Publications by Type: Patent

Forthcoming
Aksay, I. A. ; Korkut, S. A. ; Kaczmarczyk, J. ; Gurdag, S. ; Korkmaz, D. Graphene dispersions, Forthcoming.Abstract
Method of making a composition comprising graphene sheets and at least one solvent, comprising dispersing a mixture of graphene sheets and graphite particles in a solvent, wherein the graphite particles have more than about 50 layers, separating the graphene sheets and the graphite particles to obtain a dispersion of graphene sheets that contains no more than 25% of graphite particles having more than about 50 layers, based on the total number of graphite particles and graphene sheets, and flocculating the dispersion of graphene sheets. The flocculated dispersion can be added to a polymer matrix to make a composite. The composite can be formed into articles.
Pope, M. A. ; Alain-Rizzo, V. ; Dabbs, D. M. ; Lettow, J. S. ; Aksay, I. A. Batteries incorporating graphene membranes for extending the cycle-life of lithium-ion batteries, Forthcoming.Abstract
Embodiments of the present invention relate to energy storage devices and associated methods of manufacture. In one embodiment, an energy storage device comprises an electrolyte. An anode is at least partially exposed to the electrolyte. A selectively permeable membrane comprising a graphene-based material is positioned proximate to the anode. The selectively permeable membrane reduces a quantity of a component that is included in the electrolyte from contacting the anode and thereby reduces degradation of the anode.
Aksay, I. A. ; Sallah, K. Conducting elastomers, Forthcoming.Abstract
The present invention relates to conducting elastomers and assocd. fabrication methods. In one embodiment, the conducting elastomer comprises a filler powder and a polymer. The filler powder includes carbon black and functionalized graphene sheets. The polymer has a mol. wt. of about 200 g/mol to about 5000 g/mol and is a liquid at room temperature.
Aksay, I. A. ; Dabbs, D. M. ; Pope, M. A. Electrodes incorporating composites of graphene and selenium-sulfur compounds for improved rechargeable lithium batteries. Forthcoming.Abstract
Embodiments of the present invention relate to battery electrodes incorporating composites of graphene and selenium-sulfur compds. for improved rechargeable batteries. In one embodiment, a conductive compn. comprises a conductive compn. having a Se-S compd., a conductive additive. The Se-S compd. is present as SexS8-x, wherein x is greater than zero and less than eight.
Aksay, I. A. ; Alain-Rizzo, V. ; Bozlar, M. ; Bozym, D. J. ; Dabbs, D. M. ; Szamreta, N. ; Ustundag, C. B. Electrohydrodynamically formed structures of carbonaceous material, Forthcoming.Abstract
A method for the electrohydrodynamic deposition of carbonaceous materials utilizing an electrohydrodynamic cell comprising two electrodes comprised of a conductive material, by first combining a solid phase comprising a carbonaceous material and a suspension medium, placing the suspension between the electrodes, applying an electric field in a first direction, varying the intensity of the electric field sufficiently to drive lateral movement, increasing the electric field to stop the lateral transport and fix the layers in place, then removing the applied field and removing the electrodes. Among the many different possibilities contemplated, the method may advantageously utilize: varying the spacing between the electrodes; removing the buildup from one or both electrodes; placing the electrodes into different suspensions; adjusting the concentration, pH, or temperature of the suspension(s); and varying the direction, intensity or duration of the electric fields.
2018
Aksay, I. A. ; Korkut, S. ; Pope, M. ; Punckt, C. Graphene-ionic liquid composites, 2018.Abstract
Method of making a graphene-ionic liquid composite. The composite can be used to make electrodes for energy storage devices, such as batteries and supercapacitors.
Prud'homme, R. K. ; Aksay, I. A. Thermal overload device containing a polymer composition containing thermally exfoliated graphite oxide and method of making the same, 2018.Abstract
A thermal overload device containing a polymer composite, which contains at least one polymer and a modified graphite oxide material, containing thermally exfoliated graphite oxide having a surface area of from about 300 m2/g to 2600 m2/g, and a method of making the same.
Aksay, I. A. ; Milius, D. L. ; Korkut, S. ; Prud'homme, R. K. Functionalized graphene sheets having high carbon to oxygen ratios, 2018.Abstract
Functionalized graphene sheets having a carbon to oxygen molar ratio of at least about 23:1 and method of preparing the same.
Aksay, I. A. ; Buyukdincer, B. ; Javaherian, N. ; Lettow, J. S. ; Pino, G. ; Redmond, K. ; Yildirim, I. O. Reinforced polymeric articles, 2018.Abstract
Polymeric article reinforced with a reinforcing component. The reinforcing component includes a composition made from at least one polymer and graphene sheets.
Crain, J. M. ; Lettow, J. S. ; Aksay, I. A. ; Korkut, S. ; Chiang, K. S. ; Chen, C. - H. ; Prud'homme, R. K. Printed electronics, 2018.Abstract
Printed electronic device comprising a substrate onto at least one surface of which has been applied a layer of an electrically conductive ink comprising functionalized graphene sheets and at least one binder. A method of preparing printed electronic devices is further disclosed.
Pan, S. ; Aksay, I. A. ; Prud'homme, R. K. Multifunctional graphene-silicone elastomer nanocomposite, method of making the same, and uses thereof, 2018.Abstract
A nanocomposite composition having a silicone elastomer matrix having therein a filler loading of greater than 0.05 wt %, based on total nanocomposite weight, wherein the filler is functional graphene sheets (FGS) having a surface area of from 300 m2/g to 2630 m2/g; and a method for producing the nanocomposite and uses thereof.
2017
Prud’homme, R. K. ; Aksay, I. A. Conductive circuit containing a polymer composition containing thermally exfoliated graphite oxide and method of making the same, 2017.Abstract
A conductive circuit containing a polymer composite, which contains at least one polymer and a modified graphite oxide material, containing thermally exfoliated graphite oxide having a surface area of from about 300 m2/g to 2600 m2/g, and a method of making the same.
Aksay, I. A. ; Milius, D. L. ; Korkut, S. ; Prud'homme, R. K. Functionalized Graphene Sheets having High Carbon to Oxygen Ratios, 2017.Abstract
The present invention relates to functionalized graphene sheets having low oxygen content and methods for their prepartion.
2016
Aksay, I. A. ; Korkut, S. ; Pope, M. ; Punckt, C. Graphene-Ionic Liquid Composites, 2016.Abstract
Method of making a graphene-ionic liquid composite. The composite can be used to make electrodes for energy storage devices, such as batteries and supercapacitors. Disclosed and claimed herein is method of making a graphene-ionic liquid composite, comprising combining a graphene source with at least one ionic liquid and heating the combination at a temperature of at least about 130 °C.
Liu, J. ; Aksay, I. A. ; Kou, R. ; Wang, D. H. Mesoporous Metal Oxide Graphene Nanocomposite Materials, 2016.Abstract
A nanocomposite material formed of graphene and a mesoporous metal oxide having a demonstrated specific capacity of more than 200 F/g with particular utility when employed in supercapacitor applications. A method for making these nanocomposite materials by first forming a mixture of graphene, a surfactant, and a metal oxide precursor, precipitating the metal oxide precursor with the surfactant from the mixture to form a mesoporous metal oxide. The mesoporous metal oxide is then deposited onto a surface of the graphene.
Pan, S. Y. ; Aksay, I. A. ; Prud'homme, R. K. Multifunctional Graphene-Silicone Elastomer Nanocomposite, Method of Making the Same, and Uses Thereof, 2016.Abstract
A nanocomposite composition having a silicone elastomer matrix having therein a filler loading of greater than 0.05 wt %, based on total nanocomposite weight, wherein the filler is functional graphene sheets (FGS) having a surface area of from 300 m2/g to 2630 m2/g; and a method for producing the nanocomposite and uses thereof.
Crain, J. M. ; Lettow, J. S. ; Aksay, I. A. ; Korkut, S. ; Chiang, K. S. ; Chen, C. H. ; Prud'homme, R. K. Printed Electronics, 2016.Abstract
Printed electronic device comprising a substrate onto at least one surface of which has been applied a layer of an electrically conductive ink comprising functionalized graphene sheets and at least one binder. A method of preparing printed electronic devices is further disclosed.
Aksay, I. A. ; Buyukdincer, B. ; Javeherian, N. ; Lettow, J. S. ; Pino, G. ; Redmond, K. ; Yildirim, I. Reinforced Polymeric Articles, 2016.Abstract
The present invention relates to polymeric articles reinforced with a reinforcing agent made from compositions comprising at least one polymer and graphene sheets.
Aksay, I. A. ; Buyukdincer, B. ; Javaherian, N. ; Lettow, J. S. ; Pino, G. ; Redmond, K. ; Yildirim, I. O. Reinforced Polymeric Articles, 2016.Abstract
Polymeric article reinforced with a reinforcing component. The reinforcing component includes a composition made from at least one polymer and graphene sheets.
2015
Crain, J. M. ; Lettow, J. S. ; Aksay, I. A. ; Prud'homme, R. K. ; Korkut, S. Coatings Containing Functionalized Graphene Sheets and Articles Coated Therewith, 2015.Abstract
Coatings are provided containing functionalized graphene sheets and at least one binder. In one embodiment, the coatings are electrically conductive.
Liu, J. ; Aksay, I. A. ; Choi, D. W. ; Wang, D. H. ; Yang, Z. G. Nanocomposite of Graphene and Metal Oxide Materials, 2015.Abstract
Nanocomposite materials comprising a metal oxide bonded to at least one graphene material. The nanocomposite materials exhibit a specific capacity of at least twice that of the metal oxide material without the graphene at a charge/discharge rate greater than about 10 C.
Crain, J. M. ; Lettow, J. S. ; Aksay, I. A. ; Korkut, S. ; Chiang, K. S. ; Chen, C. H. ; Prud'homme, R. K. Printed Electronics, 2015.Abstract
Printed electronic device comprising a substrate onto at least one surface of which has been applied a layer of an electrically conductive ink comprising functionalized graphene sheets and at least one binder. A method of preparing printed electronic devices is further disclosed.
Aksay, I. A. ; Buyukdincer, B. ; Javaherian, N. ; Lettow, J. S. ; Pino, G. ; Redmond, K. ; Yildirim, I. Reinforced Polymeric Materials, 2015.Abstract
Polymeric article reinforced with a reinforcing component. The reinforcing component includes a composition made from at least one polymer and graphene sheets.
Liu, J. ; Aksay, I. A. ; Choi, D. W. ; Kou, R. ; Nie, Z. M. ; Wang, D. H. ; Yang, Z. G. Self-Assembled Multi-Layer Nanocomposite of Graphene and Metal Oxide Materials, 2015.Abstract
Nanocomposite materials having at least two layers, each layer consisting of one metal oxide bonded to at least one graphene layer were developed. The nanocomposite materials will typically have many alternating layers of metal oxides and graphene layers, bonded in a sandwich type construction and will be incorporated into an electrochemical or energy storage device.
2014
Crain, J. M. ; Lettow, J. S. ; Aksay, I. A. ; Korkut, S. A. ; Chiang, K. S. ; Chen, C. - H. ; Prud'homme, R. K. Printed electronics, 2014.Abstract
Printed electronic device comprising a substrate onto at least one surface of which has been applied a layer of an electrically conductive ink comprising functionalized graphene sheets and at least one binder. A method of preparing printed electronic devices is further disclosed.
Prud'homme, R. K. ; Aksay, I. A. Conductive circuit containing a polymer composition containing thermally exfoliated graphite oxide and method of making the same, 2014.Abstract
A conductive circuit containing a polymer composite, which contains at least one polymer and a modified graphite oxide material, containing thermally exfoliated graphite oxide having a surface area of from about 300 m2/g to 2600 m2/g, and a method of making the same.
Aksay, I. A. ; Saville, D. A. ; Poon, H. F. ; Korkut, S. ; Chen, C. - H. Electrohydrodynamic printing and manufacturing, 2014.Abstract
An stable electrohydrodynamic filament is obtained by causing a straight electrohydrodynamic filament formed from a liquid to emerge from a Taylor cone, the filament having a diameter of from 10 nm to 100 µm. Such filaments are useful in electrohydrodynamic printing and manufacturing techniques and their application in liquid drop/particle and fiber production, colloidal deployment and assembly, and composite materials processing.
2013
Aksay, I. A. ; Buyukdincer, B. ; Javaherian, N. ; Lettow, J. S. ; Pino, G. ; Redmond, K. ; Yildirim, I. O. Reinforced polymeric articles, 2013.Abstract
Polymeric article reinforced with a reinforcing component. The reinforcing component includes a composition made from at least one polymer and graphene sheets.
Liu, J. ; Aksay, I. A. ; Choi, D. ; Wang, D. ; Yang, Z. Nanocomposite of graphene and metal oxide materials, 2013.Abstract
Nanocomposite materials comprising a metal oxide bonded to at least one graphene material. The nanocomposite materials exhibit a specific capacity of at least twice that of the metal oxide material without the graphene at a charge/discharge rate greater than about 10 C.
Liu, J. ; Aksay, I. A. ; Choi, D. ; Kou, R. ; Nie, Z. ; Wang, D. ; Yang, Z. Self assembled multi-layer nanocomposite of graphene and metal oxide materials, 2013.Abstract
Nanocomposite materials having at least two layers, each layer consisting of one metal oxide bonded to at least one graphene layer were developed. The nanocomposite materials will typically have many alternating layers of metal oxides and graphene layers, bonded in a sandwich type construction and will be incorporated into an electrochemical or energy storage device.
2012
Prud'homme, R. K. ; Aksay, I. A. ; Herrera-Alonso, M. Separation medium containing thermally exfoliated graphite oxide, 2012.Abstract
A separation medium, such as a chromatography filling or packing, containing a modified graphite oxide material, which is a thermally exfoliated graphite oxide with a surface area of from about 300 m2/g to 2600 m2/g, wherein the thermally exfoliated graphite oxide has a surface that has been at least partially functionalized.
Prud'homme, R. K. ; O'Neil, C. ; Ozbas, B. ; Aksay, I. A. ; Register, R. ; Adamson, D. Functional graphene-polymer nanocomposites for gas barrier applications, 2012.Abstract
A gas diffusion barrier contains a polymer matrix and a functional graphene which displays no signature of graphite and/or graphite oxide, as determined by X-ray diffraction.
Prud'homme, R. K. ; Aksay, I. A. Gas storage cylinder formed from a composition containing thermally exfoliated graphite, 2012.Abstract
A gas storage cylinder or gas storage cylinder liner, formed from a polymer composite, containing at least one polymer and a modified graphite oxide material, which is a thermally exfoliated graphite oxide with a surface area of from about 300 m2/g to 2600 m2/g.
Aksay, I. A. ; Yeh, T. C. - H. ; Saville, D. A. Supercapacitor and battery electrode containing thermally exfoliated graphite oxide, 2012.Abstract
A supercapacitor or battery electrode containing a modified graphite oxide material, which is a thermally exfoliated graphite oxide with a surface area of from about 300 m2/g to 2600 m2/g.
Liu, J. ; Aksay, I. A. ; Choi, D. ; Wang, D. ; Yang, Z. Nanocomposite of graphene and metal oxide materials, 2012.Abstract
Nanocomposite materials comprising a metal oxide bonded to at least one graphene material. The nanocomposite materials exhibit a specific capacity of at least twice that of the metal oxide material without the graphene at a charge/discharge rate greater than about 10C.
Crain, J. M. ; Lettow, J. S. ; Aksay, I. A. ; Korkut, S. A. ; Chiang, K. S. ; Chen, C. - H. ; Prud'homme, R. K. Printed electronics, 2012.Abstract
Printed electronic device comprising a substrate onto at least one surface of which has been applied a layer of an elec. conductive ink comprising functionalized graphene sheets and at least one binder. A method of prepg. printed electronic devices is further disclosed.
2011
Aksay, I. A. ; Milius, D. L. ; Korkut, S. ; Prud'homme, R. K. Functionalized graphene sheets having high carbon to oxygen ratios, 2011.Abstract
Functionalized graphene sheets having a C to O molar ratio of at least ∼23:1 and method of prepg. the same. [on SciFinder(R)]
Pan, S. ; Aksay, I. A. ; Prudhomme, R. K. Multifunctional graphene-silicone elastomer nanocomposite, method of making the same, and uses thereof, 2011.Abstract
In a nanocomposite compn. having a silicone elastomer matrix having therein a filler loading of greater than 0.05 wt %, based on total nanocomposite wt., the filler is functional graphene sheets (FGS) having a surface area of from 300 m2/g to 2630 m2/g; and a method for producing the nanocomposite and uses thereof. [on SciFinder(R)]
Liu, J. ; Aksay, I. A. ; Choi, D. ; Kou, R. ; Nie, Z. ; Wang, D. ; Yang, Z. Self assembled multi-layer nanocomposite of graphene and metal oxide materials, 2011.Abstract
Nanocomposite materials having at least two layers, each layer consisting of one metal oxide bonded to at least one graphene layer were developed. The nanocomposite materials will typically have many alternating layers of metal oxides and graphene layers, bonded in a sandwich type construction and will be incorporated into an electrochem. or energy storage device. [on SciFinder(R)]
Liu, J. ; Choi, D. ; Kou, R. ; Nie, Z. ; Wang, D. ; Yang, Z. ; Aksay, I. A. Self assembled multi-layer nanocomposite of graphene and metal oxide materials, 2011.Abstract
Nanocomposite materials having at least two layers, each layer consisting of one metal oxide bonded to at least one graphene layer were developed. The nanocomposite materials will typically have many alternating layers of metal oxides and graphene layers, bonded in a sandwich type construction and will be incorporated into an electrochem. or energy storage device. [on SciFinder(R)]
Roy-Mayhew, J. ; Aksay, I. Semiconductor coated microporous graphene scaffolds for solar cells, 2011.Abstract
The invention refers to a high surface area scaffold to be used for a solar cell, made of a three-dimensional percolated network of functionalized graphene sheets. It may be used in the prepn. of a high surface area electrode by coating with a semiconductive material. Electronic devices can be made therefrom, including solar cells such as dye-sensitized solar cells. [on SciFinder(R)]
2010
Prud'homme, R. K. ; O'Neil, C. D. ; Ozbas, B. ; Aksay, I. A. ; Register, R. A. ; Adamson, D. H. Functional graphene-polymer nanocomposites for gas barrier applications, 2010.Abstract
A gas diffusion barrier contains a polymer matrix and a functional graphene which displays no signature of graphite and/or graphite oxide, as detd. by X-ray diffraction. [on SciFinder(R)]
Prud'homme, R. K. ; Ozbas, B. ; Aksay, I. A. ; Register, R. A. ; Adamson, D. H. Functional graphene-rubber nanocomposites, 2010.Abstract
A polymer compn., contg. a polymer matrix which contains an elastomer; and a functional graphene which displays no signature of graphite and/or graphite oxide, as detd. by x-ray diffraction, exhibits excellent strength, toughness, modulus, thermal stability and elec. cond. [on SciFinder(R)]
Liu, J. ; Aksay, I. A. ; Choi, D. ; Wang, D. ; Yang, Z. Nanocomposite of graphene and metal oxide materials, 2010.Abstract
Nanocomposite materials consist of a metal oxide bonded to at least one graphene material. The graphene layer has a carbon to oxygen ratio of (20-500):1 and a surface area of 600-2630 m2/g. The metal oxide can be an oxide of Ti, Sn, Ni, Mn, V, Si, or Co, preferably titania in the form of rutile or anatase, or tin oxide. The nanocomposite materials exhibit a specific capacity of at least twice that of the metal oxide material without the graphene at a charge/discharge rate of ⪆10 C. The nanocomposite material is prepd. by providing graphene in a first suspension; dispersing the graphene with a surfactant, esp. sodium dodecyl sulfate; adding a metal oxide precursor to the dispersed graphene to form a second suspension; and pptg. the metal oxide from the second suspension onto at least one surface of the dispersed graphene to form the nanocomposite material. The nanocomposite material can be used in an energy storage device, esp. in a lithium ion battery as electrode material. [on SciFinder(R)]
Liu, J. ; Aksay, I. A. ; Choi, D. ; Wang, D. ; Yang, Z. Nanocomposite of graphene and metal oxide materials and its use in energy storage devices, 2010.Abstract
Nanocomposite materials consists of a metal oxide bonded to at least one graphene material. The graphene layer has a carbon to oxygen ratio of (20-500):1 and a surface area of 600-2630 m2/g. The metal oxide can be an oxide of Ti, Sn, Ni, Mn, V, Si, or Co, preferably titania in the form of rutile or anatase, or tin oxide. The nanocomposite materials exhibit a specific capacity of at least twice that of the metal oxide material without the graphene at a charge/discharge rate of ⪆10 C. The nanocomposite material is prepd. by providing graphene in a first suspension; dispersing the graphene with a surfactant, esp. sodium dodecyl sulfate; adding a metal oxide precursor to the dispersed graphene to form a second suspension; and pptg. the metal oxide from the second suspension onto at least one surface of the dispersed graphene to form the nanocomposite material. The nanocomposite material can be used in an energy storage device, esp. in a lithium ion battery as electrode material. [on SciFinder(R)]
Aksay, I. A. ; Bekircan, S. H. ; Crain, J. M. ; Gurdag, S. ; Guven, E. ; Javaherian, N. ; Lettow, J. S. ; Redmond, K. ; Tekmek, O. ; Vatansever, A. ; et al. Polymeric fibers and articles and forming reinforced fiber, 2010.Abstract
Fibers comprise a compn. including a polymer and graphene sheets. The fibers can be further formed into yarns, cords, and fabrics. The fibers can be polyamide, polyester, acrylic, acetate, modacrylic, spandex, lyocell fibers, and the like. Such fibers can take on a variety of forms, including, staple fibers, spun fibers, monofilaments, multifilaments, and the like. [on SciFinder(R)]
Aksay, I. A. ; Buyukdincer, B. ; Javaherian, N. ; Lettow, J. S. ; Pino, G. ; Redmond, K. ; Yildirim, I. O. Reinforced polymeric articles comprising a graphene sheet-reinforced polymers, 2010.Abstract
The reinforcing component of these articles includes a compn. made from at least one polymer and graphene sheets. [on SciFinder(R)]
Prud'homme, R. K. ; Aksay, I. A. ; Adamson, D. ; Abdala, A. Thermally exfoliated graphite oxide and polymer nanocomposites, 2010.Abstract
A modified graphite oxide material contains a thermally exfoliated graphite oxide with a surface area of from ∼300-2600 m2/g, wherein the thermally exfoliated graphite oxide displays no signature of the original graphite and/or graphite oxide, as detd. by x-ray diffraction. [on SciFinder(R)]
Aksay, I. A. ; Gurdag, S. ; Javaherian, N. ; Lettow, J. S. ; Pino, G. ; Redmond, K. ; Vatansever, A. ; Yildirim, I. O. Tire cords comprising spun monofilaments of polymer matrix-graphene sheets and an adhesive, 2010.Abstract
Tire cords comprising fibers including at least one polymer and graphene sheets. Graphene sheets are added to poly(ethylene terephthalate) (PET) by melt compounding in an extruder to yield a PET compn. comprising about 0.25 wt.% graphene sheets. The PET compn. is then solid phase polymd. at 215° to an IV of about 1 dL/g. The compn. is spun into monofilaments that are then post drawn to a draw ratio of about 4 to 5. After drawing, the filaments have a diam. of about 120 μ. The storage modulus of the monofilaments is then measured as a function of temp. using a dynamic mech. analyzer (DMA). [on SciFinder(R)]
2009
Herrera-Alonso, M. ; McAllister, M. J. ; Aksay, I. A. ; Prud'homme, R. K. Bridged graphite oxide materials for hydrogen storage, 2009.Abstract
The present invention is a bridged graphite oxide material, comprising at least two graphite oxide sheets in which a plurality of graphite oxide sheets are bridged to at least one other graphite oxide sheet by at least one diamine bridging group. The bridged graphite oxide is formed by the covalent reaction of one amino group of a diamine with a reactive group on the surface or edge of one graphite oxide sheet and the covalent reaction of another amino group of the same diamine with a reactive group on the surface or edge of another graphite oxide sheet. The bridged graphite oxide material may be incorporated in polymer composites or used in hydrogen adsorption media. [on SciFinder(R)]
Aksay, I. A. ; Milius, D. L. ; Korkut, S. ; Prud'homme, R. K. Functionalized graphene sheets having high carbon to oxygen ratios for polymer composite, 2009.Abstract
Functionalized graphene sheets having a carbon to oxygen molar ratio of at least about 23:1. A polymer composite comprises the functionalized graphene sheet and ≥1 polymer. [on SciFinder(R)]
2008
Prud'homme, R. K. ; Ozbas, B. ; Aksay, I. A. ; Register, R. A. ; Adamson, D. H. Electrically conductive polymer nanocomposites containing functional graphene, 2008.Abstract
A polymer compn. comprises a polymer matrix comprising an elastomer, and a functional graphene which displays no signature of graphite and/or graphite oxide, as detd. by X-ray diffraction. The functional graphene-contg. polymer compns. have excellent strength, toughness, thermal stability, elec. cond., and can be used for prodn. of gas-barrier materials. Thus, films (200-400 μm) made of a silicone rubber RTV 615 compn. contg. 5% of functional graphene nanoparticles had a Young's modulus 12.18 and a tensile strength 6.52 times higher than the resp. values for neat rubber. Similar films made of a silicone rubber RTV 615 compn. contg. 5% of clay nanoparticles had a Young's modulus 1.28 and a tensile strength 2.38 times higher than the resp. values for neat rubber. [on SciFinder(R)]
Prudhomme, R. K. ; O'Neil, C. D. ; Ozbas, B. ; Aksay, I. A. ; Register, R. A. ; Adamson, D. H. Functional graphene-polymer nanocomposites for gas barrier applications, 2008.Abstract
A gas diffusion barrier contains a polymer (e.g., natural rubber) matrix and a functional graphene which displays no signature of graphite and/or graphite oxide, as detd. by X-ray diffraction. [on SciFinder(R)]
2007
Prud'homme, R. K. ; Aksay, I. A. ; Adamson, D. ; Abdala, A. Thermally exfoliated graphite oxide and its use in nanocomposites, 2007.Abstract
A modified graphite oxide material contains a thermally exfoliated graphite oxide with a surface area of from ∼300 m2/g to 2600 m2/g, wherein the thermally exfoliated graphite oxide displays no signature of the original graphite and/or graphite oxide, as detd. by x-ray diffraction. The modified graphite oxide is useful in nanocomposites with, e.g., PMMA. [on SciFinder(R)]
2005
Aksay, I. A. ; Wahl, C. M. ; Dabbs, D. M. ; Yilgor, I. L3-silica/polyurethane thermally insulating nanocomposite, 2005.Abstract
The present invention provides thermal insulator composites based upon nanostructured L3-silica microparticles and polyurethane foam chem. that are both easy to process and have superior insulating properties for use in household and com. refrigeration, construction, and shipping applications. The composite material retains many of the attractive processing characteristics of polyurethane foams such as vol. expansion and shape-filling during polymn. and demonstrates a total thermal cond. between 32% and 44% that of com. available polyurethane foams. [on SciFinder(R)]
2001
Hayward, R. C. ; Poon, H. F. ; Xiao, Y. ; Saville, D. ; Aksay, I. Electrohydrodynamically patterned colloidal crystals, 2001.Abstract
A method for assembling patterned cryst. arrays of colloidal particles using UV illumination of an optically-sensitive semiconducting anode while using the anode to apply an electronic field to the colloidal particles. The UV illumination increases c.d., and consequently, the flow of the colloidal particles. As a result, colloidal particles can be caused to migrate from nonilluminated areas of the anode to illuminated areas of the anode. Selective illumination of the anode can also be used to permanently affix colloidal crystals to illuminated areas of the anode while not affixing them to nonilluminated areas of the anode. [on SciFinder(R)]
Vartuli, J. S. ; Milius, D. L. ; Li, X. ; Shih, W. H. ; Shih, W. Y. ; Prud'homme, R. K. ; Aksay, I. A. Multilayer ceramic piezoelectric laminates with zinc oxide conductors, 2001.Abstract
A modification of the traditional unimorph flextensional actuator is provided by replacing the metal shim with an elec. conducting oxide. Comprised of Pb zirconate titanate (PZT) and ZnO that is co-sintered, the laminate composite obtains large axial displacements while maintaining moderate axial loads. The varistor properties of ZnO dictate that the conductance increases several orders of magnitude when a crit. elec. field is applied. The versatility of the processing over other actuator system facilitates miniaturization, while maintaining comparable performance characteristics. Functional gradients in the material properties are created in the green body by layering thin tape cast sheets. The unique PZT-ZnO composite not only controls the piezoelec. gradient, but permits control of the sintering kinetics leading to the processing of either flat or highly domed structures. [on SciFinder(R)]
Aksay, I. A. ; Ker, H. L. Plastically deformable aqueous ceramic slurries and methods for their manufacture, 2001.Abstract
The ceramic particles from plastically deformable aq. ceramic slurrys have on their surface a closely-packed anionic surfactant bilayer or an anionic/nonionic surfactant bilayer. Optionally, ceramic particles have on their surface a closely-packed cationic surfactant bilayer or a cationic/nonionic surfactant bilayer. Slurries prepg. includes (a) dispersing ceramic particles in an amt. of water to form an aq. ceramic slurry, (b) adding an anionic surfactant or a mixt. of an anionic and nonionic surfactant, and (c) adjusting the pH value to adsorb on the ceramic particle surface a closely-packed anionic surfactant bilayer or anionic/nonionic surfactant bilayer. [on SciFinder(R)]
2000
Blohowiak, K. Y. ; Garrigus, D. F. ; Luhman, T. S. ; McCrary, K. E. ; Strasik, M. ; Aksay, I. ; Dogan, F. ; Hicks, W. C. ; Martin, C. B. Making large, single crystal, 123 YBCO superconductors, 2000.Abstract
Large (in excess of 2 cm in diam.), single crystal YBa2Cu3O7-x [123 YBCO] crystals, where x ≤ 0.6, can be grown in a seventeen step process or some variant thereof from finely ground and well mixed 123 YBCO and 211 YBCO powders with a small amt. of Pt by controlling the rate of cooling from within a compact of the powders using a temp. gradient in the radial and axial planes (independently) of ∼1-20°/in. diam. of compact to nucleate the crystal growth. Crystal growth is also promoted as well using a Sm oxide seed crystal, preferably SmBa2Cu3O7-y, where y ≤ 1.6. After nucleation the compact is cooled slowly at a rate from ∼0.1-1°/h to promote the single crystal development. [on SciFinder(R)]
1999
Aksay, I. A. ; Trau, M. ; Manne, S. ; Honma, I. Biomimetic pathways for assembling inorganic thin films and oriented mesoscopic silicate patterns through guided growth, 1999.Abstract
A process directed to prepg. surfactant-polycryst. inorg. nanostructured materials having designed microscopic patterns. The process includes forming a polycryst. inorg. substrate having a flat surface and placing in contact with the flat surface of the substrate a surface having a predetd. microscopic pattern. An acidified aq. reacting soln. is then placed in contact with an edge of the surface having the predetd. microscopic pattern. The soln. wicks into the microscopic pattern by capillary action. The reacting soln. has an effective amt. of a silica source and an effective amt. of a surfactant to produce a mesoscopic silica film upon contact of the reacting soln. with the flat surface of the polycryst. inorg. substrate and absorption of the surfactant into the surface. Subsequently an elec. field is applied tangentially directed to the surface within the microscopic pattern. The elec. field is sufficient to cause electro-osmotic fluid motion and enhanced rates of fossilization by localized Joule heating. [on SciFinder(R)]
Aksay, I. A. ; Vicenzi, E. P. ; Milius, D. L. ; Lettow, J. S. Producing ceramic superconductor single crystals, 1999.Abstract
A bulk high-temp. superconductor single crystal MBa2Cu3O7-x, where M = Y, Sm, Eu, Gd, Dy, Ho, Er, or Yb; and x = ∼0.1 to ∼1.0, are produced by a novel process incorporating: (i) starting powders produced by combustion spray pyrolysis; (ii) a novel setter powder; and/or (iii) a monitored isothermal growth process. [on SciFinder(R)]
Cates, Gordon D., J. ; Aksay, I. A. ; Happer, W. ; Hsu, M. F. ; Dabbs, D. M. Sol-gel coated polarization vessels, 1999.Abstract
The invention relates to a polarization cell which is coated with glass deposited from a sol-gel used for hyperpolarizing noble gases. The invention also includes a method for hyperpolarizing noble gases utilizing the polarization cell coated with glass deposited from a sol-gel. These polarization cells can also be incorporated into containers used for storage and transport of the hyperpolarized noble gases. [on SciFinder(R)]
1998
McGrath, K. M. ; Dabbs, D. M. ; Aksay, I. A. ; Gruner, S. M. Mesoporous monolithic ceramics, their manufacture using a lyotropic liquid crystalline L3 phase, and their use, 1998.Abstract
The ceramics have pore diam. approx. 10-100 nm, and are manufd. by templating with a ceramic precursor a lyotropic liq. cryst. L3 phase consisting of a 3-dimensional, random, nonperiodic network packing of a multiconnection continuous membrane. The ceramics are manufd. by prepg. a template of a lyotropic liq. cryst. L3 phase, coating the template with a ceramic precursor, and converting the coated membrane to a ceramic membrane. More specifically, the lyotropic liq. cryst. L3 phase is prepd. by mixing a surfactant with a cosurfactant and HCl, coating the template with a precursor ceramic material by adding to the L3 phase (MeO)4Si or (EtO)4Si, and converting the coated template by removing any liq. The ceramic material, coated with a light- or radiation-sensitive material may be used as optical sensor, and further as filter, data storage device, energy storage device, with TiO2 as ultracapacitor device, in HPLC, with oxides or salts for ceramics and nonoxide ceramics. [on SciFinder(R)]
1997
Aksay, I. A. ; Milius, D. L. ; Vicenzi, E. P. ; Lettow, J. S. Preparation of ceramic superconductor single crystals, 1997.Abstract
A single crystal of a high-temp. superconductor of the formula MBa2Cu3O7-x, where M = Y, Sm, Eu, Gd, Dy, Ho, Er, or Yb and x = 0.1-1.0, is prepd. by forming a starting powder by combustion spray pyrolysis, then growth of a crystal on a settling powder of the compn. Ba4Cu2PtOx and/or controlled isothermal growth. [on SciFinder(R)]
1996
Staley, J. T. ; Aksay, I. A. ; Graff, G. L. ; Pellerin, N. B. ; Ren, T. Process for suspension of ceramic or metal particles using biologically produced polymers, 1996.Abstract
A method for producing a highly loaded, aq. suspension having a pourable viscosity and contg. 20-50 vol.% colloidal ceramic or metal particles is described. A biol. produced polymer dispersant having a high d. of carboxyl functional groups and an av. mol. wt. of ≥1000 is solubilized in H2O in an amt. of <1.0% dry wt. basis of particles. The ceramic or metal particles are then introduced into the soln., and agitated to form a substantially nonagglomerated suspension. The polymer dispersant may be produced by a bacterium grown in situ with the particles. A biol. produced polymer gelling agent that is miscible with the polymer dispersant may be mixed into the suspension, which is then maintained in a nongelled state while being supplied to a mold. The suspension is then exposed to a gel-triggering condition to form a gelled, sinterable article. [on SciFinder(R)]
1992
Hama, M. ; Dabbs, D. M. ; Aksay, I. A. Manufacture of ultrasmooth ceramics by low-temperature sintering, 1992.Abstract
The process comprises forming a consolidated ceramic, e.g., green compact of Al2O3 powder, impregnating the greenware with an inorg. polymer, e.g., polyaluminoxane having general formula [-M(R)n-X(R1)p-]m, (M = trivalent or tetravalent inorg. ion; when M = trivalent, n = 1, when M = tetravalent, n = 2; X is O-2, S-2, or N-3; when X = O-2 or S-2, p = 0; when X is N-3, p = 1; R, R1 = alkyl, alkoxy, acyloxy, Ph, or phenoxy group contg. a chain of ≥3 C atoms; and m = 5-1000) and sintering the greenware, preferably at 1000-1400°. The ceramics are useful for the electronics industry. [on SciFinder(R)]
1991
Aksay, I. A. ; Han, C. ; Maupin, G. D. ; Martin, C. B. ; Kurosky, R. P. ; Stangle, G. C. Ceramic precursor composition and method for manufacture of superconductive and nonsuperconductive ceramic powders using the precursor composition, 1991.Abstract
Ceramic precursor mixt. comprising a metal cation capable of being converted to a metal oxide by thermal energy, a carbohydrate, and an anion capable of participating in an anionic oxidn.-redn. reaction with the carbohydrate is converted to ceramic powder by forming droplets of the precursor mixt., removing all the solvent from the droplets, thermally initiating an anionic oxidn.-redn. reaction between the anion and carbohydrate to form a multiphase ceramic material consisting of carbonates, hydroxides, and oxides of metal cation, and heating the particles to convert the multiphase ceramic into a single-phase ceramic. This process is used for the manuf. of superconductive and nonsuperconductive ceramic powders.
Laine, R. M. ; Youngdahl, K. A. ; Aksay, I. A. ; Martin, C. B. ; Lannutti, J. J. Method for Producing High-Temperature Superconducting Ceramic Products Employing Tractable Ceramic Precursors, 1991.
1988
Sonuparlak, B. ; Aksay, I. A. Manufacture of porous ceramics using decomposable polymeric microspheres, and the resultant products, 1988.Abstract
The title porous ceramics, having a controlled microstructure consisting of pores of predetd. size, shape, and spatial distribution, are prepd. by (a) forming a colloidal suspension of ceramic material and uniform and identical polymeric microspheres, (b) stabilizing the interaction between the microspheres and the ceramic particles, (c) consolidating the colloidal suspension by removing the liq. and forming a compact body, and (d) heating the body to decomp. the microspheres and sintering the body to obtain a porous ceramic body having multiple, evenly distributed, noncontiguous pores. These porous ceramics are useful for a variety of applications, including multilayer tape casting. A 54-vol.% aq. α-Al2O3 suspension was prepd. using 0.5 wt.% NH4 salt of polyacrylic acid as anion surfactant and 0.08 wt.% (based on dry Al2O3) citric acid as a stabilizer. The suspension was treated with ultrasound to break up agglomerates with a polystyrene suspension (30-40 vol.%), and the colloidal suspension was then slip-cast, dried, and sintered to form a single porous layer, that was slowly dried, heated to 1000° at 22.5°/h, and sintered at 1550° to obtain a ceramic body with controlled microstructure. [on SciFinder(R)]
1987
Pyzik, A. J. ; Aksay, I. A. A multipurpose boron carbide-aluminum composite and its manufacture via the control of the microstructure, 1987.Abstract
The low-d. composite consists of B carbide porous compact and infiltrated Al, or Al alloy (e.g., Al-Cu, Al-Mg, Al-Si, Al-Mn-Mg, and/or Al-Cu-Mg-Cr-Zn). To reduce the reaction rate between B carbide and Al during infiltration, the B carbide is heated to 1800-2250° in the presence of free C (e.g., graphite). Prepn. of the composite comprising (1) dispersing a B carbide having particle size <10 μ in water or an inorg. medium; (2) consolidating B carbide into a porous compact by slip casting, pressure casting, injection molding, or isostatic pressing; (3) infiltrating the compact with Al by submerging in molten Al bath at 1150-1250°; (4) heat treatment at <1800°. Optionally, the porous compact is sintered at ∼1800-2250° prior to Al infiltration. The composite has high fracture toughness, strength, hardness, and stiffness. Thus, B carbide powder was dispersed in water at pH = 8, and the suspension was consolidated by slip casting. The porous compact was removed from the mold, dried 12 h at 45°, and 24 h at 110°, and heat treated 30 min at 2150°. The resulting compact was infiltrated with molten Al in a graphite furnace under vacuum at 1190° for 30 min. Final microstructure of the composite included B carbide 64, and Al 31%. The composite had fracture toughness of 9.7 MPa m1/2, fracture strength 621 MPa, and Young's modulus of 290 GPa. [on SciFinder(R)]
1986
Halverson, D. C. ; Pyzik, A. J. ; Aksay, I. A. Boron-carbide-aluminum and boron-carbide-reactive metal cermets, 1986.Abstract
Cermets based on a ternary system with B, C, and a reactive metal are manufd. with controlled structures having ≥1 ceramic phases distributed in an alloy matrix. A starting compn. as well as reaction temp., time, and atm. are selected for controlling the manufg. process and final structures, with emphasis on initial powder consolidation, early melt wetting, and final sintering. Surfactant selection is considered for obtaining a uniform blend of initial feed powders having particle size of ≤5 μ. Thus, powd. B4C (av. size 5 μ) 80 and Al 20 vol.% were mixed in EtOH by using an ultrasonic probe, and slip cast in a mold from plaster of Paris for dewatering. The powder mixt. removed from the mold was pressed at 10,000 psi and room temp. Pellet preforms were heated in 10 min to 1050° in a furnace, and then sintered at 800° for 24 h. The final composite contained an unknown Al-rich phase 34, B4C 32, AlB2 23, Al 5, α-AlB12 3, Al4C3 2, and AlB12C2 1 vol.%. The unknown phase showed crystallog. structure intermediate between hexagonal and rhombohedral. Cermet products of this type showed bend strength >110 kpsi and fracture toughness 12 kpsi-in.0.5, with the latter exceeding the value of ∼4 for conventional Al2O3-B4C composites. [on SciFinder(R)]