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Post by aqt on Mar 3, 2010 17:01:51 GMT -5
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Post by aqt on Mar 3, 2010 17:03:21 GMT -5
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Post by aqt on Mar 3, 2010 17:05:44 GMT -5
www.flipkart.com/supramolecular-chemistry-organic-inorganic-hybrid/047037621x-0xw3f9skciThe combination of supramolecular chemistry, inorganic solids, and nanotechnology has already led to significant advances in many areas such as sensing, controlled motion, and delivery. By making possible an unprecedented tunability of the properties of nanomaterials, these techniques open up whole new areas of application for future supramolecular concepts The Supramolecular Chemistry of Organic-Inorganic Hybrid Materials gathers current knowledge on the subject and provides an overview of the present state and upcoming challenges in this rapidly growing, highly cross- or interdisciplinary research field
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Post by aqt on Mar 3, 2010 17:09:15 GMT -5
www.wiley.com/WileyCDA/WileyTitle/productCd-047037621X.htmlThe book details how these designed materials can improve existing materials or generate novel functional features such as chemical amplification, cooperative binding and signal enhancement that are difficult or not at all achievable by classical organic supramolecular chemistry. It also discusses issues related to nanofabrication or nanotechnology such as the directed and controlled assembly or disassembly, biomimetic functions and strategies, and the gating and switching of surface functions or morphology
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Post by aqt on Mar 3, 2010 17:14:07 GMT -5
www.science24.com/paper/7554The relatively new tendency in the nanotechnology of inorganic particles is a development of technologies based on the organic-inorganic hybrids, which allow to achieve of the inorganic mesoporous objects of macroscopic dimensions ( the so-called monoliths). Calcination of the above mentioned hybrids may lead to the hierarchically ordered mesoporous inorganic materials from nanoorganisation of a single pore to the assembly of pores and finally to the macroscopic morphology. Ozin calls materials that are controllable on all of these length scales "panoscopic materials" [1]. The synthesis and the analysis of microstructures of organic-inorganic hybrids as well as inorganic structures after their calcination are the goal of this work. Two classes of hybrid organic - inorganic materials were considered. Class I is characterized by inorganic molecules embedded in polymer matrix. Class II involves materials displaying strong interactions between inorganic and organic components. Here a new molecular precursor is first synthesized and then used in a conventional sol-gel process to get the hybrid material. Precursor of the inorganic phase was a complex of the (tetra-isopropyl)orthotitanate with the methacrylic acid. The mesomorphic polymer (2-hydroxypropyl)cellulose (HPC) was used as self-organization matrix, around which there were formed "in situ" nanoparticles phase of TiO2.As a result of our investigations we obtained: (a)-organic-inorganic nanocomposites of HPC/TiO2, (b)-mesoporous and nanocrystalline particles diameter 200-500nm of TiO2 (anatas) as well as solid supported mesoporous and transparent thin films of TiO2, (c)-wires of nanocrystalline TiO2 (30mm x 1cm), showing high optical anisotropy.References [1] G.A. Ozin , Chem. Commun., (6), 419, (2000) Acknowledgement This research has been financially supported by the State Committee for Scientific Research (KBN) under contract No. PBZ-KBN 095/ T08
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Post by aqt on Mar 3, 2010 17:29:09 GMT -5
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Post by aqt on Mar 3, 2010 17:32:36 GMT -5
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Post by skyship on Mar 3, 2010 20:29:11 GMT -5
www.sciencedirect.com/science?_ob....eb6cc999db73c45These findings bring an idea that i ncorporation of calcium ion (Ca2+) and Si–OH group into organic substances leads to a bioactive hybrid. It was confirmed that organic–inorganic hybrids containing calcium salt, which were synthesized from vinyltrimethoxysilane (VS) or 3-methacryloxypropyltrimethoxysilane (MPS), showed the apatite formation in Kokubo solution. Such type of organic–inorganic hybrids can be blended with organic polymer.
============== looks like these biohybrids(org/inorg) are then............blended with the organic polymer this is from organic chemistry, DNA maybe) not inorganic chemistry- the invisible by gases. vinyltrimethoxysilane (VS) tiny.cc/FkLc9 www.sigmaaldrich.com/catalog/ProductDetail.do?D7=0&N5=SEARCH_CONCAT_PNO|BRAND_KEY&N4=235768| ALDRICH&N25=0&QS=ON&F=SPEC or 3-methacryloxypropyltrimethoxysilane (MPS) Oh my gosh, if is a frickin tin oxide, the worst thing ever. When it should be gold.............. found another culprit............... Sigma Aldrich............ ====================== The Continuing Dangers of Tin Whiskers and Attempts to Control Them with Conformal CoatingAbstract: A 1998 commercial satellite failure caused by tin whisker induced shorts prompted NASA Goddard Space Flight Center (GSFC) to issue a NASA Advisory (NA-044 and NA-044A) (1,2) to remind the NASA community of the tin whisker phenomenon and the inherent risks associated with the use of pure tin plated components. Indeed the NASA Advisory served as a “reminder” since the spontaneous growth of tin whiskers from some tin plated surfaces has been known and studied for over 50 years with dozens of technical publications and several GIDEP Alerts produced during that time. During the 1990s the US Military modified most (but not all) of their electronic component specifications to prohibit the use of pure tin finishes in order to minimize the risks of whiskering.However, as regulations and a world economy push today’s electronics industry to use environmentally friendly (Pb-free) alternatives, the prevalence of pure tin plated components is bound to increase potentially increasing NASA's risk of exposure to risks associated with tin whiskers significantly.In an effort to evaluate risk mitigation techniques, NASA GSFC initiated experiments to study the effects of Uralane 5750 (a commonly used conformal coat) on tin whisker growth. After more than two years of experimentation, we have found that conformal coat does not prevent tin whisker formation although it does appear to substantially reduce the rate of growth. We have observed that a tin whisker has grown through an area of conformal coat that is approximately 1/4 mil thick (see figure 1). Numerous tin nodules growing beneath a nominal 2 mil thick coating are also being monitored to determine if and when they will be able to penetrate this barrier.
We have also observed that tin whiskers can bend in response to forces of electrostatic attraction; thus increasing the probability of tin whisker shorts either from two whiskers colliding or from one whisker bending to contact another conductor. Especially for long duration missions, use of conformal coat as a sole means of risk mitigation may not be completely effective. Research is ongoing. BACKGROUND: The growth of tin whiskers on pure tin plated electronic components and associated hardware has been documented for decades. Notable examples of pure tin plated components that have exhibited tin whisker formations include electromagnetic relays, transistors, hybrid microcircuit packages, terminal lugs and very recently ceramic chip capacitors. A few such examples are shown below in figure 2: tiny.cc/LY9oI nepp.nasa.gov/docuploads/95565195-0E5A-40D8-98D88425FF668F68/JayBrusseRevision2.pdf skyship
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Post by skyship on Mar 3, 2010 20:38:24 GMT -5
Dimers made at Aldrich, now the tinwhiskers? homodimers, heterodimers, bet they made the nanotubes, buckyballs............. sure as hhhhh they did: tiny.cc/aeviP skyship
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Post by skyship on Mar 3, 2010 20:52:07 GMT -5
Another new word: Stannaspherene: Cage Clusters of Gold and Tin: Golden Buckyballs and Stannaspherene Wang, Lai-Sheng American Physical Society, 2008 APS March Meeting, March 10-14, 2008, abstract #B21.005 Photoelectron spectroscopy (PES) yields direct electronic structure information for size-selected clusters. Combining PES with theoretical calculations has become an effective approach to obtain structural information for small and medium-sized clusters. We present recent discoveries of two classes of cage clusters in gold and tin. Negatively charged gold clusters (Aun^-) have been shown to exhibit a remarkable structural diversity from 2D structures for n = 4-12 and the pyramidal structure for n = 20. Using PES and DFT calculations, we have found that gold clusters with n = 16-18 possess unprecedented hollow cage structures. We have been able to successfully dope a variety of transition-metal atoms into the empty spaces in the golden cages, confirming their structural robustness, as well as demonstrating chemical tuning of their electronic, magnetic, and catalytic properties. Unlike carbon, the heavier congeners of the group 14 elements are not known to form hollow cage structures similar to the fullerenes. In PES studies of tin clusters, we noted that the spectrum of Sn12^- is distinctly different from that of its neighbors or its Si/Ge counterpart. This observation led to our discovery of a highly symmetric and stable icosahedral Sn12^2- cage, for which we coined a name ``stannaspherene'' to describe its high symmetry and spherical pi bonding. We have also shown that all transition metals including the f-block elements can be doped inside Sn12^2- to form a whole class of endohedral stannaspherenes, which may be used as potential building blocks for new cluster-assembled materials. In a preliminary experiment to synthesize stannaspherene in the bulk, a new cluster, Pd2@Sn18^4-, was crystallized and characterized, suggesting all stannaspherene and endohedral stannasphernes may be fabricated in the bulk under suitable conditions. ......adsabs.harvard.edu/abs/2008APS..MARB21005WI would say Harvard is getting worse and worse, even the icon of the founder of Harvard is not he.................joke on campus............. What phonies.............. did they not know that tin is wrong? ?and nickel? to be dumped on our heads from buckyballs? I do so wonder if Teller recommended tin? Or was that the plan? Never to use the real dust? to actually heal people, to heal the earth. No put tin out there and nickle instead.................. Got your tin ship ready folks? .......One TIN soldier walked away! Tin particles, nickel particles................still trying to make tin into Lead.......oops Gold? Skyship
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Post by skyship on Mar 3, 2010 21:08:16 GMT -5
stannaspherene and endohedral stannasphernes mmmmmmm what is this? www.azouk.com/196694/2008-APS-March-Meeting/7,500? ABSTRACTS? www.aps.org/meetings/march/scientific/index.cfmFERMI ARCS? ?? copper based? This image graphs the calculated amount of electrons emitted by copper-based superconductors when exposed to ultraviolet light. The color pattern ranges from low emissions (light blue) to very high emissions (white). The unique patterns seen in the image are a consequence of the superconducting electrons arranging themselves in a stripelike pattern. The graph plots the intensity at the Fermi energy in one quadrant of the two dimensional Brillouin zone. The original Fermi surface can be seen as a circular arc, with various images appearing due to zone folding by the magnetic stripe wavevector. The images in the upper left and lower right corners are the pockets observed by quantum oscillation measurements. This image was featured in the APS 2009 March Meeting Image Gallery. Gray arrow "Stripe order, electron pockets, and Fermi arcs" Gray arrow March Meeting Image Gallery The work for this paper, by Andrew Millis (Department of Physics, Columbia University) and Michael Norman (Materials Science Division, Argonne National Laboratory), was supported by the Department of Energy, the National Science Foundation, and the Aspen Center for Physics. www.aps.org/about/physics-images/stripes.cfm==================== This gets more and more sci fi? ? there is the real science and then their is the magic distorted version. okay, then.......... Skyship
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Post by aqt on Mar 4, 2010 16:36:52 GMT -5
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Post by aqt on Mar 4, 2010 16:38:08 GMT -5
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Post by aqt on Mar 4, 2010 16:39:44 GMT -5
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Post by aqt on Mar 4, 2010 16:46:34 GMT -5
Recent advances in self-assembly include novel synthetic pathways to well-ordered porous materials with channel and cavity dimensions that traverse multiple length scales. A creative amalgamation of surfactant and colloidal crystal templating methods together with microfabrication techniques allow unprecedented control over the organization of inorganic and organic building units and the construction of angstrom to millimeter composite architectures. These structurally and topologically complex solids display hierarchical building principles and properties that transcend those of the individual components. Possible utility for materials of this genre include, fuel cell electrodes, solid state battery electrolytes and plasticizers, chemical sensors, photovoltaics, bone implants, membranes, chromatography supports and chemical delivery systems.tiny.cc/lfpWo
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Post by aqt on Mar 4, 2010 16:50:25 GMT -5
Periodic Mesoporous Organosilicas (PMOs): Nanostructured Organic-Inorganic Hybrid MaterialsLateral thinking in biomimetic materials chemistry has permitted chemists to create fascinating structures that mimic the biomaterials optimized by Nature. The integration of organic and inorganic chemistry at multiple length scales gives optimal performance characteristics to biomaterials, such as bone. In a similar fashion, lateral thinking in our lab has enabled us to consolidate the chemistry of inorganic surfactant-templated mesoporous materials with the organic-inorganic hybrid structure of amorphous xerogels. A new class of materials, periodic mesoporous organosilicas (PMOs), has emerged that marries organic and solid-state chemistry in the channels of hexagonally ordered mesoporous materials. Various organic and organometallic groups may be integrated into the framework, creating materials with novel, tunable properties. Surfactant can be solvent-extracted or ion-exchanged to create a high surface area PMO with the framework and the organic group intact. This renders the organic groups accessible for reaction to give a new type of "chemistry of the channels". www.mrs.org/s_mrs/sec_subscribe.asp?CID=2379&DID=181306&action=detail
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Post by aqt on Mar 4, 2010 16:58:44 GMT -5
form of solids particles on different length scales is a rapidly developing field (recently coined definitions are “panoscopic materials”1 or “chemistry of form”2). ...
Synthesis of MoSx (5 > x > 6) Amorphous Sulfides and Their Use for Preparation of MoS2 Monodispersed Microspheres
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Post by aqt on Mar 4, 2010 17:02:26 GMT -5
Silicon is the "veteran" semiconductor in the management of electrons. ... tiny.cc/0spdc
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Post by aqt on Mar 4, 2010 17:05:13 GMT -5
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Post by beammeup on Mar 6, 2010 14:30:49 GMT -5
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Post by aqt on Mar 7, 2010 16:06:59 GMT -5
Molecular sieves are crystalline metal aluminosilicates having a threedimensional interconnecting network of silica and alumina tetrahedra. Natural water of hydration is removed from this network by heating to produce uniform cavities which selective... www.utdallas.edu/~balkus/Research.html
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Post by aqt on Mar 7, 2010 16:16:04 GMT -5
Self Healing Inorganic Films Our strategy for self healing inorganic films is shown below where a metal oxide layer is placed on top of a polymer layer that has been impregnated with polymer nanospheres or nanofibers (<100nm) that contain a reactive metal oxide precursor. When stress is applied to the metal oxide film microcracks are formed, which allow the diffusion of oxygen and moisture to the polymer layer. The nanocapsules will be composed of polymers that dissolve or degrade in the presence of water, thus releasing the reactive metal oxide precursor. Potential reactive species would be metal halides and metal akyls such as TiCl4 or Al(Me)3. This volatile liquid will quickly diffuse into the crack and hydrolyze to form TiO2, resulting in a continuous metal oxide film. An alternative to placing the nanocapsules in a polymer matrix would be to disperse them directly in the metal oxide coating. Then as stress cracks initiate the nanocapsules would dissolve and self healing of the oxide film would be realized. The prototype nanocapsules have been made from polylactic acid (PLA) and polyglycolic acid (PGA) as well as their co-polymers. The initial metal oxide precursor studied was TiCl4, a volatile liquid that reacts violently with water to form TiO2. We have employed microemulsion techniques to incorporate TiCl4 in polylactic acid core-shell structures. We have prepared hollow capsules and porous nanofibers of PLA by electrostatic deposition. We have shown the evolution of TiO2 from the PLA after exposure to controlled humidity. Next these nanocapsules were imbedded in a polymethylmethacrylate (PMMA) film, which is commonly used as a planarization layer for metal oxide coatings. This was followed by coating of the polymer with an alumina layer. The stress induced cracks are then filled with TiO2 from the PMMA embedded fibers.www.utdallas.edu/~balkus/Research.html#self
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Post by aqt on Mar 7, 2010 16:22:18 GMT -5
Electrospun Fibers Support from NSF and US Air Force AAAAAWe have developed a novel method for the preparation of molecular sieve fibers using electrospinning ( US Patents pending ). In this technique a synthesis gel is subjected to 25,000 volts over a distance of 20 cm. The charged particles in the gel are accelerated to a substrate/electrode. Some of the interesting DAM-1 and SBA-15 fibers are shown right. Interesting composite meshes have also been prepared using molecular sieves and various polymers., including the conductive, luminescent MEH-PPV. We are preparing for solar cells donor-acceptor fiber composites. Mesoporous TiO 2 fibers have been prepared for this application. PEO and PEI composites with the molecular sieves as well as hectorite and nanoscale laponite clays have been electrospun as free standing paper. This could lead to smart paper and textiles. In particular we our focused on developing conductive fibers including TiN, ITO and F-SnO2 . We are also developing magnetic paper based on this technology that would be white and useful in labels and packaging. Additionally we are working on plasmonic fibers based on <20nm gold shells prepared around PEI nanofibers, which are transparent and highly conductive. Carbon nanotubes have also been electrospun with the polymer clay composites. We are currently growing cells (eg HELA) on scaffolds constructed from such fibers. Other applications in the areas of sensors, electrochromics, solar cells and fuel cells are in development. www.utdallas.edu/~balkus/Research.html#electrospun
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Post by aqt on Mar 7, 2010 16:24:16 GMT -5
Novel Hybrid White Light Emitting Diodes AAAAADespite recent major advances in solid state lighting, further significant improvements can be expected from advancements in the fundamental science associated with white light emitting materials themselves. From our standpoint, the ideal emitting material(s) should exhibit luminescence from a single source with the following desired characteristics: (1) high quantum efficiency, (2) brightness in the solid state at room temperature, (3) chromaticity suitable for the application, (4) amenable to thin film deposition, (5) stability for long operational lifetimes, (6) suitability for conventional and flexible substrates, and (7) low manufacturing cost. The satisfaction of ALL these conditions is difficult and requires an extremely careful design that considers fundamental principles in spectroscopy, chemistry, physics, materials science, and electrical engineering. We recently discovered a 3 hour microwave synthesis of the zinc gallophosphate molecular sieve NTHU-4 which we can process as powders or as thin films by pulsed laser ablation. AAAAA The structure of NTHU-4 shown in Figure 1 is composed of corner shared tetrahedra of GaO4 , ZnO4 and PO4 /HPO4 . The 14 membered rings (14MR) in NTHU-4 define an elliptical pore 1.13nm in diameter. Interestingly, NTHU-4 can be prepared as 2 polymorphs designated NTHU-4Y and NTHU-4W. This arises because of MO4 and HPO4 disorder sites on the rim of the channels. The NTHU-4Y material emits yellow light at 550nm regardless of the excitation frequency over the range of 280-520nm. By heating the NTHU-4Y sample at 280 o C for 4 hours or by using a different synthesis route , the more ordered NTHU-4W was obtained which emits yellow light when excited >420nm and white light when excited below 420nm. The chromaticity coordinates for the white light generated by excitation at 390nm were 0.29,0.34 on a CIE diagram. This may be the first example of an intrinsic white light phosphor. We are currently studying hybrid composite materials comprising an organic electroluminescent material that emits at wavelengths <420nm, in turn exciting a nanoporous zinc gallophosphate molecular sieve to produce white light. The combination of high efficiency organic light emitting materials with inorganic phosphors should provide high efficiency, long term stability, and thin-film processability. We firmly believe that this work will make major strides in all research objectives confronting the advancement of hybrid materials for practical solid state lighting applications. -------------------------------------------------------------------------------- www.utdallas.edu/~balkus/Research.html#novel
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Post by aqt on Mar 7, 2010 16:30:50 GMT -5
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Post by aqt on Mar 7, 2010 16:31:32 GMT -5
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