Journal of Nanomaterials The latest articles from Hindawi © 2017 , Hindawi Limited . All rights reserved. Rapid Detection and Identification of miRNAs by Surface-Enhanced Raman Spectroscopy Using Hollow Au Nanoflowers Substrates Thu, 19 Oct 2017 00:00:00 +0000 MicroRNAs (miRNAs) are recognized as regulators of gene expression during the biological processes of cells as well as biomarkers of many diseases. Development of rapid and sensitive miRNA profiling methods is crucial for evaluating the pattern of miRNA expression related to normal and diseased states. This work presents a novel hollow Au nanoflowers (HAuNFs) substrate for rapid detection and identification of miRNAs by surface-enhanced Raman scattering (SERS) spectroscopy. We synthesized the HAuNFs by a seed-mediated growth approach. Then, HAuNFs substrates were fabricated by depositing HAuNFs onto the surfaces of (3-aminopropyl)triethoxysilane- (APTES-) functionalized ITO glass. The result demonstrated that HAuNFs substrates had very good reproducibility, homogeneous SERS activity, and high SERS effect. The substrates enabled us to successfully obtain the SERS spectra of miR-10a-5p, miR-125a-5p, and miR-196a-5p. The difference spectra among the three kinds of miRNAs were studied to better interpret the spectral differences and identify miRNA expression patterns with high accuracy. The principal component analysis (PCA) of the SERS spectra was used to distinguish among the three kinds of miRNAs. Considering its time efficiency, being label-free, and its sensitivity, the SERS based on HAuNFs substrates is very promising for miRNA research and plays an important role in early disease detection and prevention. Xiaowei Cao, Min Bao, Yibo Shan, Wei Li, and Hongcan Shi Copyright © 2017 Xiaowei Cao et al. All rights reserved. Mechanical Properties of Epoxy and Its Carbon Fiber Composites Modified by Nanoparticles Thu, 19 Oct 2017 00:00:00 +0000 Compressive properties are commonly weak parts in structural application of fiber composites. Matrix modification may provide an effective way to improve compressive performance of the composites. In this work, the compressive property of epoxies (usually as matrices of fiber composites) modified by different types of nanoparticles was firstly investigated for the following study on the compressive property of carbon fiber reinforced epoxy composites. Carbon fiber/epoxy composites were fabricated by vacuum assisted resin infusion molding (VARIM) technique using stitched unidirectional carbon fabrics, with the matrices modified with nanosilica, halloysite, and liquid rubber. Testing results showed that the effect of different particle contents on the compressive property of fiber/epoxy composites was more obvious than that in epoxies. Both the compressive and flexural results showed that rigid nanoparticles (nanosilica and halloysite) have evident strengthening effects on the compression and flexural responses of the carbon fiber composite laminates fabricated from fabrics. Fang Liu, Shiqiang Deng, and Jianing Zhang Copyright © 2017 Fang Liu et al. All rights reserved. Fabrication of a Large-Area Superhydrophobic SiO2 Nanorod Structured Surface Using Glancing Angle Deposition Mon, 16 Oct 2017 00:00:00 +0000 A glancing angle deposition (GLAD) technique was used to generate SiO2 nanorods on a glass substrate to fabricate a low-cost superhydrophobic functional nanostructured surface. GLAD-deposited SiO2 nanorod structures were fabricated using various deposition rates, substrate rotating speeds, oblique angles, and deposition times to analyze the effects of processing conditions on the characteristics of the fabricated functional nanostructures. The wettability of the surface was measured after surface modification with a self-assembled monolayer (SAM). The measured water contact angles were primarily affected by substrate rotation speed and oblique angle because the surface fraction of the GLAD nanostructure was mainly affected by these parameters. A maximum contact angle of 157° was obtained from the GLAD sample fabricated at a rotation speed of 5 rpm and an oblique angle of 87°. Although the deposition thickness (height of the nanorods) was not a dominant factor for determining the wettability, we selected a deposition thickness of 260 nm as the optimum processing condition based on the measured optical transmittance of the samples because optically transparent films can serve as superhydrophobic functional nanostructures for optical applications. Xun Lu, Seok-min Kim, and Seong Jun Seo Copyright © 2017 Xun Lu et al. All rights reserved. Enhanced Piezoelectric Behavior of PVDF Nanocomposite by AC Dielectrophoresis Alignment of ZnO Nanowires Sun, 15 Oct 2017 00:00:00 +0000 In contrast to commercial piezoelectric ceramics, lead-free materials such as ZnO and a polymer matrix are proper candidates for use in ecofriendly applications. In this article, the authors represent a technique using ZnO nanowires with a polyvinylidene fluoride (PVDF) matrix in a piezoelectric polymer composite. By aligning the nanowires in the matrix in a desired direction by AC dielectrophoresis, the piezoelectric behavior was enhanced. The dielectric constant of the composite was improved by increasing the concentration of the ZnO nanowires as well. Specifically, the resulting dielectric constant shows an improvement of 400% with aligned ZnO nanowires by increasing the poling effect compared to that of a randomly oriented nanowire composite without a poling process. Kyungwho Choi, Woongchul Choi, Choongho Yu, and Yong Tae Park Copyright © 2017 Kyungwho Choi et al. All rights reserved. Enhancement of Fluorescence and Photostability Based on Interaction of Fluorescent Dyes with Silver Nanoparticles for Luminescent Solar Concentrators Sun, 15 Oct 2017 00:00:00 +0000 For luminescent solar concentrators (LSCs), it is important to enhance the fluorescence quantum yield (FQY) and photostability. Our measurements have demonstrated that the addition of silver nanoparticles to dye solution causes broadening of absorption bands, so the spectral range of sunlight absorbed by LSC has increased. Silver nanoparticles (NPs) were characterized by X-ray diffraction (XRD) and UV-Vis absorption spectra. UV-Vis spectrum showed a single peak at 442 nm due to the surface plasmon resonance (SPR). The position of SPR peak exhibited a red shift after the sample was exposed to UV irradiation (unfiltered light). The optical band gap values have a reduction from 2.46 to 2.37 eV after irradiation for 960 minutes. Such reduction in optical band gap may be due to change in particle size calculated using Mie theory. The photostability of organic dyes used was improved after adding silver nanoparticles. The area under fluorescence spectra of dyes with silver NPs increased by 41–31% when compared with identical dye concentrations without silver nanoparticles as a result of interaction of the species with silver NPs. Sara El-Molla, A. F. Mansour, and A. E. Hammad Copyright © 2017 Sara El-Molla et al. All rights reserved. Effects of Nanosilica on Early Age Stages of Cement Hydration Thu, 12 Oct 2017 08:52:08 +0000 Effects of nanosilica on cement hydration have been broadly investigated in the literature and early age cement hydration, as a whole, has been mainly considered, disregarding the substages of the hydration. The hydration of cement is characterized by different substages and nanosilica effect on the hydration could be a result of diverse, even contradictory, behavior of nanosilica in individual stages of the hydration. In this study, effects of nanosilica on different substages of cement hydration are investigated. Isothermal calorimetry results show that at early ages (initial 72 hours) the effects of nanosilica depend on the phenomenon by which the hydration is governed: when the hydration is chemically controlled, that is, during initial reaction, dormant period, and acceleratory period, the hydration rate is accelerated by adding nanosilica; when the hydration is governed by diffusion process, that is, during postacceleratory period, the hydration rate is decelerated by adding nanosilica. The Thermal Gravimetric Analysis on the samples at the hardened state (after 28 days of curing) reveals that, after adding nanosilica, the hydration degree slightly increased compared to the plain paste. Forood Torabian Isfahani, Elena Redaelli, Weiwen Li, and Yaru Sun Copyright © 2017 Forood Torabian Isfahani et al. All rights reserved. Gelatin Template Synthesis of Aluminum Oxide and/or Silicon Oxide Containing Micro/Mesopores Using the Proteic Sol-Gel Method Thu, 12 Oct 2017 08:01:01 +0000 Aluminum oxide and/or silicon oxide-based supports were synthesized by proteic sol-gel method. The characterization was performed through the analysis of TG, XRD, FTIR, SEM, and N2 physisorption. The XRD diffractograms showed an amorphous material profile. TG results indicate the total liberation of the organic and inorganic material in the calcination temperature used, occurring in different mass loss range. This piece of information was reaffirmed by the FTIR spectra, which presented characteristic bands of gelatin structure before calcinations which disappear in the spectrum of the solid after calcinations, indicating the loss of organic matter from gelatin after heat treatment. The spectra exhibited M-O stretching vibration at low wavenumbers after calcinations related to metal oxides. The acquired images by SEM suggest the obtaining of a highly porous material with very different characteristics depending on the composition of the support. The N2 isotherms indicate the presence of a micro/mesoporous oxide with interesting textural properties, particularly for the supports containing aluminum and silicon oxide. The ethanol dehydration results showed greater selectivity to diethyl ether compared to ethylene. From the reaction data, the following order of acid strength was obtained: 2Si-Al > Si-2Al > Si-Al > Al, which is related to the Si-Al ratio. Amanda Sayure Kasuya de Oliveira, Adriana Perpetua Figueiredo Paulista, Ana Ellen Valentim de Alencar, and Tiago Pinheiro Braga Copyright © 2017 Amanda Sayure Kasuya de Oliveira et al. All rights reserved. A Novel Poly(3,4-ethylenedioxythiophene)-graphene Oxide/Titanium Dioxide Composites Counter Electrode for Dye-Sensitized Solar Cell Thu, 12 Oct 2017 00:00:00 +0000 PEDOT-based material counter electrodes (CEs) are recently given an enormous attention as new renewable energy sources due to their cost-effectiveness and accessibility, coupled with the simplicity of production. The existing dye-sensitized solar cells (DSSCs) are expensive because they are made using platinum-based glass electrode. In this work, a new CE, that is, poly(3,4-ethylenedioxythiophene)-graphene oxide/titanium dioxide (PEDOT-GO/TiO2) with a low charge transfer resistance ( Ω), was fabricated. In addition, PEDOT-GO/TiO2 CE possesses a good electrocatalytic activity (ECA) toward the tri-iodide ions reduction and an improved efficiency of 1.166% was reached in DSSC. Muhammad Norhaffis Mustafa, Suhaidi Shafie, Zulkarnain Zainal, and Yusran Sulaiman Copyright © 2017 Muhammad Norhaffis Mustafa et al. All rights reserved. Impact on CO2 Uptake of MWCNT after Acid Treatment Study Wed, 11 Oct 2017 00:00:00 +0000 Greenhouse effect is responsible for keeping average temperature of Earth’s atmosphere at level of about 288 K. Its intensification leads to warming of our planet and may contribute to adverse changes in the environment. The most important pollution intensifying greenhouse effect is anthropogenic carbon dioxide. This particular gas absorbs secondary infrared radiation, which in the end leads to an increase of average temperature of Earth’s atmosphere. Main source of CO2 is burning of fossil fuels, like oil, natural gas, and coal. Therefore, to reduce its emission, a special CO2 capture and storage technology is required. Carbonaceous materials are promising materials for CO2 sorbents. Thus multiwalled carbon nanotubes, due to the lack of impurities like ash in activated carbons, were chosen as a model material for investigation of acid treatment impact on CO2 uptake. Remarkable 43% enhancement of CO2 sorption capacity was achieved at 273 K and relative pressure of 0.95. Samples were also thoroughly characterized in terms of texture (specific surface area measurement, transmission electron microscope) and chemical composition (X-ray photoelectron spectroscopy). Michal Zgrzebnicki, Nikola Krauze, Andżelika Gęsikiewicz-Puchalska, Joanna Kapica-Kozar, Ewa Piróg, Anna Jędrzejewska, Beata Michalkiewicz, Urszula Narkiewicz, Antoni W. Morawski, and Rafal J. Wrobel Copyright © 2017 Michal Zgrzebnicki et al. All rights reserved. Liquid Phase Synthesis of CoP Nanoparticles with High Electrical Conductivity for Advanced Energy Storage Mon, 09 Oct 2017 00:00:00 +0000 Transition metal phosphide alloys possess the metalloid characteristics and superior electrical conductivity and are a kind of high electrical conductive pseudocapacitive materials. Herein, high electrical conductive cobalt phosphide alloys are fabricated through a liquid phase process and a nanoparticles structure with high surface area is obtained. The highest specific capacitance of 286 F g−1 is reached at a current density of 0.5 A g−1. 63.4% of the specific capacitance is retained when the current density increased 16 times and 98.5% of the specific capacitance is maintained after 5000 cycles. The AC//CoP asymmetric supercapacitor also shows a high energy density (21.3 Wh kg−1) and excellent stability (97.8% of the specific capacitance is retained after 5000 cycles). The study provides a new strategy for the construction of high-performance energy storage materials by enhancing their intrinsic electrical conductivity. Guo-Qun Zhang, Bo Li, Mao-Cheng Liu, Shang-Ke Yuan, and Leng-Yuan Niu Copyright © 2017 Guo-Qun Zhang et al. All rights reserved. A Study of Photocatalysis of Methylene Blue of TiO2 Fabricated by Electric Spark Discharge Method Sun, 08 Oct 2017 00:00:00 +0000 This study used the Electric Spark Discharge Method (ESDM) to prepare nano-Ti colloid. The results showed that the process efficiency increased according to the current and selecting different discharge periods (-). The preparation process is pollution-free and very contributive to using TiO2 for photocatalytic reaction to degrade organic compounds. This study used 99.9% pure Ti metal to examine the effects of different discharge parameter settings on the photocatalysis of methylene blue. The experimental results showed that the discharge period (-) has an effect on the characteristics of the prepared nano-Ti colloid but affects its concentration. The nano-Ti colloid, as prepared under different parameters, has poor photocatalytic reaction with methylene blue at the concentration of 50 mg/L. The nano-Ti colloid does not have favorable effect on degrading methylene blue above 50 mg/L. For degrading methylene blue at a low concentration of 10 mg/L, the 100-100 nano-Ti parameter is preferable. For degrading methylene blue at a high concentration of 30 mg/L, nano-Ti colloid with exceeding 100 and fixed at 100 is better. As the nano-Ti colloid prepared by ESDM was free of chemical agents, when TiO2 was used in photocatalytic reaction to degrade organic compounds, there was no secondary pollution to the environment. Kuo-Hsiung Tseng, Meng-Yun Chung, Chaur-Yang Chang, and Ting-Shou Cheng Copyright © 2017 Kuo-Hsiung Tseng et al. All rights reserved. Recent Advances in Nanoparticles Enhanced Oil Recovery: Rheology, Interfacial Tension, Oil Recovery, and Wettability Alteration Sun, 08 Oct 2017 00:00:00 +0000 Chemically enhanced oil recovery methods are utilized to increase the oil recovery by improving the mobility ratio, altering the wettability, and/or lowering the interfacial tension between water and oil. Surfactants and polymers have been used for this purpose for the last few decades. Recently, nanoparticles have attracted the attention due to their unique properties. A large number of nanoparticles have been investigated for enhanced oil recovery applications either alone or in combination with surfactants and/or polymers. This review discusses the various types of nanoparticles that have been utilized in enhanced oil recovery. The review highlights the impact of nanoparticles on wettability alteration, interfacial tension, and rheology. The review also covers the factors affecting the oil recovery using nanoparticles and current challenges in field implementation. Muhammad Shahzad Kamal, Ahmad A. Adewunmi, Abdullah S. Sultan, Mohammed F. Al-Hamad, and Umer Mehmood Copyright © 2017 Muhammad Shahzad Kamal et al. All rights reserved. Nanostructures for Flexible Electronics and Drug Delivery Sun, 01 Oct 2017 07:48:25 +0000 Chuanfei Guo, Jian Zhong, Liqian Gao, Jinwei Gao, and Siya Huang Copyright © 2017 Chuanfei Guo et al. All rights reserved. Thermal Stability of Cryomilled Al-Mg-Er Powders Thu, 28 Sep 2017 00:00:00 +0000 In this study, the thermal stability of nanostructured Al-Mg alloy powders was investigated. Two alloy compositions, Al-5Mg-0.1Er and Al-5Mg-0.5Er (wt.%), were cryogenically milled for 30 h to produce nanostructured powders. The microstructure of the milled powders with increasing temperature was investigated by differential scanning calorimetry (DSC) with one-hour annealing performed at selected temperatures followed by X-ray diffraction (XRD) and electron microscopy analysis. Prolonged milling led to significant oxygen pick-up in the powders. The Al-5Mg-0.1Er powders experienced grain growth typical of cryomilled Al-Mg powders, while the Al-5Mg-0.5Er alloy showed improved thermal stability. An average grain size of ~20 nm was observed up to 400°C (~0.8) in the Al-5Mg-0.5Er powders, and abnormal growth at 550°C resulted in a maximum observed grain size of 234 nm. Thermal stability in the Al-Mg-Er powders is attributed to the combined effects of solute/impurity drag and second-phase pinning (nanoscale oxides, nitrides, and oxynitrides) that impede grain boundary motion. Bamidele Akinrinlola, Raynald Gauvin, Carl Blais, and Mathieu Brochu Copyright © 2017 Bamidele Akinrinlola et al. All rights reserved. Physical Background for Luminescence Thermometry Sensors Based on Pr3+:LaF3 Crystalline Particles Sun, 24 Sep 2017 06:30:52 +0000 The main goal of this study was creating multifunctional nanoparticles based on rare-earth doped LaF3 nanocrystals, which can be used as fluorescence thermal sensors operating over the 80–320 K temperature range including physiological temperature range (10–50°C). The Pr3+:LaF3 ( = 1%) microcrystalline powder and the Pr3+:LaF3 ( = 12%, 20%) nanoparticles were studied. It was proved that all the samples were capable of thermal sensing into the temperature range from 80 to 320 K. It was revealed that the mechanisms of temperature sensitivity for the microcrystalline powder and the nanoparticles are different. In the powder, the 3P1 and 3P0 states of Pr3+ ion share their electronic populations according to the Boltzmann and thermalization of the 3P1 state takes place. In the nanoparticles, two temperature dependent mechanisms were suggested: energy migration within 3P0 state in the temperature range from 80 K to 200 K followed by quenching of 3P0 state by OH groups at higher temperatures. The values of the relative sensitivities for the Pr3+:LaF3 ( = 1%) microcrystalline powder and the Pr3+:LaF3 ( = 12%, 20%) nanoparticles into the physiological temperature range (at 45°C) were 1, 0.5, and 0.3% °C−1, respectively. Maksim S. Pudovkin, Oleg A. Morozov, Vitaly V. Pavlov, Stella L. Korableva, Elena V. Lukinova, Yury N. Osin, Vladimir G. Evtugyn, Roman A. Safiullin, and Vadim V. Semashko Copyright © 2017 Maksim S. Pudovkin et al. All rights reserved. Reaction and Characterization of Low-Temperature Effect of Transition Nanostructure Metal Codoped SCR Catalyst Wed, 20 Sep 2017 00:00:00 +0000 Typical p-type semiconductor MnO codoped with n-type semiconductors such as CeO2 and V2O5 was reported to achieve high efficiency in catalytic NO removal by NH3. In this paper, we present novel Mn-Ce codoped V2O5/TiO2 catalyst which exhibited an excellent NO conversion efficiency of 90% at 140°C. By using this codoped catalyst, the best low-temperature activity was greatly decreased when compared with single Mn- or Ce-doped catalyst. According to the characterization results from BET, XRD, and XPS, the codoped catalyst was composed of both CeO2 and amorphous Mn. The electron circulation formed between doping elements is believed to promote the electron transfer, which may be one of the reasons for excellent low-temperature denitration performance. Ke Yang, Weiwei Xiao, Quan Xu, Jiaojiao Bai, Yan Luo, Hao Guo, Li Cao, Wei Cai, Peng Pu, and Lulu Cai Copyright © 2017 Ke Yang et al. All rights reserved. Corrigendum to “Critical Review on Nanofluids: Preparation, Characterization, and Applications” Wed, 20 Sep 2017 00:00:00 +0000 Mohamoud Jama, Tejvir Singh, Seifelislam Mahmoud Gamaleldin, Muammer Koc, Ayman Samara, Rima J. Isaifan, and Muataz A. Atieh Copyright © 2017 Mohamoud Jama et al. All rights reserved. Viscosity and Morphology Modification of Length Sorted Single-Walled Carbon Nanotubes in PIB Matrices Mon, 18 Sep 2017 07:44:40 +0000 This work evaluates the effectiveness of nanoscale particulates in producing non-Einstein-like responses in polymer matrices, to reduce their negative effects in low shear rate processing. This is of value to material processing applications which encompass extrusion, flow into cold mold, and generalized processing of nanocomposites. Through control and understanding of the structure processing relationships entailed through nanoscale additive materials, we begin to manage dispersion characteristics for more reliable and defect-free product development. In pursuit of identifying system characteristics that produce non-Einstein-like responses we isolate and characterize homogenous fractions of single-walled carbon nanotubes (SWNTs) with singular lengths. This enables the definition of a well-defined nanoscale particulate phase, within the polymer matrices. The effect of nanotube length and weight fraction on the polyisobutylene (PIB) matrices was evaluated with thermal and rheological testing. Our findings show that the viscosity of the produced nanocomposite systems has a length dependence and does not demonstrate the expected monotonous increases in the viscosity with an increase in weight fraction of nanotube additive within the matrix, demonstrating a non-Einstein-like viscosity response. Furthermore, we demonstrate length dependent crystallization in the studied systems, as an intermediate length nanotube initiates crystallization of polyisobutylene (PIB) affecting viscosity and mechanical properties. Hanxiao Huang, Bohao Li, Clayton E. Simien, and Daneesh O. Simien Copyright © 2017 Hanxiao Huang et al. All rights reserved. Nanoporosity of MCM-41 Materials and Y-Zeolites Created by Deposition of Tournefortia hirsutissima L. Plant Extract Mon, 18 Sep 2017 00:00:00 +0000 Hybrid materials based on MCM-41 silica and Y-zeolites with a variable Si/Al ratio and an appropriate countercationic composition were prepared by impregnating inorganic substrates with an organic extract. The organic phase was previously characterized by GC-MS and IRTF, while XRD, SEM, TEM, N2-physisorption, and TPD of NH3 were used to analyze the selected inorganic supports. The effect of size- and shape-selectivity was manifested in MCM-41 and Y-zeolites. Texture results confirm that the extract containing relatively large branched organic molecules is deposited in the internal voids of MCM-41 material and on the outer area of Y-zeolites. In the case of Y-zeolites, the results demonstrate the effect of the SiO2/ molar ratio and countercations on the textural properties of the samples. Miguel Angel Hernández, Gabriela Itzel Hernández, Roberto Portillo, Martha Alicia Salgado, Fernando Rojas, and Vitalii Petranovskii Copyright © 2017 Miguel Angel Hernández et al. All rights reserved. Electrospun Polyaniline-Based Composite Nanofibers: Tuning the Electrical Conductivity by Tailoring the Structure of Thiol-Protected Metal Nanoparticles Sun, 17 Sep 2017 00:00:00 +0000 Composite nanofibers made of a polyaniline-based polymer blend and different thiol-capped metal nanoparticles were prepared using ex situ synthesis and electrospinning technique. The effects of the nanoparticle composition and chemical structure on the electrical properties of the nanocomposites were investigated. This study confirmed that Brust’s procedure is an effective method for the synthesis of sub-10 nm silver, gold, and silver-gold alloy nanoparticles protected with different types of thiols. Electron microscopy results demonstrated that electrospinning is a valuable technique for the production of composite nanofibers with similar morphology and revealed that nanofillers are well-dispersed into the polymer matrix. X-ray diffraction tests proved the lack of a significant influence of the nanoparticle chemical structure on the polyaniline chain arrangement. However, the introduction of conductive nanofillers in the polymer matrix influences the charge transport noticeably improving electrical conductivity. The enhancement of electrical properties is mediated by the nanoparticle capping layer structure. The metal nanoparticle core composition is a key parameter, which exerted a significant influence on the conductivity of the nanocomposites. These results prove that the proposed method can be used to tune the electrical properties of nanocomposites. Filippo Pierini, Massimiliano Lanzi, Paweł Nakielski, and Tomasz Aleksander Kowalewski Copyright © 2017 Filippo Pierini et al. All rights reserved. Fabrication of PLA-PEG Nanoparticles as Delivery Systems for Improved Stability and Controlled Release of Catechin Thu, 14 Sep 2017 00:00:00 +0000 The purpose of this study was to develop an oral delivery system for the controlled release of catechin and evaluate the antioxidant potential and stability of catechin loaded PLA/PEG nanoparticles (CATNP). Nanoparticles were synthesized using a double emulsion solvent evaporation method. The fabricated nanoparticles were relatively small with a hydrodynamic diameter of 300 nm and an encapsulation efficiency of 95%. SEM image analysis showed uniform sized and spherically shaped nanoparticles. In vitro release profiles indicated a slow and sustained release of catechin from the nanoparticle. Stability of the nanoparticle in simulated gastric and intestinal fluids is maintained due to the PEG coating on the nanoparticles, which effectively protected catechin against gastrointestinal enzyme activity. Enhanced inhibition action of free radicals and metal chelation potential was noted when catechin was encapsulated in these polymeric nanoparticles. The reports obtained from this study would provide an opportunity for designing an oral delivery system aimed at inhibiting oxidative stress in the human body. Neha Atulkumar Singh, Abul Kalam Azad Mandal, and Zaved Ahmed Khan Copyright © 2017 Neha Atulkumar Singh et al. All rights reserved. Effect of Surface Charge and Hydrophobicity Modulation on the Antibacterial and Antibiofilm Potential of Magnetic Iron Nanoparticles Tue, 12 Sep 2017 00:00:00 +0000 Unmodified magnetic nanoparticles (MNPs) lack antibacterial potential. We investigated MNPs surface modifications that can impart antibacterial activity. Six MNPs species were prepared and characterized. Their antibacterial and antibiofilm potentials, surface affinity, and cytotoxicity were evaluated. Prepared MNPs were functionalized with citric acid, amine group, amino-propyl trimethoxy silane (APTMS), arginine, or oleic acid (OA) to give hydrophilic and hydrophobic MNPs with surface charge ranging from −30 to +30 mV. Prepared MNPs were spherical in shape with an average size of 6–15 nm. Hydrophobic (OA-MNPs) and positively charged MNPs (APTMS-MNPs) had significant concentration dependent antibacterial effect. OA-MNPs showed higher inhibitory potential against S. aureus and E. coli (80%) than APTMS-MNPs (70%). Both particles exhibited surface affinity to S. aureus and E. coli. Different concentrations of OA-MNPs decreased S. aureus and E. coli biofilm formation by 50–90%, while APTMS-MNPs reduced it by 30–90%, respectively. Up to 90% of preformed biofilms of S. aureus and E. coli were destroyed by OA-MNPs and APTMS-MNPs. In conclusion, surface positivity and hydrophobicity enhance antibacterial and antibiofilm properties of MNPs. Rania Ibrahim Shebl, Faten Farouk, and Hassan Mohamed El-Said Azzazy Copyright © 2017 Rania Ibrahim Shebl et al. All rights reserved. Morphology, Microstructure, and Hydrogen Content of Carbon Nanostructures Obtained by PECVD at Various Temperatures Mon, 11 Sep 2017 09:33:39 +0000 Carbon nanostructures were obtained by acetylene injection into an argon plasma jet in the presence of hydrogen. The samples were synthesized in similar conditions, except that the substrate deposition temperatures were varied, ranging from 473 to 973 K. A strong dependence of morphology, structure, and graphitization upon was found. We obtained vertical aligned carbon nanotubes (VA-CNTs) at low temperatures as 473 K, amorphous carbon nanoparticles (CNPs) at temperatures from about 573 to 673 K, and carbon nanowalls (CNWs) at high temperatures from 773 to 973 K. Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, elastic recoil detection analysis, X-ray photoelectron spectroscopy, and Raman spectroscopy were used to substantiate the differences in these material types. It is known that hydrogen concentration modifies strongly the properties of the materials. Different concentrations of hydrogen-bonded carbon could be identified in amorphous CNP, VA-CNT, and CNW. Also, the H : C ratios along depth were determined for the obtained materials. M. Acosta Gentoiu, R. Betancourt-Riera, S. Vizireanu, I. Burducea, V. Marascu, S. D. Stoica, B. I. Bita, G. Dinescu, and R. Riera Copyright © 2017 M. Acosta Gentoiu et al. All rights reserved. Phytosynthesis of Silver and Gold Nanoparticles Using the Hot Water Extract of Mixed Woodchip Powder and Their Antibacterial Efficacy Mon, 11 Sep 2017 09:24:30 +0000 This study investigates the phytosynthesis, characterization, and antibacterial efficacy of silver and gold nanoparticles (NPs) produced using the hot water extract of mixed woodchip powder. The woodchip extract (WCE) was successfully used as both a reducing and stabilizing agent for the phytosynthesis of both crystalline metal NPs. The effects of different physicochemical factors affecting the formation of the metal NPs including reaction pH, concentration of the precursor metal salts, amount of WCE, and external energy input were evaluated. The characterization of the metal NPs was performed by transmission electron microscopy, selected area electron diffraction (SAED), energy dispersive X-ray (EDX) spectroscopy, and X-ray diffraction (XRD) pattern analysis. In addition, the antibacterial efficacy of the phytosynthesized NPs was measured. The AgNPs showed clear antibacterial activity against four representative bacterial strains. However, the AuNPs did not exhibit bactericidal activity, probably due to their surface modifications and relatively large size. These results suggest that the phytosynthesis of the metal NPs using WCE is highly efficient, and its convenience makes it suitable for use in large-scale production. Min-Ho Joe, Hyun-Tak Jeong, Hyung-Min Lee, Hae-Jun Park, Dong-Ho Kim, Don-Hee Park, and Suk Bai Copyright © 2017 Min-Ho Joe et al. All rights reserved. Optical and Magnetic Properties of Ni Doped ZnS Diluted Magnetic Semiconductors Synthesized by Hydrothermal Method Mon, 11 Sep 2017 00:00:00 +0000 Diluted magnetic semiconductors with different consistency ratio ( = 0, 0.01, 0.03, 0.05, and 0.07) were successfully synthesized by hydrothermal method using ethylenediamine as a modifier. The influence of Ni doping concentration on the microstructure, morphology, and optical and magnetic properties of undoped and Ni doped ZnS nanocrystals was characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), X-ray energy dispersive spectrometry (XEDS), ultraviolet-visible spectroscopy (UV-vis), Fourier transform infrared spectroscopy (FT-IR), photoluminescence spectra (PL), and the vibrating sample magnetometer (VSM), respectively. The experiment results show the substitution of Ni2+ on Zn2+ sites without changing the hexagonal wurtzite structure of ZnS and generate single-phase with good crystallization. The lattice constant causes distortion and decreases with the increase of Ni2+ doped concentration. The appearance of the samples is one-dimensional well-dispersed nanorods. UV-vis spectra reveal the band gap of all samples greater than that of bulk ZnS (3.67 eV), and blue shift phenomenon occurs. The photoluminescence spectra of undoped and doped samples possess the broad blue emission band in the range of 400–650 nm; the PL intensities of nanorods increase with the increase of Ni content comparing to pure ZnS and reach maximum for = 0.03. Magnetic measurements indicated that the undoped ZnS samples are superparamagnetic, whereas the doped samples exhibit ferromagnetism. Meirong Wu, Zhiqiang Wei, Wenhua Zhao, Xuan Wang, and Jinlong Jiang Copyright © 2017 Meirong Wu et al. All rights reserved. CO Gas-Induced Resonance Frequency Shift of ZnO-Functionalized Microcantilever in Humid Air Sun, 10 Sep 2017 08:01:11 +0000 Resonance frequency shift of a zinc oxide- (ZnO-) functionalized microcantilever as a response to carbon monoxide (CO) gas has been investigated. Here, ZnO microrods were grown on the microcantilever surface by a hydrothermal method. The measurement of resonance frequency of the microcantilever vibrations due to the gas was carried out in two conditions, that is, gas flow with and without air pumping into an experiment chamber. The results show that the resonance frequency of the ZnO-functionalized microcantilever decreases because of CO in air pumping condition, while it increases when CO is introduced without air pumping. Such change in the resonance frequency is influenced by water vapor condition, and a possible model based on water-CO combination was proposed. Lia Aprilia, Ratno Nuryadi, Dwi Gustiono, Nurmahmudi, Arief Udhiarto, Djoko Hartanto, Brian Yuliarto, Makoto Hosoda, Yoichiro Neo, and Hidenori Mimura Copyright © 2017 Lia Aprilia et al. All rights reserved. Surface Plasmon Enhanced Light Trapping in Metal/Silicon Nanobowl Arrays for Thin Film Photovoltaics Sun, 10 Sep 2017 00:00:00 +0000 Enhancing the light absorption in thin film silicon solar cells with nanophotonic and plasmonic structures is important for the realization of high efficiency solar cells with significant cost reduction. In this work, we investigate periodic arrays of conformal metal/silicon nanobowl arrays (MSNBs) for light trapping applications in silicon solar cells. They exhibited excellent light-harvesting ability across a wide range of wavelengths up to infrared regimes. The optimized structure (MSNBsH) covered by SiO2 passivation layer and hemisphere Ag back reflection layer has a maximal short-circuit density () 25.5 mA/cm2, which is about 88.8% higher than flat structure counterpart, and the light-conversion efficiency () is increased two times from 6.3% to 12.6%. The double-side textures offer a promising approach to high efficiency ultrathin silicon solar cells. Ruinan Sun, Haoxin Fu, Jiang Wang, Yachun Wang, Xingchen Du, Haichuan Zhao, Chenliang Huo, and Kuiqing Peng Copyright © 2017 Ruinan Sun et al. All rights reserved. Nanosized Minicells Generated by Lactic Acid Bacteria for Drug Delivery Thu, 07 Sep 2017 00:00:00 +0000 Nanotechnology has the ability to target specific areas of the body, controlling the drug release and significantly increasing the bioavailability of active compounds. Organic and inorganic nanoparticles have been developed for drug delivery systems. Many delivery systems are through clinical stages for development and market. Minicell, a nanosized cell generated by bacteria, is a potential particle for drug delivery because of its size, safety, and biodegradability. Minicells produced by bacteria could drive therapeutic agents against cancer, microbial infection, and other diseases by targeting. In addition, minicells generated by lactic acid bacteria being probiotics are more interesting than others because of their benefits like safety, immunological improvement, and biodegradation. This review aims to highlight the stages of development of nanoparticle for drug delivery and discuss their advantages and limitations to clarify minicells as a new opportunity for the development of potential nanoparticle for drug delivery. Huu Ngoc Nguyen, Santa Romero Jovel, and Tu Hoang Khue Nguyen Copyright © 2017 Huu Ngoc Nguyen et al. All rights reserved. Influence of Carbon Modification on the Morphological, Structural, and Optical Properties of Zinc Oxide Nanoparticles Synthesized by Pneumatic Spray Pyrolysis Technique Wed, 06 Sep 2017 00:00:00 +0000 This paper reveals the influence of doping on the morphological, structural, and optical properties of zinc oxide (ZnO) nanoparticles (NPs) synthesized by pneumatic spray pyrolysis technique (PSP), using zinc ethoxide Zn as the precursor. The prepared samples were characterized by XRD, HRTEM, SEM-EDX, UV-Vis spectroscopy, and RS. RS analysis has revealed that the unmodified ZnO and carbon modified ZnO samples have characteristic Raman optic modes at 325 cm−1, 373 cm−1, and 432 cm−1 belonging to Wurtzite ZnO structure. The XRD ZnO (C:ZnO) NPS have characteristic peaks of hexagonal Wurtzite ZnO structure. HRTEM analysis has revealed that the synthesized ZnO NPs have particle size range of 8.8–11.82 nm. EDX spectra of both unmodified and modified ZnO nanoparticles have revealed prominent peaks at 0.51 keV, 1.01 keV, 1.49 keV, 8.87 keV, and 9.86 keV. The occurrence of these peaks in the EDX spectra endorses the existence of Zn and O atoms in the PSP synthesized ZnO NPs. The UV-Vis spectroscopy has revealed a red shift of the absorption edge, with the increase in C dopant level. The effect of nanocrystallite size and the gradual prominence of C into ZnO matrix due to increase in C dopant level in the PSP synthesized ZnO NPs was meticulously elaborated through Raman spectroscopy analysis. R. Taziwa, E. Meyer, D. Katwire, and L. Ntozakhe Copyright © 2017 R. Taziwa et al. All rights reserved. An Accurate PSO-GA Based Neural Network to Model Growth of Carbon Nanotubes Wed, 06 Sep 2017 00:00:00 +0000 By combining particle swarm optimization (PSO) and genetic algorithms (GA) this paper offers an innovative algorithm to train artificial neural networks (ANNs) for the purpose of calculating the experimental growth parameters of CNTs. The paper explores experimentally obtaining data to train ANNs, as a method to reduce simulation time while ensuring the precision of formal physics models. The results are compared with conventional particle swarm optimization based neural network (CPSONN) and Levenberg–Marquardt (LM) techniques. The results show that PSOGANN can be successfully utilized for modeling the experimental parameters that are critical for the growth of CNTs. Mohsen Asadnia, Amir Mahyar Khorasani, and Majid Ebrahimi Warkiani Copyright © 2017 Mohsen Asadnia et al. All rights reserved.