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Full-Text Articles in Engineering

Mild Yet Phase-Selective Preparation Of Tio2 Nanoparticles From Ionic Liquids – A Critical Study, Tarek Alammar, Heshmat Noei, Yuemin Wang, Anja V. Mudring Jan 2013

Mild Yet Phase-Selective Preparation Of Tio2 Nanoparticles From Ionic Liquids – A Critical Study, Tarek Alammar, Heshmat Noei, Yuemin Wang, Anja V. Mudring

Anja V. Mudring

The phase selective synthesis of nanocrystalline TiO2, titania, in ionic liquids (ILs) is explored. The influence not only of the IL but also of the Ti-precursor, pH, and temperature is investigated. Sonochemical synthesis, microwave synthesis and conventional heating are compared. In the case of Ti(OiPr)4 (OiPr ¼ isopropyl) as the Ti-source the ILs [C4mim][Tf2N] (1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide), [C3mimOH][Tf2N] (1-(3-hydroxypropyl)-3-methylimidazolium bis(trifluoromethanesulfonyl)amide), [C4Py]- [Tf2N] (butylpyridinium bis(trifluoromethanesulfonyl)amide), [N1888][Tf2N] (methyltrioctylammonium bis- (trifluoromethanesulfonyl)amide), and [P66614][Tf2N] (tetradecyltrihexyl phosphonium bis(trifluoromethanesulfonyl) amide) led at ambient temperature to TiO2 in the form of anatase. The morphology of nano-anatase is controlled by the IL cation. Anatase nanospheres with a crystal size …


Phase And Morphology Selective Interface-Assisted Synthesis Of Highly Luminescent Ln3+-Doped Nagdf4 Nanorods, Anja V. Mudring, Qiang Ju Jan 2013

Phase And Morphology Selective Interface-Assisted Synthesis Of Highly Luminescent Ln3+-Doped Nagdf4 Nanorods, Anja V. Mudring, Qiang Ju

Anja V. Mudring

Making use of the multifunctional properties of ionic liquids by employing them as a fluoride resource and hydrophilic phase, we have grown small, monodisperse, highly luminescent Ln3+-doped NaGdF4 nanorods at the interface between octadecene and the reactive ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate. The obtained nanocrystals could further be endowed with functional groups and rendered water dispersible, which allows them to be used for biodetection.


On The Mesophase Formation Of 1,3-Dialkylimidazolium Ionic Liquids, Mei Yang, Bert Mallick, Anja V. Mudring Jan 2013

On The Mesophase Formation Of 1,3-Dialkylimidazolium Ionic Liquids, Mei Yang, Bert Mallick, Anja V. Mudring

Anja V. Mudring

A series of seven different 1,3-dialkylimidazolium-based ion-pair salts with the same molecular weight and size but different symmetries was synthesized. For all salts, bromide was chosen as the counterion, giving the series ([CnIMCm][Br]), where IM = imidazolium and Cn and Cm are varying N-alkyl substituents with n + m = 13. Thus, the effect of symmetry on the physicochemical properties, such as thermal transitions, densities and viscosities and particularly mesophase formation, is investigated herein. All salts are fully characterized by NMR spectroscopy and mass spectrometry, and their physicochemical properties such as thermal transitions, densities, and viscosities are reported. Single crystal …


Mercuric Ionic Liquids: [Cnmim][Hgx3], Where N = 3, 4 And X = Cl, Br, Bert Mallick, Andreas Metlen, Mark Nieuwenhuyzen, Robin D. Rogers, Anja V. Mudring Jan 2012

Mercuric Ionic Liquids: [Cnmim][Hgx3], Where N = 3, 4 And X = Cl, Br, Bert Mallick, Andreas Metlen, Mark Nieuwenhuyzen, Robin D. Rogers, Anja V. Mudring

Anja V. Mudring

A series of mercury(II) ionic liquids, [Cnmim][HgX3], where [Cnmim] = n-alkyl-3-methylimidazolium with n = 3, 4 and X = Cl, Br, have been synthesized following two different synthetic approaches, and structurally characterized by means of single-crystal X-ray structure analysis ([C3mim][HgCl3] (1), Cc (No. 9), Z = 4, a = 16.831(4) Å, b = 10.7496(15) Å, c = 7.4661(14) Å, β = 105.97(2)°, V = 1298.7(4) Å3 at 298 K; [C4mim][HgCl3] (2), Cc (No. 9), Z = 4, a = 17.3178(28) Å, b = 10.7410(15) Å, c = 7.4706(14) Å, β = 105.590(13)°, V = 1338.5(4) Å3 at 170 K; [C3mim][HgBr3] …


Ionic Liquids As Crystallization Media: Weakly-Coordinating Anions Do Coordinate In 1∞[Eu(Otf)3(Ch3cn)3], Sifu Tang, Anja V. Mudring Jan 2011

Ionic Liquids As Crystallization Media: Weakly-Coordinating Anions Do Coordinate In 1∞[Eu(Otf)3(Ch3cn)3], Sifu Tang, Anja V. Mudring

Anja V. Mudring

Tris(acetonitrile)tris(trifluoromethanesulfonato)-europium(III), 1∞[Eu(OTf)3(CH3CN)3], is the first structurally characterized Ln(OTf)3-solvate where triflate is still in the coordination sphere of the Ln(III) cation and not substituted by solvate molecules. This fact is attributed to the unique crystallization conditions that an ionic liquid provides: 1∞[Eu(OTf)3(CH3CN)3] was obtained from a solution of europium(III) triflate, Eu(OTf)3, with acetonitrile in the ionic liquid [C4py][OTf] (1-butylpyridinium triflate). The crystal structure (triclinic, P1̅ (no. 2), a = 5.734(1) Å, b = 10.500(2) Å, c = 19.088(4) Å, α = 98.09(3)°, β = 93.79(3)°, γ = 91.46(3)°, V = 1134.5(4) Å3, Z = 2, R1 for 4388 reflections with Io …


Stability And Growth Behavior Of Transition Metal Nanoparticles In Ionic Liquids Prepared By Thermal Evaporation: How Stable Are They Really?, Kai Richter, Alexander Birkner, Anja V. Mudring Jan 2011

Stability And Growth Behavior Of Transition Metal Nanoparticles In Ionic Liquids Prepared By Thermal Evaporation: How Stable Are They Really?, Kai Richter, Alexander Birkner, Anja V. Mudring

Anja V. Mudring

Recently we developed an access to metal- and metal-oxide colloids based on thermal evaporation of metals into ionic liquids (ILs). Here we present systematic studies on the long-time stability of gold and copper nanoparticles (NPs) in different ILs. The influence of metal concentration and temperature on the ripening of the as-prepared gold NPs in different ILs was investigated by transmission electron microscopy (TEM) and UV-vis absorption measurements. Short alkyl chain-length-methyl-imidazolium salts with weakly coordinating perfluorinated counter anions (PF6, BF4 or Tf2N, bis(trifluoromethanesulfonyl)amide) were found to be better stabilizers compared to ILs with cations bearing long alkyl chains (trihexyltetradecylphosphonium, 1-octyl-3-methylimidazolium) and …


In-Situ Crystal Growth And Properties Of The Magnetic Ionic Liquid [C2mim][Fecl4], Tobias Backer, Oliver Breunig, Klaus Merz, Vera Vasylyeva, Anja V. Mudring Jan 2011

In-Situ Crystal Growth And Properties Of The Magnetic Ionic Liquid [C2mim][Fecl4], Tobias Backer, Oliver Breunig, Klaus Merz, Vera Vasylyeva, Anja V. Mudring

Anja V. Mudring

[C2mim][FeCl4] behaves like a paramagnetic liquid at room temperature. Specific heat measurements indicate that there is a magnetic ordering below 3.8 K. The released entropy is far from the expected value for a J = 5/2 system, implying that the magnetic state is partly disordered. Full magnetic polarization was reached in fields above 4 T, and the anomaly in the magnetic susceptibility can be fully suppressed in higher B fields. Hence, the suggested magnetic ground state is superparamagnetic. In order to better understand the magnetic nature of this compound, structural investigations were carried out. Raman and IR-spectroscopy as well as …


A New Open-Framework Iron Borophosphate From Ionic Liquids: Kfe[Bp2o8(Oh)], Guangmei Wang, Anja V. Mudring Jan 2011

A New Open-Framework Iron Borophosphate From Ionic Liquids: Kfe[Bp2o8(Oh)], Guangmei Wang, Anja V. Mudring

Anja V. Mudring

A new open-framework iron borophosphate, KFe[BP2O8(OH)], has been obtained by ionothermal synthesis from KH2PO4, FeCl3∙4H2O, H3BO3 and [C4mpyr]Br (1-butyl-1-methylpyrrolidinium bromide). Single-crystal X-ray diffraction analysis shows that KFe[BP2O8(OH)] (monoclinic, P21/c, a = 9.372(2) Å , b = 8.146(2)Å , c = 9.587(2) Å, β = 101.18(3)°, V = 718.0(2)Å3 and Z = 4) has a three-dimensional (3-D) framework structure composed by {Fe(III)O5(OH)} octahedra as well as {BO3(OH)} and {PO4} tetrahedra. As anionic structural sub-unit, KFe[BP2O8(OH)], contains an infinite open-branched {[BP2O8(OH)]4-} chain which is formed by alternating {BO3(OH)} and {PO4} tetrahedra. {Fe(III)O5(OH)} octahedra share common O corners with five phosphate tetrahedra and …


The First Lanthanide Telluride-Bromide: La3te4br, A Valence Compound, Markus Larres, Anja V. Mudring, Gerd Meyer Jan 2011

The First Lanthanide Telluride-Bromide: La3te4br, A Valence Compound, Markus Larres, Anja V. Mudring, Gerd Meyer

Anja V. Mudring

The first ternary lanthanide telluride-bromide La3Te4Br was obtained from a mixture of LaTe and LaBr3 (in the presence of iridium) in a sealed tantalum container at elevated temperatures. The crystal structure (orthorhombic, Pnma, a = 1634.3(2), b = 435.0(1), c = 1426.6(2) pm, Z = 4, R1 (I0 > 2s(I0)) = 0.0349) is built from dicapped trigonal prisms of tellurium and bromine atoms surrounding lanthanum in two different ways. The dicapped trigonal prisms are connected via common edges to a threedimensional structure, in the same fashion as is known for the binary U3Te5. La3Te4Br is a valence compound according to (La3+)3(Te2-)4(Br-) …


Use Of A Porous Membrane For Gas Bubble Removal In Microfluidic Channels: Physical Mechanisms And Design Criteria, Jie Xu, Regis Vaillant, Daniel Attinger Oct 2010

Use Of A Porous Membrane For Gas Bubble Removal In Microfluidic Channels: Physical Mechanisms And Design Criteria, Jie Xu, Regis Vaillant, Daniel Attinger

Daniel Attinger

We demonstrate and explain a simple and efficient way to remove gas bubbles from liquid-filled microchannels, by integrating a hydrophobic porous membrane on top of the microchannel. A prototype chip is manufactured in hard, transparent polymer with the ability to completely filter gas plugs out of a segmented flow at rates up to 7.4 μl/s/mm2 of membrane area. The device involves a bubble generation section and a gas removal section. In the bubble generation section, a T-junction is used to generate a train of gas plugs into a water stream. These gas plugs are then transported toward the gas removal …


[Ni(Tmen)(Acac)][B(Ph)4] A Probe For The Anion Basicity Of Ionic Liquids, Joanna Bartosik, Anja V. Mudring Jan 2010

[Ni(Tmen)(Acac)][B(Ph)4] A Probe For The Anion Basicity Of Ionic Liquids, Joanna Bartosik, Anja V. Mudring

Anja V. Mudring

An optical basicity scale of various ionic liquids (IL) anions has been determined by UV-Vis absorption spectroscopy. The indicator complex [Ni(tmen)(acac)][B(Ph)4] (tmen = tetramethylethylendiamine, acac = acetylacetonate) shows to be a sensitive probe as the position of the 3A2g(F) → 3T1g(F) absorption maximum of square planar to octahedral Ni2+ shifts distinctly depending on the electron donor ability of the respective ionic liquid anion. If the Lewis basicity of the anion becomes stronger a change to a tetrahedral coordination around Ni2+ is observed. Here the 3T1(F) → 3T2(F) and 3T1(F) → 3T1(P) transitions are helpful for monitoring the IL anion basicity. …


On The Dissolution Of Non-Metallic Solid Elements (Sulfur, Selenium, Tellurium And Phosphorus) In Ionic Liquids, Eva Boros, Martyn J. Earle, Manuela A. Gilea, Andreas Metlen, Anja V. Mudring, Franziska Rieger, Allan J. Robertson, Kenneth R. Seddon, Alina A. Tomaszowska, Lev Trusov, Joseph S. Vyle Jan 2010

On The Dissolution Of Non-Metallic Solid Elements (Sulfur, Selenium, Tellurium And Phosphorus) In Ionic Liquids, Eva Boros, Martyn J. Earle, Manuela A. Gilea, Andreas Metlen, Anja V. Mudring, Franziska Rieger, Allan J. Robertson, Kenneth R. Seddon, Alina A. Tomaszowska, Lev Trusov, Joseph S. Vyle

Anja V. Mudring

Ionic liquids are shown to be good solvents for elemental sulfur, selenium, phosphorus and tellurium, and can be designed to maximise the solubility of these elements. The presence of the [S3]˙− radical anion in diluted solutions of sulfur in some ionic liquids has been confirmed, and is the origin of their intense blue colour (cf. lapis lazuli).


Facile Preparation Of Quantum Cutting Gdf3 : Eu3+ Nanoparticles From Ionic Liquids, Chantal Lorbeer, Joanna Cybinska, Anja V. Mudring Jan 2010

Facile Preparation Of Quantum Cutting Gdf3 : Eu3+ Nanoparticles From Ionic Liquids, Chantal Lorbeer, Joanna Cybinska, Anja V. Mudring

Anja V. Mudring

Microwave reaction of Ln(OAc)3·xH2O, Ln = Gd, Eu; OAc = acetate) with and in the ionic liquid [C4mim][BF4] (C4mim = 1-butyl-3-methylimidazolium) allows the fast and efficient synthesis of small, uniform, oxygen-free lanthanide nanofluorides with excellent photophysical behaviour. For GdF3 : Eu3+ nanoparticles a quantum efficiency of up to 145% was determined.


Easy Access To Ultra Long-Time Stable, Luminescent Europium(Ii) Fluoride Nanoparticles In Ionic Liquids, Nina Von Prondzinski, Joanna Cybinska, Anja V. Mudring Jan 2010

Easy Access To Ultra Long-Time Stable, Luminescent Europium(Ii) Fluoride Nanoparticles In Ionic Liquids, Nina Von Prondzinski, Joanna Cybinska, Anja V. Mudring

Anja V. Mudring

Physical vapour deposition into ionic liquids allows for the first time the synthesis of a reduced lanthanide halide on the nanoscale. The obtained EuF2 nanoparticles show a bright blue luminescence and form long-time stable-colloidal solutions in the ionic liquids.


Optical Basicity Of Ionic Liquids, Slawomir Pitula, Anja V. Mudring Jan 2010

Optical Basicity Of Ionic Liquids, Slawomir Pitula, Anja V. Mudring

Anja V. Mudring

The concept of optical basicities initially developed by Duffy for solid oxides was successfully transferred to low melting salts such as ionic liquids (ILs). Several ionic liquids (ILs) were doped with Mn(NTf2)2 (NTf2 = bis(trifluoromethanesulfonyl)imide) as a probe to investigate the IL anion basicity by means of UV-Vis spectroscopy. The 6A1 → 4A, 4E(G) transition band of Mn2+ is influenced by the electron donor properties, i.e., Lewis basicity, of the coordinating ligands but remains—to the first order—independent from the ligand field. The change in the optical spectra for various Mn(NTf2)2 doped ILs is predominantly dependent on the anion. No significant …


The Missing Link Crystallized From The Ionic Liquid 1-Ethyl-3-Methylimidazolium Tosylate: Bis-Aqua-(P-Toluenesulfonato-O)-Europium(Iii)-Bis-P-Toluenesulfonate Dihydrate, Si-Fu Tang, Anja V. Mudring Jan 2009

The Missing Link Crystallized From The Ionic Liquid 1-Ethyl-3-Methylimidazolium Tosylate: Bis-Aqua-(P-Toluenesulfonato-O)-Europium(Iii)-Bis-P-Toluenesulfonate Dihydrate, Si-Fu Tang, Anja V. Mudring

Anja V. Mudring

Bis-aqua-(p-toluenesulfonato-O)-europium(III)-bis-p-toluenesulfonate-dihydrate (1) was synthesized and structurally characterized. The crystal structure contains eight-coordinate europium(III) atoms. One oxygen atom from p-toluenesulfonate and seven aqua ligands form a slightly distorted square antiprism around Eu(III). A variety of O−H···O and intermolecular C−H···O hydrogen bonds link the asymmetric units into a two-dimensional layer, and these layers are further assembled into a three-dimensional supramolecular structure through intermolecular C−H···O hydrogen bonds and edge-to-face C−H···π interactions. The compound represents the structural missing link between the well-known lanthanide (Ln) tosylate (Tos) hydrates [(Ln(H2O)9](p-Tos)3(H2O) with noncoordinating tosylate and [Ln(H2O)6(p-Tos)2](p-Tos)2(H2O)3 where two tosylate groups coordinate to the lanthanide cation. It is …


Dysprosium-Based Ionic Liquid Crystals: Thermal, Structural, Photo- And Magnetophysical Properties, Anna Getsist, Benjamin Balke, Claudia Felser, Anja V. Mudring Jan 2009

Dysprosium-Based Ionic Liquid Crystals: Thermal, Structural, Photo- And Magnetophysical Properties, Anna Getsist, Benjamin Balke, Claudia Felser, Anja V. Mudring

Anja V. Mudring

[C12mim]3[DyBr6] (C12mim = 1-dodecyl-3-methylimidazolium) represents a new material with interesting luminescent behavior as well as mesomorphic and magnetic properties. The compound was found to show thermotropic liquid crystalline behavior and forms smectic mesophases which were investigated by hot-stage polarizing optical microscopy and differential scanning calorimetry. The emission color of [C12mim]3[DyBr6] can be tuned from white to orange-yellow by the choice of the excitation wavelength. Sample excitation with λex = 366 nm leads to the blue-whitish luminescence from the imidazolium cation itself. With λex = 254 nm the common Dy(III) emission is observed which mainly arises from the 4F9/2 → 6H13/2 …


Temperature-Driven Mixing-Demixing Behavior Of Binary Mixtures Of The Ionic Liquid Choline Bis(Trifluoromethylsulfonyl)Imide And Water, Peter Nockeman, Koen Binnemans, Ben Thijs, Tatjana N. Parc-Vogt, Klaus Merz, Anja V. Mudring, Preethy Chirukandath Menon, Ravindran Nair Rajesh, George Cordoyianis, Jan Thoen, Jan Leys, Christ Glorieux Jan 2009

Temperature-Driven Mixing-Demixing Behavior Of Binary Mixtures Of The Ionic Liquid Choline Bis(Trifluoromethylsulfonyl)Imide And Water, Peter Nockeman, Koen Binnemans, Ben Thijs, Tatjana N. Parc-Vogt, Klaus Merz, Anja V. Mudring, Preethy Chirukandath Menon, Ravindran Nair Rajesh, George Cordoyianis, Jan Thoen, Jan Leys, Christ Glorieux

Anja V. Mudring

Home Browse the Journal Articles ASAP Current Issue Submission & Review Open Access Subscribe About the Journal J. Phys. Chem. A B C Letters Pre-1997 System Maintenance: Thursday, October 22, 5pm to 9pm EDT Please be aware that pubs.acs.org will undergo maintenance from 5pm on Thursday, October 22 with all applications expected to resume normal operation by 9pm. This upgrade will impact applications that require a login or ACS ID, including the "Registration" and "MyAccount" functions. Log-in will be temporarily disabled for features including C&EN Delivery, ChemWorx and Galleys. Individual users will not be able to log-in to access their …


Facile, Environmentally Friendly Fabrication Of Porous Silver Monoliths Using The Ionic Liquid N-(2-Hydroxyethyl)Ammonium Formate, Kai Richter, Tobias Backer, Anja V. Mudring Jan 2009

Facile, Environmentally Friendly Fabrication Of Porous Silver Monoliths Using The Ionic Liquid N-(2-Hydroxyethyl)Ammonium Formate, Kai Richter, Tobias Backer, Anja V. Mudring

Anja V. Mudring

The environmentally friendly ionic liquid N-(2-hydroxyethyl)ammonium formate works as a reaction medium, reducing and templating agent in the mild microwave synthesis (5 min, 80 °C) of a macroporous silver framework from AgNO3.


A New Class Of Double Alkyl-Substituted, Liquid Crystalline Imidazolium Ionic Liquids—A Unique Combination Of Structural Features, Viscosity Effects, And Thermal Properties, Xinjiao Wang, Frank W. Heinemann, Mei Yang, Berthold U. Melcher, Melinda Fekete, Anja V. Mudring, Peter Wasserscheid, Karsten Meyer Jan 2009

A New Class Of Double Alkyl-Substituted, Liquid Crystalline Imidazolium Ionic Liquids—A Unique Combination Of Structural Features, Viscosity Effects, And Thermal Properties, Xinjiao Wang, Frank W. Heinemann, Mei Yang, Berthold U. Melcher, Melinda Fekete, Anja V. Mudring, Peter Wasserscheid, Karsten Meyer

Anja V. Mudring

1,3-Didodecylimidazolium salts have been prepared as first representatives of a new class of ionic liquid crystals (ILCs), showing thermotropic liquid crystalline behaviour in an extended temperature range below 70 °C. Remarkably strong non-Newtonian viscosity behaviour was found for the liquid-crystalline state of these ILCs.


The Dissipated Power In Atomic Force Microscopy Due To Interactions With A Capillary Fluid Layer, Nicole N. Hashemi, M.R. Paul, H. Dankowicz, W. Jhe Jan 2008

The Dissipated Power In Atomic Force Microscopy Due To Interactions With A Capillary Fluid Layer, Nicole N. Hashemi, M.R. Paul, H. Dankowicz, W. Jhe

Nastaran Hashemi

We study the power dissipated by the tip of an oscillating micron-scale cantilever as it interacts with a sample using a nonlinear model of the tip-surface force interactions that includes attractive, adhesive, repulsive, and capillary contributions. The force interactions of the model are entirely conservative and the dissipated power is due to the hysteretic nature of the interaction with the capillary fluid layer. Using numerical techniques tailored for nonlinear and discontinuous dynamical systems we compute the exact dissipated power over a range of experimentally relevant conditions. This is accomplished by computing precisely the fraction of oscillations that break the fluid …


(Crcl3)3@2[C4mim][Ome]—Molecular Cluster-Type Chromium(Iii) Chloride Stabilized In A Salt Matrix, Bert Mallick, Harald Kierspel, Anja V. Mudring Jan 2008

(Crcl3)3@2[C4mim][Ome]—Molecular Cluster-Type Chromium(Iii) Chloride Stabilized In A Salt Matrix, Bert Mallick, Harald Kierspel, Anja V. Mudring

Anja V. Mudring

In [C4mim]2[CrCl3]3[OMe]2 molecular (CrCl3)3 units are embedded in a salt matrix of [C4mim][OMe]. This structural subunit can be viewed as a trapped molecular polymorph of CrCl3. Experimental and theoretical investigations indicate that, in contrast to bulk CrCl3, metal−metal bonds are formed at low temperatures.


A Bubble-Powered Micro-Rotor: Conception, Manufacturing, Assembly And Characterization, Jonathan Kao, Xiaolin Wang, John Warren, Jie Xu, Daniel Attinger Dec 2007

A Bubble-Powered Micro-Rotor: Conception, Manufacturing, Assembly And Characterization, Jonathan Kao, Xiaolin Wang, John Warren, Jie Xu, Daniel Attinger

Daniel Attinger

A steady fluid flow, called microstreaming, can be generated in the vicinity of a micro-bubble excited by ultrasound. In this paper, we use this phenomenon to assemble and power a microfabricated rotor at rotation speeds as high as 625 rpm. The extractible power is estimated to be of the order of a few femtowatts. A first series of experiments with uncontrolled rotor shapes is presented, demonstrating the possibility of this novel actuation scheme. A second series of experiments with 65 µm rotors micromanufactured in SU-8 resin is then presented. Variables controlling the rotation speed and rotor stability are investigated, such …


Control And Ultrasonic Actuation Of A Gas–Liquid Interface In A Microfluidic Chip, Jie Xu, Daniel Attinger Mar 2007

Control And Ultrasonic Actuation Of A Gas–Liquid Interface In A Microfluidic Chip, Jie Xu, Daniel Attinger

Daniel Attinger

This paper describes the design and manufacturing of a microfluidic chip, allowing for the actuation of a gas–liquid interface and of the neighboring fluid. The first way to control the interface motion is to apply a pressure difference across it. In this case, the efficiency of three different micro-geometries at anchoring the interface is compared. Also, the critical pressures needed to move the interface are measured and compared to a theoretical result. The second way to control the interface motion is by ultrasonic excitation. When the excitation is weak, the interface exhibits traveling waves, which follow a dispersion equation. At …


Ionic Liquids With Perfluorinated Alkoxyaluminates, Tudor Timofte, Anja V. Mudring, Slawomir Pitula Jan 2007

Ionic Liquids With Perfluorinated Alkoxyaluminates, Tudor Timofte, Anja V. Mudring, Slawomir Pitula

Anja V. Mudring

Ionic liquids with the weakly coordinating perfluoroalkoxyaluminate anions, Al(ORF)4-, are obtained by a metathesis reaction of LiAl(ORF)4 and [bmim]Cl or [bmpyr]Cl in high yields. The compounds [bmim][Al(hfip)4] and [bmpyr][Al(hfip)4] have surprisingly low viscosities at elevated temperatures (60 °C) and an exceptionally high electrochemical window, which might render them useful for certain applications.


Cluster-Type Basic Lanthanide Iodides [M6(Μ6-O)(Μ3-Oh)8(H2o)24]I8(H2o)8 (M = Nd, Eu, Tb, Dy), Anja V. Mudring, Tudor Timofte, Arash Babai Jan 2006

Cluster-Type Basic Lanthanide Iodides [M6(Μ6-O)(Μ3-Oh)8(H2o)24]I8(H2o)8 (M = Nd, Eu, Tb, Dy), Anja V. Mudring, Tudor Timofte, Arash Babai

Anja V. Mudring

Ln6(μ6-O)(μ3-OH)8(H2O)24]I8(H2O)8 (Ln = Nd, Eu, Tb, Dy) compounds are obtained as the final hydrolysis products of lanthanide triiodides in an aqueous solution. Their X-ray crystal structure features a body-centered arrangement of oxygen-centered {Ln6X8}8+ cluster cores:  [Nd6(μ6-O)(μ3-OH)8(H2O)24]I8(H2O)8 [Pearson code oP156, orthorhombic, Pnnm (No. 58), Z = 2, a = 1310.4(3) pm, b = 1502.1(3) pm, c = 1514.9(3) pm, 3384 reflections with I0 > 2σ(I0), R1 = 0.0340, wR2 = 0.0764, GOF = 1.022, T = 298(2) K], [Eu6(μ6-O)(μ3-OH)8(H2O)24]I8(H2O)8 [Pearson code oP156, orthorhombic, Pnnm (No. 58), Z = 2, a = 1306.6(2) pm, b = 1498.15(19) pm, c = 1499.41(18) pm, 4262 …


Homoleptic Alkaline Earth Metal Bis(Trifluoromethanesulfonyl)Imide Complex Compounds Obtained From An Ionic Liquid, Arash Babai, Anja V. Mudring Jan 2006

Homoleptic Alkaline Earth Metal Bis(Trifluoromethanesulfonyl)Imide Complex Compounds Obtained From An Ionic Liquid, Arash Babai, Anja V. Mudring

Anja V. Mudring

The first homoleptic alkaline earth bis(trifluoromethanesulfonyl)imide (Tf2N) complexes [mppyr]2[Ca(Tf2N)4], [mppyr]2[Sr(Tf2N)4], and [mppyr][Ba(Tf2N)3] were crystallized from a solution of the respective alkaline earth bis(trifluoromethanesulfonyl)imide and the ionic liquid [mppyr][Tf2N] (mppyr = 1,1-N-methyl-N-propylpyrrolidinium). In the calcium and strontium compounds, the alkaline earth metal (AE) is coordinated by four bidentately chelating Tf2N ligands to form isolated (distorted) square antiprismatic [AE(Tf2N)4]2- complexes which are separated by N-methyl-N-propylpyrrolidinium cations. In contrast, the barium compound, [mppyr][Ba(Tf2N)3], forms an extended structure. Here the alkaline earth cation is surrounded by six oxygen atoms belonging to three Tf2N- anions which coordinate in a bidentate chelating fashion. Three further oxygen …


The First Homoleptic Bis(Trifluoromethanesulfonyl)Amide Complex Compounds Of Trivalent F-Elements, Anja V. Mudring, Arash Babai Jan 2006

The First Homoleptic Bis(Trifluoromethanesulfonyl)Amide Complex Compounds Of Trivalent F-Elements, Anja V. Mudring, Arash Babai

Anja V. Mudring

The synthesis and crystal structures of the first true homoleptic bis(trifluoromethanesulfonyl)amide complex compounds of trivalent f-elements are reported with [bmpyr]2[Ln(Tf2N)5], Ln = Nd, Tb and [bmpyr][Ln(Tf2N)4], Ln = Tm, Lu.


Crystal Engineering In Ionic Liquids. The Crystal Structures Of [Mppyr]3[Ndi6] And [Bmpyr]4[Ndi6][Tf2n], Arash Babai, Anja V. Mudring Jan 2006

Crystal Engineering In Ionic Liquids. The Crystal Structures Of [Mppyr]3[Ndi6] And [Bmpyr]4[Ndi6][Tf2n], Arash Babai, Anja V. Mudring

Anja V. Mudring

Single crystals of [mppyr][NdI6] and [bmpyr][NdI6][Tf2N] are the first surprising examples of how the cation of an ionic liquid determines the compound formation from an ionic liquid. Depending upon the variation of the length of the alkyl chain of the quaternary pyrrolidinium cation (C3 and C4, respectively), incorporation of the anion of the ionic liquid, [Tf2N]-, can either be evoked or suppressed.


Rare-Earth Iodides In Ionic Liquids:  The Crystal Structure Of [Set3]3[Lni6] (Ln = Nd, Sm), Anja V. Mudring, Arash Babai Jan 2005

Rare-Earth Iodides In Ionic Liquids:  The Crystal Structure Of [Set3]3[Lni6] (Ln = Nd, Sm), Anja V. Mudring, Arash Babai

Anja V. Mudring

Crystals of [SEt3]3[LnI6] (Ln = Nd, Sm) were obtained by the reaction of LnI2 with the ionic liquid [SEt3][Tf2N] [Tf2N = bis(trifluoromethanesulfonyl)imide]. The compounds are characterized by octahedral [LnI6]3- units that are surrounded by a distorted cube of triethylsulfonium cations.