Nanomaterials

2371 KiB

Open AccessArticle

Aqueous Chemical Solution Deposition of Novel, Thick and Dense Lattice-Matched Single Buffer Layers Suitable for YBCO Coated Conductors: Preparation and Characterization

by Vyshnavi Narayanan, Sigelinde Van Steenberge, Petra Lommens and Isabel Van Driessche

Nanomaterials 2012, 2(3), 298-311; https://doi.org/10.3390/nano2030298 - 10 Sep 2012

Cited by 4 | Viewed by 6561

Abstract

In this work we present the preparation and characterization of cerium doped lanthanum zirconate (LCZO) films and non-stoichiometric lanthanum zirconate (LZO) buffer layers on metallic Ni-5% W substrates using chemical solution deposition (CSD), starting from aqueous precursor solutions. La₂Zr₂O [...] Read more.

In this work we present the preparation and characterization of cerium doped lanthanum zirconate (LCZO) films and non-stoichiometric lanthanum zirconate (LZO) buffer layers on metallic Ni-5% W substrates using chemical solution deposition (CSD), starting from aqueous precursor solutions. La₂Zr₂O₇ films doped with varying percentages of Ce at constant La concentration (La_0.5Ce_xZr_1−xO_y) were prepared as well as non-stoichiometric La_0.5+xZr_0.5−xO_ybuffer layers with different percentages of La and Zr ratios. The variation in the composition of these thin films enables the creation of novel buffer layers with tailored lattice parameters. This leads to different lattice mismatches with the YBa₂Cu₃O_7−x (YBCO) superconducting layer on top and with the buffer layers or substrate underneath. This possibility of minimized lattice mismatch should allow the use of one single buffer layer instead of the current complicated buffer architectures such as Ni-(5% W)/LZO/LZO/CeO₂. Here, single, crack-free LCZO and non-stoichiometric LZO layers with thicknesses of up to 140 nm could be obtained in one single CSD step. The crystallinity and microstructure of these layers were studied by XRD, and SEM and the effective buffer layer action was studied using XPS depth profiling. Full article

(This article belongs to the Special Issue New Developments in Nanomaterial Analysis)

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893 KiB

Open AccessArticle

Influence of High Shear Dispersion on the Production of Cellulose Nanofibers by Ultrasound-Assisted TEMPO-Oxidation of Kraft Pulp

by Eric Loranger, André-Olivier Piché and Claude Daneault

Nanomaterials 2012, 2(3), 286-297; https://doi.org/10.3390/nano2030286 - 10 Sep 2012

Cited by 35 | Viewed by 8799

Abstract

Cellulose nanofibers can be produced using a combination of TEMPO, sodium bromide (NaBr) and sodium hypochlorite, and mechanical dispersion. Recently, this process has been the subject of intensive investigation. However, studies on the aspects of mechanical treatment of this process remain marginal. The [...] Read more.

Cellulose nanofibers can be produced using a combination of TEMPO, sodium bromide (NaBr) and sodium hypochlorite, and mechanical dispersion. Recently, this process has been the subject of intensive investigation. However, studies on the aspects of mechanical treatment of this process remain marginal. The main objective of this study is to evaluate the high shear dispersion parameters (e.g., consistency, stator-rotor gap, recirculation rate and pH) and determine their influences on nanocellulose production using ultrasound-assisted TEMPO-oxidation of Kraft pulp. All nanofiber gels produced in this study exhibited rheological behaviors known as shear thinning. From all the dispersion parameters, the following conditions were identified as optimal: 0.042 mm stator-rotor gap, 200 mL/min recycle rate, dispersion pH of 7 and a feed consistency of 2%. High quality cellulose gel could be produced under these conditions. This finding is surely of great interest for the pulp and paper industry. Full article

(This article belongs to the Special Issue Composite Nanomaterials)

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1792 KiB

Open AccessCommunication

Assembly of DNA Architectures in a Non-Aqueous Solution

by Amethist S. Finch, Christopher M. Anton, Christina M. Jacob, Thomas J. Proctor and Dimitra N. Stratis-Cullum

Nanomaterials 2012, 2(3), 275-285; https://doi.org/10.3390/nano2030275 - 31 Aug 2012

Cited by 5 | Viewed by 6747

Abstract

In the present work, the procedures for the creation of self-assembled DNA nanostructures in aqueous and non-aqueous media are described. DNA-Surfactant complex formation renders the DNA soluble in organic solvents offering an exciting way to bridge the transition of DNA origami materials electronics [...] Read more.

In the present work, the procedures for the creation of self-assembled DNA nanostructures in aqueous and non-aqueous media are described. DNA-Surfactant complex formation renders the DNA soluble in organic solvents offering an exciting way to bridge the transition of DNA origami materials electronics applications. The DNA retains its structural features, and these unique geometries provide an interesting candidate for future electronics and nanofabrication applications with potential for new properties. The DNA architectures were first assembled under aqueous conditions, and then characterized in solution (using circular dichroism (CD) spectroscopy) and on the surface (using atomic force microscopy (AFM)). Following aqueous assembly, the DNA nanostructures were transitioned to a non-aqueous environment, where butanol was chosen for optical compatibility and thermal properties. The retention of DNA hierarchical structure and thermal stability in non-aqueous conditions were confirmed via CD spectroscopy. The formation and characterization of these higher order DNA-surfactant complexes is described in this paper. Full article

(This article belongs to the Special Issue Trends of Nanomaterials in Life Sciences)

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650 KiB

Open AccessCommunication

All-Solid-State Textile Batteries Made from Nano-Emulsion Conducting Polymer Inks for Wearable Electronics

by Di Wei, Darryl Cotton and Tapani Ryhänen

Nanomaterials 2012, 2(3), 268-274; https://doi.org/10.3390/nano2030268 - 13 Aug 2012

Cited by 18 | Viewed by 7851

Abstract

A rollable and all-solid-state textile lithium battery based on fabric matrix and polymer electrolyte that allows flexibility and fast-charging capability is reported. When immerged into poly(3,4-ethylenedioxythiophene) (PEDOT) nano-emulsion inks, an insulating fabric is converted into a conductive battery electrode for a fully solid [...] Read more.

A rollable and all-solid-state textile lithium battery based on fabric matrix and polymer electrolyte that allows flexibility and fast-charging capability is reported. When immerged into poly(3,4-ethylenedioxythiophene) (PEDOT) nano-emulsion inks, an insulating fabric is converted into a conductive battery electrode for a fully solid state lithium battery with the highest specific energy capacity of 68 mAh/g. This is superior to most of the solid-state conducting polymer primary and/or secondary batteries reported. The bending radius of such a textile battery is less than 1.5 mm while lightening up an LED. This new material combination and inherent flexibility is well suited to provide an energy source for future wearable and woven electronics. Full article

(This article belongs to the Special Issue Composite Nanomaterials)

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932 KiB

Open AccessArticle

Effects of Varied Cleaning Methods on Ni-5% W Substrate for Dip-Coating of Water-based Buffer Layers: An X-ray Photoelectron Spectroscopy Study

by Vyshnavi Narayanan, Els Bruneel, Ruben Hühne and Isabel Van Driessche

Nanomaterials 2012, 2(3), 251-267; https://doi.org/10.3390/nano2030251 - 09 Aug 2012

Cited by 2 | Viewed by 6515

Abstract

This work describes various combinations of cleaning methods involved in the preparation of Ni-5% W substrates for the deposition of buffer layers using water-based solvents. The substrate has been studied for its surface properties using X-ray photoelectron spectroscopy (XPS). The contaminants in the [...] Read more.

This work describes various combinations of cleaning methods involved in the preparation of Ni-5% W substrates for the deposition of buffer layers using water-based solvents. The substrate has been studied for its surface properties using X-ray photoelectron spectroscopy (XPS). The contaminants in the substrates have been quantified and the appropriate cleaning method was chosen in terms of contaminants level and showing good surface crystallinity to further consider them for depositing chemical solution-based buffer layers for Y₁Ba₂Cu₃O_y (YBCO) coated conductors. Full article

(This article belongs to the Special Issue New Developments in Nanomaterial Analysis)

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417 KiB

Open AccessReview

Rafts, Nanoparticles and Neural Disease

by Vishal Gulati and Ron Wallace

Nanomaterials 2012, 2(3), 217-250; https://doi.org/10.3390/nano2030217 - 06 Aug 2012

Cited by 3 | Viewed by 8717

Abstract

This review examines the role of membrane rafts in neural disease as a rationale for drug targeting utilizing lipid-based nanoparticles. The article begins with an overview of methodological issues involving the existence, sizes, and lifetimes of rafts, and then examines raft function in [...] Read more.

This review examines the role of membrane rafts in neural disease as a rationale for drug targeting utilizing lipid-based nanoparticles. The article begins with an overview of methodological issues involving the existence, sizes, and lifetimes of rafts, and then examines raft function in the etiologies of three major neural diseases—epilepsy, Parkinson’s disease, and Alzheimer’s disease—selected as promising candidates for raft-based therapeutics. Raft-targeting drug delivery systems involving liposomes and solid lipid nanoparticles are then examined in detail. Full article

(This article belongs to the Special Issue Trends of Nanomaterials in Life Sciences)

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Nanomaterials, Volume 2, Issue 3 (September 2012) – 6 articles , Pages 217-311

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