http://www.mdpi.com/journal/nanomaterials Latest open access articles published in Nanomaterials at http://www.mdpi.com/journal/nanomaterials http://www.mdpi.com/2079-4991/3/2/303 This study demonstrates the advantages of the combination between atomic force microscopy and scanning electrochemical microscopy. The combined technique can perform nano-electrochemical measurements onto agarose surface and nano-electrografting of non-conducting polymers onto conducting surfaces. This work was achieved by manufacturing an original Atomic Force Microscopy-Scanning ElectroChemical Microscopy (AFM-SECM) electrode. The capabilities of the AFM-SECM-electrode were tested with the nano-electrografting of vinylic monomers initiated by aryl diazonium salts. Nano-electrochemical and technical processes were thoroughly described, so as to allow experiments reproducing. A plausible explanation of chemical and electrochemical mechanisms, leading to the nano-grafting process, was reported. This combined technique represents the first step towards improved nano-processes for the nano-electrografting. Nanomaterials 2013-05-17 3 2 Article 10.3390/nano3020303 303 316 2079-4991 2013-05-17 doi: 10.3390/nano3020303 Achraf Ghorbal Federico Grisotto Julienne Charlier Serge Palacin Cédric Goyer Christophe Demaille Ammar Brahim http://www.mdpi.com/2079-4991/3/2/289 The strong affinity of carbon nanotubes (CNTs) to environmental contaminants has raised serious concern that CNTs may function as a carrier of environmental pollutants and lead to contamination in places where the environmental pollutants are not expected. However, this concern will not be realized until the contaminants are desorbed from CNTs. It is well recognized that the desorption of environmental pollutants from pre-laden CNTs varies with the environmental conditions, such as the solution pH and ionic strength. However, comprehensive investigation on the influence of solution chemistry on the desorption process has not been carried out, even though numerous investigations have been conducted to investigate the impact of solution chemistry on the adsorption of environmental pollutants on CNTs. The main objective of this study was to determine the influence of solution chemistry (e.g., pH, ionic strength) and surface functionalization on the desorption of preloaded 1,3,5-trichlorobenzene (1,3,5-TCB) from multi-walled carbon nanotubes (MWNTs). The results suggested that higher pH, ionic strength and natural organic matter in solution generally led to higher desorption of 1,3,5-TCB from MWNTs. However, the extent of change varied at different values of the tested parameters (e.g., pH < 7 vs. pH > 7). In addition, the impact of these parameters varied with MWNTs possessing different surface functional groups, suggesting that surface functionalization could considerably alter the environmental behaviors and impact of MWNTs. Nanomaterials 2013-05-17 3 2 Article 10.3390/nano3020289 289 302 2079-4991 2013-05-17 doi: 10.3390/nano3020289 Xingmao Ma Sheikh Uddin http://www.mdpi.com/2079-4991/3/2/272 Fabrication of uniform thin coatings of multi-walled carbon nanotubes (MWCNTs) by electrophoretic deposition (EPD) on semiconductor (silicon) substrates with 3-aminopropyl-triethoxysilane (APTES) surface functionalization has been studied extensively in this report. The gradual deposition and eventual film formation of the carbon nanotubes (CNTs) is greatly assisted by the Coulombic force of attraction existing between the positively charged –NH2 surface groups of APTES and the acid treated, negatively charged nanotubes migrating towards the deposition surfaces. The remarkable deposition characteristics of the CNT coatings by EPD in comparison to the dip coating method and the influence of isopropyl (IPA)-based CNT suspension in the fabricated film quality has also been revealed in this study. The effect of varying APTES concentration (5%–100%) on the Raman spectroscopy and thickness of the deposited CNT film has been discussed in details, as well. The deposition approach has eliminated the need of metal deposition in the electrophoretic deposition approach and, therefore, establishes a cost-effective, fast and entirely room temperature-based fabrication strategy of CNT thin films for a wide range of next generation electronic applications. Nanomaterials 2013-05-13 3 2 Article 10.3390/nano3020272 272 288 2079-4991 2013-05-13 doi: 10.3390/nano3020272 Anirban Sarkar Theda Daniels-Race http://www.mdpi.com/2079-4991/3/2/242 Some of the most important advances in the life sciences have come from transitioning to thinking of materials and their properties on the nanoscale rather than the macro or even microscale. Improvements in imaging technology have allowed us to see nanofeatures that directly impact chemical and mechanical properties of natural and man-made materials. Now that these can be imaged and quantified, substantial advances have been made in the fields of biomimetics, tissue engineering, and drug delivery. For the first time, scientists can determine the importance of nanograins and nanoasperities in nacre, direct the nucleation of apatite and the growth of cells on nanostructured scaffolds, and pass drugs tethered to nanoparticles through the blood-brain barrier. This review examines some of the most interesting materials whose nanostructure and hierarchical organization have been shown to correlate directly with favorable properties and their resulting applications. Nanomaterials 2013-05-10 3 2 Review 10.3390/nano3020242 242 271 2079-4991 2013-05-10 doi: 10.3390/nano3020242 Kirsten Parratt Nan Yao http://www.mdpi.com/2079-4991/3/2/229 In this work, we have studied Joule heating in carbon nanotube based very large scale integration (VLSI) interconnects and incorporated Joule heating influenced scattering in our previously developed current transport model. The theoretical model explains breakdown in carbon nanotube resistance which limits the current density. We have also studied scattering parameters of carbon nanotube (CNT) interconnects and compared with the earlier work. For 1 µm length single-wall carbon nanotube, 3 dB frequency in S12 parameter reduces to ~120 GHz from 1 THz considering Joule heating. It has been found that bias voltage has little effect on scattering parameters, while length has very strong effect on scattering parameters. Nanomaterials 2013-04-26 3 2 Article 10.3390/nano3020229 229 241 2079-4991 2013-04-26 doi: 10.3390/nano3020229 Kaji Mohsin Ashok Srivastava Ashwani Sharma Clay Mayberry http://www.mdpi.com/2079-4991/3/2/221 Separation of short single- and double-stranded DNA typically requires gel electrophoresis followed by DNA extraction, which is a time consuming process. Graphene oxide adsorbs single-stranded DNA more quickly than double-stranded ones, allowing for selective removal of the former with a simple mixing and centrifugation operation. The effect of DNA length and salt on adsorption selectivity has been characterized and its application in DNA melting curve measurement has been demonstrated. Nanomaterials 2013-04-04 3 2 Communication 10.3390/nano3020221 221 228 2079-4991 2013-04-04 doi: 10.3390/nano3020221 Po-Jung Huang Juewen Liu http://www.mdpi.com/2079-4991/3/2/204 Nanosheet-derived Hx(Ni1/3Co1/3Mn1/3)O2 was prepared by restacking (Ni1/3Co1/3Mn1/3)O2 nanosheets with large or small lateral sizes and their electrochemical properties in a 1 M KOH aqueous solution; microstructural factors were compared with those of bulk Hx(Ni1/3Co1/3Mn1/3)O2 (HNCM). The electrodes composed of small nanosheets exhibited very large capacitances of 1241 F·g−1 (395 mAh·g−1) at a current density of 50 mA·g−1, and 430 F·g−1 (100 mAh·g−1) at a large current density of 1000 mA·g−1. These large capacitances resulted from a heterogeneous layer structure with a large surface area and pore volume. The electrodes of large nanosheets, with a strongly interconnected microstructure and a surface area slightly larger than that of HNCM, exhibited good cycle stability and capacitances larger than that of HNCM. Microstructural control through the restacking of (Ni1/3Co1/3Mn1/3)O2 nanosheets improved the electrochemical properties of Hx(Ni, Co, Mn)O2. Nanomaterials 2013-03-25 3 2 Article 10.3390/nano3020204 204 220 2079-4991 2013-03-25 doi: 10.3390/nano3020204 Masato Yano Shinya Suzuki Masaru Miyayama Masataka Ohgaki http://www.mdpi.com/2079-4991/3/1/192 This study evaluates the effectiveness of vapour-phase deposition for creating sub-monolayer coverage of aminopropyl triethoxysilane (APTES) on silicon in order to exert control over subsequent gold nanoparticle deposition. Surface coverage was evaluated indirectly by observing the extent to which gold nanoparticles (AuNPs) deposited onto the modified silicon surface. By varying the distance of the silicon wafer from the APTES source and concentration of APTES in the evaporating media, control over subsequent gold nanoparticle deposition was achievable to an extent. Fine control over AuNP deposition (AuNPs/μm2) however, was best achieved by adjusting the ionic concentration of the AuNP-depositing solution. Furthermore it was demonstrated that although APTES was fully removed from the silicon surface following four hours incubation in water, the gold nanoparticle-amino surface complex was stable under the same conditions. Atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) were used to study these affects. Nanomaterials 2013-03-21 3 1 Article 10.3390/nano3010192 192 203 2079-4991 2013-03-21 doi: 10.3390/nano3010192 Sophie Williams Philip Davies Jenna Bowen Chris Allender http://www.mdpi.com/2079-4991/3/1/173 Non-modified Multiwalled Carbon Nanotubes (MWCNT) and polypropylene (PP) in absence of compatibilizer have been chosen to elaborate MWCNT/PP nanocomposites using a simple melt-mixing dispersing method. Calorimetry results indicate little effect of MWCNTs on crystallinity of PP, revealing not much interaction between nanotubes and PP chains, which is compatible with the employed manufacturing procedure. In any case, a hindering of polymer chains motion by MWCNTs is observed in the molten state, using oscillatory flow experiments, and a rheological percolation threshold is determined. The percolation limit is not noticed by Pressure-Volume-Temperature (PVT) measurements in the melt, because this technique rather detects local motions. Keeping the nanocomposites in the molten state provokes an electrical conductivity increase of several orders of magnitude, but on ulterior crystallization, the conductivity decreases, probably due to a reduction of the ionic conductivity. For a concentration of 2% MWCNTs, in the limit of percolation, the conductivity decreases considerably more, because percolation network constituted in the molten state is unstable and is destroyed during crystallization. Nanomaterials 2013-03-06 3 1 Article 10.3390/nano3010173 173 191 2079-4991 2013-03-06 doi: 10.3390/nano3010173 Arrate Huegun Mercedes Fernández Juanjo Peña María Muñoz Antxon Santamaría http://www.mdpi.com/2079-4991/3/1/158 Gold and silver nanoparticles (NPs) were prepared in water, acetonitrile and isopropanol by laser ablation methodologies. The average characteristic (longer) size of the NPs obtained ranged from 3 to 70 nm. 4-Aminobenzebethiol (4-ABT) was chosen as the surface enhanced Raman scattering (SERS) probe molecule to determine the optimum irradiation time and the pH of aqueous synthesis of the laser ablation-based synthesis of metallic NPs. The synthesized NPs were used to evaluate their capacity as substrates for developing more analytical applications based on SERS measurements. A highly energetic material, TNT, was used as the target compound in the SERS experiments. The Raman spectra were measured with a Raman microspectrometer. The results demonstrate that gold and silver NP substrates fabricated by the methods developed show promising results for SERS-based studies and could lead to the development of micro sensors. Nanomaterials 2013-03-01 3 1 Article 10.3390/nano3010158 158 172 2079-4991 2013-03-01 doi: 10.3390/nano3010158 Gloria Herrera Amira Padilla Samuel Hernandez-Rivera http://www.mdpi.com/2079-4991/3/1/141 The main objective of this work is the grafting of polycaprolactone diol (PCL) on the surface of oxidized nanocelluloses (ONC) in order to enhance the compatibility between the hydrophilic cellulose nanofibres and the hydrophobic polymer matrix. This grafting was successfully realized with a new strategy known as click chemistry. In this context, the oxidized nanocelluloses bearing alkyl groups (ONC-PR) were prepared by reacting amino groups of propargylamine (PR) with carboxyl groups of ONC. In parallel, PCL was converted into azido-polycaprolactone (PCL-N3) in two steps: (i) tosylation of polycaprolactone (PCL-OTs) and (ii) conversion of PCL-OTs into PCL-N3 by nucleophilic displacement using sodium azide. Finally, ONC-PR was reacted with PCL-N3 in heterogeneous conditions through click chemistry in order to prepare polycaprolactone grafted oxidized nanocellulose (ONC-g-PCL), which could be suitable for improving the interfacial adhesion in the composite materials. The grafted samples were characterized by transmission electron microscopy and by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and Carbon-13 nuclear magnetic resonance spectroscopy (13C-NMR) spectroscopic techniques. Nanomaterials 2013-03-01 3 1 Article 10.3390/nano3010141 141 157 2079-4991 2013-03-01 doi: 10.3390/nano3010141 Abdelhaq Benkaddour Khalil Jradi Sylvain Robert Claude Daneault http://www.mdpi.com/2079-4991/3/1/126 The structural and surface changes undergone by the different precursors that are produced during the synthesis of imogolite are reported. The surface changes that occur during the synthesis of imogolite were determined by electrophoretic migration (EM) measurements, which enabled the identification of the time at which the critical precursor of the nanoparticles was generated. A critical parameter for understanding the evolution of these precursors is the isoelectric point (IEP), of which variation revealed that the precursors modify the number of active ≡Al-OH and ≡Si-OH sites during the formation of imogolite. We also found that the IEP is displaced to a higher pH level as a consequence of the surface differentiation that occurs during the synthesis. At the same time, we established that the pH of the reaction (pHrx) decreases with the evolution and condensation of the precursors during aging. Integration of all of the obtained results related to the structural and surface properties allows an overall understanding of the different processes that occur and the products that are formed during the synthesis of imogolite. Nanomaterials 2013-03-01 3 1 Article 10.3390/nano3010126 126 140 2079-4991 2013-03-01 doi: 10.3390/nano3010126 Nicolás Arancibia-Miranda Mauricio Escudey Mauricio Molina María García-González http://www.mdpi.com/2079-4991/3/1/117 In this work we present a novel method for synthesis of aluminosilicate nanotubes: the fluoride route. F-containing imogolite (F-IMO) exhibits an improved crystallization rate and improved yield. The structure of F-IMO was investigated and compared with F-free imogolite (IMO) by means of X-ray diffraction (XRD) and Fourier transformed infrared spectroscopy (FTIR) confirming imogolite structure. Solid state nuclear magnetic resonance (NMR) analyses show an increased crystallization rate for F-IMO and confirm the incorporation of fluorine ion in the structure. Nanomaterials 2013-02-06 3 1 Communication 10.3390/nano3010117 117 125 2079-4991 2013-02-06 doi: 10.3390/nano3010117 Atika Chemmi Jocelyne Brendlé Claire Marichal Bénédicte Lebeau http://www.mdpi.com/2079-4991/3/1/107 Conductive polymer poly-3-hexylthiophene (P3HT) needles were self-assembled using a second component (indandione derivatives) as a linking agent to enhance their long range alignment. The morphologies of the hybrid organic/organic materials were characterized by transmission electron microscopy (TEM). Both linear and branched structures could be produced, with the degree of branching depending upon the linker used. Incorporation of indandione derivatives broadened the UV absorbance band of P3HT without significant change to its photoluminescence. This hybrid material could open a promising avenue in photovoltaic applications due to its interesting morphologies and optical properties. Nanomaterials 2013-02-01 3 1 Article 10.3390/nano3010107 107 116 2079-4991 2013-02-01 doi: 10.3390/nano3010107 Nicolas Cheval Valdis Kampars Clifford Fowkes Neil Shirtcliffe Amir Fahmi http://www.mdpi.com/2079-4991/3/1/86 Specialized gold nanostructures are of interest for the development of alternative treatment methods in medicine. Photothermal therapy combined with gene therapy that supports hyperthermia is proposed as a novel multimodal treatment method for prostate cancer. In this work, photothermal therapy using small (<100 nm) gold nanoparticles and near-infrared (NIR) laser irradiation combined with gene therapy targeting heat shock protein (HSP) 27 was investigated. A series of nanoparticles: nanoshells, nanorods, core-corona nanoparticles and hollow nanoshells, were synthesized and examined to compare their properties and suitability as photothermal agents. In vitro cellular uptake studies of the nanoparticles into prostate cancer cell lines were performed using light scattering microscopy to provide three-dimensional (3D) imaging. Small gold nanoshells (40 nm) displayed the greatest cellular uptake of the nanoparticles studied and were used in photothermal studies. Photothermal treatment of the cancer cell lines with laser irradiation at 800 nm at 4 W on a spot size of 4 mm (FWHM) for 6 or 10 min resulted in an increase in temperature of ~12 °C and decrease in cell viability of up to 70%. However, in vitro studies combining photothermal therapy with gene therapy targeting HSP27 did not result in additional sensitization of the prostate cancer cells to hyperthermia. Nanomaterials 2013-01-31 3 1 Article 10.3390/nano3010086 86 106 2079-4991 2013-01-31 doi: 10.3390/nano3010086 Jennifer Leung Sherry Wu Keng Chou Ruth Signorell http://www.mdpi.com/2079-4991/3/1/70 The effect of sonication temperature on the debundling of carbon nanotube (CNT) macro-bundles is reported and demonstrated by analysis with different particle sizing methods. The change of bundle size over time and after several comparatively gentle sonication cycles of suspensions at various temperatures is reported. A novel technique is presented that produces a more homogeneous nanotube dispersion by lowering the temperature during sonication. We produce evidence that temperature influences the suspension stability, and that low temperatures are preferable to obtain better dispersion without increasing damage to the CNT walls. Nanomaterials 2013-01-31 3 1 Article 10.3390/nano3010070 70 85 2079-4991 2013-01-31 doi: 10.3390/nano3010070 Ludovic Dumée Kallista Sears Jürg Schütz Niall Finn Mikel Duke Stephen Gray http://www.mdpi.com/2079-4991/3/1/48 This work describes the first hydrothermal synthesis in fluoride medium of Ni-Al montmorillonite-like phyllosilicates, in which the only metallic elements in the octahedral sheet are Ni and Al. X-ray diffraction, chemical analysis, thermogravimetric and differential thermal analysis, scanning electron microscopy and transmission electron microscopy confirm that the synthesized samples are montmorillonite-like phyllosilicates having the expected chemical composition. The specific surface areas of the samples are relatively large (>100 m2 g−1) compared to naturally occurring montmorillonites. 29Si and 27Al nuclear magnetic resonance (NMR) indicate substitutions of Al for Si in the tetrahedral sheet. 19F NMR and Ni K-edge extended X-ray absorption fine structure (EXAFS) local probes highlight a clustering of the metal elements and of the vacancies in the octahedral sheet of the samples. These Ni-Al phyllosilicates exhibit a higher local order than in previously synthesized Zn-Al phyllosilicates. Unlike natural montmorillonites, where the distribution of transition metal cations ensures a charge equilibrium allowing a stability of the framework, synthetic montmorillonites entail clustering and instability of the lattice when the content of divalent element in the octahedral sheet exceeds ca. 20%. Synthesis of Ni-Al montmorillonite-like phyllosilicates, was successfully achieved for the first time. These new synthetic materials may find potential applications as catalysts or as materials with magnetic, optical or staining properties. Nanomaterials 2013-01-21 3 1 Article 10.3390/nano3010048 48 69 2079-4991 2013-01-21 doi: 10.3390/nano3010048 Marc Reinholdt Jocelyne Brendlé Marie-Hélène Tuilier Serge Kaliaguine Emmanuelle Ambroise http://www.mdpi.com/2079-4991/3/1/22 Our energy consumption relies heavily on the three components of fossil fuels (oil, natural gas and coal) and nearly 83% of our current energy is consumed from those sources. The use of fossil fuels, however, has been viewed as a major environmental threat because of their substantial contribution to greenhouse gases which are responsible for increasing the global average temperature. Last four decades, scientists have been searching for alternative sources of energy which need to be environmentally clean, efficient, cost-effective, renewable, and sustainable. One of the promising sustainable sources of energy can be achieved by harnessing sun energy through silicon wafer, organic polymer, inorganic dye, and quantum dots based solar cells. Among them, quantum dots have an exceptional property in that they can excite multiple electrons using only one photon. These dots can easily be synthesized, processed in solution, and incorporated into solar cell application. Interestingly, the quantum dots solar cells can exceed the Shockley-Queisser limit; however, it is a great challenge for other solar cell materials to exceed the limit. Theoretically, the quantum dots solar cell can boost the power conversion efficiency up to 66% and even higher to 80%. Moreover, in changing the size of the quantum dots one can utilize the Sun’s broad spectrum of visible and infrared ranges. This review briefly overviews the present performance of different materials-based solar cells including silicon wafer, dye-sensitized, and organic solar cells. In addition, recent advances of the quantum dots based solar cells which utilize cadmium sulfide/selenide, lead sulfide/selenide, and new carbon dots as light harvesting materials has been reviewed. A future outlook is sketched as to how one could improve the efficiency up to 10% from the current highest efficiency of 6.6%. Nanomaterials 2012-12-27 3 1 Review 10.3390/nano3010022 22 47 2079-4991 2012-12-27 doi: 10.3390/nano3010022 Mohammad Halim http://www.mdpi.com/2079-4991/3/1/1 This work presents a technique for the chirality (n, m) assignment of semiconducting single wall carbon nanotubes by solving a set of empirical equations of the tight binding model parameters. The empirical equations of the nearest neighbor hopping parameters, relating the term (2n, m) with the first and second optical transition energies of the semiconducting single wall carbon nanotubes, are also proposed. They provide almost the same level of accuracy for lower and higher diameter nanotubes. An algorithm is presented to determine the chiral index (n, m) of any unknown semiconducting tube by solving these empirical equations using values of radial breathing mode frequency and the first or second optical transition energy from resonant Raman spectroscopy. In this paper, the chirality of 55 semiconducting nanotubes is assigned using the first and second optical transition energies. Unlike the existing methods of chirality assignment, this technique does not require graphical comparison or pattern recognition between existing experimental and theoretical Kataura plot. Nanomaterials 2012-12-24 3 1 Article 10.3390/nano3010001 1 21 2079-4991 2012-12-24 doi: 10.3390/nano3010001 Md Arefin http://www.mdpi.com/2079-4991/2/4/445 Hybrid materials with superior structural and functional properties can be obtained by incorporating nanofillers into polymer matrices. Polyhedral oligomeric silsesquioxane (POSS) nanoparticles have attracted much attention recently due to their nanometer size, the ease of which these particles can be incorporated into polymeric materials and the unique capability to reinforce polymers. We review here the state of POSS-containing polymer nanocomposites. We discuss the influence of the incorporation of POSS into polymer matrices via chemical cross-linking or physical blending on the structure of nanocomposites, as affected by surface functional groups, and the POSS concentration. Nanomaterials 2012-12-06 2 4 Review 10.3390/nano2040445 445 475 2079-4991 2012-12-06 doi: 10.3390/nano2040445 Ebunoluwa Ayandele Biswajit Sarkar Paschalis Alexandridis http://www.mdpi.com/2079-4991/2/4/428 A simple method has been developed for the spontaneous deposition of Prussian blue (PB) particles from a solution containing only ferricyanide ions onto conducting substrates such as indium tin oxide glass, glassy carbon disk and carbon nanotube (CNT) materials. Formation of PB deposits was confirmed by ultraviolet-visible absorption spectrometry and electrochemical techniques. The surface morphology of the PB particles deposited on the substrates was examined by atomic force microscopy and scanning electron microscopy. CNT/PB composite modified glassy carbon electrodes exhibited an electrocatalytic property for hydrogen peroxide reduction. These modified electrodes exhibited a high sensitivity for electrocatalytic reduction of hydrogen peroxide at −0.05 V (vs. Ag|AgCl), probably due to the synergistic effect of CNT with PB. Then, CNT/PB modified electrodes were further developed as amperometric glucose biosensors. These biosensors offered a linear response to glucose concentration from 0.1 to 0.9 mM with good selectivity, high sensitivity of 0.102 A M−1 cm−2 and short response time (within 2 s) at a negative operation potential of −0.05 V (vs. Ag|AgCl). The detection limit was estimated to be 0.01 mM at a signal-to-noise ratio of 3. Nanomaterials 2012-11-27 2 4 Article 10.3390/nano2040428 428 444 2079-4991 2012-11-27 doi: 10.3390/nano2040428 Yanli Yao Xiaoyun Bai Kwok-Keung Shiu http://www.mdpi.com/2079-4991/2/4/413 In this work, maghemite intercalated montmorillonite (γFe2O3-MMT)/polymer nanocomposites loaded with 1 or 2 wt.% of nanofillers were obtained by photopolymerization of difunctional acrylate monomers. The γFe2O3-MMT nanofillers were prepared by a new method based on the in situ formation of maghemite in the interlayer space of Fe-MMT using a three step process. X-ray diffraction (XRD), chemical analysis, TG/DTA and transmission electron microscopy (TEM) characterization of these nanofillers indicated the efficiency of the synthesis. When following the kinetics of the photopolymerization of diacrylate-γFe2O3-MMT nanocomposites using FTIR spectroscopy no significant inhibition effect of the nanofillers was observed at a loading up to 2 wt.%. These innovative nanocomposites exhibit improved mechanical properties compared to the crude polymer. Nanomaterials 2012-11-19 2 4 Article 10.3390/nano2040413 413 427 2079-4991 2012-11-19 doi: 10.3390/nano2040413 Bassam Tarablsi Christelle Delaite Jocelyne Brendle Celine Croutxe-Barghorn http://www.mdpi.com/2079-4991/2/4/379 Half-Heusler (HH) alloys have attracted considerable interest as promising thermoelectric (TE) materials in the temperature range around 700 K and above, which is close to the temperature range of most industrial waste heat sources. The past few years have seen nanostructuing play an important role in significantly enhancing the TE performance of several HH alloys. In this article, we briefly review the recent progress and advances in these HH nanocomposites. We begin by presenting the structure of HH alloys and the different strategies that have been utilized for improving the TE properties of HH alloys. Next, we review the details of HH nanocomposites as obtained by different techniques. Finally, the review closes by highlighting several promising strategies for further research directions in these very promising TE materials. Nanomaterials 2012-11-14 2 4 Review 10.3390/nano2040379 379 412 2079-4991 2012-11-14 doi: 10.3390/nano2040379 Wenjie Xie Anke Weidenkaff Xinfeng Tang Qingjie Zhang Joseph Poon Terry Tritt http://www.mdpi.com/2079-4991/2/4/366 Nanocomposite films consisting of gold inclusions in the polytetrafluoroethylene (PTFE) matrix were obtained by thermal vacuum deposition. Annealing of the obtained films with different temperatures was used to measure varying of film morphologies. The dependence of optical properties of the films on their morphology was studied. It was established that absorption and profile of the nanocomposite film obtained by thermal vacuum deposition can be changed with annealing owing to the fact that different annealing temperatures lead to different average particle sizes. A method to calculate the optical properties of nanocomposite thin films with inclusions of different sizes was proposed. Thus, comparison of experimental optical spectra with the spectra obtained during the simulation enables estimating average sizes of inclusions. The calculations give the possibility of understanding morphological changes in the structures. Nanomaterials 2012-11-07 2 4 Article 10.3390/nano2040366 366 378 2079-4991 2012-11-07 doi: 10.3390/nano2040366 Konstantin Grytsenko Valeri Lozovski Galyna Strilchuk Sigurd Schrader http://www.mdpi.com/2079-4991/2/4/348 This study focused on the effect of Multi Wall Carbon Nanotubes (MWCNT) content and its surface treatment on thermo-mechanical properties of epoxy nanocomposites. MWCNTs were surface treated and incorporated into two epoxy systems. MWCNT's surface treatments were based on: (a) Titania coating obtained by sol-gel process and (b) a nonionic surfactant. Thermo-mechanical properties improvement was obtained following incorporation of treated MWCNT. It was noticed that small amounts of titania coated MWCNT (0.05 wt %) led to an increase in the glass transition temperature and stiffness. The best performance was achieved adding 0.3 wt % titania coated MWCNT where an increase of 10 °C in the glass transition temperature and 30% in storage modulus were obtained. Nanomaterials 2012-10-26 2 4 Article 10.3390/nano2040348 348 365 2079-4991 2012-10-26 doi: 10.3390/nano2040348 Shelly Simcha Ana Dotan Samuel Kenig Hanna Dodiuk http://www.mdpi.com/2079-4991/2/4/329 The polymer nanocomposite used in this work comprises elastomer poly(dimethylsiloxane) (PDMS) as a polymer matrix and multi-walled carbon nanotubes (MWCNTs) as a conductive nanofiller. To achieve uniform distribution of carbon nanotubes within the polymer, an optimized dispersion process was developed, featuring a strong organic solvent—chloroform, which dissolved PDMS base polymer easily and allowed high quality dispersion of MWCNTs. At concentrations as high as 9 wt.%, MWCNTs were dispersed uniformly through the polymer matrix, which presented a major improvement over prior techniques. The dispersion procedure was optimized via extended experimentation, which is discussed in detail. Nanomaterials 2012-10-26 2 4 Article 10.3390/nano2040329 329 347 2079-4991 2012-10-26 doi: 10.3390/nano2040329 Chao-Xuan Liu Jin-Woo Choi http://www.mdpi.com/2079-4991/2/4/312 (1) The photo-induced solubility and positive-tone direct photo-patterning of iron, copper and lanthanides chelated with 4-(2-nitrobenzyloxycarbonyl)catechol (NBOC) or 4-(6-nitroveratryloxycarbonyl)catechol (NVOC) was investigated. Photo-patterning of iron, copper, cerium, samarium, europium, terbium, dysprosium, holmium, erbium and lutetium complexes was accomplished. Continuous films were formed by the pyrolysis of metal complex films at 500 °C. (2) Based on the difference in the photo-reaction excitation wavelength profile of NBOC and NVOC complexes, a short and simple method for simultaneous micro-patterning of two independent films on each side of a transparent glass substrate was developed. Using the developed procedure, indium tin oxide and/or titanium oxide films were formed on each side of a quartz substrate without use of resist or etching. Nanomaterials 2012-10-16 2 4 Article 10.3390/nano2040312 312 328 2079-4991 2012-10-16 doi: 10.3390/nano2040312 Christopher Cordonier Hideo Honma http://www.mdpi.com/2079-4991/2/3/298 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 (La0.5CexZr1−xOy) were prepared as well as non-stoichiometric La0.5+xZr0.5−xOy buffer 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 YBa2Cu3O7−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. Nanomaterials 2012-09-10 2 3 Article 10.3390/nano2030298 298 311 2079-4991 2012-09-10 doi: 10.3390/nano2030298 Vyshnavi Narayanan Sigelinde van Steenberge Petra Lommens Isabel van Driessche http://www.mdpi.com/2079-4991/2/3/286 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. Nanomaterials 2012-09-10 2 3 Article 10.3390/nano2030286 286 297 2079-4991 2012-09-10 doi: 10.3390/nano2030286 Eric Loranger André-Olivier Piché Claude Daneault http://www.mdpi.com/2079-4991/2/3/275 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. Nanomaterials 2012-08-31 2 3 Communication 10.3390/nano2030275 275 285 2079-4991 2012-08-31 doi: 10.3390/nano2030275 Amethist S. Finch Christopher M. Anton Christina M. Jacob Thomas J. Proctor Dimitra N. Stratis-Cullum http://www.mdpi.com/2079-4991/2/3/268 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. Nanomaterials 2012-08-13 2 3 Communication 10.3390/nano2030268 268 274 2079-4991 2012-08-13 doi: 10.3390/nano2030268 Di Wei Darryl Cotton Tapani Ryhänen http://www.mdpi.com/2079-4991/2/3/251 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 Y1Ba2Cu3Oy (YBCO) coated conductors. Nanomaterials 2012-08-09 2 3 Article 10.3390/nano2030251 251 267 2079-4991 2012-08-09 doi: 10.3390/nano2030251 Vyshnavi Narayanan Els Bruneel Ruben Hühne Isabel Van Driessche http://www.mdpi.com/2079-4991/2/3/217 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. Nanomaterials 2012-08-06 2 3 Review 10.3390/nano2030217 217 250 2079-4991 2012-08-06 doi: 10.3390/nano2030217 Vishal Gulati Ron Wallace http://www.mdpi.com/2079-4991/2/2/206 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. Nanomaterials 2012-06-18 2 2 Article 10.3390/nano2020206 206 216 2079-4991 2012-06-18 doi: 10.3390/nano2020206 Aeran Kim Seongyop Lim Dong-Hyun Peck Sang-Kyung Kim Byungrok Lee Doohwan Jung http://www.mdpi.com/2079-4991/2/2/187 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. Nanomaterials 2012-06-12 2 2 Article 10.3390/nano2020187 187 205 2079-4991 2012-06-12 doi: 10.3390/nano2020187 Saïd Barazzouk Claude Daneault http://www.mdpi.com/2079-4991/2/2/163 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. Nanomaterials 2012-06-06 2 2 Review 10.3390/nano2020163 163 186 2079-4991 2012-06-06 doi: 10.3390/nano2020163 Mohamed H. Mohamed Lee D. Wilson http://www.mdpi.com/2079-4991/2/2/147 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. Nanomaterials 2012-05-29 2 2 Article 10.3390/nano2020147 147 162 2079-4991 2012-05-29 doi: 10.3390/nano2020147 Muralidharan Paramsothy Jimmy Chan Richard Kwok Manoj Gupta http://www.mdpi.com/2079-4991/2/2/134 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. Nanomaterials 2012-05-07 2 2 Article 10.3390/nano2020134 134 146 2079-4991 2012-05-07 doi: 10.3390/nano2020134 Leisha M. Armijo Yekaterina I. Brandt Dimple Mathew Surabhi Yadav Salomon Maestas Antonio C. Rivera Nathaniel C. Cook Nathan J. Withers Gennady A. Smolyakov Natalie L. Adolphi Todd C. Monson Dale L. Huber Hugh D. C. Smyth Marek Osiński http://www.mdpi.com/2079-4991/2/2/113 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. Nanomaterials 2012-04-03 2 2 Article 10.3390/nano2020113 113 133 2079-4991 2012-04-03 doi: 10.3390/nano2020113 Zhihua Zhang Wen Pei Lim Chiong Teck Wong Hairuo Xu Fenfang Yin Wee Shong Chin http://www.mdpi.com/2079-4991/2/2/92 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. Nanomaterials 2012-03-30 2 2 Review 10.3390/nano2020092 92 112 2079-4991 2012-03-30 doi: 10.3390/nano2020092 Chai-Hoon Quek Kam W. Leong http://www.mdpi.com/2079-4991/2/1/79 In order to study and develop an economical solution to environmental pollution in water, a wide variety of materials have been investigated. Natural zeolites emerge from that research as the best in class of this category. Zeolites are natural materials which are relatively abundant and non biodegradable, economical and serve to perform processes of environmental remediation. This paper contains a full description of a new method to characterize the superficial properties of natural zeolites of exotic provenience (Caribbean Islets) with atomic force microscopy (AFM). AFM works with the simplicity of the optical microscope and the high resolution typical of a transmission electron microscope (TEM). If the sample is conductive, structural information of mesoporous material is obtained using scanning and transmission electron microscopy (SEM and TEM), otherwise the sample has to be processed through the grafitation technique, but this procedure induces errors of topography. Therefore, the existing AFM method, to observe zeolite powders, is made in a liquid cell-head scanner. This work confirms that it is possible to use an ambient air-head scanner to obtain a new kind of microtopography. Once optimized, this new method will allow investigation of organic micelles, a very soft nanostructure of cetyltriammonium bromide (CTAB), upon an inorganic surface such as natural zeolites. The data also demonstrated some correlation between SEM microphotographies and AFM 3D images. Nanomaterials 2012-03-05 2 1 Article 10.3390/nano2010079 79 91 2079-4991 2012-03-05 doi: 10.3390/nano2010079 Domenico Fuoco http://www.mdpi.com/2079-4991/2/1/65 The wettability of reactively sputtered Y2O3, thermally oxidized Y-Y2O3 and Cd-CdO template assisted Y2O3 coatings has been studied. The wettability of as-deposited Y2O3 coatings was determined by contact angle measurements. The water contact angles for reactively sputtered, thermally oxidized and template assisted Y2O3 nanostructured coatings were 99°, 117° and 155°, respectively. The average surface roughness values of reactively sputtered, thermally oxidized and template assisted Y2O3 coatings were determined by using atomic force microscopy and the corresponding values were 3, 11 and 180 nm, respectively. The low contact angle of the sputter deposited Y2O3 and thermally oxidized Y-Y2O3 coatings is attributed to a densely packed nano-grain like microstructure without any void space, leading to low surface roughness. A water droplet on such surfaces is mostly in contact with a solid surface relative to a void space, leading to a hydrophobic surface (low contact angle). Surface roughness is a crucial factor for the fabrication of a superhydrophobic surface. For Y2O3 coatings, the surface roughness was improved by depositing a thin film of Y2O3 on the Cd-CdO template (average roughness = 178 nm), which resulted in a contact angle greater than 150°. The work of adhesion of water was very high for the reactively sputtered Y2O3 (54 mJ/m2) and thermally oxidized Y-Y2O3 coatings (43 mJ/m2) compared to the Cd-CdO template assisted Y2O3 coating (7 mJ/m2). Nanomaterials 2012-02-29 2 1 Article 10.3390/nano2010065 65 78 2079-4991 2012-02-29 doi: 10.3390/nano2010065 Harish C. Barshilia Archana Chaudhary Praveen Kumar Natarajan T. Manikandanath http://www.mdpi.com/2079-4991/2/1/54 Near-monodispersed water soluble SnS nanoparticles in the diameter range of 3–6 nm are synthesized by a facile, solution based one-step approach using ethanolamine ligands. The optimal amount of triethanolamine is investigated. The effect of further heat treatment on the size of these SnS nanoparticles is discussed. Diffuse reflectance study of SnS nanoparticles agrees with predictions from quantum confinement model. Nanomaterials 2012-01-16 2 1 Article 10.3390/nano2010054 54 64 2079-4991 2012-01-16 doi: 10.3390/nano2010054 Ying Xu Najeh Al-Salim Richard D. Tilley http://www.mdpi.com/2079-4991/2/1/31 New catalytic materials, based on palladium immobilized in ionic liquid supported on alginate, were elaborated. Alginate was associated with gelatin for the immobilization of ionic liquids (ILs) and the binding of palladium. These catalytic materials were designed in the form of highly porous monoliths (HPMs), in order to be used in a column reactor. The catalytic materials were tested for the hydrogenation of 4-nitroaniline (4-NA) in the presence of formic acid as hydrogen donor. The different parameters for the elaboration of the catalytic materials were studied and their impact analyzed in terms of microstructures, palladium sorption properties and catalytic performances. The characteristics of the biopolymer (proportion of β-D-mannuronic acid (M) and α-L-guluronic acid (G) in the biopolymer defined by the M/G ratio), the concentration of the porogen agent, and the type of coagulating agent significantly influenced catalytic performances. The freezing temperature had a significant impact on structural properties, but hardly affected the catalytic rate. Cellulose fibers were incorporated as mechanical strengthener into the catalytic materials, and allowed to enhance mechanical properties and catalytic efficiency but required increasing the amount of hydrogen donor for catalysis. Nanomaterials 2012-01-11 2 1 Article 10.3390/nano2010031 31 53 2079-4991 2012-01-11 doi: 10.3390/nano2010031 Claire Jouannin Chloë Vincent Isabelle Dez Annie-Claude Gaumont Thierry Vincent Eric Guibal http://www.mdpi.com/2079-4991/2/1/15 Accurate determination of the intensity-average diameter of polystyrene latex (PS-latex) by dynamic light scattering (DLS) was carried out through extrapolation of both the concentration of PS-latex and the observed scattering angle. Intensity-average diameter and size distribution were reliably determined by asymmetric flow field flow fractionation (AFFFF) using multi-angle light scattering (MALS) with consideration of band broadening in AFFFF separation. The intensity-average diameter determined by DLS and AFFFF-MALS agreed well within the estimated uncertainties, although the size distribution of PS-latex determined by DLS was less reliable in comparison with that determined by AFFFF-MALS. Nanomaterials 2012-01-05 2 1 Article 10.3390/nano2010015 15 30 2079-4991 2012-01-05 doi: 10.3390/nano2010015 Haruhisa Kato Ayako Nakamura Kayori Takahashi Shinichi Kinugasa http://www.mdpi.com/2079-4991/2/1/1 Several mesoporous silica nanoparticle (MSN) contrast agents have been synthesized using a co-condensation method to incorporate two different Gd3+ complexes at very high loadings (15.5–28.8 wt %). These MSN contrast agents, with an MCM-41 type pore structure, were characterized using a variety of methods including SEM and TEM, nitrogen adsorption measurements, thermogravimetric analysis (TGA), direct current plasma (DCP) spectroscopy, and powder X-ray diffraction (PXRD). The magnetic resonance (MR) relaxivities of these contrast agents were determined using a 3 T MR scanner. The r1 relaxivities of these nanoparticles range from 4.1 to 8.4 mM−1s−1 on a per Gd basis. Additionally, the MSN particles were functionalized with an organic fluorophore and cancer cell targeting peptide to allow for demonstration of both the optical and MR contrast enhancing capabilities in vitro. Nanomaterials 2011-12-27 2 1 Article 10.3390/nano2010001 1 14 2079-4991 2011-12-27 doi: 10.3390/nano2010001 Kathryn M. L. Taylor-Pashow Joseph Della Rocca Wenbin Lin http://www.mdpi.com/2079-4991/1/1/79 Quantum Dots (QDs) are promising alternatives to organic dyes as sensitisers for photocatalytic electrodes. This review article provides an overview of the current state of the art in this area. More specifically, different types of QDs with a special focus on heavy-metal free QDs and the methods for preparation and adsorption onto metal oxide electrodes (especially titania and zinc oxide) are discussed. Eventually, the key areas of necessary improvements are identified and assessed. Nanomaterials 2011-11-15 1 1 Review 10.3390/nano1010079 79 88 2079-4991 2011-11-15 doi: 10.3390/nano1010079 Thomas J. Macdonald Thomas Nann http://www.mdpi.com/2079-4991/1/1/64 Plasmid DNA can be used as a template to yield gold, palladium, silver, and chromium nanoparticles of different sizes based on variations in incubation time at 70 °C with gold phosphine complexes, with the acetates of silver or palladium, or chromium acetylacetonate. The employment of mild synthetic conditions, minimal procedural steps, and aqueous solvents makes this method environmentally greener and ensures general feasibility. The use of plasmids exploits the capabilities of the biotechnology industry as a source of nanoreactor materials. Nanomaterials 2011-10-21 1 1 Article 10.3390/nano1010064 64 78 2079-4991 2011-10-21 doi: 10.3390/nano1010064 Jacopo Samson Irene Piscopo Alex Yampolski Patrick Nahirney Andrea Parpas Amit Aggarwal Raihan Saleh Charles Michael Drain http://www.mdpi.com/2079-4991/1/1/31 Metal nanoparticles are being extensively used in various biomedical applications due to their small size to volume ratio and extensive thermal stability. Gold nanoparticles (GNPs) are an obvious choice due to their amenability of synthesis and functionalization, less toxicity and ease of detection. The present review focuses on various methods of functionalization of GNPs and their applications in biomedical research. Functionalization facilitates targeted delivery of these nanoparticles to various cell types, bioimaging, gene delivery, drug delivery and other therapeutic and diagnostic applications. This review is an amalgamation of recent advances in the field of functionalization of gold nanoparticles and their potential applications in the field of medicine and biology. Nanomaterials 2011-06-14 1 1 Review 10.3390/nano1010031 31 63 2079-4991 2011-06-14 doi: 10.3390/nano1010031 Pooja M. Tiwari Komal Vig Vida A. Dennis Shree R. Singh http://www.mdpi.com/2079-4991/1/1/20 The fabrication and characterization of template silver nanoshell structures and the encapsulation of gold nanoparticles using biocompatible poly(oxyethylene)-poly(butylene) diblock co-polymer vesicles is described in this work. These vesicles have a narrow diameter size distribution around 200 nm. Silver nanoparticles (Ø = 1–10 nm) functionalized with decanethiol were successfully entrapped in the hydrophobic membrane and non-functionalized gold nanoparticles (Ø = 3.0–5.5 nm) were encapsulated in the vesicle core. Transmission Electron Microscopy confirms the localisation of the particles; silver functionalized nanoparticles appear to thicken the vesicle membrane as shown with TEM image analysis. The enhancement of the optical properties is confirmed using transmission spectrophotometry; the 430 nm plasmon resonance peak of the silver nanoparticles was replaced by a broader extinction spectrum to beyond 700 nm (O.D. = 0.8). For a number density of 4.8 x 1012 mL-1 the scattering cross section was calculated to be 0.92 x 10-4 μm2 with a scattering coefficient of 0.44 mm-1. The measurements indicate scattering cross section of 3.8 x 10-5 μm2, attenuation coefficient of 0.18 mm-1 and extinction efficiency equal to 1.2 x 10-3. Stable and biocompatible block co-polymer vesicles can potentially be used as plasmon-resonant optical contrast agents for biomedical applications. Nanomaterials 2011-05-09 1 1 Article 10.3390/nano1010020 20 30 2079-4991 2011-05-09 doi: 10.3390/nano1010020 Juan Leonardo Martinez-Hurtado http://www.mdpi.com/2079-4991/1/1/3 The mechanical and electrical characteristics of films, buckypapers and fiber materials from combinations of clay, carbon nanotubes (CNTs) and chitosan are described. The rheological time-dependent characteristics of clay are maintained in clay–carbon nanotube–chitosan composite dispersions. It is demonstrated that the addition of chitosan improves their mechanical characteristics, but decreases electrical conductivity by three-orders of magnitude compared to clay–CNT materials. We show that the electrical response upon exposure to humid atmosphere is influenced by clay-chitosan interactions, i.e., the resistance of clay–CNT materials decreases, whereas that of clay–CNT–chitosan increases. Nanomaterials 2011-04-06 1 1 Article 10.3390/nano1010003 3 19 2079-4991 2011-04-06 doi: 10.3390/nano1010003 Thomas M. Higgins Holly Warren Marc in het Panhuis http://www.mdpi.com/2079-4991/1/1/1 It is my great pleasure to welcome you to Nanomaterials, a new open access journal, which is dedicated to the fabrication, characterization, functionalization, modeling and application of nanomaterials. In answer to the title question, I would like to (mis)quote one of my favourite pieces of literature: I "[We] hold these truths to be self-evident, that all men ... are endowed ... with certain unalienable rights, that among these are ..." free access to information and education. The prime goal of Nanomaterials is to publish first-class, original research articles under an open access policy with minimal fees for the authors. The quality of the published articles will be assured by a fast yet rigorous peer-review process. [...] Nanomaterials 2010-11-04 1 1 Editorial 10.3390/nano1010001 1 2 2079-4991 2010-11-04 doi: 10.3390/nano1010001 Thomas Nann