Nanomaterials

2778 KiB

Open AccessArticle

Antimicrobial Properties of Biofunctionalized Silver Nanoparticles on Clinical Isolates of Streptococcus mutans and Its Serotypes

by Ángel Manuel Martínez-Robles, Juan Pablo Loyola-Rodríguez, Norma Verónica Zavala-Alonso, Rita Elizabeth Martinez-Martinez, Facundo Ruiz, René Homero Lara-Castro, Alejandro Donohué-Cornejo, Simón Yobanny Reyes-López and León Francisco Espinosa-Cristóbal

Nanomaterials 2016, 6(7), 136; https://doi.org/10.3390/nano6070136 - 22 Jul 2016

Cited by 24 | Viewed by 6397

Abstract

(1) Background: Streptococcus mutans (S. mutans) is the principal pathogen involved in the formation of dental caries. Other systemic diseases have also been associated with specific S. mutans serotypes (c, e, f, and k). Silver nanoparticles [...] Read more.

(1) Background: Streptococcus mutans (S. mutans) is the principal pathogen involved in the formation of dental caries. Other systemic diseases have also been associated with specific S. mutans serotypes (c, e, f, and k). Silver nanoparticles (SNP) have been demonstrated to have good antibacterial effects against S. mutans; therefore, limited studies have evaluated the antimicrobial activity of biofunctionalized SNP on S. mutans serotypes. The purpose of this work was to prepare and characterize coated SNP using two different organic components and to evaluate the antimicrobial activity of SNP in clinical isolates of S. mutans strains and serotypes; (2) Methods: SNP with bovine serum albumin (BSA) or chitosan (CS) coatings were prepared and the physical, chemical and microbiological properties of SNP were evaluated; (3) Results: Both types of coated SNP showed antimicrobial activity against S. mutans bacteria and serotypes. Better inhibition was associated with smaller particles and BSA coatings; however, no significant differences were found between the different serotypes, indicating a similar sensitivity to the coated SNP; (4) Conclusion: This study concludes that BSA and CS coated SNP had good antimicrobial activity against S. mutans strains and the four serotypes, and this study suggest the widespread use of SNP as an antimicrobial agent for the inhibition of S. mutans bacteria. Full article

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5171 KiB

Open AccessArticle

Enhanced Deposition Uniformity via an Auxiliary Electrode in Massive Electrospinning

by Dezhi Wu, Zhiming Xiao, Lei Deng, Yu Sun, Qiulin Tan, Linxi Dong, Shaohua Huang, Rui Zhu, Yifang Liu, Wanxi Zheng, Yang Zhao, Lingyun Wang and Daoheng Sun

Nanomaterials 2016, 6(7), 135; https://doi.org/10.3390/nano6070135 - 22 Jul 2016

Cited by 8 | Viewed by 5450

Abstract

Uniform deposition of nanofibers in the massive electrospinning process is critical in the industrial applications of nanofibers. Tip-Induced Electrospinning (TIE) is a cost-effective large-scale nanofiber-manufacturing method, but it has poor deposition uniformity. An auxiliary conductive electrode connected to the emitting electrode was introduced [...] Read more.

Uniform deposition of nanofibers in the massive electrospinning process is critical in the industrial applications of nanofibers. Tip-Induced Electrospinning (TIE) is a cost-effective large-scale nanofiber-manufacturing method, but it has poor deposition uniformity. An auxiliary conductive electrode connected to the emitting electrode was introduced to improve the deposition uniformity of the nanofibers. The effects of the auxiliary electrode shape, the tilted angles and the position of the boat-like electrode on the electric field distribution, the diameter of the nanofibers, the jet control and the deposition uniformity were explored by using finite element analysis of the electric field and experiments. Experiments showed that the boat-like electrode at 20 mm above the reservoir bottom with a 5° tilted angle helped to decrease the relative deposition error of nanofibers in the greatest extent to about 5.66%, indicating such an auxiliary electrode is a good candidate method to greatly improve the deposition uniformity of nanofibers in massive electrospinning. Full article

(This article belongs to the Special Issue Electrospinning of Nanofibres for Energy Applications)

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2334 KiB

Open AccessReview

Nanomaterials for Tissue Engineering In Dentistry

by Manila Chieruzzi, Stefano Pagano, Silvia Moretti, Roberto Pinna, Egle Milia, Luigi Torre and Stefano Eramo

Nanomaterials 2016, 6(7), 134; https://doi.org/10.3390/nano6070134 - 21 Jul 2016

Cited by 78 | Viewed by 11600

Abstract

The tissue engineering (TE) of dental oral tissue is facing significant changes in clinical treatments in dentistry. TE is based on a stem cell, signaling molecule, and scaffold triad that must be known and calibrated with attention to specific sectors in dentistry. This [...] Read more.

The tissue engineering (TE) of dental oral tissue is facing significant changes in clinical treatments in dentistry. TE is based on a stem cell, signaling molecule, and scaffold triad that must be known and calibrated with attention to specific sectors in dentistry. This review article shows a summary of micro- and nanomorphological characteristics of dental tissues, of stem cells available in the oral region, of signaling molecules usable in TE, and of scaffolds available to guide partial or total reconstruction of hard, soft, periodontal, and bone tissues. Some scaffoldless techniques used in TE are also presented. Then actual and future roles of nanotechnologies about TE in dentistry are presented. Full article

(This article belongs to the Special Issue Nanomaterials for Tissue Engineering)

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5806 KiB

Open AccessReview

Nanomaterials for Cardiac Myocyte Tissue Engineering

by Rodolfo Amezcua, Ajay Shirolkar, Carolyn Fraze and David A. Stout

Nanomaterials 2016, 6(7), 133; https://doi.org/10.3390/nano6070133 - 19 Jul 2016

Cited by 51 | Viewed by 9404

Abstract

Since their synthesizing introduction to the research community, nanomaterials have infiltrated almost every corner of science and engineering. Over the last decade, one such field has begun to look at using nanomaterials for beneficial applications in tissue engineering, specifically, cardiac tissue engineering. During [...] Read more.

Since their synthesizing introduction to the research community, nanomaterials have infiltrated almost every corner of science and engineering. Over the last decade, one such field has begun to look at using nanomaterials for beneficial applications in tissue engineering, specifically, cardiac tissue engineering. During a myocardial infarction, part of the cardiac muscle, or myocardium, is deprived of blood. Therefore, the lack of oxygen destroys cardiomyocytes, leaving dead tissue and possibly resulting in the development of arrhythmia, ventricular remodeling, and eventual heart failure. Scarred cardiac muscle results in heart failure for millions of heart attack survivors worldwide. Modern cardiac tissue engineering research has developed nanomaterial applications to combat heart failure, preserve normal heart tissue, and grow healthy myocardium around the infarcted area. This review will discuss the recent progress of nanomaterials for cardiovascular tissue engineering applications through three main nanomaterial approaches: scaffold designs, patches, and injectable materials. Full article

(This article belongs to the Special Issue Nanomaterials for Tissue Engineering)

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2975 KiB

Open AccessArticle

A Label-Free Microelectrode Array Based on One-Step Synthesis of Chitosan–Multi-Walled Carbon Nanotube–Thionine for Ultrasensitive Detection of Carcinoembryonic Antigen

by Huiren Xu, Yang Wang, Li Wang, Yilin Song, Jinping Luo and Xinxia Cai

Nanomaterials 2016, 6(7), 132; https://doi.org/10.3390/nano6070132 - 11 Jul 2016

Cited by 18 | Viewed by 6300

Abstract

Carcinoembryonic antigen (CEA) has been an extensively used tumor marker responsible for clinical early diagnosis of cervical carcinomas, and pancreatic, colorectal, gastric and lung cancer. Combined with micro-electro mechanical system (MEMS) technology, it is important to develop a novel immune microelectrode array (MEA) [...] Read more.

Carcinoembryonic antigen (CEA) has been an extensively used tumor marker responsible for clinical early diagnosis of cervical carcinomas, and pancreatic, colorectal, gastric and lung cancer. Combined with micro-electro mechanical system (MEMS) technology, it is important to develop a novel immune microelectrode array (MEA) not only for rapid analysis of serum samples, but also for cell detection in vitro and in vivo. In this work, we depict a simple approach to modify chitosan–multi-walled carbon nanotubes–thionine (CS–MWCNTs–THI) hybrid film through one-step electrochemical deposition and the CS-MWCNTs-THI hybrid films are successfully employed to immobilize anti-CEA for fabricating simple, label-free, and highly sensitive electro-chemical immune MEAs. The detection principle of immune MEA was based on the fact that the increasing formation of the antigen-antibody immunocomplex resulted in the decreased response currents and the relationship between the current reductions with the corresponding CEA concentrations was directly proportional. Experimental results indicated that the label-free MEA had good selectivity and the limit of detection for CEA is 0.5 pg/mL signal to noise ratio (SNR) = 3. A linear calibration plot for the detection of CEA was obtained in a wide concentration range from 1 pg/mL to 100 ng/mL (r = 0.996). This novel MEA has potential applications for detecting CEA for the research on cancer cells and cancer tissue slices as well as for effective early diagnosis. Full article

(This article belongs to the Special Issue Polysaccharide-Based Nanosorbent Materials: Fundamental Science and Beyond)

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714 KiB

Open AccessReview

Lipid Nanovectors to Deliver RNA Oligonucleotides in Cancer

by Virginia Campani, Giuseppina Salzano, Sara Lusa and Giuseppe De Rosa

Nanomaterials 2016, 6(7), 131; https://doi.org/10.3390/nano6070131 - 9 Jul 2016

Cited by 33 | Viewed by 7407

Abstract

The growing knowledge on the mechanisms of gene silencing and gene regulation by non-coding RNAs (ncRNA), mainly small interfering RNA (siRNA) and microRNA (miRNA), is providing a significant boost to the development of new therapeutic strategies for the treatment of cancer. However, the [...] Read more.

The growing knowledge on the mechanisms of gene silencing and gene regulation by non-coding RNAs (ncRNA), mainly small interfering RNA (siRNA) and microRNA (miRNA), is providing a significant boost to the development of new therapeutic strategies for the treatment of cancer. However, the design of RNA-based therapeutics is hampered by biopharmaceutical issues, thus requiring the use of suitable delivery strategies. In this regards, lipid nanovectors have been successfully investigated to deliver RNA in different forms of cancer. Compared to other biomaterials, lipids offer advantages such as biocompatibility, biodegradability, easy production, low cost, limited toxicity and immunogenicity. The possibility to formulate these materials in the form of nanovectors allows overcoming biopharmaceutical issues associated to the therapeutic use of RNA, with the possibility to target tumors. This review takes stock of the main lipid nanovectors proposed to deliver ncRNA. For each considered delivery strategy, the rational design and the most meaningful in vitro and in vivo results are reported and discussed. Full article

(This article belongs to the Special Issue Nanomaterials for Cancer Therapies)

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4319 KiB

Open AccessArticle

Nanostructures Derived from Starch and Chitosan for Fluorescence Bio-Imaging

by Yinxue Zu, Jingran Bi, Huiping Yan, Haitao Wang, Yukun Song, Bei-Wei Zhu and Mingqian Tan

Nanomaterials 2016, 6(7), 130; https://doi.org/10.3390/nano6070130 - 5 Jul 2016

Cited by 20 | Viewed by 7781

Abstract

Fluorescent nanostructures (NSs) derived from polysaccharides have drawn great attention as novel fluorescent probes for potential bio-imaging applications. Herein, we reported a facile alkali-assisted hydrothermal method to fabricate polysaccharide NSs using starch and chitosan as raw materials. Transmission electron microscopy (TEM) demonstrated that [...] Read more.

Fluorescent nanostructures (NSs) derived from polysaccharides have drawn great attention as novel fluorescent probes for potential bio-imaging applications. Herein, we reported a facile alkali-assisted hydrothermal method to fabricate polysaccharide NSs using starch and chitosan as raw materials. Transmission electron microscopy (TEM) demonstrated that the average particle sizes are 14 nm and 75 nm for starch and chitosan NSs, respectively. Fourier transform infrared (FT-IR) spectroscopy analysis showed that there are a large number of hydroxyl or amino groups on the surface of these polysaccharide-based NSs. Strong fluorescence with an excitation-dependent emission behaviour was observed under ultraviolet excitation. Interestingly, the photostability of the NSs was found to be superior to fluorescein and rhodamine B. The quantum yield of starch NSs could reach 11.12% under the excitation of 360 nm. The oxidative metal ions including Cu(II), Hg(II)and Fe(III) exhibited a quench effect on the fluorescence intensity of the prepared NSs. Both of the two kinds of the multicoloured NSs showed a maximum fluorescence intensity at pH 7, while the fluorescence intensity decreased dramatically when they were put in an either acidic or basic environment (at pH 3 or 11). The cytotoxicity study of starch NSs showed that low cell cytotoxicity and 80% viability was found after 24 h incubation, when their concentration was less than 10 mg/mL. The study also showed the possibility of using the multicoloured starch NSs for mouse melanoma cells and guppy fish imaging. Full article

(This article belongs to the Special Issue Polysaccharide-Based Nanosorbent Materials: Fundamental Science and Beyond)

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4549 KiB

Open AccessReview

Electrospinning of Nanofibers for Energy Applications

by Guiru Sun, Liqun Sun, Haiming Xie and Jia Liu

Nanomaterials 2016, 6(7), 129; https://doi.org/10.3390/nano6070129 - 2 Jul 2016

Cited by 113 | Viewed by 12257

Abstract

With global concerns about the shortage of fossil fuels and environmental issues, the development of efficient and clean energy storage devices has been drastically accelerated. Nanofibers are used widely for energy storage devices due to their high surface areas and porosities. Electrospinning is [...] Read more.

With global concerns about the shortage of fossil fuels and environmental issues, the development of efficient and clean energy storage devices has been drastically accelerated. Nanofibers are used widely for energy storage devices due to their high surface areas and porosities. Electrospinning is a versatile and efficient fabrication method for nanofibers. In this review, we mainly focus on the application of electrospun nanofibers on energy storage, such as lithium batteries, fuel cells, dye-sensitized solar cells and supercapacitors. The structure and properties of nanofibers are also summarized systematically. The special morphology of nanofibers prepared by electrospinning is significant to the functional materials for energy storage. Full article

(This article belongs to the Special Issue Electrospinning of Nanofibres for Energy Applications)

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4694 KiB

Open AccessArticle

Characteristic Evaluation of Graphene Oxide for Bisphenol A Adsorption in Aqueous Solution

by Thatchaphong Phatthanakittiphong and Gyu Tae Seo

Nanomaterials 2016, 6(7), 128; https://doi.org/10.3390/nano6070128 - 2 Jul 2016

Cited by 70 | Viewed by 8107

Abstract

This paper investigates the characteristics of graphene oxide (GO) for Bisphenol A (BPA) adsorption in water. Batch experiments on the influence of significant parameters were performed. While an improvement of the adsorption capacity of BPA was obtained by the increment of contact time [...] Read more.

This paper investigates the characteristics of graphene oxide (GO) for Bisphenol A (BPA) adsorption in water. Batch experiments on the influence of significant parameters were performed. While an improvement of the adsorption capacity of BPA was obtained by the increment of contact time and the initial BPA concentration, the increment of pH above 8, GO dosage, and temperature showed the reverse results. The thermodynamic study suggested that BPA adsorption on GO was an exothermic and spontaneous process. The kinetics was explained by the pseudo-second-order model which covers all steps of adsorption. The fit of the results with the Langmuir isotherm indicated the monolayer adsorption. At 298 K, the adsorption reached equilibrium within 30 min with the maximum adsorption capacity of 49.26 mg/g. The low BPA adsorption capacity of GO can be interpreted by the occurrence of oxygen-containing functional groups (OCFGs) that are able to form hydrogen bonds with the surrounding OCFGs and water molecules. This effect inhibited the role of π–π interactions that are mainly responsible for the adsorption of BPA. Full article

(This article belongs to the Special Issue 2D Nanomaterials: Graphene and Beyond Graphene)

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2086 KiB

Open AccessArticle

A Gallium Oxide-Graphene Oxide Hybrid Composite for Enhanced Photocatalytic Reaction

by Seungdu Kim, Kook In Han, In Gyu Lee, Won Kyu Park, Yeojoon Yoon, Chan Sei Yoo, Woo Seok Yang and Wan Sik Hwang

Nanomaterials 2016, 6(7), 127; https://doi.org/10.3390/nano6070127 - 1 Jul 2016

Cited by 10 | Viewed by 6314

Abstract

Hybrid composites (HCs) made up of gallium oxide (GaO) and graphene oxide (GO) were investigated with the intent of enhancing a photocatalytic reaction under ultraviolet (UV) radiation. The material properties of both GaO and GO were preserved, even after the formation of the [...] Read more.

Hybrid composites (HCs) made up of gallium oxide (GaO) and graphene oxide (GO) were investigated with the intent of enhancing a photocatalytic reaction under ultraviolet (UV) radiation. The material properties of both GaO and GO were preserved, even after the formation of the HCs. The incorporation of the GO into the GaO significantly enhanced the photocatalytic reaction, as indicated by the amount of methylene blue (MB) degradation. The improvements in the reaction were discussed in terms of increased surface area and the retarded recombination of generated charged carriers. Full article

(This article belongs to the Special Issue Nanomaterials for Flexible and Stretchable Devices: Synthesis, Processes, and Applications)

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3752 KiB

Open AccessArticle

Quaternized Chitosan-Capped Mesoporous Silica Nanoparticles as Nanocarriers for Controlled Pesticide Release

by Lidong Cao, Huirong Zhang, Chong Cao, Jiakun Zhang, Fengmin Li and Qiliang Huang

Nanomaterials 2016, 6(7), 126; https://doi.org/10.3390/nano6070126 - 28 Jun 2016

Cited by 130 | Viewed by 13837

Abstract

Nanotechnology-based pesticide formulations would ensure effective utilization of agricultural inputs. In the present work, mesoporous silica nanoparticles (MSNs) with particle diameters of ~110 nm and pore sizes of ~3.7 nm were synthesized via a liquid crystal templating mechanism. A water-soluble chitosan (CS) derivative [...] Read more.

Nanotechnology-based pesticide formulations would ensure effective utilization of agricultural inputs. In the present work, mesoporous silica nanoparticles (MSNs) with particle diameters of ~110 nm and pore sizes of ~3.7 nm were synthesized via a liquid crystal templating mechanism. A water-soluble chitosan (CS) derivative (N-(2-hydroxyl)propyl-3-trimethyl ammonium CS chloride, HTCC) was successfully capped on the surface of pyraclostrobin-loaded MSNs. The physicochemical and structural analyses showed that the electrostatic interactions and hydrogen bonding were the major forces responsible for the formation of HTCC-capped MSNs. HTCC coating greatly improved the loading efficiency (LC) (to 40.3%) compared to using bare MSNs as a single encapsulant (26.7%). The microstructure of the nanoparticles was revealed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The pyraclostrobin-loaded nanoparticles showed an initial burst and subsequent sustained release behavior. HTCC-capped MSNs released faster than bare MSNs in the initial stage. Pyraclostrobin-loaded HTCC-capped MSNs with half doses of pyraclostrobin technical demonstrated almost the same fungicidal activity against Phomopsis asparagi (Sacc.), which obviously reduced the applied pesticide and enhanced the utilization efficiency. Therefore, HTCC-decorated MSNs demonstrated great potential as nanocarriers in agrochemical applications. Full article

(This article belongs to the Special Issue Polysaccharide-Based Nanosorbent Materials: Fundamental Science and Beyond)

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5811 KiB

Open AccessReview

Soft Interaction in Liposome Nanocarriers for Therapeutic Drug Delivery

by Domenico Lombardo, Pietro Calandra, Davide Barreca, Salvatore Magazù and Mikhail A. Kiselev

Nanomaterials 2016, 6(7), 125; https://doi.org/10.3390/nano6070125 - 25 Jun 2016

Cited by 149 | Viewed by 14808

Abstract

The development of smart nanocarriers for the delivery of therapeutic drugs has experienced considerable expansion in recent decades, with the development of new medicines devoted to cancer treatment. In this respect a wide range of strategies can be developed by employing liposome nanocarriers [...] Read more.

The development of smart nanocarriers for the delivery of therapeutic drugs has experienced considerable expansion in recent decades, with the development of new medicines devoted to cancer treatment. In this respect a wide range of strategies can be developed by employing liposome nanocarriers with desired physico-chemical properties that, by exploiting a combination of a number of suitable soft interactions, can facilitate the transit through the biological barriers from the point of administration up to the site of drug action. As a result, the materials engineer has generated through the bottom up approach a variety of supramolecular nanocarriers for the encapsulation and controlled delivery of therapeutics which have revealed beneficial developments for stabilizing drug compounds, overcoming impediments to cellular and tissue uptake, and improving biodistribution of therapeutic compounds to target sites. Herein we present recent advances in liposome drug delivery by analyzing the main structural features of liposome nanocarriers which strongly influence their interaction in solution. More specifically, we will focus on the analysis of the relevant soft interactions involved in drug delivery processes which are responsible of main behaviour of soft nanocarriers in complex physiological fluids. Investigation of the interaction between liposomes at the molecular level can be considered an important platform for the modeling of the molecular recognition processes occurring between cells. Some relevant strategies to overcome the biological barriers during the drug delivery of the nanocarriers are presented which outline the main structure-properties relationships as well as their advantages (and drawbacks) in therapeutic and biomedical applications. Full article

(This article belongs to the Special Issue Nanomaterials for Cancer Therapies)

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3267 KiB

Open AccessArticle

Nanostructured TiO₂ Surfaces Promote Human Bone Marrow Mesenchymal Stem Cells Differentiation to Osteoblasts

by Marco Vercellino, Gabriele Ceccarelli, Francesco Cristofaro, Martina Balli, Federico Bertoglio, Gianna Bruni, Laura Benedetti, Maria Antonietta Avanzini, Marcello Imbriani and Livia Visai

Nanomaterials 2016, 6(7), 124; https://doi.org/10.3390/nano6070124 - 24 Jun 2016

Cited by 27 | Viewed by 6534

Abstract

Micro- and nano-patterning/modification are emerging strategies to improve surfaces properties that may influence critically cells adherence and differentiation. Aim of this work was to study the in vitro biological reactivity of human bone marrow mesenchymal stem cells (hBMSCs) to a nanostructured titanium dioxide [...] Read more.

Micro- and nano-patterning/modification are emerging strategies to improve surfaces properties that may influence critically cells adherence and differentiation. Aim of this work was to study the in vitro biological reactivity of human bone marrow mesenchymal stem cells (hBMSCs) to a nanostructured titanium dioxide (TiO₂) surface in comparison to a coverglass (Glass) in two different culture conditions: with (osteogenic medium (OM)) and without (proliferative medium (PM)) osteogenic factors. To evaluate cell adhesion, hBMSCs phosphorylated focal adhesion kinase (pFAK) foci were analyzed by confocal laser scanning microscopy (CLSM) at 24 h: the TiO₂ surface showed a higher number of pFAK foci with respect to Glass. The hBMSCs differentiation to osteoblasts was evaluated in both PM and OM culture conditions by enzyme-linked immunosorbent assay (ELISA), CLSM and real-time quantitative reverse transcription PCR (qRT-PCR) at 28 days. In comparison with Glass, TiO₂ surface in combination with OM conditions increased the content of extracellular bone proteins, calcium deposition and alkaline phosphatase activity. The qRT-PCR analysis revealed, both in PM and OM, that TiO₂ surface increased at seven and 28 days the expression of osteogenic genes. All together, these results demonstrate the capability of TiO₂ nanostructured surface to promote hBMSCs osteoblast differentiation and its potentiality in biomedical applications. Full article

(This article belongs to the Special Issue Nanomaterials for Tissue Engineering)

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3980 KiB

Open AccessArticle

Stress Waves and Characteristics of Zigzag and Armchair Silicene Nanoribbons

by Yu-Cheng Fan, Te-Hua Fang and Tao-Hsing Chen

Nanomaterials 2016, 6(7), 120; https://doi.org/10.3390/nano6070120 - 24 Jun 2016

Cited by 9 | Viewed by 5475

Abstract

The mechanical properties of silicene nanostructures subject to tensile loading were studied via a molecular dynamics (MD) simulation. The effects of temperature on Young’s modulus and the fracture strain of silicene with armchair and zigzag types were examined. The maximum in-plane stress and [...] Read more.

The mechanical properties of silicene nanostructures subject to tensile loading were studied via a molecular dynamics (MD) simulation. The effects of temperature on Young’s modulus and the fracture strain of silicene with armchair and zigzag types were examined. The maximum in-plane stress and the corresponding critical strain of the armchair and the zigzag silicene sheets at 300 K were 8.85 and 10.62, and 0.187 and 0.244 N/m, respectively. The in-plane stresses of the silicene sheet in the armchair direction at the temperatures of 300, 400, 500, and 600 K were 8.85, 8.50, 8.26, and 7.79 N/m, respectively. The in-plane stresses of the silicene sheet in the zigzag direction at the temperatures of 300, 400, 500, and 600 K were 10.62, 9.92, 9.64, and 9.27 N/m, respectively. The improved mechanical properties can be calculated in a silicene sheet yielded in the zigzag direction compared with the tensile loading in the armchair direction. The wrinklons and waves were observed at the shear band across the center zone of the silicene sheet. These results provide useful information about the mechanical and fracture behaviors of silicene for engineering applications. Full article

(This article belongs to the Special Issue Nanomaterials for Flexible and Stretchable Devices: Synthesis, Processes, and Applications)

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145 KiB

Open AccessEditorial

Nanoparticles for Catalysis

by Sergio Navalón and H. García

Nanomaterials 2016, 6(7), 123; https://doi.org/10.3390/nano6070123 - 23 Jun 2016

Cited by 62 | Viewed by 5978

Abstract

Nanoscience emerged in the last decades of the 20th century with the general aim to determine those properties that appear when small particles of nanometric dimensions are prepared and stabilized.[...] Full article

(This article belongs to the Special Issue Nanoparticles for Catalysis)

143 KiB

Open AccessEditorial

Plasma Nanoengineering and Nanofabrication

by Krasimir Vasilev and Melanie Macgregor Ramiasa

Nanomaterials 2016, 6(7), 122; https://doi.org/10.3390/nano6070122 - 23 Jun 2016

Cited by 3 | Viewed by 5025

Abstract

With the recent advances in nanotechnology, plasma nanofabrication has become an exciting new niche because plasma-based approaches can deliver unique structures at the nanoscale that cannot be achieved by other techniques and/or in a more economical and environmentally friendly manner.[...] Full article

(This article belongs to the Special Issue Plasma Nanoengineering and Nanofabrication)

2095 KiB

Open AccessArticle

A Fast Response Ammonia Sensor Based on Coaxial PPy–PAN Nanofiber Yarn

by Penghong Liu, Shaohua Wu, Yue Zhang, Hongnan Zhang and Xiaohong Qin

Nanomaterials 2016, 6(7), 121; https://doi.org/10.3390/nano6070121 - 23 Jun 2016

Cited by 39 | Viewed by 6587

Abstract

Highly orientated polypyrrole (PPy)–coated polyacrylonitrile (PAN) (PPy–PAN) nanofiber yarn was prepared with an electrospinning technique and in-situ chemical polymerization. The morphology and chemical structure of PPy–PAN nanofiber yarn was characterized by scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM), transmission electron [...] Read more.

Highly orientated polypyrrole (PPy)–coated polyacrylonitrile (PAN) (PPy–PAN) nanofiber yarn was prepared with an electrospinning technique and in-situ chemical polymerization. The morphology and chemical structure of PPy–PAN nanofiber yarn was characterized by scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and fourier transform infrared spectroscopy (FTIR), which indicated that the PPy as the shell layer was homogeneously and uniformly polymerized on the surface of PAN nanofiber. The effects of different concentration of doping acid on the responses of PPy–PAN nanofiber yarn sensor were investigated. The electrical responses of the gas sensor based on the PPy–PAN nanofiber yarn to ammonia were investigated at room temperature. The nanoyarn sensor composed of uniaxially aligned PPy–PAN nanofibers with a one-dimensional structure exhibited a transient response, and the response time was less than 1 s. The excellent sensing properties mentioned above give rise to good potential application prospects in the field of ammonia sensor. Full article

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Nanomaterials, Volume 6, Issue 7 (July 2016) – 17 articles

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