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A number of researchers have deployed silver (Ag) nanoparticles through a number of techniques on various substrates including carbon, zeolites and polymers for water disinfection applications. However, Ag impregnated on an inorganic... more
A number of researchers have deployed silver (Ag) nanoparticles through a number of techniques on various substrates including carbon, zeolites and polymers for water disinfection applications. However, Ag impregnated on an inorganic fiberglass surface through a simple electroless process was only recently reported for the first time. Fiberglass impregnated with Ag nanoparticles displays superior performance over carbon-based silver support systems but little is known about the factors that affect the architecture of the system, its interfacial properties and its consequent bactericidal activity. In this study, Ag content and particle size on a fiberglass substrate were manipulated by adjusting the AgNO3 concentration, immersion time, temperature, solution pH and reduction temperature. The reduction chemistry of the Ag-nanoparticle-impregnated fiberglass is described and supported with thermal gravimetric analysis (TGA) and photoelectron spectroscopy (XPS) measurements. The Ag content along with the particle size and particle size distribution were characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive x-ray spectroscopy (EDS) and x-ray diffraction (XRD). The Ag content on the fiberglass mats ranged from 0.04 to 4.7 wt% Ag/g-fiber with a size distribution of 10-900 nm under standard processing conditions. Inductively coupled plasma mass spectrometry (ICP-MS) was used to analyze the Ag desorption from the fiberglass substrate, while the bactericidal properties were evaluated against Escherichia coli (E. coli).
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Novel composite polymer membranes for fuel-cell applications were prepared by solution blending sulfonated poly(ether ether ketone) (sPEEK) and polyacrylonitrile (PAN) in DMF and heating under nitrogen at 380°C. The incorporation of PAN... more
Novel composite polymer membranes for fuel-cell applications were prepared by solution blending sulfonated poly(ether ether ketone) (sPEEK) and polyacrylonitrile (PAN) in DMF and heating under nitrogen at 380°C. The incorporation of PAN into sPEEK membranes significantly reduced the swelling in hot water and decreased methanol permeability of the membranes. An optimum ratio of sPEEK and PAN for proton conductivity was
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... Two carbon blacks, Pearls 2000 and Vulcan XC72 were obtained from Cabot Corporation. ... 3. Effect of ratio of carbon black (Pearls 2000) to phenolic resin on the BET surface area and volumes of micropores and mesopores of carbons... more
... Two carbon blacks, Pearls 2000 and Vulcan XC72 were obtained from Cabot Corporation. ... 3. Effect of ratio of carbon black (Pearls 2000) to phenolic resin on the BET surface area and volumes of micropores and mesopores of carbons prepared with NaOH activation at 600 °C. ...
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ABSTRACT
Research Interests: Electrochemistry, Nanofibers, Electrospinning, Crystallization, Nanotechnology, and 13 moreMultidisciplinary, Processing, Mechanical Stress, Particle Size, Surface Properties, Elastic Modulus, Molecular Conformation, Small, Carbon Fibers, Carbon Fiber, Materials Testing, Tensile Strength, and Nanotubes Carbon
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A highly efficient adsorbent for arsenic removal from water has been prepared by impregnating high surface area iron oxides on glass fibers. Arsenic in water can easily and efficiently be removed by this adsorbent, without the need to... more
A highly efficient adsorbent for arsenic removal from water has been prepared by impregnating high surface area iron oxides on glass fibers. Arsenic in water can easily and efficiently be removed by this adsorbent, without the need to pre-oxidize As(III) to As(V). The iron oxides coated on glass fibers (IOCGFs) can remove both arsenic species well below EPA MCL (10 ppb). IOCGFs should have the following four additional advantages: greatly improved contact efficiency; higher adsorption capacity because of high surface area; low cost and easily available adsorbent since the starting reagents (FeCl3 and NH3·H2O) and glass fiber are cheap and readily available; and high adsorption efficiency of As(III) and As(V).
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... Two carbon blacks, Pearls 2000 and Vulcan XC72 were obtained from Cabot Corporation. ... 3. Effect of ratio of carbon black (Pearls 2000) to phenolic resin on the BET surface area and volumes of micropores and mesopores of carbons... more
... Two carbon blacks, Pearls 2000 and Vulcan XC72 were obtained from Cabot Corporation. ... 3. Effect of ratio of carbon black (Pearls 2000) to phenolic resin on the BET surface area and volumes of micropores and mesopores of carbons prepared with NaOH activation at 600 °C. ...
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Research Interests: Engineering, Materials Engineering, Mechanical Engineering, Condensed Matter Physics, Glass, and 26 moreNanoparticle, Scanning Electron Microscopy, PHOTOELECTRON SPECTROSCOPY, Nanomaterials, Transmission Electron Microscopy, Nanotechnology, Multidisciplinary, Metal Nanoparticles, Silver, Escherichia coli, Silica, Ultrasonics, Reaction Time, Deposition, Surface plasmon resonance, Nucleation and Growth, Polyethylene, CHEMICAL SCIENCES, Surfaces, X ray diffraction, Particle Size, Surface Properties, Silver Nanoparticle, Water Microbiology, Aqueous Solution, and Organometallic Compounds(Nanoparticle, Scanning Electron Microscopy, PHOTOELECTRON SPECTROSCOPY, Nanomaterials, Transmission Electron Microscopy, Nanotechnology, Multidisciplinary, Metal Nanoparticles, Silver, Escherichia coli, Silica, Ultrasonics, Reaction Time, Deposition, Surface plasmon resonance, Nucleation and Growth, Polyethylene, CHEMICAL SCIENCES, Surfaces, X ray diffraction, Particle Size, Surface Properties, Silver Nanoparticle, Water Microbiology, Aqueous Solution, and Organometallic Compounds)
(Nanoparticle, Scanning Electron Microscopy, PHOTOELECTRON SPECTROSCOPY, Nanomaterials, Transmission Electron Microscopy, Nanotechnology, Multidisciplinary, Metal Nanoparticles, Silver, Escherichia coli, Silica, Ultrasonics, Reaction Time, Deposition, Surface plasmon resonance, Nucleation and Growth, Polyethylene, CHEMICAL SCIENCES, Surfaces, X ray diffraction, Particle Size, Surface Properties, Silver Nanoparticle, Water Microbiology, Aqueous Solution, and Organometallic Compounds)
Removal of a wide range of trace organic contaminants from water to concentrations below USEPA Maximum Contaminant Levels (MCL) remains an important goal for the water industry. Design of advanced carbon based adsorption systems... more
Removal of a wide range of trace organic contaminants from water to concentrations below USEPA Maximum Contaminant Levels (MCL) remains an important goal for the water industry. Design of advanced carbon based adsorption systems represents a unique approach to solving these problems. A number of successful examples are cited in this paper and are briefly summarized in the following section.
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Novel composite polymer membranes for fuel-cell applications were prepared by solution blending sulfonated poly(ether ether ketone) (sPEEK) and polyacrylonitrile (PAN) in DMF and heating under nitrogen at 380°C. The incorporation of PAN... more
Novel composite polymer membranes for fuel-cell applications were prepared by solution blending sulfonated poly(ether ether ketone) (sPEEK) and polyacrylonitrile (PAN) in DMF and heating under nitrogen at 380°C. The incorporation of PAN into sPEEK membranes significantly reduced the swelling in hot water and decreased methanol permeability of the membranes. An optimum ratio of sPEEK and PAN for proton conductivity was
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Polyacrylonitrile (PAN) cationic and anionic exchange NF membranes were prepared from ultrafiltration (UF) membranes through a convenient way developed recently by us. By the reaction between nitrile groups and NaOH or... more
Polyacrylonitrile (PAN) cationic and anionic exchange NF membranes were prepared from ultrafiltration (UF) membranes through a convenient way developed recently by us. By the reaction between nitrile groups and NaOH or 3-(dimethylamino)propyl amine, negative or positive functional groups were introduced into the meso-macropores of PAN UF membranes. These meso-macropores were then reduced into the range of micro-mesopores by taking advantage of surface tension forces within the capillary pores during heat treatment in the presence of ZnCl2.The effective pore radius of the commercial cationic exchange NF membrane, NTR 7450, was measured from pure water permeability coefficients by a simple method, which utilized univalent alkaline ions as probes.
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ABSTRACT
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ABSTRACT
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... Zhongren Yuea, James Economy*a, Kishore Rajagopalanb, Gary Bordsonb, Marv Piwonib, Li Dingc, Vernon L. Snoeyinkc and Benito J. Mariñasc. ... 13, Q. Li, VL Snoeyink, BJ Marinas and C. Campos, Water Res., 2003, 37(20), 486372 Article... more
... Zhongren Yuea, James Economy*a, Kishore Rajagopalanb, Gary Bordsonb, Marv Piwonib, Li Dingc, Vernon L. Snoeyinkc and Benito J. Mariñasc. ... 13, Q. Li, VL Snoeyink, BJ Marinas and C. Campos, Water Res., 2003, 37(20), 486372 Article ChemPort . ...
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Research Interests: Engineering, Kinetics, Carbon, Water Purification, Water Pollution, and 16 moreHazardous Waste, Porous Materials, Adsorption, Activated Carbon, Porosity, Charcoal, Pellet, Temperature, Hazardous Materials, Chromium, Fiberglass, Surface Area, Porous Material, Functional Group, Oxidation, and Low Temperature
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A new, low-cost fiber glass supported activated carbon (FGAC) filter has been prepared that displays enhanced adsorption characteristics for the removal of BTEX (benzene, toluene, ethylbenzene, and p-xylene) from water to below maximum... more
A new, low-cost fiber glass supported activated carbon (FGAC) filter has been prepared that displays enhanced adsorption characteristics for the removal of BTEX (benzene, toluene, ethylbenzene, and p-xylene) from water to below maximum contaminant level (MCL) regulated by USEPA and two chemical warfare agent simulants (diisopropylmethyl phosphonate and 2-chloroethyl ethyl sulfide) to barely detectable levels. Breakthrough curves for both the FGAC filter and a commercially available granular activated carbon (GAC) filter containing equal weights of adsorbent show that the FGAC filter has greatly improved kinetics of adsorption over the GAC filter for all six chemical contaminants. Benzene breakthrough curves showed the FGAC filter effluent to contain less than one ppb as compared to several parts per million in the GAC filter effluent. This was 2 orders of magnitude better than the GAC and represents a major advance in generating good water quality for the military as well as the general public. The FGAC filter showed a much lower pressure drop and could be completely regenerated at least 6 times by heating to 190 degrees C under vacuum.
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The pore size distribution (PSD) of adsorbents has been found to be an important factor that affects adsorption capacity for organic compounds; consequently, it should influence competitive adsorption in multisolute systems. This research... more
The pore size distribution (PSD) of adsorbents has been found to be an important factor that affects adsorption capacity for organic compounds; consequently, it should influence competitive adsorption in multisolute systems. This research was conducted to show howthe PSD of activated carbon affects the competition between natural organic matter (NOM) and the trace organic contaminant atrazine, with a primary emphasis on quantifying the pore blocking mechanism of NOM competition. Isotherm tests were performed for both atrazine and NOM from a groundwater on five powdered activated carbons (PACs) with widely different PSDs. The capacity for NOM correlated best with the surface area of pores in the diameter range of 15-50 A, although some NOM also adsorbed in the smaller pores as evidenced by a reduction in capacity for atrazine when NOM was present. Kinetic tests for atrazine on PACs with various levels of preadsorbed NOM showed that the magnitude of the pore blockage effect by NOM was lower for PACs with higher surface area of pores with diameter in the range of 15-50 A. Therefore increasing pores in the size range where NOM adsorb can reduce the extent of the pore blockage competitive effect on the target compound atrazine. The effect of PSD was further studied with a flow-through PAC-membrane hybrid watertreatment system, in which experimental results successfully verified model simulations by the COMPSORB model.
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