Advanced Nano Research Articles

On-Demand Probabilistic Polling for Nanonetworks Under Dynamic IoT Backhaul Network Conditions

Driven by the high sensing resolution provided by advanced nano technologies, electromagnetic-based wireless nano sensor networks (EM-WNSNs) operating in the terahertz (THz) band is becoming an integral part of the Internet of Things (IoT). Data acquisition for EM-WNSNs faces two challenges: 1) the dynamic IoT backhaul bandwidth and 2) THz channel conditions that jointly impact resource utilization efficiency. Specifically, the mismatch between the demands of the EM-WNSNs and the available bandwidth of the backhaul link reduces the bandwidth efficiency of IoT backhaul or the energy efficiency of EM-WNSNs. To address the new constraints that emerge from the EM-WNSN, an on-demand probabilistic (OP) polling scheme is proposed for the backhaul tier of EM-WNSNs which is composed of nano sinks that aggregate and transport data from nano sensors to the IoT gateway. OP polling adjusts the packet aggregation process of nano sinks according to the up-to-date network conditions. From performance evaluation, OP polling achieves an 18% higher bandwidth efficiency compared to the previously proposed on-demand efficient polling and 69% less energy consumption compared to the greedy polling.

High Volume Zero Power Low Cost PPB Level Printed Nano-Sensors for Iot

The sensing capabilities of Carbon nanotubes [CNTs] are often reported in the literature [1,2] but we describe here a commercial sensor based on an amperometric detection method using CNT electrodes. The commercial availability means that it has been thoroughly vetted not only for sensitivity, but also for practical response time, selectivity, and stability in T, P, RH and time dimensions. The CNT-composite electrodes are robust, and while not as inert as the sp4 diamond, they exhibit chemical stability >sp3 carbons. The significant advantage is the extremely high surface area with virtually every atom a surface atom and therefore high catalytic activity at low loadings. These characteristics are important in high volume sensors so that small size and low cost are enabled along with the inherent low power of electrochemical sensors. This combination of characteristics along with the practical manufacturing by using printed electronics approaches is our key to bridge the cost-performance gap and penetrate into high volume consumer and environmental markets with these sensors. The first two environmental gases that use the nano-catalyst electrodes are NO2 and O3 in air at ppb levels. In order to address global problems with sensors, we know that we will need millions to billions of sensors. This implies a low cost and a sensor design amenable to high volume production. The solution to the World Health Organization’s recognized air quality crisis is accelerated by a global air quality network and this network will need Ozone and nitrogen dioxide sensors as these are lung irritants produced by anthropogenic activity. Business models for the practicality of trillions of connected devices and sensors are emerging in the IoT. Our manufacturing process for the nano-catalyst electrodes involves screen printing for low cost and high volume and it combines the best practices of the semiconductor microfabrication industry with the speed and low cost of the Printed Electronics revolution. This approach can meet the needs for new high volume low cost sensors and accelerate our fight against climate change. Many more sensor products and applications are expected as crowd-sourced pollution measurements are enabled and IoT connected devices allow instant communication of vital information. 1] J. R. Stetter and G. J, Maclay, “Carbon Nanotubes and Sensors: A Review,” in Advanced Micro and Nano Systems, Volume I, Chapter 10, Baltes et al., eds. Wiley-VCH Verlag-GmbH and Co., Weinheim, Germany, pp357-382, 2004 ISBN 3-527 30746-X, [Invited].2] A. Star, T-R.Han, V. Joshi, and J.R. Stetter, “Sensing with Coated Carbon Nanotube Field Effect Transistors,” Electroanalysis 2004, 16 (1-2), 108-112.

Hierarchical Multi-Diameter Single-Crystal Silicon Nanowires by Successive Wet Chemical Etching.

A simple and low cost top–down wet chemical etching method was developed to fabricate hierarchical multi-diameter well-ordered single-crystal silicon nanowires. The procedure starts with forming single diameter silicon nanowire arrays by using nanosphere lithography and metal-assisted chemical etching of single crystal silicon wafer, which is followed by anisotropic radial etching of the wires. Successive repetitions of these etching steps result in arrays of multi-diameter single crystal nanowires. This technique can allow engineering nanowires in a hierarchical three-dimensional geometry for the development of advanced nano devices.

Cover Image, Volume 8, Issue 6

image The cover image, by Gang Zheng et al., is based on the Advanced Review Multimodal micro, nano, and size conversion ultrasound agents for imaging and therapy, DOI: 10.1002/wnan.1398.

Design and development of pH-responsive HSPC:C12H25-PAA chimeric liposomes

The application of stimuli-responsive medical practices has emerged, in which pH-sensitive liposomes figure prominently. This study investigates the impact of the incorporation of different amounts of pH-sensitive polymer, C12H25-PAA (poly(acrylic acid) with a hydrophobic end group) in l-α-phosphatidylcholine, hydrogenated (Soy) (HSPC) phospholipidic bilayers, with respect to biomimicry and functionality. PAA is a poly(carboxylic acid) molecule, classified as a pH-sensitive polymer, whose pH-sensitivity is attributed to its regulative –COOH groups, which are protonated under acidic pH (pKa ∼4.2). Our concern was to fully characterize, in a biophysical and thermodynamical manner, the mixed nanoassemblies arising from the combination of the two biomaterials. At first, we quantified the physicochemical characteristics and physical stability of the prepared chimeric nanosystems. Then, we studied their thermotropic behavior, through measurement of thermodynamical parameters, using Differential Scanning Calorimetry (DSC). Finally, the loading and release of indomethacin (IND) were evaluated, as well as the physicochemical properties and stability of the nanocarriers incorporating it. As expected, thermodynamical findings are in line with physicochemical results and also explain the loading and release profiles of IND. The novelty of this investigation is the utilization of these pH-sensitive chimeric advanced Drug Delivery nano Systems (aDDnSs) in targeted drug delivery which relies entirely on the biophysics and thermodynamics between such designs and the physiological membranes and environment of living organisms.

Nanoparticulate Drug Delivery to Colorectal Cancer: Formulation Strategies and Surface Engineering.

The evolution of polymer-based nanoparticle as a drug delivery carrier has greatly contributed to the development of advanced nano and micro-medicine in the past few decades. The polymer-based nanoparticles of biodegradable and biocompatible polymers such as poly (lactide-co-glycolide) and chitosan which have been approved by Food & Drug Administration and/or European Medicine Agency can particularly facilitate the maintaining of specific properties for a real transition from laboratory to the clinical oral and parental administration. This review presents an overview of the strategies of preparing polymeric nanoparticles and using them for targeting colorectal cancer. Theranostics and surface engineering aspects of nanoparticle design in colonic cancer delivery are also highlighted.

Immobilized Particle Imaging for Quantification of Nano- and Microparticles.

The quantification of nano- and microparticles is critical for diverse applications relying on the exact knowledge of the particle concentration. Although many techniques are available for counting particles, there are some limitations in regards to counting with low-scattering materials and facile counting in harsh organic solvents. Herein, we introduce an easy and rapid particle counting technique, termed "immobilized particle imaging" (IPI), to quantify fluorescent particles with different compositions (i.e., inorganic or organic), structures (i.e., solid, porous, or hollow), and sizes (50-1000 nm) dispersed in either aqueous or organic solutions. IPI is achieved by immobilizing particles of interest in a cell matrix-like scaffold (e.g., agarose) and imaging using standard microscopy techniques. Imaging a defined volume of the immobilized particles allows for the particle concentration to be calculated from the count numbers in a fixed volume. IPI provides a general and facile approach to quantify advanced nano- and microparticles, which may be helpful to researchers to obtain new insights for different applications (e.g., nanomedicine).

Optimal designing of polyurethane‐based nanocomposite system for aerostat envelope

ABSTRACTThis article reports an optimal designing of thermoplastic polyurethane (TPU) nanocomposite formulation, particularly targeting aerostat envelope for enhanced weathering and gas barrier properties. The synergistic effect of conventional UV protective additive with advanced nano materials (i.e. nanoclay and graphene) on TPU‐based formulations was explored. A series of formulations were prepared in accordance with a mixture design for three components additives (UV stabilizer, nanoclay, and graphene) and coated on to a woven polyester (PET) fabric. The coated systems were evaluated for resistance to UV radiation, resistance to helium gas permeability, and loss in both the properties against accelerated artificial weathering. The composition of the additive mixture was simultaneously optimized by desirability function approach with a view to maximize UV radiation protection and minimize helium gas permeability. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43529.

Intrinsic magnetic properties of plant leaf-derived graphene quantum dots

Hexagonal graphene quantum dots (GQDs) derived from plant leaves with diameters in the range of 5–7nm with zig-zag edges were synthesized and its intrinsic defects and magnetic properties were investigated. Our results showed paramagnetic behavior below 15K. The origin of paramagnetism was ascribed to the edge spin effect presented in the GQDs and largely based on the GQDs hexagonal nanoislands with zigzag edges. Our results are further consistent with the theoretical prediction. The excellent spin and magnetic properties exhibited by these GQDs could potentially lead to new and advanced nano spin-manipulation devices.

Pss – taking legacy to the future

AbstractDear readers,2016 has a special anniversary coming up for physica status solidi (pss): Its most‐ever‐cited article “Optical Properties and Electronic Structure of Amorphous Germanium” by J. Tauc, R. Grigorovici, and A. Vancu (then Prague and Bucharest) was published half a century ago [1]. Printed about two months after receipt of the manuscript on June 1st 1966, it is a witness of the impressively fast publication times of pss back then. The article went online 40 years later in 2006, when Wiley had the pre‐internet‐era content scanned.Citations (right axis) and cumulative citations (left axis) to “Optical Properties and Electronic Structure of Amorphous Germanium” by J. Tauc et al., pss (1966) [1] versus year (Data from Web of Sci‐ence SCI, Dec 2015).magnified imageCitations (right axis) and cumulative citations (left axis) to “Optical Properties and Electronic Structure of Amorphous Germanium” by J. Tauc et al., pss (1966) [1] versus year (Data from Web of Sci‐ence SCI, Dec 2015).Beyond the reach of contemporary journal‐usage metrics, it has been collecting citations throughout 50 years, and recently we even saw a pronounced acceleration due to renewed interest in amorphous materials, with groups analyzing and developing the method proposed by Tauc et al. further [2]. pss proudly continues to provide, promote, and safeguard this valuable piece of information, and to accompany it through the changing times of its lasting legacy for the solid state physics research community.All the while, we are working with our authors, reviewers, board members, and guest editors to add content to the journal that has the potential for a similarly impressive career in scientific literature. Much of pss ' most interesting content is attracted by specially compiled, topical publications in collaboration with guest editors these days, and we can mention only a few of them here. Prominently in 2015, pss leaned in on the recent physics Nobel Prize topic again with a double issue on Nitride Semiconductors [3], and also the January issue of pss (b) in 2016 is dedicated to the specific challenges of Polarization‐Field Control in Nitride Light Emit‐ters [4]. Regarding long‐lasting topics we should mention the “20 Years of Science for Diamond” issue in pss (a) [5], and on the contemporary device physics line both “Transparent Conductive Oxides – Fundamentals and Applications” [6] and the issue dedicated to “Advanced Materials and Nano‐ technology for Photovoltaics” [7]. Reflecting the intense activity in the field and its impact on the world energy economy, photovoltaics based on inorganic as well as organic electronics have been increasingly prominent throughout the pss journal family, also resulting in the pss (RRL) standing topical section “RRL solar”. pss (b) has a very interesting collection on the physics of low‐dimensional structures, including graphene, nanotubes, and transition‐metal dichalcogenides, in “Electronic Properties of Novel Materials: Molecular Nanostructures” [8]. Venturing into more inter‐ disciplinary areas, pss (b) also published “Auxetics and Other Systems of ‘Negative’ Characteristics” with 32 contributions from physics, mathematics, and engineering perspectives [9] and pss (a) had “Engineering of Functional Interfaces” [10].This year we are looking forward to “Carbononics – Integrating Electronics, Photonics and Spintronics with Graphene Quantum Dots” [11], a Focus Issue in pss (RRL), and many other interesting projects.In 2015, physica status solidi (c) – current topics in solid state physics joined the other pss family journals on the editorial platform Editorial Manager. With system data on a new level of transparency, we may report for the year that pss published 1172 articles, worked with 71 guest editors and received approximately 4400 reviewer reports (including re‐reviews). As is obvious from these numbers, the journal family flourishes due to its lively interaction and the lasting strong support from the solid state researcher community. We would like to convey our sincere gratitude to all board members, guest editors, reviewers, and authors for the time and work they invest. And of course, we remain open for your future suggestions, and we will observe closely which topic may be poised to become the next pss evergreen.With best wishes for a prosperous year 2016,Sabine Bahrs, Nadezda Panarina, and Stefan HildebrandtEditorsphysica status solidi

The grinding behavior of ground copper powder for Cu/CNT nanocomposite fabrication by using the dry grinding process with a high-speed planetary ball mill

The behavior of ground copper powder for copper-carbon nanotube (copper-CNT) nanocomposite fabrication during high-speed planetary ball milling was investigated because the study of the behavior characteristics of copper powder has recently gained scientific interest. Also, studies of Cu/CNT composites have widely been done due to their useful applications to enhanced, advanced nano materials and components, which would significantly improve the properties of new mechatronics-integrated materials and components. This study varied experimental conditions such as the rotation speed and the grinding time with and without CNTs, and the particle size distribution, median diameter, crystal structure and size, and particle morphology were monitored for a given grinding time. We observed that pure copper powders agglomerated and that the morphology changed with changing rotation speed. The particle agglomerations were observed with maximum experiment conditions (700 rpm, 60 min) in this study of the grinding process for mechanical alloys in the case of pure copper powders because the grinding behavior of Cu/CNT agglomerations was affected by the addition of CNTs. Indeed, the powder morphology and the crystal size of the composite powder could be changed by increasing the grinding time and the rotation speed.

Size dependent energy release rate of notched FGM beams based on a modified couple stress theory

The experimental observations indicate that the mechanical behavior of micro and nano scale structures is size-dependent. In this study, employing the modified couple stress theory the size-dependent strain energy release rate of notched Euler-Bernoulli beams made of functionally graded material (FGM) is formulated. The normalized energy release rate for the problem of three-point bending in notched FG beams is obtained using the procedure established by Kienzler and Herrmann [Kienzler R, Herrmann G, An elementary theory of defective beams. Acta Mech 1986; 62:37–46]. It is assumed that the material properties vary continuously along the beam thickness according to a power law distribution. In order to verification, the results of the present model for a homogenous beam are compared to the results of previous works. Also, a parametric study is performed to examine the influences of the material length scale parameter, elastic properties and power law index of the micro FG beam on the normalized strain energy release rate. The obtained results show that as the ratio of the length scale parameter to the beam thickness increases, the difference between the classical and non-classical results increases too, but for the small value of the length scale parameter, the difference diminishes.Selection and Peer-review under responsibility of the Conference Committee of 6th International Conference on Advanced Nano Materials.

Green synthesis of thermally stable Ag-rGO-CNT nano composite with high sensing activity

Advanced nano composite, containing Ag, was synthesized by coating on reduced graphene oxide (rGO)-carbon nanotube (CNT). Ag-rGO-CNT nanocomposite obtained by hydrothermal treatment of an aqueous dispersion of graphene oxide (GO) and CNTs. After the rGO-CNT composites have been dipped in silver salt solution, the spontaneous redox reaction between these two leads to the formation of nanohybrid materials consisting of rGO-CNT decorated with Ag NPs. Physicochemical characterization of Ag-rGO-CNT was carried out by scanning electron microscopy/energy-dispersive spectroscopy (SEM/EDS), fourier transform infrared spectroscopy (FT-IR) and TGA. Electrical resistivity measurements and thermal effect on resistivity of Ag-rGO-CNT was also studied after acid treatment. The dc conductivity was found within the range of 0.08–0.4 Ω cm for pure composite, measured by 4-in line–probe dc electrical conductivity measuring technique. Thermal conductivity is stable with all temperatures in isothermal studies showing excellent stability of Ag-rGO-CNT material. Graphene is attributed to its unique physical and chemical properties, e.g., subtle electronic characteristics, attractive π–π interaction, and strong adsorptive capability. This is used for in-vitro studies of dopamine on carbon fibre microelectrode that shows an excellent performance for dopamine with a detection limit of 0.033 μM and response time of 12s.

Comparative Study for the Standardization of Grinding Equipment During Dry Grinding Process by Various Grinding Mills

The study of grinding behavior characteristics on the metal powders has recently gained scientific interest due to their useful applications to enhance advanced nano materials and components. This could significantly improve the property of new mechatronics integrated materials and components. So, a new evaluation method for standardizing grinding equipment and a comparative study for the grinding experiment during the grinding process with various grinding mills were investigated. The series of grinding experiments were carried out by a traditional ball mill, stirred ball mill, and planetary ball mill with various experimental conditions. The relationship between the standardization of equipment and experimental results showed very significant conclusions. Furthermore, the comparative study on the grinding experiment, which investigated changes in particle size, particle morphology, and crystal structure of materials with changes in experimental conditions for grinding equipment, found that the value of particle size distribution is related to the various experimental conditions as a revolution speed of grinding mill and media size.

Biophysics and Thermodynamics: The Scientific Building Blocks of Bio-inspired Drug Delivery Nano Systems.

Biophysics and thermodynamics are considered as the scientific milestones for investigating the properties of materials. The relationship between the changes of temperature with the biophysical variables of biomaterials is important in the process of the development of drug delivery systems. Biophysics is a challenge sector of physics and should be used complementary with the biochemistry in order to discover new and promising technological platforms (i.e., drug delivery systems) and to disclose the 'silence functionality' of bio-inspired biological and artificial membranes. Thermal analysis and biophysical approaches in pharmaceuticals present reliable and versatile tools for their characterization and for the successful development of pharmaceutical products. The metastable phases of self-assembled nanostructures such as liposomes should be taken into consideration because they represent the thermal events can affect the functionality of advanced drug delivery nano systems. In conclusion, biophysics and thermodynamics are characterized as the building blocks for design and development of bio-inspired drug delivery systems.

Elemental distribution and porosity enhancement in advanced nano bimetallic catalyst

Nano heterobimetallic catalysts are used for many industrial applications. Organic precursors are widely used to induce uniform distribution of metal atoms and enhance the porosity of catalysts. In this work, a novel chemical process was developed to enhance the catalyst porosity by distributing the Zn–Al metals in heterobimetallic cluster. 2, 2′-bipyridine was used as a ligand to interlink Zn–Al metal atoms in 2-propanol and dimethylformamide (DMF) environment. Central Composite Design (CCD) method was employed to optimise the yield of monometallic and heterobimetallic clusters. The crystalline products were then characterised by FTIR, FESEM, EDX, TGA, DSC and XRD. The produced heterobimetallic complex and nano particles deposited by aerosol-assisted chemical vapour deposition (AACVD) on the stainless steel (SS) substrate have shown enhanced porosity and crystal morphology. The optimized experimental yield for Zn-complex, Al-complex and Zn–Al complex were 80%, 78% and 78.5%, which were in good agreement with the predicted yield by CCD. A systematic approach for the scale-up application of this material was also developed in this study. This study proved that the newly developed “Two-Step” process can be used for production of advanced heterometallic complexes, catalysts and composite materials with enhanced porosity and specific composition.

Effect of Reinforcement of Nano Al2O3 on Mechanical Properties of Al2024 NMMCs

For advanced aerospace applications aluminum nano metal matrix composites (NMMC's) are increasingly becoming more attractive because their properties can be enhanced through the addition of selected reinforcements. Due to their good specific strength and specific stiffness at room or elevated temperatures particulate reinforced NMMC's have recently found special interest. It is well known that the elastic properties of nano metal matrix composites are strongly influenced by micro structural parameters of the reinforcement such as shape, size, orientation, distribution and volume fraction. The main objective of this paper is to carry out a study of effect of nano Al2O3 reinforcement on the mechanical properties of aluminum metal matrix particulate composite. The reinforcing particulates in the MMC's vary from 0% to 2% by weight with an increment of 0.5%. The liquid metallurgy method coupled with powder metallurgy is employed to fabricate the composites, in which the reinforcements are poured into the vortex created by stirring the molten metal by means of mechanical two stage stirrer. The composites so produced are subjected to tensile and hardness tests. It was observed that increasing the reinforcement content within the aluminum matrix results in significant increases in the ultimate Tensile Strength (UTS) and hardness values. Scanning Electron Micrograph (SEM) images of the cast NMMC's are also taken in order to study the dispersion of reinforcements in the matrix.

Review on Reinforcement of Aerogel for Development of Advanced Nano Insulation Material for Application in Sustainable Buildings

Installation of insulation materials in buildings can reduce the usage of air conditioners by retarding heat flow into the building. Aerogel is one of the best insulation materials with distinctive properties that can replace existing building insulation materials such as fibre glass and polyurethane. However, brittleness of Aerogel makes it difficult to handle and disqualifies its viability as a building insulation material. Reinforcement of Aerogel with binding materials can improve its mechanical and thermal properties to overcome its brittleness. However, only a few studies have been carried out on this area. Furthermore, from the few existing studies, vital information such as thermal conductivity and specific application of the reinforced Aerogel studied were not considered. As an initiative to fill in this research gap, a review on reinforcement of Aerogel is presented.

Bio-inspired chimeric drug delivery nano systems (Chi-DDnSs): their fractal hologram and regulatory aspects.

Pharmaceutical Nanotechnology can provide challenges for producing innovative drugs based on bio-inspired nanostructures (advanced Drug Delivery nano Systems—aDDnSs) [1]. These systems could be correlated to the living organisms due to their self-assembly properties, their hierarchical structural organization, as well as to their biocompatibility and biodegradability characteristics. aDDnSs can be considered as new therapeutic outcomes in nanomedicine that may be able to deliver pharmacomolecules to specific tissues and can improve their PK/PD (pharmacokinetics/pharmacodynamics) behavior and affect their total bioavailability. Drug delivery is a scientific sector that promotes the innovation by designing formulation approaches that can produce aDDnSs. Drug nanocarriers produced by the combination of bionanomaterials, such as liposomes, (co)polymers and dendrimers, are considered as new classes of complex self-assembled soft nanostructures.

The metastable phases as modulators of biophysical behavior of liposomal membranes

In this work, we investigate the alterations of the physicochemical, morphological, and thermotropic characteristics of conventional, stealth, and chimeric DPPC (dipalmitoylphosphatidylcholine) liposomes, caused by the incorporation of PEGylated lipid and block copolymers with different architectures and compositions. 1,2-Dipalmitoyl-sn-glycero-3-phosphoethanolamine-N-[Methoxy(Polyethylene glycol)-3000] (DPPE-PEG 3000) is the PEGylated lipid, poly(ethylene oxide)-block-poly(e-caprolactone) (PEO-b-PCL) is the block copolymer, and poly(2-methyl-2-oxazoline)-grad-poly(2-phenyl-2-oxazoline) (MPOx) is the gradient block copolymer, which are selected for preparing the liposomal systems. Light scattering techniques and differential scanning calorimetry (DSC) were used in order to extract information on the physicochemical/thermodynamic balance of the prepared liposomal systems. The physicochemical characteristics and the morphology via fractal analysis of these chimeric nanoassemblies were found to depend on the composition of the polymeric component, while DPPC liposomes were used for comparison reasons (reference system). The incorporation of polymeric components into liposomes promotes a structural rearrangement of lipid bilayers and affects their behavior, as DSC experiments indicated. The fluidity, the intervesicle interactions and the cooperativity of structural elements of liposomes were also changed significantly by polymer addition. It could be concluded that the different macromolecular architectures of the polymeric guest affect the thermotropic behavior of liposomal membrane by producing new metastable phases, and consequently promote new insights in the field of biophysical concept for designing and developing chimeric advanced drug delivery nano systems (aDDnSs).