http://www.mdpi.com/journal/materials/special_issues/nanomat-preparation/ Dear Colleagues, The targeted synthesis of functional nanomaterials is an essential and challenging task for the development of a future nanotechnology. Especially for complex and tailored materials, the simultaneous control of particle size/morphology, structure and composition requires highly tunable synthetic routes, because these features are often decisive for the construction of new nanoscale devices. Developing new preparative ways towards nanomaterials thus requires a creative interaction between synthetic chemists and specialists from neighbouring disciplines. With this Special Issue of “Materials”, we present a survey of recent developments in this field. The interdisciplinary potential of designing nanomaterials for new applications is tremendous and with our selection of articles, we demonstrate how nanomaterials synthesis is currently revolutionizing the well-known laboratory practices in chemistry. While heading for new types of synergistic materials and composites, scientists in the field keep crossing the borders between the “classical” disciplines of chemistry. Although the role of nanomaterials preparation as a “melting pot” for a multitude of synthetic techniques has led to remarkable innovations and breakthroughs, we do not want to conceal the fact that many of these processes still remain to be fully understood from the mechanistic point of view. However, the liveliness and creativity of nanoscientists has brought forward sophisticated approaches over the past years to grasp and to control the complexity of synthetic processes with various in-situ and ex-situ techniques. We hope that this Special Issue is an enjoyable reading and an inspiration for many scientists to dive into the fascinating world of nanomaterials and to contribute their special skills and views to this world-wide community. Prof. Dr. Greta R. Patzke Guest Editor Submission All manuscripts should be submitted to materials@mdpi.com with a copy to the Guest Editor. Manuscripts can be submitted until the deadline. Papers will be published continuously (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website. Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are refereed through a peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Materials is an international peer-reviewed Open Access monthly journal published by MDPI. Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this Open Access journal is 800 CHF per accepted paper. http://www.mdpi.com/1996-1944/3/11/4871/ The catalytic chemical vapor deposition (CCVD) is currently the most flexible and economically attractive method for the growth of carbon nanotubes. Although its principle is simple, the precisely controlled growth of carbon nanotubes remains very complex because many different parameters influence the growth process. In this article, we review our recent results obtained on the synthesis of carbon nanotubes via CCVD. We discuss the role of the catalyst and the catalyst support. Our recent results obtained from the water assisted growth and the equimolar C2H2-CO2 reaction are also discussed. Both procedures lead to significantly enhanced carbon nanotube growth. In particular, the latter allows growing carbon nanotubes on diverse substrate materials at low temperatures. http://www.mdpi.com/1996-1944/3/11/4871/ Mon, 01 Nov 2010 00:00:00 CET Materials 2010-11-01 3 11 Review 4871 4891 1996-1944 Catalytic CVD Synthesis of Carbon Nanotubes: Towards High Yield and Low Temperature Growth 2010-11-01 doi: 10.3390/ma3114871 Arnaud Magrez Jin Won Seo Rita Smajda Marijana Mionić László Forró http://www.mdpi.com/1996-1944/3/8/4428/ Numerous examples of closed-cage nanostructures, such as nested fullerene-like nanoparticles and nanotubes, formed by the folding of materials with layered structure are known. These compounds include WS2, NiCl2, CdCl2, Cs2O, and recently V2O5. Layered materials, whose chemical bonds are highly ionic in character, possess relatively stiff layers, which cannot be evenly folded. Thus, stress-relief generally results in faceted nanostructures seamed by edge-defects. V2O5, is a metal oxide compound with a layered structure. The study of the seams in nearly perfect inorganic "fullerene-like" hollow V2O5 nanoparticles (NIF-V2O5) synthesized by pulsed laser ablation (PLA), is discussed in the present work. The relation between the formation mechanism and the seams between facets is examined. The formation mechanism of the NIF-V2O5 is discussed in comparison to fullerene-like structures of other layered materials, like IF structures of MoS2, CdCl2, and Cs2O. The criteria for the perfect seaming of such hollow closed structures are highlighted. http://www.mdpi.com/1996-1944/3/8/4428/ Wed, 18 Aug 2010 00:00:00 CEST Materials 2010-08-18 3 8 Article 4428 4445 1996-1944 Stability Criteria of Fullerene-like Nanoparticles: Comparing V2O5 to Layered Metal Dichalcogenides and Dihalides 2010-08-18 doi: 10.3390/ma3084428 Roi Levi Maya Bar-Sadan Ana Albu-Yaron Ronit Popovitz-Biro Lothar Houben Yehiam Prior Reshef Tenne http://www.mdpi.com/1996-1944/3/8/4355/ A wide variety of nanoscale hollow spheres can be obtained via a microemulsion approach. This includes oxides (e.g., ZnO, TiO2, SnO2, AlO(OH), La(OH)3), sulfides (e.g., Cu2S, CuS) as well as elemental metals (e.g., Ag, Au). All hollow spheres are realized with outer diameters of 10-60 nm, an inner cavity size of 2-30 nm and a wall thickness of 2-15 nm. The microemulsion approach allows modification of the composition of the hollow spheres, fine-tuning their diameter and encapsulation of various ingredients inside the resulting “nanocontainers”. This review summarizes the experimental conditions of synthesis and compares them to other methods of preparing hollow spheres. Moreover, the structural characterization and selected properties of the as-prepared hollow spheres are discussed. The latter is especially focused on container-functionalities with the encapsulation of inorganic salts (e.g., KSCN, K2S2O8, KF), biomolecules/bioactive molecules (e.g., phenylalanine, quercetin, nicotinic acid) and fluorescent dyes (e.g., rhodamine, riboflavin) as representative examples. http://www.mdpi.com/1996-1944/3/8/4355/ Thu, 12 Aug 2010 00:00:00 CEST Materials 2010-08-12 3 8 Review 4355 4386 1996-1944 Nanoscale Hollow Spheres: Microemulsion-Based Synthesis, Structural Characterization and Container-Type Functionality 2010-08-12 doi: 10.3390/ma3084355 Henriette Gröger Christian Kind Peter Leidinger Marcus Roming Claus Feldmann http://www.mdpi.com/1996-1944/3/8/4175/ A wide range of vanadium oxides have been obtained via the hydrothermal treatment of aqueous V(V) solutions. They exhibit a large variety of nanostructures ranging from molecular clusters to 1D and 2D layered compounds. Nanotubes are obtained via a self-rolling process while amazing morphologies such as nano-spheres, nano-flowers and even nano-urchins are formed via the self-assembling of nano-particles. This paper provides some correlation between the molecular structure of precursors in the solution and the nanostructure of the solid phases obtained by hydrothermal treatment. http://www.mdpi.com/1996-1944/3/8/4175/ Mon, 02 Aug 2010 00:00:00 CEST Materials 2010-08-02 3 8 Review 4175 4195 1996-1944 Hydrothermal Synthesis of Nanostructured Vanadium Oxides 2010-08-02 doi: 10.3390/ma3084175 Jacques Livage http://www.mdpi.com/1996-1944/3/3/2069/ Two new mesogenic monomers, namely 3,3’-dimethoxy-4,4’-di(hydroxyhexoxy)-N-benzylidene-o-Tolidine (Ia) and 4,4’-di(6-hydroxyhexoxy)-N-benzylidene-o-Tolidine (IIa), were reacted with cadmium sulfide (CdS) via an in situ chemical precipitation method in ethanol to produce CdS nanocomposites. A series of different mass compositions of CdS with Ia and IIa ranging from 0.1:1.0 to 1.0:1.0 (w/w) were prepared and characterized using X-ray Diffraction (XRD), Raman spectroscopy, Fourier Transform Infrared Spectroscopy (FT-IR), Transmission Electron Microscopy (TEM), Polarizing Optical Microscopy (POM) and Differential Scanning Calorimetry (DSC), X-ray Photoelectron Spectroscopy (XPS) and Photoluminescence Spectroscopy (PL). XRD showed that the broad peaks are ascribed to the formation of cubic CdS nanoparticles in both Ia and IIa. The average particle size for both nanocomposites was less than 5 nm with a narrower size distribution when compared with pure CdS nanoparticles. The analyses from POM and DSC demonstrated that mass composition from 0.1:1.0 up to 0.5:1.0 of CdS:Ia nanocomposites showed their enantiotropic nematic phase. On the other hand, polarizing optical microscopy (POM) for IIa nanocomposites showed that the liquid crystal property vanished completely when the mass composition was at 0.2:1.0. PL emissions for CdS: Ia or IIa nanocomposites indicated deep trap defects occurred in these both samples. The PL results revealed that addition of CdS to Ia monomers suppressed the photoluminescence intensity of Ia. However, the introduction of CdS to IIa monomers increased the photoluminescence and was at a maximum when the mass composition was 0.3:1.0, then decreased in intensity as more CdS was added. The XPS results also showed that the stoichiometric ratios of S/Cd were close to 1.0:1.0 for both types of nanocomposites for a mass composition of 1.0:1.0 (CdS:matrix). http://www.mdpi.com/1996-1944/3/3/2069/ Fri, 19 Mar 2010 00:00:00 CET Materials 2010-03-19 3 3 Article 2069 2086 1996-1944 Thermal and Optical Properties of CdS Nanoparticles in Thermotropic Liquid Crystal Monomers 2010-03-19 doi: 10.3390/ma3032069 Lee Mohammed Belmahi Assouar Rinnert Alnot