Nanoscale Materials in Chemistry, Second edition
Book file PDF easily for everyone and every device.
You can download and read online Nanoscale Materials in Chemistry, Second edition file PDF Book only if you are registered here.
And also you can download or read online all Book PDF file that related with Nanoscale Materials in Chemistry, Second edition book.
Happy reading Nanoscale Materials in Chemistry, Second edition Bookeveryone.
Download file Free Book PDF Nanoscale Materials in Chemistry, Second edition at Complete PDF Library.
This Book have some digital formats such us :paperbook, ebook, kindle, epub, fb2 and another formats.
Here is The CompletePDF Book Library.
It's free to register here to get Book file PDF Nanoscale Materials in Chemistry, Second edition Pocket Guide.
These results could not be attributed solely to higher surface areas, but the nanocrystalline materials of MgO and CaO exhibited inherently high surface reactivities. Then, by adding small amounts of transition metals, a catalytic ion-mixing took place.
It was rationalized that the lower melting FeCl3 was mobile in the CaO or MgO matrix, and, due to a thermodynamic driving force, exchanged the Cl-, forming an iron oxide species capable of reaction again. In this way, complete reaction of the bimetallic oxide took place. These favorable findings proved to hold for other high temperature destructive adsorption reactions for a series of chlorocarbons and for acid gases such as SO2 These results suggest that nanoscale crystalline solids can be viewed as a new class of near stoichiometric chemical reagents.
Large surface areas, coupled with enhanced surface reactivities, coupled with strategic addition of small amounts of catalytic transition metal ions make this a reality for a large number of environmental remediation chemistries.
Lower Temperature Chemistry It soon became apparent that nanoscale oxides were capable of destructive adsorption of organohalides and organophosphorus compounds at much lower temperatures, in many cases, at room temperature. This observation opened up a large number of environmental remediation possibilities. Of even more interest were studies of differing masses that equaled moles surface oxide to one mole 2-CEES in order to correct for surface area effects.
These results and others 20 led to in-depth studies of nano-MgO, CaO, Al2O3 with real chemical warfare agents 21—23 , and these are covered in Chapter 7 by Dr. George Wagner. Also, commercial products have been developed by NanoScale Corporation, based on the accumulation of data on the efficacy and 5 In Nanoscale Materials in Chemistry: Environmental Applications; Erickson, L. A wide variety of toxic industrial chemicals TICs have been found to be susceptible to treatment by these destructive adsorbents.
- Software Product Lines: Experience and Research Directions.
- Nanoscale materials in chemistry / edited by Kenneth J. Klabunde - Details - Trove?
- About the TSCA Chemical Substance Inventory.
- Change at Hand: Balancing Your Energy Through Palmistry, Chakras & Mudras!
- Nanoscience & Nanotechnology – New books | MIT Libraries;
Remediation of chemical spills, contaminants in commercial gases, and odors in air are now commonplace with this class of safe-to-use nano-metal oxides 3. Biocidal Nanoscale Materials Biological toxins, including bacteria, bacterial spores, such as anthrax, and viruses are probably the most serious threats. The need is growing for broadspectrum biocides that can decontaminate tough-to-kill spores, as well as other biological threats, such as prions.
There are numerous effective biocides available, such as bleach solution, chlorine dioxide gas, volatile halogens Cl2, Br2 , methyl bromide gas, and high energy radiation. However, there are very few effective, solid biocides. Therefore, we considered the high sorption capacities of these nanocrystalline metal oxides, and did some experiments where gaseous biocides were adsorbed on their surfaces, with the idea that thereby biocidal solids would be produced.
This led to the formation of metal oxide-halogen and metal oxide-mixed halogen adducts, where the halogens were chemisorbed rather strongly, but in a zero-valent state, thus allowing the solid oxides to provide active halogen toward bacteria, spores, and viruses 24— Indeed, these high surface area solids were very effective for destroying E-Coli, Bacillus Cerus, and Bacillus Subtilis spores, Sterne strain anthrax spores, and several viruses.
There were four modes of action discerned: 1 electrostatic attraction of the spores to the nanoparticles, 2 high local pH weakening the spore protective outer layer, 3 abrasive action, and 4 oxidative reactions with the attached zero-valent halogens. These nano-oxide-halogen adducts are effective in dry contact with the biothreat, or as water slurries.
Types of Nanoparticles
One set of experiments was very interesting. In a level 3 biocidal chamber, Bacillus Subtillus spore-water solution was sprayed as a mist. Five minutes later, MgO-Cl2 yellow-green adduct was sprayed as a dry, fine powder. Air samples pulled air down and around agar plates. In this way the sticky agar trapped airborne spores and nanopowders aggregates. These plates were incubated, and showed, with the help of control experiments, that the trapped spores were completely decontaminated see Figure 3 All of these results were quite positive, and the halogen adducts are strongly biocidal as powders or in pellet form.
Indeed, they are very active zero-valent halogen sources, even capable to selective halogenation of organic alkenes and alkanes On the negative side, these adducts are too reactive to allow exposure to animals or humans. On the positive side, they are very effective, and in the environment rather rapidly degrade to mineral and salt substances, and so are not long-term pollutants. Nonetheless, the search for easier to handle and safer biocides must go on, and work with nano-oxides containing silver as a biocide is discussed in Chapter Fuels, textiles, chemicals, and reduced automobile emissions have all been profoundly affected by such heterogeneous catalysts 2.
As discussed in Chapter 15, indoor air quality is another area of application. In more recent years, three related areas of interest in catalysis have been explored, as discussed below.
Catalytic Transition Metal Ions in Destructive Adsorption Solid-gas chemical reactions at elevated temperatures can often be enhanced to stoichiometric reactions by the use of transition metal ions in metal oxides. TEM micrograph of untreated a and treated b and c B. Figure 3. Room size chamber for mixing and sampling air-borne spores and air-borne nanoparticles. Reproduced with permission from reference Similar enhancements were observed for CCl4 0. As shown in Figure 5, upon reaction VCl3 exchanged chloride to eventually yield V2O3, which could migrate back to the surface for further reaction with CCl4 Additional studies showed that quite a wide range of environmentally problematic compounds can be destroyed stoichiometrically by utilizing small amounts of Fe2O3 as a catalyst coupled with MgO, CaO, ZnO, or Al2O3 nanocrystalline materials A particularly interesting result was that hydrogen sulfide H2S could be converted to metal sulfides under very mild conditions, and the best nanoscale materials for this were [Fe2O3]CaO and ZnO 32, Show related SlideShares at end.
Nanoscale Materials in Chemistry, 2nd Edition
Educationtempe36 Follow. Published in: Science. Full Name Comment goes here. Are you sure you want to Yes No. Be the first to like this. No Downloads. Views Total views. Actions Shares.
Download Product Flyer
Embeds 0 No embeds. No notes for slide. Nanoscale materials in chemistry pdf 1.
Classic theory of nucleation and growth of crystals assumes that crystals grow by ordering atoms monomers one at at a time in prescribed positions in the crystal structure. However, modern studies of growth mechanisms of crystals shows that crystals more typically grow by aggregation of nanoparticles. Crystallization pathways may involve formation of multi-ion complexes from dissociated ions, to organization of these complexes into isolated nanoparticles with very short range order, to oriented aggregates of nanoparticles, and ultimate formation of macroscopic crystals.
Nanoscience & Nanotechnology – New books
Examples of this type of crystallization pathway of crystals forming from aggregates of nanoparticles can be found in calcium carbonates, calcium phosphates, ferric hydroxides and hydroxyl-sulfates, and aluminosilicate nanoparticles. One of the most important properties of nanominerals is solubility. The size effect on dissolution has long been described by this modified version of Kelvin equation.
In the diagram, So is the solubility of the bulk macro material and can be substituted for Po. It is typically measured in conventional dissolution studies.
Nanoscience & Nanotechnology Series
S is the solubility of fine nano-scale particles and can be substituted for P. This equation indicates that, as the particle size decreases, the solubility is expected to exponentially increase. This plot shows the ratio of S to So vs particle radius for quartz grains. It was calculated according to this equation using the parameters of quartz grains. Nothing changes with the size. Only when the size goes down to the nanoscale , the ratio substantially deviates from 1 and the size effect on solubility can be observed.
However, this equation was proposed based on theoretic calculation. Very few experimental studies have been reported to support it. But wait! There's more! In addition, the range of validity of the modified kelvin equation has been questioned.