Boulder, CO, United States

Eltron Research & Development Inc.

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Boulder, CO, United States

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Fraenkel D.,Eltron Research & Development Inc.
Journal of Physical Chemistry B | Year: 2011

The smaller-ion shell (SiS) model of strong binary electrolyte solutions extends the Debye-Hückel theory to the case of ions of unequal size; it is effective for many electrolytes of the various families in water at 25 °C up to moderate concentrations, with ion-size parameters (ISPs) of co-ions being equal to the ionic diameters, and with a varying degree of ISP additivity. A SiS analysis is now provided for aqueous solutions of the acids HCl, HBr, HI, and HClO4 at 25 °C; theory fits very well with experiment when the mean effective ionic diameter of the proton (H3O+) is chosen as ∼1.1 Å and the mean anion size is the corresponding crystallographic diameter, as with other electrolytes having the same anion. The ISP nonadditivity is positive and large, apparently reflecting a strong polarizing effect of the small proton on the large anion. The SiS-derived single-ion activity coefficients of the proton allow calculation of the pH of the acids, and reliable values are obtained below the known limit of pH ≈ 2, i.e., smaller and even negative values. The computed pH compares well with the experimentally derived Hammett acidity function, H0, up to moderate concentration; differences between the two functions at higher concentration shed light on the activity coefficients of Hammett indicators and their response to increasing acid strength. © 2010 American Chemical Society.


The recently introduced smaller-ion shell (SiS) treatment of strong binary electrolyte solutions [Fraenkel, D. Mol. Phys.2010, 108, 1435] that extends the Debye-Hückel theory to size-dissimilar ions is very effective for many electrolytes of various families up to moderate ionic concentration. The (molal) mean ionic activity coefficient, γ±, as a function of the reciprocal screening length, κ, hence ionic strength, I, is given by an analytic mathematical expression that incorporates the three ion-size parameters (ISPs). Experimental γ± data are fitted with calculated values derived from ISPs that seem to adequately represent the relevant mean effective ionic sizes. The SiS analysis has been lately shown effective for aqueous HCl, HBr, HI, and HClO4 at 25 °C, at which the solvent permittivity, ε, is 78.4 [Fraenkel, D. J. Phys. Chem. B2011, 115, 557]. In this paper, the behavior of HCl in solvents ranging in ε between approximately 10 and 80 is analyzed and discussed. The SiS treatment is found again suitable for computing γ± values that agree with experiment. Within the concentration range of the available experimental data, ion pairing is not indicated and, contrary to literature claims, HCl appears fully ionized even at 0.5 m (molal) with ε < 10. ISPs do not seem to be affected by temperature, but co-ion ISPs increase linearly with 1/ε. The chemical nature of the solution has no observable effect on γ± and on ISPs. The present analysis supports the view that electrolyte theories in which the solvent is considered at the McMillan-Mayer level can be successful and valuable. © 2011 American Chemical Society.


Fraenkel D.,Eltron Research & Development Inc.
Journal of Physical Chemistry B | Year: 2012

The almost century-old dispute over the validity of the experimentally derived activity of a single ion, ai, is still unsettled; current interest in this issue is nourished by recent progress in electrochemical cell measurements using ion-specific electrodes (ISEs) and advanced liquid junctions. Ionic solution theories usually give expressions for ai values of the positive and negative ions, that is, the respective a+ and a -, and combine these expressions to compute the mean ionic activity, a±, that is indisputably a thermodynamically valid property readily derivable from experiment. Adjusting ion-size parameters optimizes theory's fit with experiment for a± through "optimizing" a+ and a-. Here I show that theoretical ai values thus obtained from the smaller-ion shell treatment of strong electrolyte solutions [Fraenkel, Mol. Phys.2010, 108, 1435] agree with ai values estimated from experiment; however, theoretical ai values derived from the primitive model, the basis of most modern ionic theories, do not agree with experiment. © 2012 American Chemical Society.


Fraenkel D.,Eltron Research & Development Inc.
Journal of Physical Chemistry B | Year: 2012

According to the literature, when H2SO4 dissolves in water, (1) it retains its molecular formula and tetrahedral structure of two O atoms and two OH groups bonded to a central S atom, and (2) it ionizes partially, as a 1-1 electrolyte, to H+ (H3O+) and HSO4 -; the latter ion further dissociates at low concentrations (<0.1 M) to H+ and SO4 2-. Using the Debye-Hückel (DH) limiting law at very low concentration, and the smaller-ion shell (SiS) model of strong electrolyte solutions-an extension of the DH model for ion size dissimilarity-up to moderate concentration, I examine the theory-experiment fit of the mean ionic activity coefficient (γ±) of the acid as a function of concentration (at 0 to ∼6 m) and of temperature (at 0-60 °C). The fit is impossible if H 2SO4 in water is assumed to be a 1-1 or 1-2 electrolyte, but is excellent when the acid is treated instead as a strong 1-3 electrolyte; that is, aqueous sulfuric acid behaves as a fully dissociated H3A acid. At 25 °C, the SiS best fit is achieved with the H+ diameter being 1.16 Å (as obtained for strong mineral 1-1 protonic acids) and with the A3- ionic diameter being 5.77 Å. On the basis of the present study, H2SO4 in water may be H4SO 5 (dubbed "sulfoxuric", or parasulfuric acid) completely ionized to 3H+ and the ("bisulfoxate", or parabisulfate) anion HSO5 3-. The calculated standard potential of a newly proposed half-cell reaction, H2 + HSO5 3- ↔ H+ + SO4 2- + H2O + 2e -, at 25 °C, is -1.0933 V. © 2012 American Chemical Society.


Grant
Agency: Department of Defense | Branch: Navy | Program: SBIR | Phase: Phase I | Award Amount: 150.00K | Year: 2013

Eltron Research & Development, Inc (Eltron) has developed a refractory, flexible, inorganic paint that has shown excellent performance in protecting polymers from direct heat sources. In this project, Eltron will coat portable helipad mat materials such as polyethylene and polyester as well as other high temperature polymers and lightweight materials with refractory paint. Eltron"s refractory, ceramic coating will be completely inorganic and highly refractory with a melting point of>1000 & #176;C which will improve the thermal resistance of mat materials to be able to withstand 650 & #176;F minimum for 20 minutes minimum. We"ve developed a series of methods to provide excellent adhesion of our coatings to a variety of substrates including polymers, ceramics, and metals. Since Eltron"s coating provides a thin, refractory layer, there should be little change in weight, density, or volume compared to uncoated mats. The refractory coating should provide no change in corrosion and weather resistance, installation, ground preparation, ground securing, or dust suppression compared to uncoated mats. The structural and thermal properties of refractory coated mat samples will be shown to be superior to uncoated samples while maintaining many of the puncture strength, tear resistance, and air permeability properties required for a portable helipad.


Patent
Eltron Research & Development Inc. | Date: 2015-06-30

Composition and method for production of peroxycarboxylic acid solutions for various disinfection and cleaning compositions that utilizes non-equilibrium peroxycarboxylic acid. More specifically compositions comprise peracetic acid (PAA) and methods for making non-equilibrium PAA are provided. Frozen compositions useful as antimicrobial ice are provided.


Patent
Eltron Research & Development Inc. | Date: 2016-10-06

Composition and method for production of peroxycarboxylic acid solutions for various disinfection and cleaning compositions that utilizes non-equilibrium peroxycarboxylic acid. More specifically compositions comprise peracetic acid (PAA) and methods for making non-equilibrium PAA are provided. Frozen compositions useful as antimicrobial ice are provided.


Patent
Eltron Research & Development Inc. | Date: 2013-06-03

Composition and method for production of peroxycarboxylic acid solutions for various disinfection and cleaning compositions that utilizes non-equilibrium peroxycarboxylic acid. More specifically compositions comprise peracetic acid (PAA) and methods for making non-equilibrium PAA are provided. Frozen compositions useful as antimicrobial ice are provided.


Grant
Agency: Department of Energy | Branch: | Program: SBIR | Phase: Phase II | Award Amount: 1.00M | Year: 2011

Although means currently exist to capture CO2 from combustion and other sources, capture at atmospheric levels is difficult. Once captured, CO2 needs to be released in concentrated form and sequestered: e.g., it can be buried under ocean water or in underground vaults, or it can be reacted with basic metal oxides to form metal carbonates. It may also be reduced to methane (another greenhouse gas), which requires compression and cryogenic liquefaction. Thus, the opportunity and need exists for development of new approaches for capturing, sequestering, and utilizing atmospheric CO2. The Phase I approach addressed development of an integrated system for the concomitant capture of CO2 from air and conversion to more valuable product. The system utilizes a new nanostructured adsorbent material which possesses base sites and is electrochemical regenerated, resulting in conversion of captured atmospheric CO2 and water to more valuable products. The adsorbent is integrated with the cathode of an electrochemical cell to concomitantly capture and reduce (electrochemically strip) CO2 while the anode incorporates a hydrogen oxidation electrocatalyst. Reaction of captured CO2 and H2 produced by a separate electrolyzer produces a precursor chemical. Identification of preferred adsorbent, demonstration of core unit operations, and preliminary design of the overall process and system were key Phase I objectives that were met. CO2 adsorbents and integrated cathodes will optimized and a prototype system fabricated and the overall process demonstrated during Phase II. Commercial Applications and Other Benefits: There is broad interest in CO2 capture and re-use technologies in anticipation of more regulation. Eltron has received commercial interest in this particular technology by wind power developers seeking to make use of electricity produced off-peak or in excess of local demand.. Consequently, Eltron expects significant commercial interest in the technology upon successful prototype demonstration on the proposed program


Grant
Agency: Department of Defense | Branch: Army | Program: SBIR | Phase: Phase II | Award Amount: 730.00K | Year: 2012

Cold spray has many benefits compared to conventional thermal spray including lower deposition temperatures, higher bond strengths, less substrate preparation and better control of coating composition, phase structure, and oxide contamination. In cold spray, particles are accelerated by an expanding gas to 180-1200 m/s, where they collide with a substrate to form a coating on the surface in the solid state. Since reduced deposition temperatures are used, coatings have the same properties as the initial particles. However, in the cold spray process, particles smaller than 5 microns in diameter have insufficient momentum to penetrate a shock wave region next to the substrate. Nanoparticles offer many benefits in strength, hardness, and reactivity but are unable to be used in the cold spray process due to insufficient mass and, therefore, momentum. In the Phase I project, Eltron developed a method for spray drying agglomerates of nanoparticles for use in the cold spray process. Spray drying is a low-cost, well-established powder processing method used often in the food and catalyst industries. The objectives of this Phase II project include: 1) produce larger (10-20 lb.) batches of powder for consolidation by cold spray at the Army Research Laboratory, 2) develop a system for consolidating smaller, more reactive, un-passivated metal particles, 3) determine the effect of slurry flow rate, nozzle diameter, gas flow rate, nanoparticle size, binder concentration and binder choice with larger volume slurries on agglomerate morphology, size, and size distribution, 4) characterize agglomerates using optical and scanning electron microscopy, chemical analysis, density measurements, x-ray diffraction, and surface area/pore size and volume analysis, and 5) optimize economic considerations including nanoparticle, metallic binder precursor, and solvent costs, leading to an estimate of powder costs when produced on a commercial scale. Work towards these objectives will lead to a flexible process for producing relatively inexpensive nanostructured powders that enables use of a variety of nanoparticle compositions and particle sizes (from 10 200 nm). During Phase II, larger volume slurries will be optimized and process variables will be determined to best prepare for scale-up to production levels of 100 lbs/day (during Phase III).

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