented here clearly demonstrate that process-controlled molecular orientation of the conjugated polymer chains can result in high device performances (mobilities over 40 cm2·V−1·s−1 and solar cells with efficiencies over 10%). Furthermore, the peculiar interactions between molecularly oriented polymers and polarized light have the potential not only to generate low-cost and low energy consumption polarized light sources but also to fabricate innovative devices such as solar cell integrated LCDs or bipolarized LEDs. Varun Vohra and Takuya Anzai Copyright © 2017 Varun Vohra and Takuya Anzai. All rights reserved. Oxalic Acid-Assisted Hydrothermal Synthesis and Luminescent of Hexagonal NaYF4:Ln3+ (Ln = Sm, Eu, Yb/Er) Micro/Nanoplates Tue, 21 Mar 2017 00:00:00 +0000 Hexagonal NaYF4:Ln3+ micro/nanoplates were successfully synthesized via a hydrothermal method using oxalic acid as a shape modifier. X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and selected area electron diffraction (SAED) have been used to study the morphologies and crystal structure of the products. The effects of the pH values and the molar ratio of oxalic acid to NaOH on the crystal growth have been investigated in detail. The time-dependent experiments have been conducted to investigate the morphology evolution process, and based on the results, a possible growth mechanism was proposed. The photoluminescence properties of 5 mol% Eu3+ and 3 mol% Sm3+ doped NaYF4 and 20 mol% Yb3+/2 mol% Er3+ codoped NaYF4 micro/nanoplates were investigated. The experimental results showed that NaYF4:Ln3+ micro/nanoplates have excellent luminescence and can be potential application in the field of light display systems, lasers, and optoelectronic devices. Feng Tao, Zhishun Shen, Zhijun Wang, Da Shu, Qi Liu, and Yufeng Sun Copyright © 2017 Feng Tao et al. All rights reserved. Lanthanum-Based Perovskite-Type Oxides La1−xCexBO3 (B = Mn and Co) as Catalysts: Synthesis and Characterization Mon, 20 Mar 2017 09:42:54 +0000 La1−xCexCoO3 ( = 0, 0.2, 0.4) and La1−xCexMnO3 ( = 0, 0.2) perovskite-type oxides were prepared by sol-gel process. Characterization techniques EDS, FTIR, XRD, BET, and XPS experiments were performed to survey the composition, bulk structure, and the surface properties of perovskites. The reduction behavior, thermal stability, and catalytic activity were studied by H2-TPR and catalytic performance. All synthesized samples showed well crystalline perovskite structure, 8–22 nm crystallite sizes, and SSA with 2–27 m2 g−1. The XRD results showed that the Ce substitution promoted the structural transformation for LaCoO3 from rhombohedral into cubic and for LaMnO3 no change in lattice geometry. Substitution with cerium ( = 0.2) showed smaller crystallite size, higher SSA, and the highest reducibility and catalytic activity for LaCoO3. Nyamdavaa Erdenee, Uyanga Enkhnaran, Sevjidsuren Galsan, and Altantsog Pagvajav Copyright © 2017 Nyamdavaa Erdenee et al. All rights reserved. Influence of Heat Treatment on the Morphologies of Copper Nanoparticles Based Films by a Spin Coating Method Mon, 20 Mar 2017 00:00:00 +0000 We have investigated the influence of heat treatment on the morphologies of copper nanoparticles based films on glass slides by a spin coating method. The experiments show that heat treatment can modify the sizes and morphologies of copper nanoparticles based films on glass slides. We suggest that through changing the parameters of heat treatment process may be helpful to vary the scattering and absorbing intensity of copper nanoparticles when used in energy harvesting/conversion and optical devices. Wei Liu, Jiayu Guo, Zhonghua Fan, Xiaorong Wang, Dingkun Yu, Rong Chen, Shisheng Huang, and Peng He Copyright © 2017 Wei Liu et al. All rights reserved. Tunable SnO2 Nanoribbon by Electric Fields and Hydrogen Passivation Mon, 20 Mar 2017 00:00:00 +0000 Under external transverse electronic fields and hydrogen passivation, the electronic structure and band gap of tin dioxide nanoribbons (SnO2NRs) with both zigzag and armchair shaped edges are studied by using the first-principles projector augmented wave (PAW) potential with the density function theory (DFT) framework. The results showed that the electronic structures of zigzag and armchair edge SnO2NRs exhibit an indirect semiconducting nature and the band gaps demonstrate a remarkable reduction with the increase of external transverse electronic field intensity, which demonstrate a giant Stark effect. The value of the critical electric field for bare Z-SnO2NRs is smaller than A-SnO2NRs. In addition, the different hydrogen passivation nanoribbons (Z-SnO2NRs-2H and A-SnO2NRs-OH) show different band gaps and a slightly weaker Stark effect. The band gap of A-SnO2NRs-OH obviously is enhanced while the Z-SnO2NRs-2H reduce. Interestingly, the Z-SnO2NRs-OH presented the convert of metal-semiconductor-metal under external transverse electronic fields. In the end, the electronic transport properties of the different edges SnO2NRs are studied. These findings provide useful ways in nanomaterial design and band engineering for spintronics. Xin-Lian Chen, Bao-Jun Huang, Chang-Wen Zhang, Ping Li, and Pei-Ji Wang Copyright © 2017 Xin-Lian Chen et al. All rights reserved. Growth and Mechanism of MoS2 Nanoflowers with Ultrathin Nanosheets Sun, 19 Mar 2017 07:50:50 +0000 Two-dimensional molybdenum disulfide (MoS2) with few layers, due to their excellent optical and electrical properties, has great potential for applications in electronic and optoelectronic devices. In this work, flower-like MoS2 nanostructures with ultrathin nanosheets (petals) were successfully deposited onto silicon substrates by a facile process based on chemical vapor deposition via using MoO3 and S powders as starting materials. Their composition and structure were explored by field emission scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and photoluminescence. The reported nanoflowers vertically and separately stood on the substrates, consisting of several bonded MoS2 nanosheets with a thickness of 10–30 nm and high crystallinity. On the basis of these results, a growth mechanism for the MoS2 nanoflowers was proposed. Yifei Guo, Xiuli Fu, and Zhijian Peng Copyright © 2017 Yifei Guo et al. All rights reserved. Halloysite Nanotubes Noncovalently Functionalised with SDS Anionic Surfactant and PS-b-P4VP Block Copolymer for Their Effective Dispersion in Polystyrene as UV-Blocking Nanocomposite Films Sun, 19 Mar 2017 00:00:00 +0000 A simple and versatile method is reported for the noncovalent functionalisation of natural and “green” halloysite nanotubes (HNTs) allowing their effective dispersion in a polystyrene (PS) thermoplastic matrix via solvent mixing. Initially, HNTs (pristine HNTs) were modified with physically adsorbed surfactant molecules of sodium dodecyl sulphate (SDS) and PS-b-P4VP [P4VP: poly(4-vinylpyridine)] block copolymer (BCP). Hereafter, SDS and BCP modified HNTs will be indicated as SDS-m-HNT and BCP-m-HNT. Nanocomposite films with 1, 2, and 5 wt.% HNT loadings were prepared, abbreviated as PS-SDS-m-HNT1, PS-SDS-m-HNT2, and PS-SDS-m-HNT5 and PS-BCP-m-HNT1, PS-BCP-m-HNT2, and PS-BCP-m-HNT5 (where 1, 2, and 5 correspond to the wt.% of HNTs). All nanocomposites depicted improved thermal degradation compared to the neat PS as revealed by thermogravimetric analysis (TGA). Transmission electron microscopy (TEM) confirmed the good dispersion state of HNTs and the importance of modification by SDS and BCP. X-ray diffraction (XRD) studies showed the characteristic interlayer spacing between the two silicate layers of pristine and modified HNTs. The PS/HNT nanocomposite films exhibited excellent ultraviolent-visible (UV-vis) absorbance properties and their potential application as UV-filters could be envisaged. Lazaros Tzounis, Shreya Herlekar, Antonios Tzounis, Nikolaos D. Charisiou, Maria Goula, and Manfred Stamm Copyright © 2017 Lazaros Tzounis et al. All rights reserved. Functional Nanomaterials for Renewable Energy and Sustainability Sun, 19 Mar 2017 00:00:00 +0000 Xiulin Fan, Xuezhang Xiao, and Zheng Zhang Copyright © 2017 Xiulin Fan et al. All rights reserved. Modulation of Optical and Electrical Characteristics by Laterally Stretching DNAs on CVD-Grown Monolayers of MoS2 Sun, 19 Mar 2017 00:00:00 +0000 Monolayer MoS2 (1L-MoS2) is an ideal platform to examine and manipulate two dimensionally confined exciton complexes, which provides a large variety of modulating the optical and electrical properties of 1L-MoS2. Extensive studies of external doping and hybridization exhibit the possibilities of engineering the optical and electrical performance of 1L-MoS2. However, biomodifications of 1L-MoS2 and the characterization and applications of such hybrid structures are rarely reported. In this paper, we present a bio-MoS2 hybrid structure fabricated by laterally stretching strands of DNAs on CVD-grown 1L-MoS2. We observed a strong modification of photoluminescence and Raman spectra with reduced PL intensity and red-shift of PL peak and Raman peaks, which were attributed to electron doping by the DNAs and the presence of tensile strain in 1L-MoS2. Moreover, we observed a significant enhancement of electric mobility in the DNA/1L-MoS2 hybrid compared to that in the pristine 1L-MoS2, which may have been caused by the induced strain in 1L-MoS2. Guru P. Neupane, Minh Dao Tran, Hyun Kim, and Jeongyong Kim Copyright © 2017 Guru P. Neupane et al. All rights reserved. Hydrothermal Synthesis of PbO2/RGO Nanocomposite for Electrocatalytic Degradation of Cationic Red X-GRL Mon, 13 Mar 2017 06:09:22 +0000 PbO2 nanoparticles were prepared using a simple hydrothermal method with β-PbO as precursor and ammonium peroxydisulfate as oxidant. During the hydrothermal condition with ammonium peroxydisulfate, the formed hydroxyl radical has played a key role in the oxidation of β-PbO to PbO2. The size of as-prepared PbO2 nanoparticles was in the range of 25–50 nm. Reduced graphene oxide (RGO) was successfully prepared by the simple reduction reaction of graphene oxide by sodium borohydride and the obtained RGO was then incorporated into the PbO2 nanoparticles. The surface of ITO electrode was modified with the as-prepared PbO2/RGO nanocomposite. The constructed PbO2/RGO/ITO electrode was subsequently applied for the catalytic degradation of cationic red X-GRL which was an azo dye in wastewater. The effects of reaction time, applied current density, and initial concentration of dye on the color removal and COD removal were thoroughly investigated. All results demonstrated that the degradation performance of the electrode modified with PbO2/RGO nanocomposite was extremely excellent. Weidong Li, Huayun Yang, and Qi Liu Copyright © 2017 Weidong Li et al. All rights reserved. Elastomeric Nanocomposite Based on Exfoliated Graphene Oxide and Its Characteristics without Vulcanization Mon, 13 Mar 2017 00:00:00 +0000 Rubber nanocomposites have emerged as one of the advanced materials in recent years. The aim of this work was to homogeneously disperse graphene oxide (GO) sheets into Nitrile Butadiene Rubber (NBR) and investigate the characteristics of GO/NBR nanocomposite without vulcanization. A suitable solvent was found to dissolve dry NBR while GO was exfoliated completely in an aqueous base solution using sonication. GO was dispersed into NBR at different loadings by solution mixing to produce unvulcanized GO/NBR nanocomposites. Scanning Electron Microscopy (SEM), Fourier-Transform Infrared Spectroscopy (FTIR), and X-Ray Diffraction (XRD) were used to characterize the samples. Furthermore, mechanical and electrical properties of unvulcanized GO/NBR nanocomposites were carried out to determine the influence of GO on the NBR properties. The results showed that the modulus of GO/NBR nanocomposite at 1 wt% of GO was enhanced by about 238% compared with unfilled NBR. These results provide insight into the properties of unvulcanized GO/NBR nanocomposite for application as coatings or adhesives. Nasser Abdullah Habib, Buong Woei Chieng, Norkhairunnisa Mazlan, Umer Rashid, Robiah Yunus, and Suraya Abdul Rashid Copyright © 2017 Nasser Abdullah Habib et al. All rights reserved. A Simulation Study for Trimetallic Nanosized Alloy (Ni, Cu, and Ag) in Hydrogenation of Organic Compounds: A Case Study of “Nitrophenols” Mon, 13 Mar 2017 00:00:00 +0000 Trimetallic system (Ni, Cu, and Ag) supported on alumina was utilized for hydrogenation of nitrophenols. The catalytic active centers for hydrogenation were attributed only to the presence of Ni. However, the presence of bi- or trimetallic systems improves the catalytic activity via extra synergism. The catalytic activity was measured as the time for reaching 100% conversion. The function of synergism was fitted for both bimetallic systems (Ni:Ag; Ni:Cu) individually. Subsequently, three-dimensional function was fitted for trimetallic system (Ni:Cu:Ag) based on the linear combination of data for individual bimetallic system. After a complex calculation areal function was evaluated. An Excel program was written to simply evaluate the catalytic activity of trimetallic system with high accuracy. Characterization of catalysts was performed using EPR and pulsed chemisorption by hydrogen. These characterizations of samples enable us to evaluate particle size, metallic surface area, and degree of dispersion. These values were successfully correlated with the synergism function. The program written then could be capable of predicting these values for any trimetallic system. Salem M. Bawaked, Islam Hamdy Abd El Maksod, and Abdulmohsen Alshehri Copyright © 2017 Salem M. Bawaked et al. All rights reserved. Poly(3,4-ethylenedioxythiophene) Doped with Carbon Materials for High-Performance Supercapacitor: A Comparison Study Sun, 12 Mar 2017 10:45:09 +0000 A comparative study of multiwalled carbon nanotube (MWCNT), graphene oxide (GO), and nanocrystalline cellulose (NCC) as a dopant in the preparation of poly(3,4-ethylenedioxythiophene)- (PEDOT-) based hybrid nanocomposites was presented here. The hybrid nanocomposites were prepared via the electrochemical method in aqueous solution. The FTIR and Raman spectra confirmed the successful incorporation of dopants (MWCNT, GO, and NCC) into PEDOT matrix in the process of formation of the hybrid nanocomposites. It was observed that the choice of the carbon material affected the morphologies and supercapacitive properties of the hybrid nanocomposites. Incorporation of GO with PEDOT produces a paper-like sheet nanocomposite in which the wrinkled surface results in larger surface area compared to the network-like and rod-like structures of PEDOT/MWCNT and PEDOT/NCC, respectively. Owing to larger surface area, PEDOT/GO exhibits the highest specific capacitance (120.13 F/g), low equivalent series resistance (34.44 Ω), and retaining 87.99% of the initial specific capacitance after 1000 cycles, signifying a long-term cycling stability. Furthermore, the high performance of PEDOT/GO is also demonstrated by its high specific energy and specific power. Shariffah Nur Jannah Syed Zainol Abidin, Nur Hawa Nabilah Azman, Shalini Kulandaivalu, and Yusran Sulaiman Copyright © 2017 Shariffah Nur Jannah Syed Zainol Abidin et al. All rights reserved. Optimal Zn-Modified Ca–Si-Based Ceramic Nanocoating with Zn Ion Release for Osteoblast Promotion and Osteoclast Inhibition in Bone Tissue Engineering Thu, 09 Mar 2017 09:01:22 +0000 We investigated the slow release of Zn ion (Zn2+) from nanocoatings and compared the in vitro response of osteoblasts (MC3T3-E1) and proosteoclasts (RAW 264.7) cultured on Ca2ZnSi2O7 nanocoated with different Zn/Ca molar ratios on a Ti-6Al-4V (i.e., Ti) substrate to optimize cell behaviors and molecule levels. Significant morphology differences were observed among samples. By comparing with pure Ti and CaSiO3 nanocoating, the morphology of Ca2ZnSi2O7 ceramic nanocoatings was rough and contained small nanoparticles or aggregations. Slow Zn2+ release from nanocoatings was observed and Zn2+ concentration was regulated by varying the Zn/Ca ratios. The cell-response results showed Ca2ZnSi2O7 nanocoating at different Zn/Ca molar ratios for osteoblasts and osteoclasts. Compared to other nanocoatings and Ti, sample Zn/Ca (0.3) showed the highest cell viability and upregulated expression of the osteogenic differentiation genes ALP, COL-1, and OCN. Additionally, sample Zn/Ca (0.3) showed the greatest inhibition of RAW 264.7 cell growth and decreased the mRNA levels of osteoclast-related genes OAR, TRAP, and HYA1. Therefore, the optimal Zn-Ca ratio of 0.3 in Ca2ZnSi2O7 ceramic nanocoating on Ti had a dual osteoblast-promoting and osteoclast-inhibiting effect to dynamically balance osteoblasts/osteoclasts. These optimal Zn-Ca ratios are valuable for Ca2ZnSi2O7 ceramic nanocoating on Ti-coated implants for potential applications in bone tissue regeneration. Jiangming Yu, Lizhang Xu, Ning Xie, Kai Li, Yanhai Xi, Xiling Liu, Xuebin Zheng, Xiongsheng Chen, Xiaojian Ye, and Daixu Wei Copyright © 2017 Jiangming Yu et al. All rights reserved. Dynamic Interferometry Lithography on a TiO2 Photoresist Sol-Gel for Diffracting Deflector Module Thu, 09 Mar 2017 00:00:00 +0000 Solar electricity is one of the most promising renewable energy resources. However, the ratio module’s cost/energy produced remains a major issue for classical photovoltaic energy. Many technologies have been developed to solve this problem, by using micro- or nanostructuring on the solar cell or on the module. These kinds of structuring are often used as antireflection and light-trapping tools. In the meantime, other solar technologies are considered, such as concentration photovoltaic modules. This article presents a module combining both approaches, that is, nanostructures and concentration, in order to increase the module’s profitability. Sol-gel derived TiO2 diffraction gratings, made by dynamic interferometric lithography, are added on the top of the glass cover to deflect unused light onto the solar cell, increasing the module efficiency. V. Gâté, L. Berthod, M. Langlet, F. Vocanson, I. Verrier, C. Veillas, A. Kaminski, O. Parriaux, and Y. Jourlin Copyright © 2017 V. Gâté et al. All rights reserved. Electrochemical Deposition of Zinc Oxide on the Surface of Composite Membrane Polysulfone-Graphene-Polystyrene in the Presence of Water Soluble Polymers Thu, 09 Mar 2017 00:00:00 +0000 The aim of this study consisted in the development of an alternative synthesis procedure for hybrid ultrafiltration membranes for water purification. The membranes were obtained by wet-phase inversion method based on aliquots of polysulfone (PSF) and graphene nanoplatelets modified with poly(styrene) (G-PST). The hybrid materials were modified by electrochemical deposition of zinc oxide (ZnO) on one side of the membranes in the presence of water soluble polymers. Raman, XPS, and TGA analyses were used to characterize the chemical and thermal characteristics of the PST-G. SEM analysis showed the formation of asymmetric porous configuration in all cases and the generation of ZnO with different shapes/structures on the bottom surface of the membrane or inside the porous channels. EDS analysis confirmed the formation of ZnO. Alexandra Mocanu, Edina Rusen, Aurel Diacon, Celina Damian, Adrian Dinescu, and Mirela Suchea Copyright © 2017 Alexandra Mocanu et al. All rights reserved. CoFe2O4-TiO2 Hybrid Nanomaterials: Synthesis Approaches Based on the Oil-in-Water Microemulsion Reaction Method Wed, 08 Mar 2017 10:13:44 +0000 CoFe2O4 nanoparticles decorated and wrapped with TiO2 nanoparticles have been prepared by mixing well-dispersed CoFe2O4 with amorphous TiO2 (impregnation approach) and growing amorphous TiO2 over the magnetic core (seed approach), respectively, followed by thermal treatment to achieve TiO2 crystallinity. Synthesis strategies were based on the oil-in-water microemulsion reaction method. Thermally treated nanomaterials were characterized in terms of structure, morphology, and composition, to confirm hybrid nanoparticles formation and relate with the synthesis approaches; textural, optical, and magnetic properties were evaluated. X-ray diffraction revealed coexistence of cubic spinel-type CoFe2O4 and tetragonal anatase TiO2. Electron microscopy images depicted crystalline nanoparticles (sizes below 25 nm), with homogeneous Ti distribution for the hybrid nanoparticles synthesized by seed approach. EDX microanalysis and ICP-AES corroborated established chemical composition. XPS evidenced chemical states, as well as TiO2 predominance over CoFe2O4 surface. According to BET measurements, the hybrid nanoparticles were mesoporous. UV-Vis spectroscopy showed optical response along the UV-visible light region. Magnetic properties suggested the breaking order of magnetic domains due to modification with TiO2, especially for mediated seed approach sample. The properties of the obtained hybrid nanoparticles were different in comparison with its individual components. The results highlight the usefulness of designed microemulsion approaches for the straightforward synthesis of CoFe2O4-TiO2 nanostructured hybrids. Arturo Adrián Rodríguez-Rodríguez, Sagrario Martínez-Montemayor, César Cutberto Leyva-Porras, Francisco Enrique Longoria-Rodríguez, Eduardo Martínez-Guerra, and Margarita Sánchez-Domínguez Copyright © 2017 Arturo Adrián Rodríguez-Rodríguez et al. All rights reserved. An Enhanced-Solvent Deasphalting Process: Effect of Inclusion of SiO2 Nanoparticles in the Quality of Deasphalted Oil Wed, 08 Mar 2017 09:29:41 +0000 In this work, the effect of nanoparticles in deasphalting heavy oil and extra-heavy oil process at laboratory-scale based on the conventional solvent deasphalting process was studied and named enhanced-solvent deasphalting (e-SDA) process. This work evaluated the effect of the nanoparticles of SiO2 in the separation efficiency based on deasphalted oil (DAO) fraction quality compared to the conventional process of deasphalting (SDA). Different effects have been assessed such as solvent to oil ratio, operating temperatures, type of solvent, and SiO2 nanoparticles dosage. The DAO quality was based on the asphaltene and sulfur contents, API gravity, distillable fraction, and rheological properties. The improvement of the process from the use of nanoparticles was confirmed with important reductions in the asphaltene and sulfur contents in the DAO of up to 24% and 23%, respectively, in comparison with the SDA process. Also, the API gravity can be increased by approximately 14% with the e-SDA process. The rheological properties of the DAO were improved by the inclusion of nanoparticles showing reductions in the viscosities of the DAO greater than 50% in comparison with the conventional process. These results lead to the conclusion that the e-SDA process improves the DAO quality when compared with the typical deasphalting process. Juan D. Guzmán, Camilo A. Franco, and Farid B. Cortés Copyright © 2017 Juan D. Guzmán et al. All rights reserved. Advances in Functionalized Materials Research 2016 Wed, 08 Mar 2017 07:16:49 +0000 Daniela Predoi, Mikael Motelica-Heino, Régis Guegan, and Philippe Le Coustumer Copyright © 2017 Daniela Predoi et al. All rights reserved.