In this study, the flexible polymer substrate polyethylene naphthalate (PEN) was modified under t... more In this study, the flexible polymer substrate polyethylene naphthalate (PEN) was modified under two different plasma chemistries, namely helium–oxygen (He–O 2) and helium–water vapor (He–H 2 O) plasmas at atmospheric pressure and room temperature. Surface changes related to wettability, chemical functionalization, surface energy, and morphology after plasma treatment were investigated using water contact angle (WCA) goniometry, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). Each plasma resulted in a more hydrophilic PEN surface, with WCA decreasing by 68% and 85% for He–O 2 and He–H 2 O plasma treated PEN, respectively, after only 1.0 s of exposure. An aging study of plasma treated PEN shows an increase in WCA that is still 30° lower than that of the as-received PEN after 1 month. XPS and AFM results show that improved wettability of the plasma modified PEN is due to the oxidation of the surface and not due to the increased surface roughness. To promote a roll-to-roll process of atmospheric plasma treatment and inkjet deposition, printing was performed using the conductive polymer poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) on the as-received and plasma treated PEN surfaces where the shape and morphology of the lines were studied. Each plasma treated PEN surface exhibited well-defined, uniform inkjet-printed lines due to the improved wettability and increased surface energy. After scanning electron microscopy (SEM) analysis of the PEDOT:PSS dispersion of a single drop on each substrate, the He–H 2 O plasma treated surface led to less agglomeration of PEDOT:PSS and a more homogeneous drop deposit. Published by Elsevier B.V.
Because of the extensive costs associated with building composite laminates, the U.S. Army is exp... more Because of the extensive costs associated with building composite laminates, the U.S. Army is exploring approaches to reducing process steps associated with hybridized structures. One area of focus is in surface preparation for secondary bonding. An important quality of an effective surface preparation method is its ability to consistently provide clean and highly chemically active substrates for bonding. In this report, we examine peel ply surface preparation methods for secondary bonding of composite substrates using FM 94K epoxy film adhesive by mechanical testing, elemental surface analysis, and high-resolution imaging of failure surfaces. Woven S2 fiberglass infused with SC-15 toughened epoxy resin composites laminates, were fabricated by the Vacuum Assisted Resin Transfer Molding process. Tool-side surfaces of the composites were prepared using nine commercial off-the-shelf peel plies, including dry and impregnated forms. Two preparation methods for bonding were investigated: ...
Because of the extensive costs associated with building composite laminates, the U.S. Army is exp... more Because of the extensive costs associated with building composite laminates, the U.S. Army is exploring approaches to reduce the processing steps associated with hybridized structures. One area of focus is in surface preparation for secondary bonding. An important quality of an effective surface preparation method is its ability to consistently provide clean and highly chemically active substrates for bonding. In this report, we examine peel ply surface preparation methods for secondary bonding of composite substrates using FM 94K epoxy film adhesive by mechanical testing, elemental surface analysis, and high-resolution imaging of failure surfaces. Woven S2 fiberglass infused with SC-15-toughened epoxy resin composite laminates was fabricated by the vacuum-assisted resin transfer molding process. Tool-side surfaces of the composites were prepared using nine commercial off-the-shelf peel plies, including dry and impregnated forms. Two preparation methods for bonding were investigated...
Public reporting burden for this collection of information is estimated to average 1 hour per res... more Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing the burden, to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number.
Public reporting burden for this collection of information is estimated to average 1 hour per res... more Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing the burden, to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number.
The generation of air-based plasmas under atmospheric plasma conditions was studied to assess the... more The generation of air-based plasmas under atmospheric plasma conditions was studied to assess their antimicrobial efficacy against commonly found pathogenic bacteria. The mixture of initial gases supplied to the plasma was found to be critical for the formation of bactericidal actives. The optimal gas ratio for bactericidal effect was determined to be 99% nitrogen and 1% oxygen, which led to a 99.999% reduction of a pathogenic strain of Escherichia coli on stainless steel surfaces. The experimental substrate, soil load on the substrate, flow rate of the gases, and addition of ethanol vapor all were found to affect antimicrobial efficacy of studied plasmas. Optical emission spectroscopy was used to identify the species that were present in the plasma bulk phase for multiple concentrations of nitrogen and oxygen ratios. The collected spectra indicate a unique series of bands present in the ultraviolet region of the electromagnetic spectrum that can be attributed to nitric oxide species known to be highly antimicrobial. This intense spectral profile dramatically changes as the concentration of nitrogen decreases.
ABSTRACT Summary form only given. Surface treatment of polymers using plasma has teen widely impl... more ABSTRACT Summary form only given. Surface treatment of polymers using plasma has teen widely implemented to enhance the adhesion and wettability of the material through the inclusion of polar functional groups. In the case of high-strength organic fibers for composite applications, it is imperative to apply such a technique to overcome interfacial discontinuities that exist between two thermodynamically different materials. Through the use of atmospheric pulsed-dielectric barrier discharges (DBD), ultra -high -molecular weight polyethylene (UHMW-PE) films were treated with nitrogen gas to the effect where nitrogen-and oxygen-containing functional groups were deposited on the surface. To avoid the effects of oxidative degradation during and after plasma treatments, various treatment times and gas flow-rates were used to achieve higher uptake of N-containing species over that of O-containing species. Using surface analysis techniques such as attenuated total reflectance-Fourier transform infrared (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), and water contact angle measurements, variation in surface energy and chemical composition has been studied. To understand the mechanism of interaction between the plasma and the surface of the polymer, optical emission spectroscopy has been applied to identify and characterize key chemical species present in the DBD plasma.
ABSTRACT In this study, the flexible polymer substrate polyethylene naphthalate (PEN) was modifie... more ABSTRACT In this study, the flexible polymer substrate polyethylene naphthalate (PEN) was modified under two different plasma chemistries, namely helium–oxygen (He–O2) and helium–water vapor (He–H2O) plasmas at atmospheric pressure and room temperature. Surface changes related to wettability, chemical functionalization, surface energy, and morphology after plasma treatment were investigated using water contact angle (WCA) goniometry, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). Each plasma resulted in a more hydrophilic PEN surface, with WCA decreasing by 68% and 85% for He–O2 and He–H2O plasma treated PEN, respectively, after only 1.0 s of exposure. An aging study of plasma treated PEN shows an increase in WCA that is still 30° lower than that of the as-received PEN after 1 month. XPS and AFM results show that improved wettability of the plasma modified PEN is due to the oxidation of the surface and not due to the increased surface roughness. To promote a roll-to-roll process of atmospheric plasma treatment and inkjet deposition, printing was performed using the conductive polymer poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) on the as-received and plasma treated PEN surfaces where the shape and morphology of the lines were studied. Each plasma treated PEN surface exhibited well-defined, uniform inkjet-printed lines due to the improved wettability and increased surface energy. After scanning electron microscopy (SEM) analysis of the PEDOT:PSS dispersion of a single drop on each substrate, the He–H2O plasma treated surface led to less agglomeration of PEDOT:PSS and a more homogeneous drop deposit.
ABSTRACT In this study, the surfaces of ultrahigh molecular weight polyethylene (UHMWPE), poly( e... more ABSTRACT In this study, the surfaces of ultrahigh molecular weight polyethylene (UHMWPE), poly( ethylene terephthalate) (PET), and polytetrafluoroethylene (PTFE) films were treated with a helium-water vapor plasma at atmospheric pressure and room temperature. Surface changes related to hydrophilicity, chemical funtionalization, surface energy, and adhesive strength after plasma treatment were investigated using water contact angle (WCA) measurements, Xray photoelectron spectroscopy (XPS), and mechanical T-peel tests. Results indicate increased surface energy accompanied with enhanced hydrophilicity. WCA decreased by 36, 50, and 16% for UHMWPE, PET, and PTFE, respectively, after only 0.4 s treatment. For UHMWPE, it is shown that the surface functionalization can be tailored depending on the plasma exposure time. Aging studies performed for these three polymers show the stability of the surface groups as indicated by a small increase in WCA values of plasma treated samples which can be attributed to cross-linking of surface and subsurface polymer chains. XPS analysis of the surfaces show increased oxygen content via the formation of polar, hydroxyl-based functional groups. Furthermore, major changes in the polymer structure of PET are observed, possibly due to the opening of the aromatic rings caused by the plasma energetic species. T-peel test results show an 8, 7.5, and 400-fold increase in peel strength for UHMWPE, PET, and PTFE, respectively. Most importantly, it is shown that water-vapor based plasmas can be a promising, "green,'' inexpensive route to promote the surface activation of polymers.
Invasive species are described as the greatest threat to biodiversity, after habitat destruction ... more Invasive species are described as the greatest threat to biodiversity, after habitat destruction and climate change, potentially imposing economic impacts and indigenous species impairment. Commonly applied chemical controls present the potential for legacy contamination and non-target organism injury. This study investigated the effects of different substrates and novel topographical surfaces on the behavioral and mechanical associations of the terrestrial gastropod Otala lactea. The gastropod preferentially aestivated on rough glass (61% increase, P < 0.01) relative to smooth glass but avoided a cross-patterned surface tessellation on silicone (82% reduction, P < 0.01) relative to smooth silicone. Significant deviations in turning behavior were found on the cross-patterned topographical surface and hydrophobic Teflon surfaces. The strongest correlation with gastropod adhesion strength to surfaces was found for surface elastic modulus (R = 0.88, P = 0.03), followed by hydrophobicity (R = - 0.71, P = 0.14), but no relationship with roughness (P = 0.36). Preliminary data suggest surface roughness controlled aestivation behavior while elastic modulus (surface flexibility) controlled adhesion strength. In spite of greater adhesion to high-modulus materials, surface modulus was not a statistically significant controlling factor on gastropod aestivation preference. Understanding and exploiting the behavioral and mechanistic cues that organisms use while attaching to surfaces may lead to more environmentally benign control approaches.
The currently used multistep chemical synthesis for making surfaces antimicrobial by attaching to... more The currently used multistep chemical synthesis for making surfaces antimicrobial by attaching to them hydrophobic polycations is replaced herein by an aerosol-assisted plasma deposition procedure. To this end, N,N-hexyl,methyl-PEI (HMPEI) is directly plasma-coated onto a glass surface. The resultant immobilized HMPEI coating has been thoroughly characterized and shown to be robust, bactericidal against Escherichia coli, and virucidal against human influenza virus.
The surface pretreatment regiment currently being used for ceramic materials includes aggressive ... more The surface pretreatment regiment currently being used for ceramic materials includes aggressive surface cleaning with small alumina particles (grit blasting) coupled with chemical treatments such as priming and the application of silane coupling agents. Grit blasting, while effective at removing surface contaminants such as adventitious carbon, also acts to reduce flexural strength by exacerbating existing surface flaw populations. The aim of this work is to develop a surface treatment that will remove surface contamination and functionalize the surface without having detrimental effects on the mechanical strength. As an alternative to grit blasting, atmospheric plasma treatments were used to remove surface contaminants and chemically functionalize the surface of alumina in one step. Atmospheric plasma processing of materials removes the surface residual impurities and causes chemical modification, improving surface wettability and chemical reactivity.
Public reporting burden for this collection of information is estimated to average 1 hour per res... more Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing the burden, to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number.
In this study, the flexible polymer substrate polyethylene naphthalate (PEN) was modified under t... more In this study, the flexible polymer substrate polyethylene naphthalate (PEN) was modified under two different plasma chemistries, namely helium–oxygen (He–O 2) and helium–water vapor (He–H 2 O) plasmas at atmospheric pressure and room temperature. Surface changes related to wettability, chemical functionalization, surface energy, and morphology after plasma treatment were investigated using water contact angle (WCA) goniometry, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). Each plasma resulted in a more hydrophilic PEN surface, with WCA decreasing by 68% and 85% for He–O 2 and He–H 2 O plasma treated PEN, respectively, after only 1.0 s of exposure. An aging study of plasma treated PEN shows an increase in WCA that is still 30° lower than that of the as-received PEN after 1 month. XPS and AFM results show that improved wettability of the plasma modified PEN is due to the oxidation of the surface and not due to the increased surface roughness. To promote a roll-to-roll process of atmospheric plasma treatment and inkjet deposition, printing was performed using the conductive polymer poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) on the as-received and plasma treated PEN surfaces where the shape and morphology of the lines were studied. Each plasma treated PEN surface exhibited well-defined, uniform inkjet-printed lines due to the improved wettability and increased surface energy. After scanning electron microscopy (SEM) analysis of the PEDOT:PSS dispersion of a single drop on each substrate, the He–H 2 O plasma treated surface led to less agglomeration of PEDOT:PSS and a more homogeneous drop deposit. Published by Elsevier B.V.
Because of the extensive costs associated with building composite laminates, the U.S. Army is exp... more Because of the extensive costs associated with building composite laminates, the U.S. Army is exploring approaches to reducing process steps associated with hybridized structures. One area of focus is in surface preparation for secondary bonding. An important quality of an effective surface preparation method is its ability to consistently provide clean and highly chemically active substrates for bonding. In this report, we examine peel ply surface preparation methods for secondary bonding of composite substrates using FM 94K epoxy film adhesive by mechanical testing, elemental surface analysis, and high-resolution imaging of failure surfaces. Woven S2 fiberglass infused with SC-15 toughened epoxy resin composites laminates, were fabricated by the Vacuum Assisted Resin Transfer Molding process. Tool-side surfaces of the composites were prepared using nine commercial off-the-shelf peel plies, including dry and impregnated forms. Two preparation methods for bonding were investigated: ...
Because of the extensive costs associated with building composite laminates, the U.S. Army is exp... more Because of the extensive costs associated with building composite laminates, the U.S. Army is exploring approaches to reduce the processing steps associated with hybridized structures. One area of focus is in surface preparation for secondary bonding. An important quality of an effective surface preparation method is its ability to consistently provide clean and highly chemically active substrates for bonding. In this report, we examine peel ply surface preparation methods for secondary bonding of composite substrates using FM 94K epoxy film adhesive by mechanical testing, elemental surface analysis, and high-resolution imaging of failure surfaces. Woven S2 fiberglass infused with SC-15-toughened epoxy resin composite laminates was fabricated by the vacuum-assisted resin transfer molding process. Tool-side surfaces of the composites were prepared using nine commercial off-the-shelf peel plies, including dry and impregnated forms. Two preparation methods for bonding were investigated...
Public reporting burden for this collection of information is estimated to average 1 hour per res... more Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing the burden, to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number.
Public reporting burden for this collection of information is estimated to average 1 hour per res... more Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing the burden, to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number.
The generation of air-based plasmas under atmospheric plasma conditions was studied to assess the... more The generation of air-based plasmas under atmospheric plasma conditions was studied to assess their antimicrobial efficacy against commonly found pathogenic bacteria. The mixture of initial gases supplied to the plasma was found to be critical for the formation of bactericidal actives. The optimal gas ratio for bactericidal effect was determined to be 99% nitrogen and 1% oxygen, which led to a 99.999% reduction of a pathogenic strain of Escherichia coli on stainless steel surfaces. The experimental substrate, soil load on the substrate, flow rate of the gases, and addition of ethanol vapor all were found to affect antimicrobial efficacy of studied plasmas. Optical emission spectroscopy was used to identify the species that were present in the plasma bulk phase for multiple concentrations of nitrogen and oxygen ratios. The collected spectra indicate a unique series of bands present in the ultraviolet region of the electromagnetic spectrum that can be attributed to nitric oxide species known to be highly antimicrobial. This intense spectral profile dramatically changes as the concentration of nitrogen decreases.
ABSTRACT Summary form only given. Surface treatment of polymers using plasma has teen widely impl... more ABSTRACT Summary form only given. Surface treatment of polymers using plasma has teen widely implemented to enhance the adhesion and wettability of the material through the inclusion of polar functional groups. In the case of high-strength organic fibers for composite applications, it is imperative to apply such a technique to overcome interfacial discontinuities that exist between two thermodynamically different materials. Through the use of atmospheric pulsed-dielectric barrier discharges (DBD), ultra -high -molecular weight polyethylene (UHMW-PE) films were treated with nitrogen gas to the effect where nitrogen-and oxygen-containing functional groups were deposited on the surface. To avoid the effects of oxidative degradation during and after plasma treatments, various treatment times and gas flow-rates were used to achieve higher uptake of N-containing species over that of O-containing species. Using surface analysis techniques such as attenuated total reflectance-Fourier transform infrared (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), and water contact angle measurements, variation in surface energy and chemical composition has been studied. To understand the mechanism of interaction between the plasma and the surface of the polymer, optical emission spectroscopy has been applied to identify and characterize key chemical species present in the DBD plasma.
ABSTRACT In this study, the flexible polymer substrate polyethylene naphthalate (PEN) was modifie... more ABSTRACT In this study, the flexible polymer substrate polyethylene naphthalate (PEN) was modified under two different plasma chemistries, namely helium–oxygen (He–O2) and helium–water vapor (He–H2O) plasmas at atmospheric pressure and room temperature. Surface changes related to wettability, chemical functionalization, surface energy, and morphology after plasma treatment were investigated using water contact angle (WCA) goniometry, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). Each plasma resulted in a more hydrophilic PEN surface, with WCA decreasing by 68% and 85% for He–O2 and He–H2O plasma treated PEN, respectively, after only 1.0 s of exposure. An aging study of plasma treated PEN shows an increase in WCA that is still 30° lower than that of the as-received PEN after 1 month. XPS and AFM results show that improved wettability of the plasma modified PEN is due to the oxidation of the surface and not due to the increased surface roughness. To promote a roll-to-roll process of atmospheric plasma treatment and inkjet deposition, printing was performed using the conductive polymer poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) on the as-received and plasma treated PEN surfaces where the shape and morphology of the lines were studied. Each plasma treated PEN surface exhibited well-defined, uniform inkjet-printed lines due to the improved wettability and increased surface energy. After scanning electron microscopy (SEM) analysis of the PEDOT:PSS dispersion of a single drop on each substrate, the He–H2O plasma treated surface led to less agglomeration of PEDOT:PSS and a more homogeneous drop deposit.
ABSTRACT In this study, the surfaces of ultrahigh molecular weight polyethylene (UHMWPE), poly( e... more ABSTRACT In this study, the surfaces of ultrahigh molecular weight polyethylene (UHMWPE), poly( ethylene terephthalate) (PET), and polytetrafluoroethylene (PTFE) films were treated with a helium-water vapor plasma at atmospheric pressure and room temperature. Surface changes related to hydrophilicity, chemical funtionalization, surface energy, and adhesive strength after plasma treatment were investigated using water contact angle (WCA) measurements, Xray photoelectron spectroscopy (XPS), and mechanical T-peel tests. Results indicate increased surface energy accompanied with enhanced hydrophilicity. WCA decreased by 36, 50, and 16% for UHMWPE, PET, and PTFE, respectively, after only 0.4 s treatment. For UHMWPE, it is shown that the surface functionalization can be tailored depending on the plasma exposure time. Aging studies performed for these three polymers show the stability of the surface groups as indicated by a small increase in WCA values of plasma treated samples which can be attributed to cross-linking of surface and subsurface polymer chains. XPS analysis of the surfaces show increased oxygen content via the formation of polar, hydroxyl-based functional groups. Furthermore, major changes in the polymer structure of PET are observed, possibly due to the opening of the aromatic rings caused by the plasma energetic species. T-peel test results show an 8, 7.5, and 400-fold increase in peel strength for UHMWPE, PET, and PTFE, respectively. Most importantly, it is shown that water-vapor based plasmas can be a promising, "green,'' inexpensive route to promote the surface activation of polymers.
Invasive species are described as the greatest threat to biodiversity, after habitat destruction ... more Invasive species are described as the greatest threat to biodiversity, after habitat destruction and climate change, potentially imposing economic impacts and indigenous species impairment. Commonly applied chemical controls present the potential for legacy contamination and non-target organism injury. This study investigated the effects of different substrates and novel topographical surfaces on the behavioral and mechanical associations of the terrestrial gastropod Otala lactea. The gastropod preferentially aestivated on rough glass (61% increase, P < 0.01) relative to smooth glass but avoided a cross-patterned surface tessellation on silicone (82% reduction, P < 0.01) relative to smooth silicone. Significant deviations in turning behavior were found on the cross-patterned topographical surface and hydrophobic Teflon surfaces. The strongest correlation with gastropod adhesion strength to surfaces was found for surface elastic modulus (R = 0.88, P = 0.03), followed by hydrophobicity (R = - 0.71, P = 0.14), but no relationship with roughness (P = 0.36). Preliminary data suggest surface roughness controlled aestivation behavior while elastic modulus (surface flexibility) controlled adhesion strength. In spite of greater adhesion to high-modulus materials, surface modulus was not a statistically significant controlling factor on gastropod aestivation preference. Understanding and exploiting the behavioral and mechanistic cues that organisms use while attaching to surfaces may lead to more environmentally benign control approaches.
The currently used multistep chemical synthesis for making surfaces antimicrobial by attaching to... more The currently used multistep chemical synthesis for making surfaces antimicrobial by attaching to them hydrophobic polycations is replaced herein by an aerosol-assisted plasma deposition procedure. To this end, N,N-hexyl,methyl-PEI (HMPEI) is directly plasma-coated onto a glass surface. The resultant immobilized HMPEI coating has been thoroughly characterized and shown to be robust, bactericidal against Escherichia coli, and virucidal against human influenza virus.
The surface pretreatment regiment currently being used for ceramic materials includes aggressive ... more The surface pretreatment regiment currently being used for ceramic materials includes aggressive surface cleaning with small alumina particles (grit blasting) coupled with chemical treatments such as priming and the application of silane coupling agents. Grit blasting, while effective at removing surface contaminants such as adventitious carbon, also acts to reduce flexural strength by exacerbating existing surface flaw populations. The aim of this work is to develop a surface treatment that will remove surface contamination and functionalize the surface without having detrimental effects on the mechanical strength. As an alternative to grit blasting, atmospheric plasma treatments were used to remove surface contaminants and chemically functionalize the surface of alumina in one step. Atmospheric plasma processing of materials removes the surface residual impurities and causes chemical modification, improving surface wettability and chemical reactivity.
Public reporting burden for this collection of information is estimated to average 1 hour per res... more Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing the burden, to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number.
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