Synthesis Of Inorganic Materials Research Articles

Biomimetically modified chitosan for electrophoretic deposition of composites

A one-step cathodic electrophoretic deposition (EPD) method has been developed for the deposition of chitosan (CHIT) films modified with catechol. Our approach was based on the use of 3,4-dihydroxybenzaldehyde (DHBA) molecules, which contain a catechol moiety for CHIT modification using a Schiff base reaction. We discussed the deposition mechanism as well as advantages of our one-step EPD method, compared to other techniques. It was found that the EPD method allowed the fabrication of redox-active films. A conceptually new strategy has been developed based on the use of CHIT-DHBA as a reducing, capping, dispersing, charging and film forming agent for the in-situ reduction of Ag+ ions, followed by catecholate type bonding of CHIT-DHBA to Ag particles, their electrosteric dispersion and EPD of composite CHIT-DHBA-Ag films. Building on the processing advantages offered by one-step cathodic deposition and remarkable bonding properties of catechol we performed EPD of CHIT-DHBA-hydroxyapatite (HA) and CHIT-DHBA-TiO2 films. Another major finding was the use of CHIT-DHBA for electrosteric co-dispersion and charging of HA and TiO2, followed by EPD of composite CHIT-DHBA-TiO2-HA films. Comprehensive electrochemical and electron microscopy testing was used to characterize the microstructure of the films, as well as the electrochemical properties. The results of this investigation pave the way for the synthesis and agglomerate-free processing of various functional inorganic materials and fabrication of organic-inorganic composites for biomedical, sensor and water purification applications.

DNA-assisted rational design of BaF 2 linear and erythrocyte-shaped nanocrystals

Abstract The synthesis of inorganic materials with special morphologies with the assistance of biological molecules is a potential development in the field of controllable growth and assembly of nanomaterials. In this paper, BaF2 nanocrystals in patterns of well-defined linear and erythrocyte-shaped structure were synthesized with the assistance of Escherichia coli DNA. Morphology and the arrangement of BaF2 particles on DNA were controllable by altering the reaction condition. Square nanoparticles arranged in linear chains were gained with the assistance of normal DNA; while, erythrocyte-shaped BaF2 nanospheres were synthesized with the assistance of denatured DNA. Besides, the influences of solvent, reaction temperature, concentration of reactants and the heating time on the morphology of the BaF2 particles were studied.

Graphene‐Tailored Thermodynamics and Kinetics to Fabricate Metal Borohydride Nanoparticles with High Purity and Enhanced Reversibility

AbstractDue to their ultrahigh theoretical capacity, metal borohydrides are considered to be one of the most promising candidate hydrogen storage materials. Their application still suffers, however, from high operating temperature, sluggish kinetics, and poor reversibility. Designing nanostructures is an effective way of addressing these issues, but seeking suitable approaches remains a big challenge. Here, a space‐confined solid‐gas reaction to synthesize Mg(BH4)2 nanoparticles supported on grapheme is reported, which serves as the structural support for the dispersed Mg(BH4)2 nanoparticles. More notably, density functional theory calculations reveal that graphene could weaken both the MgH bonds of MgH2 and BB bonds of B2H6, which could thermodynamically and kinetically facilitate the chemical transformation to synthesize Mg(BH4)2 with high purity. Because of the synergistic effects of both the significant reduction in particle size and the catalytic effect of graphene, an onset dehydrogenation temperature of ≈154 °C is observed for Mg(BH4)2 nanoparticles, and a complete dehydrogenation could be achieved at a temperature as low as 225 °C, with the formation of MgB2 as the by‐product. This work provides a new perspective to tailoring the thermodynamics and kinetics of chemical reactions toward the favorable synthesis of functional inorganic materials.

Synthesis and characterization of innovative insulation materials

Insulation elements are distinguished in inorganic fibrous and organic foamed materials. Foamed insulation materials are of great acceptance and use, but their major disadvantage is their flammability. In case of fire, they tend to transmit the flame producing toxic gases. In this paper, the synthesis and characterization of innovative inorganic insulation materials with properties competitive to commercial is presented. Their synthesis involves the mixing of inorganic raw material and water with reinforcing agent or/and foaming agent leading to the formation of a gel. Depending on raw materials nature, the insulation material is produced by freeze drying or ambient drying techniques of the gel. The raw material used are chemically benign and abundantly available materials, or industrial by-products and the final products are non-toxic and, in some cases, non-flammable. Their density and thermal conductivity was measured and found 0.02-0.06 g/cm3 and 0.03-0.04 W/mK, respectively.

Applications of Synthetic Biology in Materials Science

Materials are the basis for human being survival and social development. To keep abreast with the increasing needs from all aspects of human society, there are huge needs in the development of advanced materials as well as high-efficiency but low-cost manufacturing strategies that are both sustainable and tunable. Synthetic biology, a new engineering principle taking gene regulation and engineering design as the core, greatly promotes the development of life sciences. This discipline has also contributed to the development of material sciences and will continuously bring new ideas to future new material design. In this paper, we review recent advances in applications of synthetic biology in material sciences, with the focus on how synthetic biology could enable synthesis of new polymeric biomaterials and inorganic materials, phage display and directed evolution of proteins relevant to materials development, living functional materials, engineered bacteria-regulated artificial photosynthesis system as well as applications of gene circuits for material sciences.

Synthesis and characterization of innovative insulation materials

Insulation elements are distinguished in inorganic fibrous and organic foamed materials. Foamed insulation materials are of great acceptance and use, but their major disadvantage is their flammability. In case of fire, they tend to transmit the flame producing toxic gases. In this paper, the synthesis and characterization of innovative inorganic insulation materials with properties competitive to commercial is presented. Their synthesis involves the mixing of inorganic raw material and water with reinforcing agent or/and foaming agent leading to the formation of a gel. Depending on raw materials nature, the insulation material is produced by freeze drying or ambient drying techniques of the gel. The raw material used are chemically benign and abundantly available materials, or industrial by-products and the final products are non-toxic and, in some cases, non-flammable. Their density and thermal conductivity was measured and found 0.02-0.06 g/cm3 and 0.03-0.04 W/mK, respectively.

Nanowires and Nanoparticle Chains Inside Tubular Viral Templates.

One-dimensional (1D) inorganic nanomaterials, especially with magnetic and optical properties, are key components in material synthesis for applications in nanoelectronics, catalysis, and sensing. To achieve these objectives, tubular viral templates are emerging as natural anisotropic bioreactors for the control of the synthesis of inorganic materials with spatial confinement. In particular, tobacco mosaic virus (TMV) with a longitudinal cylinder shape provides a defined narrow cavity to direct the controllable synthesis of 1D inorganic nanomaterial. Based on the understanding of biological characteristics of viral capsids, we can introduce genetic modifications to tailor the arrangement of functional motifs for specific electroless deposition. Here we present an overview of methods for the utilization of the TMV-derived interior surface to realize spatially selective chemisorption, nucleation, and growth of nanocrystals into nanowires and nanoparticle chains.

Microwave-assisted synthesis of nanocrystalline binary and ternary metal oxides

ABSTRACTInterplay of chemistry and nanotechnology has effectively substantiated the ever-expanding horizons of materials chemistry, leading to a paradigm shift in (nano)materials synthesis. Current challenges of chemically processed materials include efforts to redesign synthetic procedures by using less hazardous starting materials, choosing milder reaction conditions, shortening time scale of chemical transformations and most importantly reduction of energy requirements. In this context, successful substitution of classical energy input by microwave radiation is a promising alternative in most fields of common chemical synthesis. This review highlights the latest developments in the synthesis of advanced inorganic materials by microwave-assisted chemical reactions. When compared to conventional convective and conductive heating techniques, microwave irradiation provides efficient internal volumetric heating through generation of localised high temperature zones in the reaction media by direct coupling of microwave energy to the molecules present in the reaction mixture, thereby enabling rapid synthesis with superior yield and both reduced reaction time as well as processing steps.Abbreviations: [BMIM]BF4: 1-butyl-3-methylimidazolium tetrafluoroborate; [C2mim][NTf2]: 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide; [C4mim][NTf2]: 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide; [C12Py][ClO4]: N-dodecylpyridinium perchlorate; [OMIM]TA: 1-octyl-3-methylimidazolium trifluoroacetate; AAO: anodic aluminium oxide; acac: acetylacetone; CNCs: colloidal nanocrystal clusters; CTAB: cetrimonium bromide; DEG: diethylene glycol; EDA: ethylenediamine; EG: ethylene glycol; EGMM: 2-methoxyethanol; FESEM: field emission scanning electron microscopy; FTO: fluorine-doped tin oxide; h: hours; HMT: hexamethylenetetramine; HR-TEM: high-resolution transmission electron microscopy; HPC: hydroxypropyl cellulose; IL: ionic liquids; ITO: indium tin oxide; MEA: ethanolamine; min: minutes; MPA: 3-mercaptopropionic acid; MW: microwave; nm: nanometre; NMP: n-methyl-2-pyrrolidon; OP: p-octyl polyethylene glycol phenylether; P(VP-NVP-St): polyvinylpyrrolidone-polyvinylpyrrolidone-polystyrene; P-103: polyethyleneoxide–polypropyleneoxide–polyethyleneoxide copolymer; PAA: polyacrylic acid; PC: polycarbonate; PEG: polyethylene glycol; PEG-PPO-PEG: poly(ethylene glycol-poly(p-phenyleneoxide)-poly(ethylene glycol); PET: polyethylene terephthalate; Pluronic P123: triblock copolymer; poly(ethyleneglycol)-block-poly(propyleneglycol)-block-poly(ethylene glycol); Pluronic F127: poloxamer; PPO: poly(p-phenyleneoxide); PS(540)-b-PEO(220): polystyrene-block-poly(ethyleneoxide) diblock copolymer with 540 monomerunits of styrene and 220 monomer units of ethylene oxide; PVA: polyvinyl alcohol; PVP: polyvinylpyrrolidone; QDs: quantum dots; R: ratio; s: seconds; SBA-15: Santa Barbara Amorphous-15 (mesostructured silica); SDBS: sodium dodecylbenzenesulfonate; SDS: sodium dodecyl sulphate; tan δ: dielectric loss factor; TBAH: tetrabutylammonium hydroxide; TEAB: tetraethylammonium bromide; TEG: triethylene glycol; TEM: transmission electron microscopy; TMAH: tetramethylammonium hydroxide; TMP: 2,2,6,6-tetramethylpiperidine; TOPO: trioctyl phosphine oxide; TTIP: titanium isopropoxide

Synthesis and luminescent properties of uniform monodisperse LuPO4:Eu3+/Tb3+ hollow microspheres.

Uniform monodisperse LuPO4:Eu3+/Tb3+ hollow microspheres with diameters of about 2.4 µm have been successfully synthesized by the combination of a facile homogeneous precipitation approach, an ion-exchange process and a calcination process. The possible formation mechanism for the hollow microspheres was presented. Furthermore, the luminescence properties revealed that the LuPO4:Eu3+ and LuPO4:Tb3+ phosphors show strong orange-red and green emissions under ultraviolet excitation, respectively, which endows this material with potential application in many fields, such as light display systems and optoelectronic devices. Since the synthetic process can be carried out at mild conditions, it should be straightforward to scale up the entire process for large-scale production of the LuPO4 hollow microspheres. Furthermore, this general and simple method may be of much significance in the synthesis of many other inorganic materials.

Bi12O17Cl2/(BiO)2CO3 Nanocomposite Materials for Pollutant Adsorption and Degradation: Modulation of the Functional Properties by Composition Tailoring.

Bi12O17Cl2/(BiO)2CO3 nanocomposite materials were studied as bifunctional systems for depuration of wastewater. They are able to efficiently adsorb and decompose rhodamine B (RhB) and methyl orange (MO), used as model pollutants. Bi12O17Cl2/(BiO)2CO3 nanocomposites were synthesized at room temperature and ambient pressure by means of controlled hydrolysis of BiCl3 in the presence of a surfactant (Brij 76). Cold treatments of the pristine samples with UV light or thermal annealing at different temperatures (370–500 °C) and atmospheres (air, Ar/30% O2) were adopted to modulate the relative amounts of Bi12O17Cl2/(BiO)2CO3 and hence the morphology, surface area, ζ-potential, optical absorption in the visible range, and the adsorption/degradation of pollutants. The best performance was achieved by (BiO)2CO3-rich samples, which adsorbed 80% of MO and decomposed the remaining 20% by visible light photocatalysis. Irrespective of the dye, all of the samples were able to almost complete the adsorption step within 10 min contact time. Bi12O17Cl2-rich composite materials displayed a lower adsorption ability, but thanks to the stronger absorption in the visible range they behaved as more effective photocatalysts. The obtained results evidenced the ability of the employed strategy to modulate sample properties in a wide range, thus pointing out the effectiveness of this approach for the synthesis of multifunctional inorganic materials for environmental remediation.

Preparation of magnesium aluminate spinel by self-propagating high-temperature synthesis metallurgy methods

Experimental data are presented on the high-temperature synthesis of cast inorganic materials in the MgO–Al2O3 system. Experiments were carried out in multipurpose self-propagating high-temperature synthesis (SHS) reactors at an argon pressure p = 5 MPa. The starting mixtures used in the experiments consisted of molybdenum(VI) and magnesium(II) oxides and aluminum. It has been shown that, varying synthesis parameters, one can control the phase composition and microstructure of the final oxide products. We have optimized synthesis conditions for the preparation of single-phase magnesium aluminate spinel, MgAl2O4. The SHS products have been characterized by X-ray diffraction and local microstructural analysis.

First report on soapnut extract-mediated synthesis of sulphur-substituted nanoscale NdFeB permanent magnets and their characterization

Biosynthesis of nanoscale materials has its own advantages over other physical and chemical methods. Using soapnut extract as reducing and stabilizing agent for the synthesis of inorganic nanoscale materials is novel and has not been exploited to its potential so far. Herein, we report for the first time on the effects of sulphur substitution on soapnut extract-mediated synthesis of nanoscale NdFeB (S-NdFeB) permanent magnetic powders (Nd 15%, Fe 77.5%, B 7.5% and S with molar ratios: 0.1, 0.2, 0.3, 0.4, and 0.5). To synthesize, a 10 ml of 10% soapnut extract was added to 90 ml of respective chemical composition and heated to 60 °C for 30 min and aged for 24 h. The dried powder was sintered at 500 °C for 1 h. The characterization of the as-prepared nanoscale S-NdFeB magnetic materials was done using the techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersion spectroscopy (EDS), Fourier transform infrared spectroscopy (FT-IR), dynamic light scattering (DLS for size and zeta potential measurements) and vibrating sample magnetometer (VSM)–hysteresis loop studies. The results revealed that particles were highly stable (with a negative zeta potential of 25.7 mV) with irregular and spherical shape (with measured hydrodynamic diameter 6.7 and 63.5 nm). The tetragonal structures of the formed powders were revealed by XRD micrographs. Hysteresis loop studies clearly indicate the effect of S concentration on the enhanced magnetization of the materials.

Influence of fuel type on microwave-enhanced fabrication of KOH/Ca 12 Al 14 O 33 nanocatalyst for biodiesel production via microwave heating

Abstract Microwave irradiation has attracted a great deal of attention when it comes to synthesis of organic and inorganic materials. In the present study, a microwave heating system was utilized to prepare KOH/Ca 12 Al 14 O 33 nanocatalysts via combustion method, so as to produce biodiesel from canola oil. Moreover, the effect of carbon content of fuels such as urea, ammonium acetate, glycerol and diethylene glycol used in the combustion reaction on the properties of the synthesized nanocatalysts was evaluated. The samples were analyzed by XRD, FTIR, TGA, BET-BJH, FESEM, and EDX techniques, with their basicity levels evaluated by Hammett indicator. The results showed that the combustion temperature tends to decrease with an increase in carbon content of fuel. Accordingly, the supports synthesized by urea and ammonium acetate exhibited the best crystalline structures. However, all samples showed Ca 12 Al 14 O 33 structure during impregnation by KOH and calcination step. The samples prepared by urea and ammonium acetate, as fuel, presented appropriate percentages of material-to-parent solution ratio, bringing about higher activities. Among them, the KOH/Ca 12 Al 14 O 33 synthesized by urea had the largest surface area and activity, so that it succeeded to convert 83.5% of canola oil to biodiesel via microwave irradiation at microwave power of 450 W, methanol-to-oil molar ratio of 12, catalyst concentration of 4 wt. %, and reaction time of 60 min. The sample showed high reusability when it was calcined at 700 °C after each round of reaction.

Applications of synthetic biology in materials science

Materials are the basis for human being survival and social development. To keep abreast with the increasing needs from all aspects of human society, there are huge needs in the development of advanced materials as well as high-efficiency but low-cost manufacturing strategies that are both sustainable and tunable. Synthetic biology, a new engineering principle taking gene regulation and engineering design as the core, greatly promotes the development of life sciences. This discipline has also contributed to the development of material sciences and will continuously bring new ideas to future new material design. In this paper, we review recent advances in applications of synthetic biology in material sciences, with the focus on how synthetic biology could enable synthesis of new polymeric biomaterials and inorganic materials, phage display and directed evolution of proteins relevant to materials development, living functional materials, engineered bacteria-regulated artificial photosynthesis system as well as applications of gene circuits for material sciences.

Direct Single-Enzyme Biomineralization of Catalytically Active Ceria and Ceria–Zirconia Nanocrystals

Biomineralization is an intriguing approach to the synthesis of functional inorganic materials for energy applications whereby biological systems are engineered to mineralize inorganic materials and control their structure over multiple length scales under mild reaction conditions. Herein we demonstrate a single-enzyme-mediated biomineralization route to synthesize crystalline, catalytically active, quantum-confined ceria (CeO2-x) and ceria-zirconia (Ce1-yZryO2-x) nanocrystals for application as environmental catalysts. In contrast to typical anthropogenic synthesis routes, the crystalline oxide nanoparticles are formed at room temperature from an otherwise inert aqueous solution without the addition of a precipitant or additional reactant. An engineered form of silicatein, rCeSi, as a single enzyme not only catalyzes the direct biomineralization of the nanocrystalline oxides but also serves as a templating agent to control their morphological structure. The biomineralized nanocrystals of less than 3 nm in diameter are catalytically active toward carbon monoxide oxidation following an oxidative annealing step to remove carbonaceous residue. The introduction of zirconia into the nanocrystals leads to an increase in Ce(III) concentration, associated catalytic activity, and the thermal stability of the nanocrystals.

Mechanistic Investigation of a Dual Bicyclic Photoinitiating System for Synthesis of Organic–Inorganic Hybrid Materials

One-pot synthesis of organic-inorganic hybrid materials under light requires specific photoinitiating systems which are able to release several different initiating species after light absorption. In this paper, the reaction mechanism of a photocyclic three-component initiating system based on isopropylthioxanthone as photoinitiator and an iodonium salt and a thiol as co-initiators was studied. It is shown that this system enables simultaneous release of both radicals and protons which are able to initiate a free radical photopolymerization and the hydrolysis-condensation of a sol-gel network, respectively. Time-resolved investigations by laser flash photolysis show that the initiating species are produced within two concomitant cyclic reaction mechanisms depending on the relative quantities of the co-initiators. Protons resulting from the secondary dark reaction of the photocyclic systems are detected at the microsecond scale by means of a proton-sensitive molecular probe, and corresponding quantum yields are measured. Finally, synthesis of organic, inorganic, and hybrid materials under LED light at 395 nm is evaluated with respect to the mechanistic considerations demonstrating the dual initiating character of the system.

Fabrication and Functionalization of Inorganic Materials Using Amphiphilic Molecules.

In this review, the synthesis of inorganic materials with various properties using amphiphilic molecules is examined. Amphiphilic molecules are used for the formation of highly ordered mesostructures and the surface modification. Two examples of the mesostructures are crystalline mesoporous titania (TiO2) and the novel visible light responsive mesostuructured titania modified with dye in the pores, which can be fabricated using the molecular self-assemblies of amphiphiles as templates. Surface modification using amphiphilic molecules enables the construction of self-assembled arrays of silica particles and the preparation of a film that can control adsorption/desorption behavior of bovine serum albumin (BSA) by light irradiation.

Synthesis of Titanium Oxide Nanostructures in Ionic Liquids

In recent years, the usage of ionic liquids (ILs) in the synthesis of metal oxides has been extensively studied, especially with respect to their possible advantageous effects in comparison to conventional syntheses protocols. Herein, an overview is given on the variety of different syntheses of TiO2‐based materials, which correlates to the diversity of different ionic liquids. Special emphasis is put on the historic development of the IL‐based synthesis of TiO2 materials in the general context of research on IL‐based materials synthesis. Also, the assumed advantages of both, the synthesis and the resulting TiO2 materials, are critically revised. It can be concluded that the application of ILs exerts a direct influence on several parameters, namely the phase composition, the dopants or the nanostructuring of the material. Importantly, the research on TiO2‐based materials enables fundamental insights into IL‐specific effects in the synthesis of inorganic materials in general.

Chalcogen bonding in synthesis, catalysis and design of materials

Chalcogen bonding is a type of noncovalent interaction in which a covalently bonded chalcogen atom (O, S, Se or Te) acts as an electrophilic species towards a nucleophilic (negative) region(s) in another or in the same molecule. In general, this interaction is strengthened by the presence of an electron-withdrawing group on the electron-acceptor chalcogen atom and upon moving down in the periodic table of elements, from O to Te. Following a short discussion of the phenomenon of chalcogen bonding, this Perspective presents some demonstrative experimental observations in which this bonding is crucial for synthetic transformations, crystal engineering, catalysis and design of materials as synthons/tectons.

Ionic Liquid-Assisted Synthesis and Catalytic Properties of AuPd Bimetallic Particles

Ionic liquid-assisted synthesis of inorganic materials has been demonstrated to be an efficient synthesis route in the inorganic community. Here AuPd alloy particles are successfully synthesized with the assistance of the ionic liquid 1-octyl-3-methylimidazolium chloride ([OMIM]Cl) at room temperature. The p-nitrophenol reduction reaction using the synthesized metal particles as the catalysts indicates that the synthesized Au(1)Pd(1) particles exhibit the highest catalytic activity in comparison with the studied AuPd particles, the Au and the Pd particles. Therefore, the present synthesis route could be used as an efficient synthesis strategy for fabrication of metal alloy particles with interesting catalytic properties.