Next Issue
Previous Issue

Table of Contents

Nanomaterials, Volume 2, Issue 2 (June 2012), Pages 92-216

  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Readerexternal link to open them.
View options order results:
result details:
Displaying articles 1-7
Export citation of selected articles as:

Research

Jump to: Review

Open AccessArticle From Metal Thiobenzoates to Metal Sulfide Nanocrystals: An Experimental and Theoretical Investigation
Nanomaterials 2012, 2(2), 113-133; doi:10.3390/nano2020113
Received: 15 March 2012 / Accepted: 20 March 2012 / Published: 3 April 2012
Cited by 3 | PDF Full-text (2892 KB) | HTML Full-text | XML Full-text
Abstract
A simple preparation of metal sulfide nanoparticles via the decomposition of thiobenzoate precursors at room temperature is presented and discussed. Long chain alkylamines were found to mediate the breakdown of metal thiobenzoates, such as those containing Ag, Cu, In and Cd, to [...] Read more.
A simple preparation of metal sulfide nanoparticles via the decomposition of thiobenzoate precursors at room temperature is presented and discussed. Long chain alkylamines were found to mediate the breakdown of metal thiobenzoates, such as those containing Ag, Cu, In and Cd, to produce uniform Ag2S, Cu2−xS, In2S3 and CdS nanoparticles respectively. The long chain amines are assumed to play dual roles as the nucleophilic reagent and the capping agent. It was found that sizes of the nanoparticles can be controlled by changing the type of amine used, as well as the molar ratio between amine and the precursor. We performed DFT calculations on a proposed mechanism involving an initial nucleophilic addition of amine molecule onto the thiocarboxylates. The proposed reaction was also confirmed through the analysis of by-products via infrared spectroscopy. On the basis of this understanding, we propose to manipulate the stability of the precursors by coordination with suitable stabilizing groups, such that the reaction kinetics can be modified to generate different nanostructures of interest. Full article
(This article belongs to the Special Issue From Molecules to Nanomaterials)
Open AccessArticle Iron Oxide Nanocrystals for Magnetic Hyperthermia Applications
Nanomaterials 2012, 2(2), 134-146; doi:10.3390/nano2020134
Received: 11 March 2012 / Accepted: 25 April 2012 / Published: 7 May 2012
Cited by 11 | PDF Full-text (889 KB) | HTML Full-text | XML Full-text
Abstract
Magnetic nanocrystals have been investigated extensively in the past several years for several potential applications, such as information technology, MRI contrast agents, and for drug conjugation and delivery. A specific property of interest in biomedicine is magnetic hyperthermia—an increase in temperature resulting [...] Read more.
Magnetic nanocrystals have been investigated extensively in the past several years for several potential applications, such as information technology, MRI contrast agents, and for drug conjugation and delivery. A specific property of interest in biomedicine is magnetic hyperthermia—an increase in temperature resulting from the thermal energy released by magnetic nanocrystals in an external alternating magnetic field. Iron oxide nanocrystals of various sizes and morphologies were synthesized and tested for specific losses (heating power) using frequencies of 111.1 kHz and 629.2 kHz, and corresponding magnetic field strengths of 9 and 25 mT. Polymorphous nanocrystals as well as spherical nanocrystals and nanowires in paramagnetic to ferromagnetic size range exhibited good heating power. A remarkable 30 °C temperature increase was observed in a nanowire sample at 111 kHz and magnetic field of 25 mT (19.6 kA/m), which is very close to the typical values of 100 kHz and 20 mT used in medical treatments. Full article
(This article belongs to the Special Issue Conference on Nanomaterials 2011)
Open AccessArticle Al2O3 Nanoparticle Addition to Commercial Magnesium Alloys: Multiple Beneficial Effects
Nanomaterials 2012, 2(2), 147-162; doi:10.3390/nano2020147
Received: 29 March 2012 / Revised: 24 April 2012 / Accepted: 22 May 2012 / Published: 29 May 2012
Cited by 5 | PDF Full-text (1187 KB) | HTML Full-text | XML Full-text
Abstract
The multiple beneficial effects of Al2O3 nanoparticle addition to cast magnesium based systems (followed by extrusion) were investigated, constituting either: (a) enhanced strength; or (b) simultaneously enhanced strength and ductility of the corresponding magnesium alloys. AZ31 and ZK60A nanocomposites [...] Read more.
The multiple beneficial effects of Al2O3 nanoparticle addition to cast magnesium based systems (followed by extrusion) were investigated, constituting either: (a) enhanced strength; or (b) simultaneously enhanced strength and ductility of the corresponding magnesium alloys. AZ31 and ZK60A nanocomposites containing Al2O3 nanoparticle reinforcement were each fabricated using solidification processing followed by hot extrusion. Compared to monolithic AZ31 (tension levels), the corresponding nanocomposite exhibited higher yield strength (0.2% tensile yield strength (TYS)), ultimate strength (UTS), failure strain and work of fracture (WOF) (+19%, +21%, +113% and +162%, respectively). Compared to monolithic AZ31 (compression levels), the corresponding nanocomposite exhibited higher yield strength (0.2% compressive yield strength (CYS)) and ultimate strength (UCS), lower failure strain and higher WOF (+5%, +5%, −4% and +11%, respectively). Compared to monolithic ZK60A (tension levels), the corresponding nanocomposite exhibited lower 0.2% TYS and higher UTS, failure strain and WOF (−4%, +13%, +170% and +200%, respectively). Compared to monolithic ZK60A (compression levels), the corresponding nanocomposite exhibited lower 0.2% CYS and higher UCS, failure strain and WOF (−10%, +7%, +15% and +26%, respectively). The capability of Al2O3 nanoparticles to enhance the properties of cast magnesium alloys in a way never seen before with micron length scale reinforcements is clearly demonstrated. Full article
(This article belongs to the Special Issue Composite Nanomaterials)
Open AccessArticle Amino Acid and Peptide Immobilization on Oxidized Nanocellulose: Spectroscopic Characterization
Nanomaterials 2012, 2(2), 187-205; doi:10.3390/nano2020187
Received: 18 April 2012 / Revised: 24 May 2012 / Accepted: 5 June 2012 / Published: 12 June 2012
Cited by 16 | PDF Full-text (421 KB) | HTML Full-text | XML Full-text
Abstract
In this work, oxidized nanocellulose (ONC) was synthesized and chemically coupled with amino acids and peptides using a two step coupling method at room temperature. First, ONC was activated by N-ethyl-N’-(3-dimethylaminopropyl) carbodiimide hydrochloride, forming a stable active ester in [...] Read more.
In this work, oxidized nanocellulose (ONC) was synthesized and chemically coupled with amino acids and peptides using a two step coupling method at room temperature. First, ONC was activated by N-ethyl-N’-(3-dimethylaminopropyl) carbodiimide hydrochloride, forming a stable active ester in the presence of N-hydroxysuccinimide. Second, the active ester was reacted with the amino group of the amino acid or peptide, forming an amide bond between ONC and the grafted molecule. Using this method, the intermolecular interaction of amino acids and peptides was avoided and uniform coupling of these molecules on ONC was achieved. The coupling reaction was very fast in mild conditions and without alteration of the polysaccharide. The coupling products (ONC-amino acids and ONC-peptides) were characterized by transmission electron microscopy and by the absorption, emission, Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) spectroscopic techniques. Full article
(This article belongs to the Special Issue Composite Nanomaterials)
Open AccessArticle Preparation and Characteristics of SiOx Coated Carbon Nanotubes with High Surface Area
Nanomaterials 2012, 2(2), 206-216; doi:10.3390/nano2020206
Received: 2 May 2012 / Revised: 8 June 2012 / Accepted: 11 June 2012 / Published: 18 June 2012
Cited by 4 | PDF Full-text (808 KB) | HTML Full-text | XML Full-text
Abstract
An easy method to synthesize SiOx coated carbon nanotubes (SiOx-CNT) through thermal decomposition of polycarbomethylsilane adsorbed on the surface of CNTs is reported. Physical properties of SiOx-CNT samples depending on various Si contents and synthesis conditions are [...] Read more.
An easy method to synthesize SiOx coated carbon nanotubes (SiOx-CNT) through thermal decomposition of polycarbomethylsilane adsorbed on the surface of CNTs is reported. Physical properties of SiOx-CNT samples depending on various Si contents and synthesis conditions are examined by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), nitrogen isotherm, scanning electron microscope (SEM), and transmission electron microscope (TEM). Morphology of the SiOx-CNT appears to be perfectly identical to that of the pristine CNT. It is confirmed that SiOx is formed in a thin layer of approximately 1 nm thickness over the surface of CNTs. The specific surface area is significantly increased by the coating, because thin layer of SiOx is highly porous. The surface properties such as porosity and thickness of SiOx layers are found to be controlled by SiOx contents and heat treatment conditions. The preparation method in this study is to provide useful nano-hybrid composite materials with multi-functional surface properties. Full article
(This article belongs to the Special Issue New Developments in Nanomaterial Analysis)

Review

Jump to: Research

Open AccessReview Near-Infrared Fluorescent Nanoprobes for in Vivo Optical Imaging
Nanomaterials 2012, 2(2), 92-112; doi:10.3390/nano2020092
Received: 9 January 2012 / Revised: 23 February 2012 / Accepted: 26 March 2012 / Published: 30 March 2012
Cited by 29 | PDF Full-text (1409 KB) | HTML Full-text | XML Full-text
Abstract
Near-infrared (NIR) fluorescent probes offer advantages of high photon penetration, reduced light scattering and minimal autofluorescence from living tissues, rendering them valuable for noninvasive mapping of molecular events, assessment of therapeutic efficacy, and monitoring of disease progression in animal models. This review [...] Read more.
Near-infrared (NIR) fluorescent probes offer advantages of high photon penetration, reduced light scattering and minimal autofluorescence from living tissues, rendering them valuable for noninvasive mapping of molecular events, assessment of therapeutic efficacy, and monitoring of disease progression in animal models. This review provides an overview of the recent development of the design and optical property of the different classes of NIR fluorescent nanoprobes associated with in vivo imaging applications. Full article
(This article belongs to the Special Issue From Molecules to Nanomaterials)
Open AccessReview Porous Copolymer Resins: Tuning Pore Structure and Surface Area with Non Reactive Porogens
Nanomaterials 2012, 2(2), 163-186; doi:10.3390/nano2020163
Received: 3 May 2012 / Revised: 16 May 2012 / Accepted: 29 May 2012 / Published: 6 June 2012
Cited by 12 | PDF Full-text (1072 KB) | HTML Full-text | XML Full-text
Abstract
In this review, the preparation of porous copolymer resin (PCR) materials via suspension polymerization with variable properties are described by tuning the polymerization reaction, using solvents which act as porogens, to yield microporous, mesoporous, and macroporous materials. The porogenic properties of solvents [...] Read more.
In this review, the preparation of porous copolymer resin (PCR) materials via suspension polymerization with variable properties are described by tuning the polymerization reaction, using solvents which act as porogens, to yield microporous, mesoporous, and macroporous materials. The porogenic properties of solvents are related to traditional solubility parameters which yield significant changes in the surface area, porosity, pore volume, and morphology of the polymeric materials. The mutual solubility characteristics of the solvents, monomer units, and the polymeric resins contribute to the formation of porous materials with tunable pore structures and surface areas. The importance of the initiator solubility, surface effects, the temporal variation of solvent composition during polymerization, and temperature effects contribute to the variable physicochemical properties of the PCR materials. An improved understanding of the factors governing the mechanism of formation for PCR materials will contribute to the development and design of versatile materials with tunable properties for a wide range of technical applications. Full article
(This article belongs to the Special Issue New Developments in Nanomaterial Analysis)

Journal Contact

MDPI AG
Nanomaterials Editorial Office
St. Alban-Anlage 66, 4052 Basel, Switzerland
nanomaterials@mdpi.com
Tel. +41 61 683 77 34
Fax: +41 61 302 89 18
Editorial Board
Contact Details Submit to Nanomaterials
Back to Top