Synthesis Of Inorganic Materials Research Articles

Rational Approaches toward the Design and Synthesis of Zeolitic Inorganic Open-Framework Materials

Since the first synthesis of zeolites in 1940s, these materials and related inorganic open-framework materials with regular nanoporous space have attracted considerable interest. Zeolites are important for catalysis, adsorption, and ion-exchange, and researchers are finding new applications for these materials in optics, electronics, sensors, and medicine. In particular, the petrochemical industry is interested in the synthesis of new zeolite catalysts with high catalytic activity and selectivity. Using hydrothermal, solvothermal, and the recently-developed ionothermal methods, researchers have prepared 194 types of zeolites and thousands of zeolite-related inorganic open-framework materials. However, their syntheses are based primarily on an empirical "trial-and-error" method. The rational synthesis of zeolitic inorganic open-framework materials, while targeting novel structures and functions, remains a formidable task. The challenge in rational synthesis lies in the unknown mechanism for their formation: the relationship between the synthetic parameters and structural characteristics of the products is not clear. In an effort to overcome these challenges, our group has built up a ZEOBANK, a database of zeolite structures and a database for their synthesis. ZEOBANK allows us to use data mining to find new methods for guiding the synthesis of zeolitic materials. In this Account, we describe our efforts to rationally synthesize zeolitic inorganic open-framework materials with desired structures and present computational methods for the design of these structures. In particular, we focus on the design of zeolites with desired pore geometries through constrained assembly of atoms around the predefined channels in the unit cell. Our approaches toward rational synthesis include the use of template to direct the structure, the use of heteroatoms as a framework substituent, and the use of computational data mining. Employing these strategies, we have developed innovative methods toward the synthesis of target structures with specific channel structures, such as extra-large pores and chiral channels. We expect that further data mining will increase the synthetic control for researchers interested in designing functional zeolitic materials.

ChemInform Abstract: Functionalized Emulsion and Suspension Polymer Particles: Nanoreactors for the Synthesis of Inorganic Materials.

Cross-linked acrylic emulsion polymers are prepared from ethyl acrylate, methacrylic acid, and allyl methacrylate in aqueous media. The carboxylate groups on these polymers readily form ionic complexes with cation species. These cation-loaded polymers can be burned in air to yield pure oxides at temperatures as low as 150 °C. In an analogous fashion, commercially available suspension particles composed of styrene and divinylbenzene can be functionalized by reacting with sulfuric acid. The resultant sulfonic groups have a different selectivity for cation species. This novel synthetic technique may be used with most metallic elements, and it is demonstrated here for the formation of ZrO2, CeO2, LiMn2O4, and Ba2YCu3O7, as well as catalysts in the Au/Pt and Pt/CeO2 systems. The rapid, intimate mixing of metal ions results in low formation temperatures of nanosized materials, and the myriad of potential processing techniques enables isolation of inorganic oxide powders, precipitation of isolated inorganic clus...

C12mimBr Ionic Liquid/SDS Vesicle Formation and Use As Template for the Synthesis of Hollow Silica Spheres

The phase behavior of an aqueous catanionic surfactant system, composed of a long-chain imidazolium ionic liquid 1-dodecyl-3-methylimidazolium bromide (C(12)mimBr) and sodium dodecyl sulfate (SDS), is described. The phase diagram of the catanionic system was determined by electrical conductivity measurements and the formation of vesicles in a birefringent L(alpha) phase characterized by transmission electron microscopy (TEM) and freeze-fracture transmission electron microscopy (FF-TEM). Rheological measurements were used to characterize the macroscopic properties of the birefringent L(alpha) phase. Both electrostatic and hydrophobic interactions contribute to the vesicle formation in the catanionic system. Compared to the DTAB/SDS aqueous solution, differences between the imidazolium and trimethylammonium headgroups geometric packing and charge density induce the different phase behavior in each system. Silica hollow spheres, with diameters 30-60 nm and a wall thickness of 8-10 nm, were prepared by using the vesicles as the templates. The hollow silica spheres were characterized by TEM, scanning electron microscopy (SEM), and nitrogen adsorption-desorption. The results suggest additional application for ionic liquid based vesicles to be used as templates for the synthesis of hollow inorganic materials.

Microfluidic Synthesis of Polymer and Inorganic Particulate Materials

This article reviews recent developments in the microfluidic preparation of different types of particles made of polymeric and inorganic materials. We discuss control of the particle sizes, morphologies, shapes, and structures in terms of various features of microfluidic synthesis.

Fabrication of lead tungstate microcrystals on a lead surface at room temperature

A new strategy has been successfully designed to synthesize lead tungstate (PbWO 4) microcrystals on a lead surface by employing a novel solution-phase approach at room temperature. This method consists of a liquid–solid reaction between Na 2WO 4 solution and lead substrate itself in the assistance of glycine, l-glutamic acid, sodium citrate, or sodium adipic acid, respectively. The existence of these organic molecules plays an important role in the current synthetic process (serves as a growth promoter and organic structure-directing agent). This approach provides a facile strategy to produce PbWO 4 microcrystals on a lead substrate, which may be applicable to the synthesis of other inorganic materials on other metal substrates with various potential applications.

Book Review of Inorganic Materials Synthesis and Fabrication

Inorganic Materials Synthesis and Fabrication provides an introduction to all that is solid-state inorganic materials. From chapters on crystallographic factors and chemical energetics to comprehensive chapters on synthetic methods in the gas, liquid, and solid states, to final chapters covering synthesis and fabrication techniques of nanomaterials, this text covers it all. The authors start with a fast-paced chapter on the importance of structure in determining the bulk properties of a solid and the use of crystallography in determining solid-state structures. The second chapter is a whirlwind discussion of chemical energetics with sections on equilibrium and nonequilibrium thermodynamics, bulk and surface energy considerations, and phase transformation kinetics. While well written, these two chapters are not for the novice. It is assumed that the reader has considerable familiarity with physical methods and chemical principles. The authors express their philosophy of the first two chapters best in an excerpt from a section on phase diagrams: “The following brief introduction is meant merely to encourage the reader to refer to any one of several available texts that offer r2010 American a range from introductory to comprehensive coverage of all aspects of phase equilibria”. The real gems of the text are the middle three chapters on solid-vapor reactions, solid-liquid reactions, and solid-solid reactions, respectively. If you are new to inorganic materials synthesis, you will find these chapters helpful in guiding your research endeavors. The physical and chemical considerations involved in each type of synthetic method are covered in sufficient detail to give the reader an appreciation of the overall picture. Each chapter begins with a discussion of the fundamentals of the synthetic method under consideration followed by examples to illustrate key points. The authors do a good job defining terms and using figures to clarify synthetic techniques. The tour concludes with chapters on nanomaterials synthesis and materials fabrication. The nanomaterials chapter succinctly covers both top-down physical fabrication and bottom-up chemical synthesis methodologies for nanomaterials. The final chapter provides an introduction to common fabrication techniques and an explanation of how the method of fabrication can influence the performance and suitability of a material for a specific application. Overall, the text is well written. A unique feature is the inclusion of biographical sketches of individuals who have made important contributions to the synthesis and characterization of inorganic materials. The sketches are brief, usually less than one page, but provide an often-overlooked part of science and discovery: the human aspect. Each chapter ends with an extensive list of references for the reader who seeks further clarification on a topic. Using the text as a supplement in a graduate-level special topics course on inorganic materials is conceivable. A more likely use is as a reference for the professional chemist, physicist, material scientist, or engineer interested in starting research projects in the field of inorganic solid-state materials.

Yttria stabilized zirconia synthesis in supercritical CO 2: Understanding of particle formation mechanisms in CO 2/co-solvent systems

The increasing interest of supercritical (SC) fluids for inorganic materials synthesis recently stimulated the development of innovative synthesis processes and strategies. The supercritical CO 2 aided sol–gel process, developed for preparing various ceramic oxide powders with attractive applications in cosmetics, chromatography, catalysis or solid oxide fuel cells, usually suffer from both reproducibility problems and poor knowledge of the key parameters defining the final powder characteristics. In the present work a specific effort has been put on the understanding of reaction mechanisms and process parameters like co-solvent polarity and ageing time of the starting solution, which appeared to play a crucial role for the control of powder characteristics. Two different reaction mechanisms have been proposed to explain the formation of tetragonal yttria-doped zirconia powders by a batch process in either CO 2/pentane or CO 2/isopropanol mixtures. The first mechanism corresponds to a CO 2 anti-solvent precipitation process while the other one is based on a condensation reaction as in the conventional sol–gel process. This improved understanding in particle formation allows better control of powder characteristics and reproducibility.

Inorganic Hybrid Materials with Encapsulated Polyoxometalates

This review describes the synthesis and characterization of inorganic materials containing polyoxometalates encapsulated in oxide matrices. Examples illustrating key aspects in terms of synthesis and applications are presented according to the nature of the final hybrid material: those based on non-structured silicas, on mesostructured silicas, on macrostructured silicas and on other oxides. In each part, key points of the synthetic protocols are highlighted and structural features and properties of the resultant hybrid nanocomposites are discussed.

Modelling of mass transfer coupling with crystallization kinetics in microscale

Microstructure technologies have attracted interests in chemistry, chemical engineering, and biotechnology. To investigate the mass transfer of ions and crystallization of crystals in microscale and then to explain the formation mechanism of the porous structure materials, a microscale mathematical model for mass transfer processes coupling with local reactions is proposed in which the chemical potential gradient Δ μ is used as the driving force to avoid the discontinuity of the kinetics equations in the micro-channels. Meanwhile, the dissolution kinetics of KCl at 298.15 K is measured to determine the dissolution rate constant k d and the average area of crystals Ac. The investigation for the fractional crystallization process of carnallite shows that the calculated mixing time versus channel width agree with the Einstein diffusion equation, which validates that the model can be used to describe the ion diffusion very well. Meanwhile, to have an accurate Δ μ of KCl, in the channel width of or narrower than 2.0×10 −6 m, it is enough to consider the diffusion only, while in the channel width of or wider than 2.0×10 −5 m, diffusion should be coupled with reaction. The investigation also shows the vital of the consideration of the ionic activity coefficient for the investigated systems in micron scales. Moreover, the new formation mechanism of the porous structures in the inorganic material fabrication will be proposed from the process simulation for the synthesis of porous KCl, which will provide a reference for the porous structure formation in the advanced inorganic material synthesis.

Mineralization of calcite ribbons on an Allium fistulosum L. bulb inner membrane in an ethanol–water mixed solvent under control of polyacrylic acid by a double diffusion method

This paper describes the mineralization and morphosynthesis of CaCO3 on an Allium fistulosum L. bulb inner membrane by a double diffusion method and exhibits some ingenious structures of CaCO3 formed on both surfaces of the bulb membrane. Novel calcite ribbons with smooth surfaces and film coatings consisting of petal-like building blocks have been synthesized on the inner and outer surface of the bulb membrane when two surfaces faced CaCl2 solution, respectively. The presence of polyacrylic acid (PAA), a suitable pH value and the mixed solvent system are the key primary conditions for the formation of calcite ribbons. The surface of the bulb membrane acted as an insoluble matrix providing nucleation sites for CaCO3 crystals with different morphologies. The present double diffusion method involved using a plant system and its combination with a polyelectrolyte in a mixed solvent system provides a versatile, mild and flexible tool to control the size and shape of CaCO3 crystals, which may be extended for synthesis of other inorganic materials.

Preparation of Inorganic Materials Using Ionic Liquids

Conventional synthesis of inorganic materials relies heavily on water and organic solvents. Alternatively, the synthesis of inorganic materials using, or in the presence of, ionic liquids represents a burgeoning direction in materials chemistry. Use of ionic liquids in solvent extraction and organic catalysis has been extensively studied, but their use in inorganic synthesis has just begun. Ionic liquids are a family of non-conventional molten salts that can act as templates and precursors to inorganic materials, as well as solvents. They offer many advantages, such as negligible vapor pressures, wide liquidus ranges, good thermal stability, tunable solubility for both organic and inorganic molecules, and much synthetic flexibility. In this Review, the use of ionic liquids in the preparation of several categories of inorganic and hybrid materials (i.e., metal structures, non-metal elements, silicas, organosilicas, metal oxides, metal chalcogenides, metal salts, open-framework structures, ionic liquid-functionalized materials, and supported ionic liquids) is summarized. The status quo of the research field is assessed, and some future perspectives are furnished.

Materials Science: State of the Art 2010

Each week, Advanced Materials brings you a Review of a cutting-edge topic in materials science, accompanied by a number of short Communications. This issue, however, is different. For the first time, we have selected eight review articles written by leaders in their respective fields to survey what we believe to be the state of the art in materials science in early 2010. From molecular electronics to biomaterials, solar cells to inorganic structures, we hope these reviews will provide an overview of some of the most exciting advances being made in materials science as we enter the second decade of the 20th century. As featured on the cover of this issue, Wenping Hu and Daoben Zhu (Insitute of Chemistry, Chinese Academy of Sciences) review ten years of progress in the development of nanogap electrodes. Electrodes with a nanometer gap can be used for the study of nanometer- and molecular-scale phenomena. Single-molecule transistors, carbon nanotube electrodes, DNA nanowires, and more have all been studied using this technique, and the authors predict a bright future for the field as challenges in reliable electrode manufacture and determining the number of molecules between a nanogap are met and overcome. A major theme in molecular electronics has been the study of single-molecule junctions. While this facilitates theoretical modeling, researchers have faced issues with reproducibility. Ayelet Vilan and David Cahen of the Weizmann Institute of Science and Antoine Kahn of Princeton review ensemble molecular junctions. The study of large, two-dimensional molecular monolayers on silicon has resulted in high-quality, reproducible systems for the study of charge transport mechanisms and energy levels in such hybrid systems. High-efficiency intermediate band solar cells are reviewed by Antonio Luque and Antonio Martí (Universidad Politécnica de Madrid). Since the first report of the concept more than a decade ago, their maximum theoretical efficiency of 63% has proven a tempting target, and work on systems based on quantum dots and on IB alloys have been pursued. Significant progress has been made, and further work on improving the efficiency might lead to low-cost, high-efficiency thin photovoltaics. David Kaplan (Tufts) examines the state of the art in bio-microfluidics: the application of biomaterials and bioinspired design to microfluidics. Biopolymers such as silk or fibroin can replace polydimethylsiloxane and be functionalized with bioactive or stimuli-responsive components. In the future, a bio-microfluidic system might be designed to interface with existing vasculature, disintegrating over time to be replaced with native tissue, resulting in engineered tissue with enhanced transport properties during its development. The incorporation of stem cells into strategies for tissue engineering requires better understanding of the interactions of stem cells with their synthetic environment. To this end, Jason Burdick (University of Pennsylvania) reviews how materials influence stem cell differentiation. The material structure, the chemistry, and the presentation and delivery of differentiation factors influence the differentiation of mensenchymal stem cells, as can control of the cell morphology and the mechanical properties and interactions of the surrounding matrix. Stem cells are sensitive to their microenviroments, and rationally controlling many different variables in a tissue engineering scaffold will be critical for complex regenerative medicine challenges. Rainer Haag and co-workers comprehensively discuss recent progress in developing dendritic polyglycols for biomedical applications. The well-defined structure, monodispersity, and tunable surface functionality of dendrimers, coupled with the non-recognition of polyols by the immune system, make these structures interesting targets for development of nanomedical applications. Metal oxides present a stunningly broad range of structural, electronic, optical, and magnetic properties, making them critical for technological applications as well as presenting fundamental materials science issues. In his review, Scott Chambers (Pacific Northwest National Laboratory) discusses crystalline oxide film growth and, in particular, examines doped transition metal oxides and complex oxides, giving examples where fundamental understanding of the properties has elucidated structure-function relationships. Finally, while applications of ionic liquids for solvent extraction and organic catalysis are well know, the use of ionic liquids for inorganic material synthesis is less than a decade old. As featured on the inside cover of this issue, Sheng Dai (Oak Ridge National Laboratory) and co-workers review progress in ionic liquid mediated synthesis of metal and non-metal nanoparticles, porous silica, metal oxides, metal chalcogenides, porous frameworks, and materials functionalized with ionic liquids.

ChemInform Abstract: Solvothermal Synthesis of Inorganic Materials and Their Performance as Catalysts

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Polyelectrolyte mediated formation of hydroxyapatite microspheres of controlled size and hierarchical structure

The understanding of the role of polyelectrolytes in the synthesis of inorganic materials could provide effective routes towards design of advanced materials. In this study, negatively charged poly(styrene sulfonate) (PSS) is employed as a modifier in hydrothermal synthesis of hydroxyapatite (HA). The results indicate that both the morphology and particle size could be well controlled by adjusting the PSS concentration. The presence of PSS (within the range of 0–9.6 wt%) modified the growth pattern of HA crystallites and results in particles from the ribbons to microspheres. The building units of various microspheres change from nanofibers to nanorods or nanoplates. Along with that, the microspheres become smaller and more compact at higher PSS concentrations. The adsorption of PSS onto certain crystal faces as well as the complexing effect of PSS with Ca 2+ can be considered as the controlling factors which determine the influence of PSS on the growth mode. The drug release study indicates that the flower-like HA microspheres can be possibly used as effective carriers for biomedical applications. The present synthesis method is simple and controllable, and can provide a convenient route to synthesize uniform HA microspheres with different sizes and hierarchical structures.

UTILIZATION OF ALUMINA RED MUD FOR SYNTHESIS OF INORGANIC POLYMERIC MATERIALS

Red mud is a residue coming from the metallurgical treatment of bauxite with the Bayer process. Million of tons of red mud are produced annually worldwide and disposed of on land, degrading vast areas. Therefore, red mud utilization is a first-priority issue for any alumina plant. In the present work, the potential use of red mud for synthesis of inorganic polymeric materials through geopolymerization process was studied. The main focus was the production of inorganic polymeric materials that could be used in the construction sector as artificial structural elements such as massive bricks. The geopolymerization process involves a chemical reaction between red mud and alkali metal silicate solution under highly alkaline conditions. The product of this reaction is an amorphous to semi-crystalline polymeric structure, which binds the individual particles of red mud transforming the initial granular material to a compact and strong one. The effect of main synthesis parameters—like solid-to-liquid ratio, caustic soda as well as soluble silica concentrations, and metakaolin addition—on the properties of red mud-based inorganic polymeric materials was investigated. The results showed that the produced materials have high compressive strength, very low water absorption, satisfactory apparent density, and excellent fire resistance. Therefore, this work proved that the red mud-based inorganic polymeric materials have promising properties and have the potential to be used as artificial structural elements in the construction sector.

Solvent effects in the synthesis process of tin oxide

Water is the most frequently used solvent in the chemical synthesis of inorganic materials where hydrolysis and condensation are the main reactions. In this work, we synthesized tin oxide nanoparticles using ethanol or acetic acid as a solvent by the controlled precipitation method. The main physicochemical phenomena that take place during the synthesis process and the possible reactions that led to the formation of the particles in the solution are described. The ceramic powder obtained was characterized by X-ray diffraction (XRD), thermal analysis, infrared (IR) spectroscopy and transmission electron microscopy (TEM). Interestingly, Romarchite SnO was the main crystalline phase obtained when acetic acid was used as solvent.

Honey mediated green synthesis of gold nanoparticles

Bio-directed synthesis of nanoparticles is of interest to biologists, chemists and materials scientists alike, especially in light of efforts to find greener methods of inorganic material synthesis. Though the biosynthesis of gold nanoparticles has been carried out by several groups of scientists using plants, fungi and bacteria, so far there is no report on the use of natural honey – mankind's only sweetener for centuries – for the synthesis of nanoparticles. Here, it is a report on a greener synthesis of Au nanoparticles using honey as reducing and capping agents. By adjusting the concentrations of HAuCl 4 and honey in aqueous solutions, colloids having a larger propensity of either anisotropic or spherical nanocrystals could be obtained at room temperature. The nanoparticles obtained were characterized by UV–visible spectra, high-resolution TEM and XRD. The spherical particles obtained have a size ∼15 nm as shown by XRD pattern and TEM image. The high crystallinity with fcc phase is evidenced by bright circular spots in SAED pattern and clear lattice fringes in the high-resolution TEM image. FTIR measurements were carried out to identify the possible biomolecules responsible for capping and efficient stabilization of the Au nanoparticles synthesized using honey. The carboxylic acid group vibrations and amide I and II bands indicate the binding of protein with Au surface through the amine group rather than the carboxyl group.

Viruses and protein cages as nanocontainers and nanoreactors

In this highlight, recent studies related to the use of viral capsids and other protein cages as nanocontainers and nanoreactors are discussed. The templating of chemical reactions within these biological hollow scaffolds is an emerging area which has allowed the synthesis of inorganic materials with nanoscale dimensions. Encapsulation of synthetic polymers, enzymes working within viral capsids, and the solubilisation of protein cages in organic solvents are some other examples of research that is currently being performed and reviewed in this article.

Mesoporous materials: tunable structure, morphology and composition

Mesoporous materials with controlled composition and pore characteristics have been extensively investigated during recent decades. The design, synthesis and assembly of building blocks with suitable shapes, length scales and functionalities have led to advances in the control of pore structure and morphology, the tailoring of pore surface chemistry, and the variety of framework composition. Aiming at practical applications, supporting the mesoporous materials with suitable matrices is becoming significant besides pore wall composition. In this feature article, recent progress in the synthesis of inorganic, hybrid and organic mesoporous materials at multiple length scales and morphologies is briefly summarized.

Recent advances in oriented attachment growth and synthesis of functional materials: concept, evidence, mechanism, and future

The latest advances in oriented attachment controlled morphosynthesis and crystal growth of various technically important inorganic materials have been reviewed with the focus on how to generate inorganic micro-/nanostructured materials based on the so-called oriented attachment mechanism. The overview about the basic crystallization principles nowadays falls into two types, i.e., one is the classical crystal growth mode, which is via atom-by-atom additions to an existing nucleus or dissolution of unstable phases and reprecipitation of more stable phases, and the other occurs through particle based aggregation modes involving the process of mesoscopic transformation. The systematic analysis of the particle based aggregation mechanism of oriented attachment in controllable synthesis of functional inorganic materials will be described in particular. Several fashions of attachment are undertaken in the already explored reaction systems, with nanoparticles or nanoribbons as primary building units to form 1D, 2D or 3D structures, and heterostructures. The mechanism of oriented attachment could happen in systems with addition of organic additives or without, demonstrating that organic additives are not the essential factor for this kind of growth mode, which shed new light to intensive understanding of this particular phenomenon. With organic additives, i.e., reactions in organic solvents or in aqueous solution, oriented attachment events can occur too. Current developments in oriented attachment, including the basic principles and potentials with specific examples, indubitably reinforce the understanding of detailed interaction mechanisms between inorganic nanoparticles and their subsequent high order self-assembly mechanism, which are definitely promising for rationally designing various kinds of inorganic materials with ideal hierarchy, controllable length scale, and structures in solution-based systems.