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Daniel R. Talham - One of the best experts on this subject based on the ideXlab platform.

  • organic inorganic langmuir blodgett films based on metal phosphonates 5 a magnetic manganese phosphonate film including a tetrathiafulvalene amphiphile1
    Chemistry of Materials, 2002
    Co-Authors: Melissa A Petruska, Brian C Watson, And Mark W Meisel, Daniel R. Talham
    Abstract:

    Mixed organic/inorganic Langmuir−Blodgett (LB) films have been prepared in which the polar network is a manganese phosphonate Continuous Lattice and the organic network contains a substituted tetrathiafulvalene amphiphile. The bis(phosphonic acid) amphiphile, 2,3-bis[(4‘-phosphonobutyl)thio]-6,7-bis(tetradecylthio)tetrathiafulvalene, 1, has been synthesized and deposited from an aqueous Mn2+ subphase to form Y-type LB films with stoichiometry Mn2(1)(H2O)2. Since the amphiphile is a bis(phosphonate), the inorganic network forms the Mn(O3PR)H2O structure known in other manganese phosphonate LB films and layered solids. The film becomes magnetic near 11.5 K when the manganese phosphonate network orders as a canted antiferromagnet. Attempts to subsequently oxidize the tetrathiafulvalene (TTF) network did not result in stable phases. Structural characterization was aided by the synthesis of a solid-state manganese bis(phosphonate) model compound, Mn2(2)(H2O)2, where 2 is the ligand 2,3-bis[(2‘-phosphonoethyl)t...

  • Organic/Inorganic Langmuir−Blodgett Films Based on Metal Phosphonates. 4. Thermal Stability1
    Langmuir, 2000
    Co-Authors: Melissa A Petruska, Daniel R. Talham
    Abstract:

    The thermal stability of metal phosphonate Langmuir−Blodgett (LB) films formed from the amphiphiles octadecylphosphonic acid (OPA) and an azobenzene-derivatized phosphonic acid, (4-(4‘-tetradecyloxyphenyldiazenyl)phenyl)butylphosphonic acid (A4), with divalent and trivalent metal ions has been examined. These films are characterized by the formation of a metal phosphonate Continuous Lattice in the polar region of the transferred bilayers. The behavior of the films upon heating and with temperature cycling was studied with attenuated total reflectance (ATR)-FTIR, transmission FTIR, absorbance spectroscopy, and X-ray diffraction. A reversible transition is observed between 40 and 50 °C in each film, and this process is assigned as a premelting transition in analogy to similar transitions observed in previously studied LB films. Irreversible disordering of the organic networks is observed for each film at higher temperatures, occurring near 150 °C in the lanthanum octadecylphosphonate film, near 140 °C in th...

  • Structural Characterization and Magnetic Order in Phenoxy-Substituted Divalent Metal Phosphonate Langmuir–Blodgett Films
    IEEE Journal of Solid-state Circuits, 1999
    Co-Authors: Gail E Fanucci, Melissa A Petruska, Mark W. Meisel, Daniel R. Talham
    Abstract:

    Abstract Metal phosphonate Langmuir–Blodgett (LB) films of an alkoxyphenyl-substituted phosphonic acid (P4A) have been prepared with the divalent metals Mn 2+ and Cd 2+ . Structural characterization with infrared spectroscopy, XPS, and X-ray diffraction shows that the films contain the inorganic Continuous Lattice of known layered solid-state metal phosphonates with formula M (O 3 P R )H 2 O. Magnetic characterization of the Mn-P4 LB film consists of EPR and magnetometry measurements. The Mn-P4 LB film undergoes a transition to a long-range, canted antiferromagnetic state below 14.8±0.2 K and is only the second example of a Continuous Lattice LB film to exhibit spontaneous magnetization. These results demonstrate that it is possible to prepare metal phosphonate LB films of functionalized organophosphonic acids while retaining both the inorganic Continuous Lattice structure and magnetic exchange pathways of the known solid-state metal organophosphonates.

  • Langmuir−Blodgett Films Based on Known Layered Solids: Lanthanide(III) Octadecylphosphonate LB Films
    Langmuir, 1999
    Co-Authors: Gail E. Fanucci And, Daniel R. Talham
    Abstract:

    Several lanthanide(III) octadecylphosphonate Langmuir−Blodgett (LB) films have been prepared and characterized. Films with La3+, Ce3+, Sm3+, and Gd3+ are formed one bilayer at a time using a Y-type deposition procedure that allows the metal phosphonate Continuous Lattice network to crystallize during the upstroke of the film transfer. Comparison of the phosphonate IR stretching modes of the LB films to those of known model solids shows that each film is an LB analogue of the powdered solid-state lanthanide butylphosphonates of formula LnIIIH(O3PC4H9)2 that possess a two-dimensional ionic covalent metal phosphonate network. X-ray photoelectron spectroscopy (XPS) shows that the P/Ln ratio in each of the transferred films is 2:1, which corresponds to the stoichiometry in the known layered materials, and X-ray diffraction (XRD) shows that the films are layered each with a bilayer thickness of 51 ± 1 A. The behavior of octadecylphosphonic acid Langmuir monolayers on subphases containing each metal ion is studi...

  • Organic/Inorganic Langmuir−Blodgett Films Based on Metal Phosphonates. 3. An Azobenzene-Derivatized Phosphonic Acid Forms Continuous Lattice Layers with Divalent, Trivalent, and Tetravalent Metal Ions1
    Chemistry of Materials, 1998
    Co-Authors: Melissa A Petruska, Daniel R. Talham
    Abstract:

    Metal phosphonate Langmuir−Blodgett (LB) films of an azobenzene-functionalized phosphonic acid amphiphile, (4-(4‘-tetradecyloxyphenyldiazenyl)phenyl)butylphosphonic acid (A4), have been prepared with Zr4+, La3+, Gd3+, Ba2+, Mn2+, and Cd2+. Film formation and quality are characterized with optical spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. The azobenzene chromophores are strongly H-aggregated in all of the metal phosphonate LB films. With divalent and trivalent ions, the in-plane metal phosphonate structure observed in the LB films is the same as that found in analogous solid-state layered phosphonates and depends on the identity of the metal ion. Films of A4 with the lanthanide ions La3+ and Gd3+ form with stoichiometry MH(O3PR)2. When Ba2+ is incorporated into the films, the M(HO3PR)2 structure-type is adopted, while Mn2+ and Cd2+ give rise to films of A4 with the stoichiometry M(O3PR)...

Melissa A Petruska - One of the best experts on this subject based on the ideXlab platform.

  • organic inorganic langmuir blodgett films based on metal phosphonates 5 a magnetic manganese phosphonate film including a tetrathiafulvalene amphiphile1
    Chemistry of Materials, 2002
    Co-Authors: Melissa A Petruska, Brian C Watson, And Mark W Meisel, Daniel R. Talham
    Abstract:

    Mixed organic/inorganic Langmuir−Blodgett (LB) films have been prepared in which the polar network is a manganese phosphonate Continuous Lattice and the organic network contains a substituted tetrathiafulvalene amphiphile. The bis(phosphonic acid) amphiphile, 2,3-bis[(4‘-phosphonobutyl)thio]-6,7-bis(tetradecylthio)tetrathiafulvalene, 1, has been synthesized and deposited from an aqueous Mn2+ subphase to form Y-type LB films with stoichiometry Mn2(1)(H2O)2. Since the amphiphile is a bis(phosphonate), the inorganic network forms the Mn(O3PR)H2O structure known in other manganese phosphonate LB films and layered solids. The film becomes magnetic near 11.5 K when the manganese phosphonate network orders as a canted antiferromagnet. Attempts to subsequently oxidize the tetrathiafulvalene (TTF) network did not result in stable phases. Structural characterization was aided by the synthesis of a solid-state manganese bis(phosphonate) model compound, Mn2(2)(H2O)2, where 2 is the ligand 2,3-bis[(2‘-phosphonoethyl)t...

  • Organic/Inorganic Langmuir−Blodgett Films Based on Metal Phosphonates. 4. Thermal Stability1
    Langmuir, 2000
    Co-Authors: Melissa A Petruska, Daniel R. Talham
    Abstract:

    The thermal stability of metal phosphonate Langmuir−Blodgett (LB) films formed from the amphiphiles octadecylphosphonic acid (OPA) and an azobenzene-derivatized phosphonic acid, (4-(4‘-tetradecyloxyphenyldiazenyl)phenyl)butylphosphonic acid (A4), with divalent and trivalent metal ions has been examined. These films are characterized by the formation of a metal phosphonate Continuous Lattice in the polar region of the transferred bilayers. The behavior of the films upon heating and with temperature cycling was studied with attenuated total reflectance (ATR)-FTIR, transmission FTIR, absorbance spectroscopy, and X-ray diffraction. A reversible transition is observed between 40 and 50 °C in each film, and this process is assigned as a premelting transition in analogy to similar transitions observed in previously studied LB films. Irreversible disordering of the organic networks is observed for each film at higher temperatures, occurring near 150 °C in the lanthanum octadecylphosphonate film, near 140 °C in th...

  • Structural Characterization and Magnetic Order in Phenoxy-Substituted Divalent Metal Phosphonate Langmuir–Blodgett Films
    IEEE Journal of Solid-state Circuits, 1999
    Co-Authors: Gail E Fanucci, Melissa A Petruska, Mark W. Meisel, Daniel R. Talham
    Abstract:

    Abstract Metal phosphonate Langmuir–Blodgett (LB) films of an alkoxyphenyl-substituted phosphonic acid (P4A) have been prepared with the divalent metals Mn 2+ and Cd 2+ . Structural characterization with infrared spectroscopy, XPS, and X-ray diffraction shows that the films contain the inorganic Continuous Lattice of known layered solid-state metal phosphonates with formula M (O 3 P R )H 2 O. Magnetic characterization of the Mn-P4 LB film consists of EPR and magnetometry measurements. The Mn-P4 LB film undergoes a transition to a long-range, canted antiferromagnetic state below 14.8±0.2 K and is only the second example of a Continuous Lattice LB film to exhibit spontaneous magnetization. These results demonstrate that it is possible to prepare metal phosphonate LB films of functionalized organophosphonic acids while retaining both the inorganic Continuous Lattice structure and magnetic exchange pathways of the known solid-state metal organophosphonates.

  • Organic/Inorganic Langmuir−Blodgett Films Based on Metal Phosphonates. 3. An Azobenzene-Derivatized Phosphonic Acid Forms Continuous Lattice Layers with Divalent, Trivalent, and Tetravalent Metal Ions1
    Chemistry of Materials, 1998
    Co-Authors: Melissa A Petruska, Daniel R. Talham
    Abstract:

    Metal phosphonate Langmuir−Blodgett (LB) films of an azobenzene-functionalized phosphonic acid amphiphile, (4-(4‘-tetradecyloxyphenyldiazenyl)phenyl)butylphosphonic acid (A4), have been prepared with Zr4+, La3+, Gd3+, Ba2+, Mn2+, and Cd2+. Film formation and quality are characterized with optical spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. The azobenzene chromophores are strongly H-aggregated in all of the metal phosphonate LB films. With divalent and trivalent ions, the in-plane metal phosphonate structure observed in the LB films is the same as that found in analogous solid-state layered phosphonates and depends on the identity of the metal ion. Films of A4 with the lanthanide ions La3+ and Gd3+ form with stoichiometry MH(O3PR)2. When Ba2+ is incorporated into the films, the M(HO3PR)2 structure-type is adopted, while Mn2+ and Cd2+ give rise to films of A4 with the stoichiometry M(O3PR)...

Tomasz Kubiak - One of the best experts on this subject based on the ideXlab platform.

  • tensor products of complete Lattices and their application in constructing quantales
    Fuzzy Sets and Systems, 2017
    Co-Authors: Javier Gutierrez Garcia, Ulrich Höhle, Tomasz Kubiak
    Abstract:

    Abstract This paper aims to implement tensor products of complete Lattices into fuzzy set theory. The most convenient approach for this purpose is to view the tensor product of two complete Lattices as the family of all join reversing maps between those Lattices. We show that some fundamental constructions in fuzzy set theory are tensor products. Examples of such circumstances include the following (to mention only three of them): the complete Lattice of all lower semiContinuous maps from a topological space into a Continuous Lattice is the tensor product of the topology of the space and the range Lattice; a binary operation coming from Zadeh's extension principle is the tensor product of the Minkowski multiplication with the multiplication of the underlying unital quantale; triangle functions on nonnegative left-Continuous distribution functions are tensor products of the real unit interval and the extended nonnegative half-line equipped, respectively, with a left-Continuous t -norm and the usual addition.

  • Approximating Orders in Meet-Continuous Lattices and Regularity Axioms in Many Valued Topology
    Order, 2008
    Co-Authors: Ulrich Höhle, Tomasz Kubiak
    Abstract:

    It is shown that in a meet-Continuous Lattice L endowed with a multiplicative auxiliary order ≺ the family of all members of L which satisfy the axiom of approximation, i.e. α = $$\bigvee$$ { β ∈ L : β ≺ α }, is closed under finite infs and arbitrary sups. This is a key ingredient of a meet-Continuous Lattice proof that both regularity and complete regularity of many valued topology have subbasic characterizations. As a consequence, the frame law can now be eliminated from some fundamental results on completely regular L -valued topological spaces (e.g., this is the case in regard to the Tychonoff embedding theorem).

  • FUZZY TOPOLOGIES OF SCOTT Continuous FUNCTIONS AND THEIR RELATION TO THE HYPERGRAPH FUNCTOR
    Quaestiones Mathematicae, 1992
    Co-Authors: Wesley Kotzé, Tomasz Kubiak
    Abstract:

    Abstract A new definition of the hypergraph functor from the category TOP(L) of L-fuzzy topological spaces to TOP is given which avoids the strictly less-than relation on L. For L a complete Lattice with enough primes it will have all the earlier properties of the case when L is a complete chain. With L a Continuous Lattice, the functor ωL which replaces the topology of a topological space by the L-topology consisting of all Scott Continuous functions is discussed and some sufficient and necessary conditions for an L-fuzzy space to be in ωL (TOP) are extended from L being the unit interval. Under this new approach the link between the hypergraph functor and the functor ωL is preserved for L a distributive Continuous Lattice, i.e. a Continuous Lattice with enough primes.

Ulrich Höhle - One of the best experts on this subject based on the ideXlab platform.

  • tensor products of complete Lattices and their application in constructing quantales
    Fuzzy Sets and Systems, 2017
    Co-Authors: Javier Gutierrez Garcia, Ulrich Höhle, Tomasz Kubiak
    Abstract:

    Abstract This paper aims to implement tensor products of complete Lattices into fuzzy set theory. The most convenient approach for this purpose is to view the tensor product of two complete Lattices as the family of all join reversing maps between those Lattices. We show that some fundamental constructions in fuzzy set theory are tensor products. Examples of such circumstances include the following (to mention only three of them): the complete Lattice of all lower semiContinuous maps from a topological space into a Continuous Lattice is the tensor product of the topology of the space and the range Lattice; a binary operation coming from Zadeh's extension principle is the tensor product of the Minkowski multiplication with the multiplication of the underlying unital quantale; triangle functions on nonnegative left-Continuous distribution functions are tensor products of the real unit interval and the extended nonnegative half-line equipped, respectively, with a left-Continuous t -norm and the usual addition.

  • Approximating Orders in Meet-Continuous Lattices and Regularity Axioms in Many Valued Topology
    Order, 2008
    Co-Authors: Ulrich Höhle, Tomasz Kubiak
    Abstract:

    It is shown that in a meet-Continuous Lattice L endowed with a multiplicative auxiliary order ≺ the family of all members of L which satisfy the axiom of approximation, i.e. α = $$\bigvee$$ { β ∈ L : β ≺ α }, is closed under finite infs and arbitrary sups. This is a key ingredient of a meet-Continuous Lattice proof that both regularity and complete regularity of many valued topology have subbasic characterizations. As a consequence, the frame law can now be eliminated from some fundamental results on completely regular L -valued topological spaces (e.g., this is the case in regard to the Tychonoff embedding theorem).

Paulo R. A. Campos - One of the best experts on this subject based on the ideXlab platform.

  • Adaptive evolution on a Continuous Lattice model
    Physical Review E, 2013
    Co-Authors: S. Claudino, Iram Gleria, Mariana L Lyra, Paulo R. A. Campos
    Abstract:

    In the current work, we investigate the evolutionary dynamics of a spatially structured population model defined on a Continuous Lattice. In the model, individuals disperse at a constant rate $v$ and competition is local and delimited by the competition radius $R$. Due to dispersal, the neighborhood size (number of individuals competing for reproduction) fluctuates over time. Here we address how these new variables affect the adaptive process. While the fixation probabilities of beneficial mutations are roughly the same as in a panmitic population for small fitness effects $s$, a dependence on $v$ and $R$ becomes more evident for large $s$. These quantities also strongly influence fixation times, but their dependencies on $s$ are well approximated by ${s}^{\ensuremath{-}1/2}$, which means that the speed of the genetic wave front is proportional to $\sqrt{s}$. Most important is the observation that the model exhibits a dual behavior displaying a power-law growth for the fixation rate and speed of adaptation with the beneficial mutation rate, as observed in other spatially structured population models, while simultaneously showing a nonsaturating behavior for the speed of adaptation with the population size $N$, as in homogeneous populations.