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Materials, Volume 3, Issue 2 (February 2010), Pages 755-1496

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Research

Jump to: Review

Open AccessArticle Towards the Development of Electrical Biosensors Based on Nanostructured Porous Silicon
Materials 2010, 3(2), 755-763; doi:10.3390/ma3020755
Received: 14 December 2009 / Revised: 12 January 2010 / Accepted: 25 January 2010 / Published: 27 January 2010
Cited by 8 | PDF Full-text (880 KB) | HTML Full-text | XML Full-text
Abstract
The typical large specific surface area and high reactivity of nanostructured porous silicon (nanoPS) make this material very suitable for the development of sensors. Moreover, its biocompatibility and biodegradability opens the way to the development of biosensors. As such, in this work the
[...] Read more.
The typical large specific surface area and high reactivity of nanostructured porous silicon (nanoPS) make this material very suitable for the development of sensors. Moreover, its biocompatibility and biodegradability opens the way to the development of biosensors. As such, in this work the use of nanoPS in the field of electrical biosensing is explored. More specifically, nanoPS-based devices with Al/nanoPS/Al and Au-NiCr/nanoPS/Au-NiCr structures were fabricated for the electrical detection of glucose and Escherichia Coli bacteria at different concentrations. The experimental results show that the current-voltage characteristics of these symmetric metal/nanoPS/metal structures strongly depend on the presence/absence and concentration of species immobilized on the surface. Full article
(This article belongs to the Special Issue Porous Materials)
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Open AccessArticle Spin State Control of the Perovskite Rh/Co Oxides
Materials 2010, 3(2), 786-799; doi:10.3390/ma3020786
Received: 30 December 2009 / Revised: 23 January 2010 / Accepted: 26 January 2010 / Published: 27 January 2010
Cited by 10 | PDF Full-text (616 KB) | HTML Full-text | XML Full-text
Abstract
We show why and how the spin state of transition-metal ions affects the thermoelectric properties of transition-metal oxides by investigating two perovskite-related oxides. In the A-site ordered cobalt oxide Sr3YCo4O10.5, partial substitution of Ca for Sr acts
[...] Read more.
We show why and how the spin state of transition-metal ions affects the thermoelectric properties of transition-metal oxides by investigating two perovskite-related oxides. In the A-site ordered cobalt oxide Sr3YCo4O10.5, partial substitution of Ca for Sr acts as chemical pressure, which compresses the unit cell volume to drive the spin state crossover, and concomitantly changes the magnetization and thermopower. In the perovskite rhodium oxide LaRhO3, partial substitution of Sr for La acts as hole-doping, and the resistivity and thermopower decrease systematically with the Sr concentration. The thermopower remains large values at high temperatures (>150 μV/K at 800 K), which makes a remarkable contrast to La1-xSrxCoO3. We associate this with the stability of the low spin state of the Rh3+ ions. Full article
(This article belongs to the Special Issue Novel Thermoelectric Materials and Applications)
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Open AccessArticle Stability of Nanocrystalline Spark Plasma Sintered 3Y-TZP
Materials 2010, 3(2), 800-814; doi:10.3390/ma3020800
Received: 2 December 2009 / Revised: 21 January 2010 / Accepted: 25 January 2010 / Published: 28 January 2010
Cited by 11 | PDF Full-text (814 KB) | HTML Full-text | XML Full-text
Abstract
Spark plasma sintered 3Y-TZP has been investigated with respect to hydrothermal ageing and grinding. The sintering was performed between the temperatures of 1,100 and 1,600 °C for a soaking time of 5 minutes and the resulting materials were obtained with grain sizes between
[...] Read more.
Spark plasma sintered 3Y-TZP has been investigated with respect to hydrothermal ageing and grinding. The sintering was performed between the temperatures of 1,100 and 1,600 °C for a soaking time of 5 minutes and the resulting materials were obtained with grain sizes between 65 to 800 nm and relative densities between 88.5 to 98.8%. Experiments on hydrothermal ageing in water vapour at 131 °C, 2 bars during 60 hours shows that phase stability is retained, elastic modulus and hardness of near surface region measured by nanoindentation does not change in fine grain (<200 nm) materials, in spite of porosity. In ground specimens, very small amount of transformation was found for all grain sizes studied. Full article
(This article belongs to the Special Issue Ceramics for Healthcare)
Open AccessArticle Probing the Texture of the Calamitic Liquid Crystalline Dimer of 4-(4-Pentenyloxy)benzoic Acid
Materials 2010, 3(2), 827-840; doi:10.3390/ma3020827
Received: 22 December 2009 / Revised: 20 January 2010 / Accepted: 21 January 2010 / Published: 29 January 2010
Cited by 5 | PDF Full-text (5055 KB) | HTML Full-text | XML Full-text
Abstract
The liquid crystalline dimer of 4-(4-pentenyloxy)benzoic acid, a member of the n-alkoxybenzoic acid homologous series, was synthesized using potassium carbonate supported on alumina as catalyst. The acid dimer complex exhibited three mesophases; identified as nematic, smectic X1 and smectic X2. Phase transition
[...] Read more.
The liquid crystalline dimer of 4-(4-pentenyloxy)benzoic acid, a member of the n-alkoxybenzoic acid homologous series, was synthesized using potassium carbonate supported on alumina as catalyst. The acid dimer complex exhibited three mesophases; identified as nematic, smectic X1 and smectic X2. Phase transition temperatures and the corresponding enthalpies were recorded using differential scanning calorimetry upon both heating and cooling. The mesophases were identified by detailed texture observations by variable temperature polarized light microscopy. The nematic phase was distinguished by a fluid Schlieren texture and defect points (four and two brushes) while the smectic phases were distinguished by rigid marble and mosaic textures, respectively. Full article
(This article belongs to the Special Issue Liquid Crystals)
Open AccessArticle EDTA-Reduction of Water to Molecular Hydrogen Catalyzed by Visible-Light-Response TiO2-Based Materials Sensitized by Dawson- and Keggin-Type Rhenium(V)-Containing Polyoxotungstates
Materials 2010, 3(2), 897-917; doi:10.3390/ma3020897
Received: 27 November 2009 / Revised: 12 January 2010 / Accepted: 2 February 2010 / Published: 2 February 2010
Cited by 4 | PDF Full-text (529 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The synthesis and characterization of a Keggin-type mono-rhenium(V)-substituted polyoxotungstate are described. The dimethylammonium salt [Me2NH2]4[PW11ReVO40] was obtained as analytically pure homogeneous black-purple crystals by reacting mono-lacunary Keggin polyoxotungstate with [ReIV
[...] Read more.
The synthesis and characterization of a Keggin-type mono-rhenium(V)-substituted polyoxotungstate are described. The dimethylammonium salt [Me2NH2]4[PW11ReVO40] was obtained as analytically pure homogeneous black-purple crystals by reacting mono-lacunary Keggin polyoxotungstate with [ReIVCl6]2- in water, followed by crystallization from acetone at ca. 5 °C. Single-crystal X-ray structural analysis of [PW11ReVO40]4- revealed a monomeric structure with overall Td symmetry. Characterization of [Me2NH2]4[PW11ReVO40] was also accomplished by elemental analysis, magnetic susceptibility, TG/DTA, FTIR, UV-vis, diffuse reflectance (DR) UV-vis, and solution 31P-NMR spectroscopy. Furthermore, [PW11ReVO40]4- and the Dawson-type dirhenium(V)-oxido-bridged polyoxotungstate [O{ReV(OH)(α2-P2W17O61)}2]14- were supported onto anatase TiO2 surface by the precipitation methods using CsCl and Pt(NH3)4Cl2. With these materials, hydrogen evolution from water in the presence of EDTA⋅2Na (ethylenediamine tetraacetic acid disodium salt) under visible light irradiation (≥400 nm) was achieved. Full article
(This article belongs to the Special Issue Polyoxometalate Compounds)
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Open AccessArticle Silicoaluminates as “Support Activator” Systems in Olefin Polymerization Processes
Materials 2010, 3(2), 1015-1030; doi:10.3390/ma3021015
Received: 14 January 2010 / Revised: 27 January 2010 / Accepted: 1 February 2010 / Published: 3 February 2010
Cited by 6 | PDF Full-text (511 KB) | HTML Full-text | XML Full-text
Abstract
In this work we report the polymerization behaviour of natural clays (montmorillonites, MMT) as activating supports. These materials have been modified by treatment with different aluminium compounds in order to obtain enriched aluminium clays and to modify the global Brönsted/Lewis acidity. As a
[...] Read more.
In this work we report the polymerization behaviour of natural clays (montmorillonites, MMT) as activating supports. These materials have been modified by treatment with different aluminium compounds in order to obtain enriched aluminium clays and to modify the global Brönsted/Lewis acidity. As a consequence, the intrinsic structural properties of the starting materials have been changed. These changes were studied and these new materials used for ethylene polymerization using a zirconocene complex as catalyst. All the systems were shown to be active in ethylene polymerization. The catalyst activity and the dependence on acid strength and textural properties have been also studied. The behaviour of an artificial silica (SBA 15) modified with an aluminium compound to obtain a silicoaluminate has been studied, but no ethylene polymerization activity has been found yet. Full article
(This article belongs to the Special Issue Organometallic Compounds)
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Open AccessArticle Effect of Microstructure Evolution on the Overall Response of Porous-Plastic Solids
Materials 2010, 3(2), 1031-1048; doi:10.3390/ma3021031
Received: 4 November 2009 / Revised: 26 January 2010 / Accepted: 3 February 2010 / Published: 4 February 2010
PDF Full-text (1414 KB) | HTML Full-text | XML Full-text
Abstract
Ductile fracture is the macroscopic result of a micromechanical process consisting in void nucleation and growth to coalescence. While growing in size, voids also evolve in shape because of the non-uniform deformation field in the surrounding material; this shape evolution is either disregarded
[...] Read more.
Ductile fracture is the macroscopic result of a micromechanical process consisting in void nucleation and growth to coalescence. While growing in size, voids also evolve in shape because of the non-uniform deformation field in the surrounding material; this shape evolution is either disregarded or approximately accounted for by constitutive laws for porous-plastic solids. To assess the effect of void distortion on the overall properties of a porous-plastic material prior to any coalescence-dominated event, we here present a micromechanical study in which the void-containing material is treated as a two-phase (matrix and inclusion) composite. A cylindrical representative volume element (RVE), featuring elliptic cross-section and containing a coaxial and confocal elliptic cylindrical cavity, is considered. In case of a matrix obeying J2 flow theory of plasticity, the overall yield domain and the evolution laws for the volume fraction and aspect ratio of the void are obtained. Under assigned strain histories, these theoretical findings are then compared to finite element unit-cell simulations, in order to assess the capability of the proposed results to track microstructure evolution. The improvements with respect to the customarily adopted Gurson’s model are also discussed. Full article
(This article belongs to the Special Issue Composite Materials)
Open AccessArticle A Route for Polymer Nanocomposites with Engineered Electrical Conductivity and Percolation Threshold
Materials 2010, 3(2), 1089-1103; doi:10.3390/ma3021089
Received: 17 January 2010 / Revised: 28 January 2010 / Accepted: 8 February 2010 / Published: 9 February 2010
Cited by 37 | PDF Full-text (625 KB) | HTML Full-text | XML Full-text
Abstract
Polymer nanocomposites with engineered electrical properties can be made by tuning the fabrication method, processing conditions and filler’s geometric and physical properties. This work focuses on investigating the effect of filler’s geometry (aspect ratio and shape), intrinsic electrical conductivity, alignment and dispersion within
[...] Read more.
Polymer nanocomposites with engineered electrical properties can be made by tuning the fabrication method, processing conditions and filler’s geometric and physical properties. This work focuses on investigating the effect of filler’s geometry (aspect ratio and shape), intrinsic electrical conductivity, alignment and dispersion within the polymer, and polymer crystallinity, on the percolation threshold and electrical conductivity of polypropylene based nanocomposites. The conductive reinforcements used are exfoliated graphite nanoplatelets, carbon black, vapor grown carbon fibers and polyacrylonitrile carbon fibers. The composites are made using melt mixing followed by injection molding. A coating method is also employed to improve the nanofiller’s dispersion within the polymer and compression molding is used to alter the nanofiller’s alignment. Full article
(This article belongs to the Special Issue Nanocomposites of Polymers and Inorganic Particles)
Open AccessArticle Innovative Use and Characterization of Polymers for Timber-Related Construction
Materials 2010, 3(2), 1104-1124; doi:10.3390/ma3021104
Received: 17 December 2009 / Revised: 4 February 2010 / Accepted: 9 February 2010 / Published: 10 February 2010
Cited by 1 | PDF Full-text (537 KB) | HTML Full-text | XML Full-text
Abstract
Timber gridshells have become a very popular, efficient, sustainable and beautiful structural application of timber. However, given the slender laths involved in this form of construction, there is concern over the durability of timber for this purpose, and Glass FRP (GFRP) laths have
[...] Read more.
Timber gridshells have become a very popular, efficient, sustainable and beautiful structural application of timber. However, given the slender laths involved in this form of construction, there is concern over the durability of timber for this purpose, and Glass FRP (GFRP) laths have been proposed as a possible substitution. This paper considers this possibility. It goes on to look at the possible use of Basalt FRP (BFRP) for the same purpose, from the perspective of its creep characteristics. It is shown that the use of GFRP gridshells is a viable form of construction, and that enhanced durability characteristics of BFRP could lead to their adoption for gridshells, given that the creep characteristics of basalt fibres presented here are comparable to those of glass fibres. An altogether different form of timber construction is that of joist-and-floorboard. In the UK, there are thousands of historic buildings which use this floor construction, and a sizeable proportion of this building stock now requires upgrade, strengthening and/or stiffening to allow these buildings to be fit for purpose into the future. This paper goes on to consider the possible use of Carbon FRP (CFRP) to strengthen and stiffen such timber floors. It is shown that such strengthening and stiffening is entirely feasible, offering the potential for greatly enhanced stiffness, in particular. Further, it is shown that mechanical shear connection between CFRP and timber is best conducted using perpendicular-positioned screws, rather than raked screws. Full article
(This article belongs to the Special Issue Composite Materials)
Open AccessArticle Chemoselectivity in the Dehydrocoupling Synthesis of Higher Molecular Weight Polysilanes
Materials 2010, 3(2), 1125-1137; doi:10.3390/ma3021125
Received: 19 January 2010 / Revised: 29 January 2010 / Accepted: 9 February 2010 / Published: 10 February 2010
PDF Full-text (107 KB) | HTML Full-text | XML Full-text
Abstract
The Cp2ZrCl2/2 BuLi catalyzed co-polymerization of H2MeSiSiMeH2 and PhSiH3 was compared to the homo-polymerization of H2MeSiSiPhH2. In contrast to the co-polymerization, which gave molecular weights comparable to homo-polymerization of phenylsilane, the
[...] Read more.
The Cp2ZrCl2/2 BuLi catalyzed co-polymerization of H2MeSiSiMeH2 and PhSiH3 was compared to the homo-polymerization of H2MeSiSiPhH2. In contrast to the co-polymerization, which gave molecular weights comparable to homo-polymerization of phenylsilane, the reaction of 1-methyl-2-phenyldisilane yielded a partially cross-linked high molecular weight polymer with very broad molecular weight distribution. A higher reactivity of phenyl-substituted silicon atoms compared to methyl-substituted ones was detected. Stoichiometric reactions of some disilanes with the slow dehydropolymerization catalyst CpCp*Hf(Cl)Si(SiMe3)3 gave metal disilanyl intermediates with selectivities that reflect the observed polymerization behavior. Full article
(This article belongs to the Special Issue Organometallic Compounds)
Open AccessArticle Tissue Response to, and Degradation Rate of, Photocrosslinked Trimethylene Carbonate-Based Elastomers Following Intramuscular Implantation
Materials 2010, 3(2), 1156-1171; doi:10.3390/ma3021156
Received: 27 December 2009 / Revised: 4 February 2010 / Accepted: 10 February 2010 / Published: 11 February 2010
Cited by 6 | PDF Full-text (499 KB) | HTML Full-text | XML Full-text
Abstract
Cylindrical elastomers were prepared through the UV-initiated crosslinking of terminally acrylated, 8,000 Da star-poly(trimethylene carbonate-co-ε-caprolactone) and star-poly(trimethylene carbonate-co-D,L-lactide). These elastomers were implanted intramuscularly into the hind legs of male Wistar rats to determine the influence of the comonomer on the weight loss, tissue
[...] Read more.
Cylindrical elastomers were prepared through the UV-initiated crosslinking of terminally acrylated, 8,000 Da star-poly(trimethylene carbonate-co-ε-caprolactone) and star-poly(trimethylene carbonate-co-D,L-lactide). These elastomers were implanted intramuscularly into the hind legs of male Wistar rats to determine the influence of the comonomer on the weight loss, tissue response, and change in mechanical properties of the elastomer. The elastomers exhibited only a mild inflammatory response that subsided after the first week; the response was greater for the stiffer D,L-lactide-containing elastomers. The elastomers exhibited weight loss and sol content changes consistent with a bulk degradation mechanism. The D,L-lactide-containing elastomers displayed a nearly zeroorder change in Young’s modulus and stress at break over the 30 week degradation time, while the ε-caprolactone-containing elastomers exhibited little change in modulus or stress at break. Full article
(This article belongs to the Special Issue Advances in Biomaterials)
Open AccessArticle Thermal Stability and Sublimation Pressures of Some Ruthenocene Compounds
Materials 2010, 3(2), 1172-1185; doi:10.3390/ma3021172
Received: 11 December 2009 / Revised: 29 January 2010 / Accepted: 10 February 2010 / Published: 15 February 2010
Cited by 8 | PDF Full-text (547 KB) | HTML Full-text | XML Full-text
Abstract
We set out to study the use of a series of ruthenocenes as possible and promising sources for ruthenium and/or ruthenium oxide film formation.The thermal stability of a series of ruthenocenes, including (η5-C5H4R)(η5-C
[...] Read more.
We set out to study the use of a series of ruthenocenes as possible and promising sources for ruthenium and/or ruthenium oxide film formation.The thermal stability of a series of ruthenocenes, including (η5-C5H4R)(η5-C5H4R´)Ru (1), R = R´ = H (3), R = H, R´ = CH2NMe2 (5), R = H, R´= C(O)Me (6), R = R´ = C(O)Me (7), R = H, R´ = C(O)(CH2)3CO2H (8), R = H, R´ = C(O)(CH2)2CO2H (9), R = H, R´ = C(O)(CH2)3CO2Me (10), R = H, R´= C(O)(CH2)2CO2Me (11), R = R´ = SiMe3), (η5-C4H3O-2,4-Me2)2Ru (2), and (η5-C5H5-2,4-Me2)2Ru (4) was studied by thermogravimetry. From these studies, it could be concluded that 1–4, 6 and 9–11 are the most thermally stable molecules. The sublimation pressure of these sandwich compounds was measured using a Knudsen cell. Among these, the compound 11 shows the highest vapor pressure. Full article
(This article belongs to the Special Issue Organometallic Compounds)
Open AccessArticle The One-Step Pickering Emulsion Polymerization Route for Synthesizing Organic-Inorganic Nanocomposite Particles
Materials 2010, 3(2), 1186-1202; doi:10.3390/ma3021186
Received: 5 January 2010 / Revised: 9 February 2010 / Accepted: 9 February 2010 / Published: 16 February 2010
Cited by 28 | PDF Full-text (1437 KB) | HTML Full-text | XML Full-text
Abstract
Polystyrene-silica core-shell nanocomposite particles are successfully prepared via one-step Pickering emulsion polymerization. Possible mechanisms of Pickering emulsion polymerization are addressed in the synthesis of polystyrene-silica nanocomposite particles using 2,2-azobis(2-methyl-N-(2-hydroxyethyl)propionamide (VA-086) and potassium persulfate (KPS) as the initiator. Motivated by potential applications
[...] Read more.
Polystyrene-silica core-shell nanocomposite particles are successfully prepared via one-step Pickering emulsion polymerization. Possible mechanisms of Pickering emulsion polymerization are addressed in the synthesis of polystyrene-silica nanocomposite particles using 2,2-azobis(2-methyl-N-(2-hydroxyethyl)propionamide (VA-086) and potassium persulfate (KPS) as the initiator. Motivated by potential applications of “smart” composite particles in controlled drug delivery, the one-step Pickering emulsion polymerization route is further applied to synthesize polystyrene/poly(N-isopropylacrylamide) (PNIPAAm)-silica core-shell nanoparticles with N-isopropylacrylamide incorporated into the core as a co-monomer. The polystyrene/PNIPAAm-silica composite nanoparticles are temperature sensitive and can be taken up by human prostate cancer (PC3-PSMA) cells. Full article
(This article belongs to the Special Issue Nanocomposites of Polymers and Inorganic Particles)
Open AccessArticle Synthesis, Structure and Thermal Behavior of Oxalato-Bridged Rb+ and H3O+ Extended Frameworks with Different Dimensionalities
Materials 2010, 3(2), 1281-1301; doi:10.3390/ma3021281
Received: 5 December 2009 / Revised: 25 January 2010 / Accepted: 10 February 2010 / Published: 23 February 2010
Cited by 3 | PDF Full-text (824 KB) | HTML Full-text | XML Full-text
Abstract
Correlative studies of three oxalato-bridged polymers, obtained under hydrothermal conditions for the two isostructural compounds {Rb(HC2O4)(H2C2O4)(H2O)2}1, 1, {H3O(HC2O4)(H2
[...] Read more.
Correlative studies of three oxalato-bridged polymers, obtained under hydrothermal conditions for the two isostructural compounds {Rb(HC2O4)(H2C2O4)(H2O)2}1, 1, {H3O(HC2O4)(H2C2O4).2H2O}1, 2, and by conventional synthetic method for {Rb(HC2O4)}3, 3, allowed the identification of H-bond patterns and structural dimensionality. Ferroïc domain structures are confirmed by electric measurements performed on 3. Although 2 resembles one oxalic acid sesquihydrate, its structure determination doesn’t display any kind of disorder and leads to recognition of a supramolecular network identical to hybrid s-block series, where moreover, unusual H3O+ and NH4+ similarity is brought out. Thermal behaviors show that 1D frameworks with extended H-bonds, whether with or without a metal center, have the same stability. Inversely, despite the dimensionalities, the same metallic intermediate and final compounds are obtained for the two Rb+ ferroïc materials. Full article
(This article belongs to the Special Issue Inorganic-Organic Hybrid Materials)
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Open AccessArticle Layer-by-Layer Method for the Synthesis and Growth of Surface Mounted Metal-Organic Frameworks (SURMOFs)
Materials 2010, 3(2), 1302-1315; doi:10.3390/ma3021302
Received: 31 December 2009 / Revised: 3 February 2010 / Accepted: 21 February 2010 / Published: 23 February 2010
Cited by 44 | PDF Full-text (818 KB) | HTML Full-text | XML Full-text
Abstract
A layer-by-layer method has been developed for the synthesis of metal-organic frameworks (MOFs) and their deposition on functionalized organic surfaces. The approach is based on the sequential immersion of functionalized organic surfaces into solutions of the building blocks of the MOF, i.e., the
[...] Read more.
A layer-by-layer method has been developed for the synthesis of metal-organic frameworks (MOFs) and their deposition on functionalized organic surfaces. The approach is based on the sequential immersion of functionalized organic surfaces into solutions of the building blocks of the MOF, i.e., the organic ligand and the inorganic unit. The synthesis and growth of different types of MOFs on substrates with different functionalization, like COOH, OH and pyridine terminated surfaces, were studied and characterized with different surface characterization techniques. A controlled and highly oriented growth of very homogenous films was obtained using this method. The layer-by-layer method offered also the possibility to study the kinetics of film formation in more detail using surface plasmon resonance and quartz crystal microbalance. In addition, this method demonstrates the potential to synthesize new classes of MOFs not accessible by conventional methods. Finally, the controlled growth of MOF thin films is important for many applications like chemical sensors, membranes and related electrodes. Full article
(This article belongs to the Special Issue Inorganic-Organic Hybrid Materials)
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Open AccessArticle Scaffold Sheet Design Strategy for Soft Tissue Engineering
Materials 2010, 3(2), 1375-1389; doi:10.3390/ma3021375
Received: 30 January 2010 / Accepted: 22 February 2010 / Published: 24 February 2010
Cited by 26 | PDF Full-text (638 KB) | HTML Full-text | XML Full-text
Abstract
Creating heterogeneous tissue constructs with an even cell distribution and robust mechanical strength remain important challenges to the success of in vivo tissue engineering. To address these issues, we are developing a scaffold sheet tissue engineering strategy consisting of thin (~200 μm), strong,
[...] Read more.
Creating heterogeneous tissue constructs with an even cell distribution and robust mechanical strength remain important challenges to the success of in vivo tissue engineering. To address these issues, we are developing a scaffold sheet tissue engineering strategy consisting of thin (~200 μm), strong, elastic, and porous crosslinked urethane- doped polyester (CUPE) scaffold sheets that are bonded together chemically or through cell culture. Suture retention of the tissue constructs (four sheets) fabricated by the scaffold sheet tissue engineering strategy is close to the surgical requirement (1.8 N) rendering their potential for immediate implantation without a need for long cell culture times. Cell culture results using 3T3 fibroblasts show that the scaffold sheets are bonded into a tissue construct via the extracellular matrix produced by the cells after 2 weeks of in vitro cell culture. Full article
(This article belongs to the Special Issue Advances in Biomaterials)
Open AccessArticle Polymer Nanocomposites Containing Anisotropic Metal Nanostructures as Internal Strain Indicators
Materials 2010, 3(2), 1461-1477; doi:10.3390/ma3021461
Received: 21 December 2009 / Revised: 28 January 2010 / Accepted: 23 February 2010 / Published: 24 February 2010
Cited by 8 | PDF Full-text (3224 KB) | HTML Full-text | XML Full-text
Abstract
Polymer/metal nanocomposite containing intrinsically anisotropic metal nanostructures such as metal nanorods and nanowires appeared extremely more sensitive and responsive to mechanical stimuli than nanocomposites containing spherical nanoparticles. After uniaxial stretching of the supporting polymer matrix (poly(vinyl alcohol)), the elongated silver nanostructures embedded at
[...] Read more.
Polymer/metal nanocomposite containing intrinsically anisotropic metal nanostructures such as metal nanorods and nanowires appeared extremely more sensitive and responsive to mechanical stimuli than nanocomposites containing spherical nanoparticles. After uniaxial stretching of the supporting polymer matrix (poly(vinyl alcohol)), the elongated silver nanostructures embedded at low concentration into the polymer matrix (<1 wt % of Ag) assume the direction of the drawing, yielding materials with a strong dichroic response of the absorption behavior. Accordingly, the film changed its color when observed under linearly polarized light already at moderate drawings. The results obtained suggest that nanocomposite films have potential in applications such as color polarizing filters, radiation responsive polymeric objects and smart flexible films in packaging applications. Full article
(This article belongs to the Special Issue Nanocomposites of Polymers and Inorganic Particles)
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Review

Jump to: Research

Open AccessReview Progress of the Application of Mesoporous Silica-Supported Heteropolyacids in Heterogeneous Catalysis and Preparation of Nanostructured Metal Oxides
Materials 2010, 3(2), 764-785; doi:10.3390/ma3020764
Received: 4 December 2009 / Revised: 3 January 2010 / Accepted: 13 January 2010 / Published: 27 January 2010
Cited by 36 | PDF Full-text (678 KB) | HTML Full-text | XML Full-text
Abstract
Mesoporous silica molecular sieves are a kind of unique catalyst support due to their large pore size and high surface area. Several methods have been developed to immobilize heteropolyacids (HPAs) inside the channels of these mesoporous silicas. The mesoporous silica-supported HPA materials have
[...] Read more.
Mesoporous silica molecular sieves are a kind of unique catalyst support due to their large pore size and high surface area. Several methods have been developed to immobilize heteropolyacids (HPAs) inside the channels of these mesoporous silicas. The mesoporous silica-supported HPA materials have been widely used as recyclable catalysts in heterogeneous systems. They have shown high catalytic activities and shape selectivities in some reactions, compared to the parent HPAs in homogeneous systems. This review summarizes recent progress in the field of mesoporous silica-supported HPAs applied in the heterogeneous catalysis area and preparation of nanostructured metal oxides using HPAs as precursors and mesoporous silicas as hard templates. Full article
(This article belongs to the Special Issue Polyoxometalate Compounds)
Open AccessReview Biphasic Calcium Phosphate Ceramics for Bone Regeneration and Tissue Engineering Applications
Materials 2010, 3(2), 815-826; doi:10.3390/ma3020815
Received: 1 December 2009 / Revised: 17 January 2010 / Accepted: 27 January 2010 / Published: 29 January 2010
Cited by 37 | PDF Full-text (1524 KB) | HTML Full-text | XML Full-text
Abstract
Biphasic calcium phosphates (BCP) have been sought after as biomaterials for the reconstruction of bone defects in maxillofacial, dental and orthopaedic applications. They have demonstrated proven biocompatibility, osteoconductivity, safety and predictability in in vitro, in vivo and clinical models. More recently, in
[...] Read more.
Biphasic calcium phosphates (BCP) have been sought after as biomaterials for the reconstruction of bone defects in maxillofacial, dental and orthopaedic applications. They have demonstrated proven biocompatibility, osteoconductivity, safety and predictability in in vitro, in vivo and clinical models. More recently, in vitro and in vivo studies have shown that BCP can be osteoinductive. In the field of tissue engineering, they represent promising scaffolds capable of carrying and modulating the behavior of stem cells. This review article will highlight the latest advancements in the use of BCP and the characteristics that create a unique microenvironment that favors bone regeneration. Full article
(This article belongs to the Special Issue Ceramics for Healthcare)
Open AccessReview Dinitrogen and Related Chemistry of the Lanthanides: A Review of the Reductive Capture of Dinitrogen, As Well As Mono- and Di-aza Containing Ligand Chemistry of Relevance to Known and Postulated Metal Mediated Dinitrogen Derivatives
Materials 2010, 3(2), 841-862; doi:10.3390/ma3020841
Received: 23 December 2009 / Revised: 27 January 2010 / Accepted: 29 January 2010 / Published: 1 February 2010
Cited by 10 | PDF Full-text (681 KB) | HTML Full-text | XML Full-text
Abstract
This paper reviews the current array of complexes of relevance to achieving lanthanide mediated nitrogen fixation. A brief history of nitrogen fixation is described, including a limited discussion of successful transition metal facilitated nitrogen fixation systems. A detailed discussion of the numerous lanthanide-nitrogen
[...] Read more.
This paper reviews the current array of complexes of relevance to achieving lanthanide mediated nitrogen fixation. A brief history of nitrogen fixation is described, including a limited discussion of successful transition metal facilitated nitrogen fixation systems. A detailed discussion of the numerous lanthanide-nitrogen species relevant to nitrogen fixation are discussed and are related to the Chatt cycle for nitrogen fixation. Full article
(This article belongs to the Special Issue Organometallic Compounds)
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Open AccessReview Performance of Zirconia for Dental Healthcare
Materials 2010, 3(2), 863-896; doi:10.3390/ma3020863
Received: 1 December 2009 / Revised: 26 January 2010 / Accepted: 28 January 2010 / Published: 1 February 2010
Cited by 27 | PDF Full-text (731 KB) | HTML Full-text | XML Full-text
Abstract
The positive results of the performance of zirconia for orthopedics devices have led the dental community to explore possible esthetical and mechanical outcomes using this material. However, questions regarding long-term results have opened strong and controversial discussions regarding the utilization of zirconia as
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The positive results of the performance of zirconia for orthopedics devices have led the dental community to explore possible esthetical and mechanical outcomes using this material. However, questions regarding long-term results have opened strong and controversial discussions regarding the utilization of zirconia as a substitute for alloys for restorations and implants. This narrative review presents the current knowledge on zirconia utilized for dental restorations, oral implant components, and zirconia oral implants, and also addresses laboratory tests and developments, clinical performance, and possible future trends of this material for dental healthcare. Full article
(This article belongs to the Special Issue Ceramics for Healthcare)
Open AccessReview Cement and Concrete Nanoscience and Nanotechnology
Materials 2010, 3(2), 918-942; doi:10.3390/ma3020918
Received: 24 December 2009 / Revised: 27 January 2010 / Accepted: 28 January 2010 / Published: 3 February 2010
Cited by 91 | PDF Full-text (1249 KB) | HTML Full-text | XML Full-text
Abstract
Concrete science is a multidisciplinary area of research where nanotechnology potentially offers the opportunity to enhance the understanding of concrete behavior, to engineer its properties and to lower production and ecological cost of construction materials. Recent work at the National Research Council Canada
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Concrete science is a multidisciplinary area of research where nanotechnology potentially offers the opportunity to enhance the understanding of concrete behavior, to engineer its properties and to lower production and ecological cost of construction materials. Recent work at the National Research Council Canada in the area of concrete materials research has shown the potential of improving concrete properties by modifying the structure of cement hydrates, addition of nanoparticles and nanotubes and controlling the delivery of admixtures. This article will focus on a review of these innovative achievements. Full article
(This article belongs to the Special Issue Nanocomposites of Polymers and Inorganic Particles)
Open AccessReview Porous Silicon—A Versatile Host Material
Materials 2010, 3(2), 943-998; doi:10.3390/ma3020943
Received: 31 October 2009 / Revised: 22 January 2010 / Accepted: 2 February 2010 / Published: 3 February 2010
Cited by 86 | PDF Full-text (5214 KB) | HTML Full-text | XML Full-text
Abstract
This work reviews the use of porous silicon (PS) as a nanomaterial which is extensively investigated and utilized for various applications, e.g., in the fields of optics, sensor technology and biomedicine. Furthermore the combination of PS with one or more materials which are
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This work reviews the use of porous silicon (PS) as a nanomaterial which is extensively investigated and utilized for various applications, e.g., in the fields of optics, sensor technology and biomedicine. Furthermore the combination of PS with one or more materials which are also nanostructured due to their deposition within the porous matrix is discussed. Such nanocompounds offer a broad avenue of new and interesting properties depending on the kind of involved materials as well as on their morphology. The filling of the pores performed by electroless or electrochemical deposition is described, whereas different morphologies, reaching from micro- to macro pores are utilized as host material which can be self-organized or fabricated by prestructuring. For metal-deposition within the porous structures, both ferromagnetic and non-magnetic metals are used. Emphasis will be put on self-arranged mesoporous silicon, offering a quasi-regular pore arrangement, employed as template for filling with ferromagnetic metals. By varying the deposition parameters the precipitation of the metal structures within the pores can be tuned in geometry and spatial distribution leading to samples with desired magnetic properties. The correlation between morphology and magnetic behaviour of such semiconducting/magnetic systems will be determined. Porous silicon and its combination with a variety of filling materials leads to nanocomposites with specific physical properties caused by the nanometric size and give rise to a multiplicity of potential applications in spintronics, magnetic and magneto-optic devices, nutritional food additives as well as drug delivery. Full article
(This article belongs to the Special Issue Porous Materials)
Open AccessReview A Review of Keratin-Based Biomaterials for Biomedical Applications
Materials 2010, 3(2), 999-1014; doi:10.3390/ma3020999
Received: 6 January 2009 / Revised: 24 January 2010 / Accepted: 26 January 2010 / Published: 3 February 2010
Cited by 123 | PDF Full-text (246 KB) | HTML Full-text | XML Full-text
Abstract
Advances in the extraction, purification, and characterization of keratin proteins from hair and wool fibers over the past century have led to the development of a keratin-based biomaterials platform. Like many naturally-derived biomolecules, keratins have intrinsic biological activity and biocompatibility. In addition, extracted
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Advances in the extraction, purification, and characterization of keratin proteins from hair and wool fibers over the past century have led to the development of a keratin-based biomaterials platform. Like many naturally-derived biomolecules, keratins have intrinsic biological activity and biocompatibility. In addition, extracted keratins are capable of forming self-assembled structures that regulate cellular recognition and behavior. These qualities have led to the development of keratin biomaterials with applications in wound healing, drug delivery, tissue engineering, trauma and medical devices. This review discusses the history of keratin research and the advancement of keratin biomaterials for biomedical applications. Full article
(This article belongs to the Special Issue Advances in Biomaterials)
Open AccessReview Organometallic Routes into the Nanorealms of Binary Fe-Si Phases
Materials 2010, 3(2), 1049-1088; doi:10.3390/ma3021049
Received: 4 January 2010 / Revised: 26 January 2010 / Accepted: 5 February 2010 / Published: 9 February 2010
Cited by 12 | PDF Full-text (2741 KB) | HTML Full-text | XML Full-text
Abstract
The Fe-Si binary system provides several iron silicides that have varied and exceptional material properties with applications in the electronic industry. The well known Fe-Si binary silicides are Fe3Si, Fe5Si3, FeSi, a-FeSi2 and b-FeSi
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The Fe-Si binary system provides several iron silicides that have varied and exceptional material properties with applications in the electronic industry. The well known Fe-Si binary silicides are Fe3Si, Fe5Si3, FeSi, a-FeSi2 and b-FeSi2. While the iron-rich silicides Fe3Si and Fe5Si3 are known to be room temperature ferromagnets, the stoichiometric FeSi is the only known transition metal Kondo insulator. Furthermore, Fe5Si3 has also been demonstrated to exhibit giant magnetoresistance (GMR). The silicon-rich b-FeSi2 is a direct band gap material usable in light emitting diode (LED) applications. Typically, these silicides are synthesized by traditional solid-state reactions or by ion beam-induced mixing (IBM) of alternating metal and silicon layers. Alternatively, the utilization of organometallic compounds with reactive transition metal (Fe)-carbon bonds has opened various routes for the preparation of these silicides and the silicon-stabilized bcc- and fcc-Fe phases contained in the Fe-Si binary phase diagram. The unique interfacial interactions of carbon with the Fe and Si components have resulted in the preferential formation of nanoscale versions of these materials. This review will discuss such reactions. Full article
(This article belongs to the Special Issue Organometallic Compounds)
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Open AccessReview Bone Substitute Fabrication Based on Dissolution-Precipitation Reactions
Materials 2010, 3(2), 1138-1155; doi:10.3390/ma3021138
Received: 7 December 2009 / Revised: 29 January 2010 / Accepted: 9 February 2010 / Published: 10 February 2010
Cited by 36 | PDF Full-text (1123 KB) | HTML Full-text | XML Full-text
Abstract
Although block- or granular-type sintered hydroxyapatite are known to show excellent tissue responses and good osteoconductivity, apatite powder elicits inflammatory response. For the fabrication of hydroxyapatite block or granules, sintering is commonly employed. However, the inorganic component of bone and tooth is not
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Although block- or granular-type sintered hydroxyapatite are known to show excellent tissue responses and good osteoconductivity, apatite powder elicits inflammatory response. For the fabrication of hydroxyapatite block or granules, sintering is commonly employed. However, the inorganic component of bone and tooth is not high crystalline hydroxyapatite but low crystalline B-type carbonate apatite. Unfortunately, carbonate apatite powder cannot be sintered due to its instability at high temperature. Another method to fabricate apatite block and/or granule is through phase transformation based on dissolution-precipitation reactions using a precursor phase. This reaction basically is the same as a setting and hardening reaction of calcium sulfate or plaster. In this paper, apatite block fabrication methods by phase transformation based on dissolution-precipitation reactions will be discussed, with a focus on the similarity of the setting and hardening reaction of calcium sulfate. Full article
(This article belongs to the Special Issue Ceramics for Healthcare)
Open AccessReview Carbon-Based Honeycomb Monoliths for Environmental Gas-Phase Applications
Materials 2010, 3(2), 1203-1227; doi:10.3390/ma3021203
Received: 23 December 2009 / Revised: 3 February 2010 / Accepted: 11 February 2010 / Published: 19 February 2010
Cited by 26 | PDF Full-text (934 KB) | HTML Full-text | XML Full-text
Abstract
Honeycomb monoliths consist of a large number of parallel channels that provide high contact efficiencies between the monolith and gas flow streams. These structures are used as adsorbents or supports for catalysts when large gas volumes are treated, because they offer very low
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Honeycomb monoliths consist of a large number of parallel channels that provide high contact efficiencies between the monolith and gas flow streams. These structures are used as adsorbents or supports for catalysts when large gas volumes are treated, because they offer very low pressure drop, short diffusion lengths and no obstruction by particulate matter. Carbon-based honeycomb monoliths can be integral or carbon-coated ceramic monoliths, and they take advantage of the versatility of the surface area, pore texture and surface chemistry of carbon materials. Here, we review the preparation methods of these monoliths, their characteristics and environmental applications. Full article
(This article belongs to the Special Issue Advances in Materials Science)
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Open AccessReview Review: Resin Composite Filling
Materials 2010, 3(2), 1228-1243; doi:10.3390/ma3021228
Received: 7 January 2010 / Revised: 2 February 2010 / Accepted: 9 February 2010 / Published: 19 February 2010
Cited by 9 | PDF Full-text (208 KB) | HTML Full-text | XML Full-text
Abstract
The leading cause of oral pain and tooth loss is from caries and their treatment include restoration using amalgam, resin, porcelain and gold, endodontic therapy and extraction. Resin composite restorations have grown popular over the last half a century because it can take
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The leading cause of oral pain and tooth loss is from caries and their treatment include restoration using amalgam, resin, porcelain and gold, endodontic therapy and extraction. Resin composite restorations have grown popular over the last half a century because it can take shades more similar to enamel. Here, we discuss the history and use of resin, comparison between amalgam and resin, clinical procedures involved and finishing and polishing techniques for resin restoration. Although resin composite has aesthetic advantages over amalgam, one of the major disadvantage include polymerization shrinkage and future research is needed on reaction kinetics and viscoelastic behaviour to minimize shrinkage stress. Full article
(This article belongs to the Special Issue Molecular Biomimetics and Materials Design)
Open AccessReview Magnetic and Optical Properties of Submicron-Size Hollow Spheres
Materials 2010, 3(2), 1244-1268; doi:10.3390/ma3021244
Received: 30 December 2009 / Revised: 2 February 2010 / Accepted: 19 February 2010 / Published: 21 February 2010
Cited by 14 | PDF Full-text (778 KB) | HTML Full-text | XML Full-text
Abstract
Magnetic hollow spheres with a controlled diameter and shell thickness have emerged as an important class of magnetic nanomaterials. The confined hollow geometry and pronouncedly curved surfaces induce unique physical properties different from those of flat thin films and solid counterparts. In this
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Magnetic hollow spheres with a controlled diameter and shell thickness have emerged as an important class of magnetic nanomaterials. The confined hollow geometry and pronouncedly curved surfaces induce unique physical properties different from those of flat thin films and solid counterparts. In this paper, we focus on recent progress on submicron-size spherical hollow magnets (e.g., cobalt- and iron-based materials), and discuss the effects of the hollow shape and the submicron size on magnetic and optical properties. Full article
(This article belongs to the Special Issue Magnetic Nanoparticles)
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Open AccessReview Non-Traditional Aromatic Topologies and Biomimetic Assembly Motifs as Components of Functional Pi-Conjugated Oligomers
Materials 2010, 3(2), 1269-1280; doi:10.3390/ma3021269
Received: 6 January 2010 / Revised: 2 February 2010 / Accepted: 11 February 2010 / Published: 23 February 2010
Cited by 2 | PDF Full-text (609 KB) | HTML Full-text | XML Full-text
Abstract
This article will highlight our recent work using conjugated oligomers as precursors to electroactive polymer films and self-assembling nanomaterials. One area of investigation has focused on nonbenzenoid aromaticity in the context of charge delocalization in conjugated polymers. In these studies, polymerizable pi-conjugated units
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This article will highlight our recent work using conjugated oligomers as precursors to electroactive polymer films and self-assembling nanomaterials. One area of investigation has focused on nonbenzenoid aromaticity in the context of charge delocalization in conjugated polymers. In these studies, polymerizable pi-conjugated units were coupled onto unusual aromatic cores such as methano[10]annulene. This article will also show how biologically-inspired assembly of molecularly well-defined oligopeptides that flank pi-conjugated oligomers has resulted in the aqueous construction of 1-dimensional nanomaterials that encourage electronic delocalization among the pi-electron systems. Full article
(This article belongs to the Special Issue Conjugated Oligomers)
Open AccessReview Colloidal Inorganic Nanocrystal Based Nanocomposites: Functional Materials for Micro and Nanofabrication
Materials 2010, 3(2), 1316-1352; doi:10.3390/ma3021316
Received: 11 January 2010 / Revised: 9 February 2010 / Accepted: 21 February 2010 / Published: 23 February 2010
Cited by 25 | PDF Full-text (923 KB) | HTML Full-text | XML Full-text
Abstract
The unique size- and shape-dependent electronic properties of nanocrystals (NCs) make them extremely attractive as novel structural building blocks for constructing a new generation of innovative materials and solid-state devices. Recent advances in material chemistry has allowed the synthesis of colloidal NCs with
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The unique size- and shape-dependent electronic properties of nanocrystals (NCs) make them extremely attractive as novel structural building blocks for constructing a new generation of innovative materials and solid-state devices. Recent advances in material chemistry has allowed the synthesis of colloidal NCs with a wide range of compositions, with a precise control on size, shape and uniformity as well as specific surface chemistry. By incorporating such nanostructures in polymers, mesoscopic materials can be achieved and their properties engineered by choosing NCs differing in size and/or composition, properly tuning the interaction between NCs and surrounding environment. In this contribution, different approaches will be presented as effective opportunities for conveying colloidal NC properties to nanocomposite materials for micro and nanofabrication. Patterning of such nanocomposites either by conventional lithographic techniques and emerging patterning tools, such as ink jet printing and nanoimprint lithography, will be illustrated, pointing out their technological impact on developing new optoelectronic and sensing devices. Full article
(This article belongs to the Special Issue Nanocomposites of Polymers and Inorganic Particles)
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Open AccessReview Materials for Powder-Based AC-Electroluminescence
Materials 2010, 3(2), 1353-1374; doi:10.3390/ma3021353
Received: 31 December 2009 / Revised: 11 February 2010 / Accepted: 20 February 2010 / Published: 23 February 2010
Cited by 23 | PDF Full-text (12376 KB) | HTML Full-text | XML Full-text
Abstract
At present, thick film (powder based) alternating current electroluminescence (AC-EL) is the only technology available for the fabrication of large area, laterally structured and coloured light sources by simple printing techniques. Substrates for printing may be based on flexible polymers or glass, so
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At present, thick film (powder based) alternating current electroluminescence (AC-EL) is the only technology available for the fabrication of large area, laterally structured and coloured light sources by simple printing techniques. Substrates for printing may be based on flexible polymers or glass, so the final devices can take up a huge variety of shapes. After an introduction of the underlying physics and chemistry, the review highlights the technical progress behind this development, concentrating on luminescent and dielectric materials used. Limitations of the available materials as well as room for further improvement are also discussed. Full article
(This article belongs to the Special Issue Luminescent Materials)
Open AccessReview Microstructural Characterisation and Wear Behaviour of Diamond Composite Materials
Materials 2010, 3(2), 1390-1419; doi:10.3390/ma3021390
Received: 10 January 2010 / Accepted: 22 February 2010 / Published: 24 February 2010
Cited by 20 | PDF Full-text (2762 KB) | HTML Full-text | XML Full-text
Abstract
Since the initial research leading to the production of diamond composite materials, there have been several important developments leading to significant improvements in the properties of these superhard composite materials. Apart from the fact that diamonds, whether originating from natural resources or synthesised
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Since the initial research leading to the production of diamond composite materials, there have been several important developments leading to significant improvements in the properties of these superhard composite materials. Apart from the fact that diamonds, whether originating from natural resources or synthesised commercially, are the hardest and most wear-resistant materials commonly available, there are other mechanical properties that limit their industrial application. These include the low fracture toughness and low impact strength of diamond. By incorporating a range of binder phases into the sintering production process of these composites, these critically important properties have been radically improved. These new composites can withstand much higher operating temperatures without markedly reducing their strength and wear resistance. Further innovative steps are now being made to improve the properties of diamond composites by reducing grain and particle sizes into the nano range. This review will cover recent developments in diamond composite materials with special emphasis on microstructural characterisation. The results of such studies should assist in the design of new, innovative diamond tools as well as leading to radical improvements in the productivity of cutting, drilling and sawing operations in the exploration, mining, civil construction and manufacturing industries. Full article
(This article belongs to the Special Issue Composite Materials)
Open AccessReview Self-Assembled Hydrogel Nanoparticles for Drug Delivery Applications
Materials 2010, 3(2), 1420-1460; doi:10.3390/ma3021420
Received: 13 January 2010 / Revised: 4 February 2010 / Accepted: 21 February 2010 / Published: 24 February 2010
Cited by 54 | PDF Full-text (797 KB) | HTML Full-text | XML Full-text
Abstract
Hydrogel nanoparticles—also referred to as polymeric nanogels or macromolecular micelles—are emerging as promising drug carriers for therapeutic applications. These nanostructures hold versatility and properties suitable for the delivery of bioactive molecules, namely of biopharmaceuticals. This article reviews the latest developments in the use
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Hydrogel nanoparticles—also referred to as polymeric nanogels or macromolecular micelles—are emerging as promising drug carriers for therapeutic applications. These nanostructures hold versatility and properties suitable for the delivery of bioactive molecules, namely of biopharmaceuticals. This article reviews the latest developments in the use of self-assembled polymeric nanogels for drug delivery applications, including small molecular weight drugs, proteins, peptides, oligosaccharides, vaccines and nucleic acids. The materials and techniques used in the development of self-assembling nanogels are also described. Full article
(This article belongs to the Special Issue Advances in Biomaterials)
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Open AccessReview Electrically and Thermally Conducting Nanocomposites for Electronic Applications
Materials 2010, 3(2), 1478-1496; doi:10.3390/ma3021478
Received: 10 January 2010 / Revised: 24 February 2010 / Accepted: 24 February 2010 / Published: 25 February 2010
Cited by 20 | PDF Full-text (512 KB) | HTML Full-text | XML Full-text
Abstract
Nanocomposites made up of polymer matrices and carbon nanotubes are a class of advanced materials with great application potential in electronics packaging. Nanocomposites with carbon nanotubes as fillers have been designed with the aim of exploiting the high thermal, electrical and mechanical properties
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Nanocomposites made up of polymer matrices and carbon nanotubes are a class of advanced materials with great application potential in electronics packaging. Nanocomposites with carbon nanotubes as fillers have been designed with the aim of exploiting the high thermal, electrical and mechanical properties characteristic of carbon nanotubes. Heat dissipation in electronic devices requires interface materials with high thermal conductivity. Here, current developments and challenges in the application of nanotubes as fillers in polymer matrices are explored. The blending together of nanotubes and polymers result in what are known as nanocomposites. Among the most pressing current issues related to nanocomposite fabrication are (i) dispersion of carbon nanotubes in the polymer host, (ii) carbon nanotube-polymer interaction and the nature of the interface, and (iii) alignment of carbon nanotubes in a polymer matrix. These issues are believed to be directly related to the electrical and thermal performance of nanocomposites. The recent progress in the fabrication of nanocomposites with carbon nanotubes as fillers and their potential application in electronics packaging as thermal interface materials is also reported. Full article
(This article belongs to the Special Issue Composite Materials)

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