The authors extend their appreciation to Dr. Thomas J. Emge and Wei Liu of Rutgers University for their analysis and expertise in small-angle X-ray diffraction and powder X-ray diffraction. Furthermore, the authors acknowledge Hao Wang for his support with the N2 adsorption experiments.

1. Al(OH)3 Nanoparticle Synthesis
<ol>
	<li>Dissolve 1.40 g of aluminum chloride hexahydrate in 5.822 g of deionized water.</li>
	<li>Add 2.778 g of L-arginine to the aqueous aluminum chloride solution while under magnetic stirring. Add the L-arginine slowly, so that the added arginine dissolves and does not form large clumps or chunks; furthermore, a slow addition reduces local concentrations of alkalinity and provides conditions for a more controllable hydrolysis.</li>
	<li>Once all the arginine dissolves into the solution, heat the solution for 72 h at 50 &#176;C; at this point, the solution may appear as a cloudy suspension.</li>
</ol>
2. Precipitating Al(OH)3 with NaCl
<ol>
	<li>Prepare a GPC column that is 49 in long and 1.125 in diameter. Pack the gel in successive steps of adding gel and allowing water to flow through the column to ensure proper packing, with minimal space between the gel beads. Pack the gel to about 80% of the column; the amount of gel packed varies every time and only affects the retention time of the separated species.</li>
	<li>Introduce 10 mL of as-synthesized Al(OH)3 nanoparticle suspension (prepared in step 1.3) into the column using an HPLC pump with a 10 mL injector loop. Custom-make the injector loop using tubing with an external diameter of approximately 0.125 in and a length that is calibrated to deliver 10 mL of injected sample.</li>
	<li>Collect the column elution in intervals correlating with the dRI peak location. Connect the GPC output to the input of a differential refractive index (dRI) detector. 
	NOTE: As separated species come out of the GPC, they appear on the dRI detector as a peak and are then collected in 125 mL bottles. The GPC column produces two well-resolved peaks, which are both collected and analyzed with size-exclusion chromatography (SEC) and elemental analysis (EA) to discern arginine from aluminum species. The total volume collected will depend on size of the GPC column, the total amount of packing material used, and the flow rate of the deionized water used to elute the column.
	<ol>
		<li>Collect the majority of the peak 1 fraction over 100 min at a 0.2 mL/min flow rate.</li>
		<li>Collect the eluent in 30 min intervals once a peak emerges on the RI detector of the GPC column. 
		NOTE: Changing the interval range will change the concentration and purity of the resulting purified peak 1 material. It is better to collect small intervals of the peak at first to determine which portion contains the highest concentration and purity of peak 1 species for a specific column.</li>
	</ol>
	</li>
	<li>Prepare 1 wt% of NaCl.</li>
	<li>Add the prepared NaCl solution dropwise to 10 mL of purified Al(OH)3 nanoparticles; the material prepared using NaCl precipitation is not used for further experiments.</li>
</ol>
3. Preparation of Al-MCM-41
<ol>
	<li>Activate approximately 1.0 g of MCM-41 at 120 &#176;C under vacuum for 3 h in a vacuum oven.</li>
	<li>Prepare 50.0 g of aluminum chloride solution by combining 9.6926 g of AlCl3&#183;6H2O with 40.3074 g of deionized water.</li>
	<li>Add 0.7 g of activated MCM-41 to 50.0 g of aluminum chloride solution (prepared in step 3.2).</li>
	<li>Allow adequate mixing time (1 h) to ensure homogeneity of the AlCl3 diffused throughout the MCM-41 channels.</li>
	<li>Add L-arginine to the heterogeneous mixture to an Arg/Al molar ratio of 2.75 under magnetic stirring. Similarly to step 1.2, add the arginine slowly enough so as to allow the instantaneously formed flocculates to redissolve and reduce the clumping of the arginine before continuing the addition.</li>
	<li>Once homogeneous, heat the mixture at 50 &#176;C for 72 h.</li>
	<li>Filter the obtained heterogeneous solution using a Buchner funnel, under vacuum and equipped with qualitative 90 mm filter paper circles (or any other appropriate filter papers).</li>
	<li>Wash the filtered white powder with excess deionized water to ensure the removal of unreacted aluminum chloride, arginine, or water-soluble byproducts from the produced Al-MCM-41 material.</li>
</ol>

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Mineral. 91 (1), 115-119 (2006).</li><li>Scherrer, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bestimmung+der+Grosse+und+der+inneren+Struktur+von+Kolloidteilchen+mittels+Rontgenstrahlen+.">Bestimmung der Grosse und der inneren Struktur von Kolloidteilchen mittels Rontgenstrahlen .</a> Gottingen. 26, 98-100 (1918).</li><li>Langford, J. I., Wilson, A. J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Scherrer+after+sixty+years:+a+survey+and+some+new+results+in+the+determination+of+crystallite+size.">Scherrer after sixty years: a survey and some new results in the determination of crystallite size.</a> J. Appl. Cryst. 11 (2), 102-113 (1978).</li><li>Swaddle, T. W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Kinetic+Evidence+for+Five-Coordination+in+AlOH(aq)2++Ion.">Kinetic Evidence for Five-Coordination in AlOH(aq)2+ Ion.</a> Science. 308 (5727), 1450-1453 (2005).</li><li>Casey, W. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Large+Aqueous+Aluminum+Hydroxide+Molecules.">Large Aqueous Aluminum Hydroxide Molecules.</a> Chem. Rev. 106 (1), 1-16 (2006).</li><li>Lutzenkirchen, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Adsorption+of+Al13-Keggin+clusters+to+sapphire+c-plane+single+crystals:+Kinetic+observations+by+streaming+current+measurements.">Adsorption of Al13-Keggin clusters to sapphire c-plane single crystals: Kinetic observations by streaming current measurements.</a> Appl. Surf. Sci. 256 (17), 5406-5411 (2010).</li><li>Mokaya, R., Jones, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+post-synthesis+alumination+of+MCM-41+using+aluminum+chlorohydrate+containing+Al+polycations.">Efficient post-synthesis alumination of MCM-41 using aluminum chlorohydrate containing Al polycations.</a> J. Mater. Chem. 9 (2), 555-561 (1999).</li><li>Brunauer, S., Deming, L. S., Deming, W. E., Teller, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=On+a+Theory+of+the+van+der+Waals+adsorption+of+gases.">On a Theory of the van der Waals adsorption of gases.</a> J. Am. Chem. Soc. 62 (7), 1723-1732 (1940).</li><li>Kresge, C. T., Leonowicz, M. E., Roth, W. J., Vartuli, J. C., Beck, J. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ordered+mesoporous+molecular+sieves+synthesized+by+a+liquid-crystal+template+mechanism.">Ordered mesoporous molecular sieves synthesized by a liquid-crystal template mechanism.</a> Nature. 359 (6397), 710-712 (1992).</li><li>Zeng, Q., Nekvasil, H., Grey, C. 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W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Solid-state+1H+MAS+NMR+characterization+of+&#947;-alumina+and+modified+&#947;-aluminas.">Solid-state 1H MAS NMR characterization of &#947;-alumina and modified &#947;-aluminas.</a> J. Catal. 148 (1), 76-83 (1994).</li><li>Shafran, K. L., Deschaume, O., Perry, C. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+static+anion+exchange+method+for+generation+of+high+purity+aluminium+polyoxocations+and+monodisperse+aluminum+hydroxide+nanoparticles.">The static anion exchange method for generation of high purity aluminium polyoxocations and monodisperse aluminum hydroxide nanoparticles.</a> J. Mater. Chem. 15 (33), 3415-3423 (2005).</li><li>Vogels, R. J. M. J., Kloprogge, J. T., Geus, J. 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The authors have nothing to disclose.

The preparation of an aqueous aluminum chloride solution entailed the use of a crystalline hexahydrate salt of aluminum chloride. Although the anhydrous form can also be used, it is not preferred due to its significant hygroscopic properties, which make it difficult to work with and to control the concentration of aluminum. It is noteworthy that aluminum chloride solution should be used within several days of preparation because over time, the [Al(H2O)6]3+ aqua acid hydrolyzes to yield un...

Materials made of aluminum hydroxide are promising candidates for a variety of industrial applications, including catalysis, pharmaceuticals, water treatment, and cosmetics.1,2,3,4 At elevated temperatures, aluminum hydroxide absorbs a substantial amount of heat during decomposition to yield alumina (Al2O3), making it a useful flame-retarding agent.5 The four known polymorphs of aluminum hydroxide (i.e., gibbsite, bayerite, nordstrandite, and doyleite) have been investigated using computational and experimental techniques to improve our understanding of the formation and structures thereof6. The preparation of nanoscale particles is of particular interest due to their potential to exhibit quantum effects and properties differing from those of their bulk counterparts. Nanogibbsite particles with dimensions on the order of 100 nm are easily prepared under various conditions7,8,9,10,11,12,13,14.
Overcoming inherent challenges associated with reducing the particle sizes further is difficult; therefore, only a few cases exist where nanogibbsite particles have dimensions on the order of 50 nm.14,15,16,17 To the best of our knowledge, there have been no reports of nanogibbsite particles smaller than 50 nm. In part, this is attributed to the fact that nanoparticles tend to agglomerate due to electrostatic instability and the high probability for the formation of hydrogen bonds between the colloidal particles, especially in polar protic solvents. Our objective was to synthesize small Al(OH)3 nanoparticles by using exclusively safe ingredients and precursors. In the current work, aqueous particle aggregation was inhibited by incorporating an amino acid (i.e., L-arginine) as a buffer and stabilizer. Moreover, it is reported that the guanidinium-containing arginine prevented aluminum hydroxide particle growth and aggregation to yield an aqueous colloidal suspension with average particle sizes of 10-30 nm. It is proposed here that the amphoteric and zwitterionic properties of arginine mitigated the surface charge of aluminum hydroxide nanoparticles during the mild hydrolysis to disfavor particle growth beyond 30 nm. Although arginine was not capable of reducing the particle size below 10 nm, such particles were achieved by taking advantage of the &#34;cage&#34; confinement effect within the mesopores of MCM-41. Characterization of the Al-MCM-41 composite material revealed ultrafine aluminum hydroxide nanoparticles within the mesoporous silica, which has an average pore size of 2.7 nm.

<table><tbody><tr><td>aluminum chloride hexahydrate</td><td>Alfa Aesar</td><td>12297</td><td></td></tr><tr><td>L-arginine</td><td>BioKyowa</td><td>N/A</td><td></td></tr><tr><td>aluminum hydroxide</td><td>Sigma Aldrich</td><td>239186</td><td></td></tr><tr><td>Bio-Gel P-4 Gel</td><td>Bio-Rad</td><td>150-4128</td><td></td></tr><tr><td>Mesoporous siica (MCM-41 type)</td><td>Sigma Aldrich</td><td>643645</td><td></td></tr></tbody></table>

facile preparation of ultrafine aluminum hydroxide particles with or without mesoporous mcm-41 in ambient environments

An aqueous suspension of nanogibbsite was synthesized via the titration of aluminum aqua acid [Al(H2O)6]3+ with L-arginine to pH 4.6. Since the hydrolysis of aqueous aluminum salts is known to produce a wide array of products with a wide range of size distributions, a variety of state-of-the-art instruments (i.e., 27Al/1H NMR, FTIR, ICP-OES, TEM-EDX, XPS, XRD, and BET) were used to characterize the synthesis products and identification of byproducts. The product, which was comprised of nanoparticles (10-30 nm), was isolated using gel permeation chromatography (GPC) column technique. Fourier transform infrared (FTIR) spectroscopy and powder X-ray diffraction (PXRD) identified the purified material as the gibbsite polymorph of aluminum hydroxide. The addition of inorganic salts (e.g., NaCl) induced electrostatic destabilization of the suspension, thereby agglomerating the nanoparticles to yield Al(OH)3 precipitate with large particle sizes. By utilizing the novel synthetic method described here, Al(OH)3 was partially loaded inside the highly ordered mesoporous framework of MCM-41, with average pore dimensions of 2.7 nm, producing an aluminosilicate material with both octahedral and tetrahedral Al (Oh/Td = 1.4). The total Al content, measured using energy-dispersive X-ray spectrometry (EDX), was 11% w/w with a Si/Al molar ratio of 2.9. A comparison of bulk EDX with surface X-ray photoelectron spectroscopy (XPS) elemental analysis provided insight into the distribution of Al within the aluminosilicate material. Furthermore, a higher ratio of Si/Al was observed on the external surface (3.6) as compared to the bulk (2.9). Approximations of O/Al ratios suggest a higher concentration of Al(O)3 and Al(O)4 groups near the core and external surface, respectively. The newly developed synthesis of Al-MCM-41 yields a relatively high Al content while maintaining the integrity of the ordered silica framework and can be used for applications where hydrated or anhydrous Al2O3 nanoparticles are advantageous.

Nanogibbsite Synthesis
Nanogibbsite was prepared by titrating AlCl3&#183;6H2O (14 wt%) with L-arginine to a final Arg/Al molar ratio of 2.75. The synthesis of nanogibbsite particles was monitored via SEC, which is a widely used analysis technique for partially hydrolyzed aluminum chloride solutions, capable of discerning five domains arbitrarily designated as peaks 1, 2, 3, 4, and 51...

Watch this Scientific Journal Video about Facile Preparation of Ultrafine Aluminum Hydroxide Particles with or without Mesoporous MCM-41 in Ambient Environments at JoVE.com

Facile Preparation of Ultrafine Aluminum Hydroxide Particles with or without Mesoporous MCM-41 in Ambient Environments

An ultrafine aluminum hydroxide nanoparticle suspension was prepared via the controlled titration of [Al(H2O)]3+ with L-arginine to pH 4.6 with and without cage-effect confinement within mesoporous channels of MCM-41.

An aqueous suspension of nanogibbsite was synthesized via the titration of aluminum aqua acid [Al(H2O)6]3+ with L-arginine to pH 4.6. Since the hydrolysis ...

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Research

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10.8K Views.  Colgate-Palmolive Company. An ultrafine aluminum hydroxide nanoparticle suspension was prepared via the controlled titration of [Al(H2O)]3+ with L-arginine to pH 4.6 with and without cage-effect confinement within mesoporous channels of MCM-41.

Video: Facile Preparation of Ultrafine Aluminum Hydroxide Particles with or without Mesoporous MCM-41 in Ambient Environments

Ultrahigh Density Array of Vertically Aligned Small-molecular Organic Nanowires on Arbitrary Substrates

In recent years &pi;-conjugated organic semiconductors have emerged as the active material in a number of diverse applications including large-area, low-cost displays, photovoltaics, printable and flexible electronics and organic spin valves. Organics allow (a) low-cost, low-temperature processing and (b) molecular-level design of electronic, optical and spin transport characteristics. Such features are not readily available for mainstream inorganic semiconductors, which have enabled organics to carve a niche in the silicon-dominated electronics market. The first generation of organic-based devices has focused on thin film geometries, grown by physical vapor deposition or solution processing. However, it has been realized that organic nanostructures can be used to enhance performance of above-mentioned applications and significant effort has been invested in exploring methods for organic nanostructure fabrication.	
A particularly interesting class of organic nanostructures is the one in which vertically oriented organic nanowires, nanorods or nanotubes are organized in a well-regimented, high-density array. Such structures are highly versatile and are ideal morphological architectures for various applications such as chemical sensors, split-dipole nanoantennas, photovoltaic devices with radially heterostructured "core-shell" nanowires, and memory devices with a cross-point geometry. Such architecture is generally realized by a template-directed approach. In the past this method has been used to grow metal and inorganic semiconductor nanowire arrays. More recently &pi;-conjugated polymer nanowires have been grown within nanoporous templates. However, these approaches have had limited success in growing nanowires of technologically important &pi;-conjugated small molecular weight organics, such as tris-8-hydroxyquinoline aluminum (Alq3), rubrene and methanofullerenes, which are commonly used in diverse areas including organic displays, photovoltaics, thin film transistors and spintronics.	
Recently we have been able to address the above-mentioned issue by employing a novel "centrifugation-assisted" approach. This method therefore broadens the spectrum of organic materials that can be patterned in a vertically ordered nanowire array. Due to the technological importance of Alq3, rubrene and methanofullerenes, our method can be used to explore how the nanostructuring of these materials affects the performance of aforementioned organic devices. The purpose of this article is to describe the technical details of the above-mentioned protocol, demonstrate how this process can be extended to grow small-molecular organic nanowires on arbitrary substrates and finally, to discuss the critical steps, limitations, possible modifications, trouble-shooting and future applications.

We report a simple method for fabricating an ultrahigh density array of vertically ordered small-molecular organic nanowires. This method allows for synthesis of complex heterostructured hybrid nanowire geometries, which can be inexpensively grown on arbitrary substrates. These structures have potential applications in organic electronics, optoelectronics, chemical sensing, photovoltaics and spintronics.

In  recent years &pi;-conjugated  organic semiconductors have emerged as the active material in a number of  diverse applications including large-area, ...

Engineering

Two-way Valorization of Blast Furnace Slag: Synthesis of Precipitated Calcium Carbonate and Zeolitic Heavy Metal Adsorbent

The aim of this work is to present a zero-waste process for storing CO2 in a stable and benign mineral form while producing zeolitic minerals with sufficient heavy metal adsorption capacity. To this end, blast furnace slag, a residue from iron-making, is utilized as the starting material. Calcium is selectively extracted from the slag by leaching with acetic acid (2 M CH3COOH) as the extraction agent. The filtered leachate is subsequently physico-chemically purified and then carbonated to form precipitated calcium carbonate (PCC) of high purity (&lt;2 wt% non-calcium impurities, according to ICP-MS analysis). Sodium hydroxide is added to neutralize the regenerated acetate. The morphological properties of the resulting calcitic PCC are tuned for its potential application as a filler in papermaking. In parallel, the residual solids from the extraction stage are subjected to hydrothermal conversion in a caustic solution (2 M NaOH) that leads to the predominant formation of a particular zeolitic mineral phase (detected by XRD), namely analcime (NaAlSi2O6&#8729;H2O). Based on its ability to adsorb Ni2+, as reported from batch adsorption experiments and ICP-OES analysis, this product can potentially be used in wastewater treatment or for environmental remediation applications.

A protocol for the parallel production of precipitated calcium carbonate and zeolitic material from blast furnace slag via mineral carbonation and alkaline hydrothermal conversion, respectively, is presented. The performance of the zeolitic material towards nickel adsorption is tested.

The aim of this work is to present a zero-waste process for storing CO2 in a stable and benign mineral form while producing zeolitic minerals with ...

Simultaneous Multi-surface Anodizations and Stair-like Reverse Biases Detachment of Anodic Aluminum Oxides in Sulfuric and Oxalic Acid Electrolyte

After reporting on the two-step anodization, nanoporous anodic aluminum oxides (AAOs) have been widely utilized in the versatile fields of fundamental sciences and industrial applications owing to their periodic arrangement of nanopores with relatively high aspect ratio. However, the techniques reported so far, which could be only valid for mono-surface anodization, show critical disadvantages, i.e., time-consuming as well as complicated procedures, requiring toxic chemicals, and wasting valuable natural resources. In this paper, we demonstrate a facile, efficient, and environmentally clean method to fabricate nanoporous AAOs in sulfuric and oxalic acid electrolytes, which can overcome the limitations that result from conventional AAO fabricating methods. First, plural AAOs are produced at one time through simultaneous multi-surfaces anodization (SMSA), indicating mass-producibility of the AAOs with comparable qualities. Second, those AAOs can be separated from the aluminum (Al) substrate by applying stair-like reverse biases (SRBs) in the same electrolyte used for the SMSAs, implying simplicity and green technological characteristics. Finally, a unit sequence consisting of the SMSAs sequentially combined with SRBs-based detachment can be applied repeatedly to the same Al substrate, which reinforces the advantages of this strategy and also guarantees the efficient usage of natural resources.

A protocol for fabricating nanoporous anodic aluminum oxides via simultaneous multi-surfaces anodization followed by stair-like reverse biases detachments is presented. It can be applied repeatedly to the same aluminum substrate, exhibiting a facile, high-yield, and environmentally clean strategy.

After reporting on the two-step anodization, nanoporous anodic aluminum oxides (AAOs) have been widely utilized in the versatile fields of fundamental ...

Fabrication and Testing of Catalytic Aerogels Prepared Via Rapid Supercritical Extraction

Protocols for preparing and testing catalytic aerogels by incorporating metal species into silica and alumina aerogel platforms are presented. Three preparation methods are described: (a) the incorporation of metal salts into silica or alumina wet gels using an impregnation method; (b) the incorporation of metal salts into alumina wet gels using a co-precursor method; and (c) the addition of metal nanoparticles directly into a silica aerogel precursor mixture. The methods utilize a hydraulic hot press, which allows for rapid (&#60;6 h) supercritical extraction and results in aerogels of low density (0.10 g/mL) and high surface area (200-800 m2/g). While the work presented here focuses on the use of copper salts and copper nanoparticles, the approach can be implemented using other metal salts and nanoparticles. A protocol for testing the three-way catalytic ability of these aerogels for automotive pollution mitigation is also presented. This technique uses custom-built equipment, the Union Catalytic Testbed (UCAT), in which a simulated exhaust mixture is passed over an aerogel sample at a controlled temperature and flow rate. The system is capable of measuring the ability of the catalytic aerogels, under both oxidizing and reducing conditions, to convert CO, NO and unburned hydrocarbons (HCs) to less harmful species (CO2, H2O and N2). Example catalytic results are presented for the aerogels described.

Here we present protocols for preparing and testing catalytic aerogels by incorporating metal species into silica and alumina aerogel platforms. Methods for preparing materials using copper salts and copper-containing nanoparticles are featured. Catalytic testing protocols demonstrate the effectiveness of these aerogels for three-way catalysis applications.

Protocols for preparing and testing catalytic aerogels by incorporating metal species into silica and alumina aerogel platforms are presented. Three ...

Growth and Electrostatic/chemical Properties of Metal/LaAlO3/SrTiO3 Heterostructures

The quasi 2D electron system (q2DES) that forms at the interface between LaAlO3 (LAO) and SrTiO3 (STO) has attracted much attention from the oxide electronics community. One of its hallmark features is the existence of a critical LAO thickness of 4 unit-cells (uc) for interfacial conductivity to emerge. Although electrostatic mechanisms have been proposed in the past to describe the existence of this critical thickness, the importance of chemical defects has been recently accentuated. Here, we describe the growth of metal/LAO/STO heterostructures in an ultra-high vacuum (UHV) cluster system combining pulsed laser deposition (to grow the LAO), magnetron sputtering (to grow the metal) and X-ray photoelectron spectroscopy (XPS). We study step by step the formation and evolution of the q2DES and the chemical interactions that occur between the metal and the LAO/STO. Additionally, magnetotransport experiments elucidate on the transport and electronic properties of the q2DES. This systematic work not only demonstrates a way to study the electrostatic and chemical interplay between the q2DES and its environment, but also unlocks the possibility to couple multifunctional capping layers with the rich physics observed in two-dimensional electron systems, allowing the fabrication of new types of devices.

Growth and Electrostatic/chemical Properties of Metal/LaAlO3/SrTiO3 Heterostructures

We fabricate metal/LaAlO3/SrTiO3 heterostructures using a combination of pulsed laser deposition and in situ magnetron sputtering. Through magnetotransport and in situ X-ray photoelectron spectroscopy experiments, we investigate the interplay between electrostatic and chemical phenomena of the quasi two-dimensional electron gas formed in this system.

The quasi 2D electron system (q2DES) that forms at the interface between LaAlO3 (LAO) and SrTiO3 (STO) has attracted much attention from the oxide ...

Multiscale Structures Aggregated by Imprinted Nanofibers for Functional Surfaces

Multiscale surface structures have attracted increasing interest owing to several potential applications in surface devices. However, an existing challenge in the field is the fabrication of hybrid micro-nano structures using a facile, cost-effective, and high-throughput method. To overcome these challenges, this paper proposes a protocol to fabricate multiscale structures using only an imprint process with an anodic aluminum oxide (AAO) filter and an evaporative self-aggregation process of nanofibers. Unlike previous attempts that have aimed to straighten nanofibers, we demonstrate a unique fabrication method for multiscale aggregated nanofibers with high aspect ratios. Furthermore, the surface morphology and wettability of these structures on various liquids were investigated to facilitate their use in multifunctional surfaces.

Presented is an easy method to fabricate nano-micro multiscale structures, for functional surfaces, by aggregating nanofibers fabricated using an anodic aluminum oxide filter.

Multiscale surface structures have attracted increasing interest owing to several potential applications in surface devices. However, an existing ...

A Continuous-flow Photocatalytic Reactor for the Precisely Controlled Deposition of Metallic Nanoparticles

In this work, a novel photocatalytic reactor for the pulsed and controlled excitation of the photocatalyst and the precise deposition of metallic nanoparticles is developed. Guidelines for the replication of the reactor and its operation are provided in detail. Three different composite systems (Pt/graphene, Pt/TiO2, and Au/TiO2) with monodisperse and uniformly distributed particles are produced by this reactor, and the photodeposition mechanism, as well as the synthesis optimization strategy, are discussed. The synthesis methods and their technical aspects are described comprehensively. The role of the ultraviolet (UV) dose (in each excitation pulse) on the photodeposition process is investigated and the optimum values for each composite system are provided.

For a continuous and scalable synthesis of noble-metal-based nanocomposites, a novel photocatalytic reactor is developed and its structure, operation principles, and product quality optimization strategies are described.

In this work, a novel photocatalytic reactor for the pulsed and controlled excitation of the photocatalyst and the precise deposition of metallic ...

Hydrogen Charging of Aluminum using Friction in Water

A new method of hydrogen charging of aluminum was developed by means of a friction in water (FW) procedure. This procedure can easily introduce high amounts of hydrogen into aluminum based on the chemical reaction between water and non-oxide coated aluminum.

In order to introduce high amounts of hydrogen in aluminum and aluminum alloys, a new method of hydrogen charging was developed, called the friction in water procedure.

A new method of hydrogen charging of aluminum was developed by means of a friction in water (FW) procedure. This procedure can easily introduce high ...

Rapid Mix Preparation of Bioinspired Nanoscale Hydroxyapatite for Biomedical Applications

Hydroxyapatite (HA) has been widely used as a medical ceramic due to its good biocompatibility and osteoconductivity. Recently there has been interest regarding the use of bioinspired nanoscale hydroxyapatite (nHA). However, biological apatite is known to be calcium-deficient and carbonate-substituted with a nanoscale platelet-like morphology. Bioinspired nHA has the potential to stimulate optimal bone tissue regeneration due to its similarity to bone and tooth enamel mineral. Many of the methods currently used to fabricate nHA both in the laboratory and commercially, involve lengthy processes and complex equipment. Therefore, the aim of this study was to develop a rapid and reliable method to prepare high quality bioinspired nHA. The rapid mixing method developed was based upon an acid-base reaction involving calcium hydroxide and phosphoric acid. Briefly, a phosphoric acid solution was poured into a calcium hydroxide solution followed by stirring, washing and drying stages. Part of the batch was sintered at 1,000 &#176;C for 2 h in order to investigate the products&#39; high temperature stability. X-ray diffraction analysis showed the successful formation of HA, which showed thermal decomposition to &#946;-tricalcium phosphate after high temperature processing, which is typical for calcium-deficient HA. Fourier transform infrared spectroscopy showed the presence of carbonate groups in the precipitated product. The nHA particles had a low aspect ratio with approximate dimensions of 50 x 30 nm, close to the dimensions of biological apatite. The material was also calcium deficient with a Ca:P molar ratio of 1.63, which like biological apatite is lower than the stoichiometric HA ratio of 1.67. This new method is therefore a reliable and far more convenient process for the manufacture of bioinspired nHA, overcoming the need for lengthy titrations and complex equipment. The resulting bioinspired HA product is suitable for use in a wide variety of medical and consumer health applications.

This paper describes a novel method for the rapid manufacture of high quality bioinspired nanoscale hydroxyapatite. This biomaterial is of great significance in the manufacture of a wide range of innovative medical devices for clinical applications in orthopedics, craniofacial surgery and dentistry.

Hydroxyapatite (HA) has been widely used as a medical ceramic due to its good biocompatibility and osteoconductivity. Recently there has been interest ...

Bioengineering

Synthesis and Discovery of Phosphonate-Based MOFs: A Solvothermal Approach

Discovery and Synthesis Optimization of Isoreticular Al(III) Phosphonate-Based Metal-Organic Framework Compounds Using High-Throughput Methods

High-throughput (HT) methods are an important tool for the fast and efficient screening of synthesis parameters and the discovery of new materials. This manuscript describes the synthesis of metal-organic frameworks (MOFs) from solution using an HT reactor system, resulting in the discovery of various phosphonate-based MOFs of the composition [Al2H12-x(PMP)3]Clx&#8729;6H2O (H4PMP = N,N &#39;-piperazine bis(methylenephosphonic acid)) for x = 4, 6, denoted as Al-CAU-60-xHCl, containing trivalent aluminum ions. This was accomplished under solvothermal reaction conditions by systematically screening the impact of the molar ratio of the linker to the metal and the pH of the reaction mixture on the product formation. The protocol for the HT investigation includes six steps: a) synthesis planning (DOE = design of&#160;experiment) within the HT methodology, b) dosing and working with in-house developed HT reactors, c) solvothermal synthesis, d) synthesis workup using in-house developed filtration blocks, e) characterization by HT powder X-ray diffraction, and f) evaluation of the data. The HT methodology was first used to study the influence of acidity on the product formation, leading to the discovery of Al-CAU-60&#8729;xHCl (x = 4 or 6).

Author Spotlight: Accelerating Discovery in Microporous Material Chemistry 

The targeted synthesis of new metal-organic frameworks (MOFs) is difficult, and their discovery depends on the knowledge and creativity of the chemist. High-throughput methods allow complex synthetic parameter fields to be explored quickly and efficiently, accelerating the process of finding crystalline compounds and identifying synthetic and structural trends.

High-throughput (HT) methods are an important tool for the fast and efficient screening of synthesis parameters and the discovery of new materials. This ...