Business card

Dr. Dirk Wallacher

Dr. Dirk Wallacher

graduate physicist
Department Sample Environments

Tel (030) 8062 - 43141, (030) 8062 - 14744, (030) 8062 - 18027, 35882 mail dirk.wallacher@helmholtz-berlin.de

Experimental scientist and expert for research on nanostructured and interface determined materials and characterization by gas adsorption analysis combined with neutron and x-ray scattering techniques. Scientific focus are on fundamental research in the thermodynamics and structure of meso-scaled pore condensates as well as the sorption properties of gas storage materials and molecular sieves. Responsible at Helmholtz-Centre Berlin for scientific and technical user suppport at the neutron source BER-II and the synchrotron light source BESSY-II for sample environment concerning: high pressures and temperatures, controlled gas atmospheres, cryogen free cryostats, as well as for the operation of the complementary HZB user lab DEGAS for gas adsorption studies.

Publications Publications - PDF

List of publications at HZB

2016


Bon, V.; Kavoosi, N.; Senkovska, I.; Müller, P.; Schaber, J.; Wallacher, D.; Többens, D.M.; Mueller, U.; Kaskel, S.: Tuning the flexibility in MOFs by SBU functionalization. Dalton Transactions 45 (2016), p. 4407-4415


Gruener, S.; Wallacher, D.; Greulich, S.; Busch, M.; Huber, P.: Hydraulic transport across hydrophilic and hydrophobic nanopores: Flow experiments with water and n-hexane. Physical Review E 93 (2016), p. 013102/1-13


Hofmann, T.; Wallacher, D.; Perlich, J.; Vayalil, S.K.; Huber, P.: Formation of Periodically Arranged Nanobubbles in Mesopores: Capillary Bridge Formation and Cavitation during Sorption and Solidification in an Hierarchical Porous SBA-15 Matrix. Langmuir 32 (2016), p. 2928-2936


Krause, S.; Bon, V.; Senkovska, I.; Stoeck, U.; Wallacher, D.; Többens, D.; Zander, S.; Pillai, R.S.; Maurin, G.; Coudert, F.X.; Kaskel, S.: A pressure-amplifying framework with negative gas adsorption transitions. Nature 532 (2016), p. 348-352

2015


Bon, V.; Klein, N.; Senkovska, I.; Heerwig, A.; Getzschmann, J.; Wallacher, D.; Zizak, I.; Brzhezinskaya, M.; Müller, U.; Kaskel, S.: Exceptional adsorption-induced cluster and network deformation in the flexible metal–organic framework DUT-8(Ni) observed by in situ X-ray diffraction and EXAFS. Physical Chemistry Chemical Physics 17 (2015), p. 17471-17479


Bon, V.; Pallmann, J.; Eisbein, E.; Hoffmann, H.C.; Senkovska, I.; Schwedler, I.; Schneemann, A.; Henke, S.; Wallacher, D.; Fischer, R.A.; Seifert, G.; Brunner, E.; Kaskel, S.: Characteristics of flexibility in metal-organic framework solid solutions of composition [Zn2(BME-bdc)x(DB-bdc)2-xdabco]n: In situ powder X-ray diffraction. Microporous and Mesoporous Materials 216 (2015), p. 64–74


Kunkel, N.; Reichert, C.; Springborg, M.; Wallacher, D.; Kohlmann, H.: Hydrogenation properties of LixSr1-xAlSi studied by quantum-chemical methods (0≤x≤1) and in-situ neutron powder diffraction (x=1). Journal of Solid State Chemistry 211 (2015), p. 318-324


Mascotto, S.; Kuzmicz, D.; Wallacher, D.; Siebenbürger, M.; Clemens, D.; Risse, S.; Yuan, J.; Antonietti, M.; Ballauff, M.: Poly(ionic liquid)-derived nanoporous carbon analyzed by combination of gas physisorption and small-angle neutron scattering. Carbon 82 (2015), p. 425-435


Stoeckel, D.; Wallacher, D.; Zickler, G.; Thommes, M.; Smarsly, B.: Elucidating the Sorption Mechanism of Dibromomethane in Disordered Mesoporous Silica Adsorbents. Langmuir 31 (2015), p. 6332-6342


Weidemann, S.; Kockert, M.; Wallacher, D.; Ramsteiner, M.; Mogilatenko, A.; Rademann, K.; Fischer, S.F.: Controlled Pore Formation on Mesoporous Single Crystalline Silicon Nanowires: Threshold and Mechanisms. Journal of Nanomaterials 2015 (2015), p. 672305/1-11

2014


Bon, V.; Sekovska, I.; Wallacher, D.; Többens, D.; Zizak, I.; Feyerherm, R.; Mueller, U.; Kaskel, S.: In Situ Observation of Gating Phenomena in the Flexible Porous Coordination Polymer Zn2(BPnDC)2(bpy) (SNU-9) in a Combined Diffraction and Gas Adsorption Experiment. Inorganic Chemistry 53 (2014), p. 1513-1520


Bon, V.; Senkovska, I.; Wallacher, D.; Heerwig, A.; Klein, N.; Zizak, I.; Feyerherm, R.; Dudzik, E.; Kaskel, S.: In situ monitoring of structural changes during the adsorption on flexible porous coordination polymers by X-ray powder diffraction: Instrumentation and experimental results. Microporous and Mesoporous Materials 188 (2014), p. 190-195


Kojda, D.; Wallacher, D.; Baudoin, S.; Hansen, T.; Huber, P.; Hofmann, T.: Solid phases of spatially nanoconfined oxygen: A neutron scattering study. Journal of Chemical Physics 140 (2014), p. 024705/1-9


Rother, G.; Vlcek, L.; Gruszkiewicz, M.S.; Chialvo, A.A.; Anovitz, L.M.; Banuelos, J.L.; Wallacher, D.; Grimm, N.; Cole, D.R.: Sorption Phase of Supercritical CO2 in Silica Aerogel: Experiments and Mesoscale Computer Simulations. Journal of Physical Chemistry C 118 (2014), p. 15525-15533


Stoeckel, D.; Wallacher, D.; Zickler, G.A.; Perlich, J.; Tallarek, U.; Smarsly, B.M.: Coherent Analysis of Disordered Mesoporous Adsorbents using Small Angle X-Ray Scattering and Physisorption Experiments. Physical Chemistry Chemical Physics 16 (2014), p. 6583-6592

2013


Campbell, S.J.; Hofmann, M.; Mole, R.A.; Prokes, K.; Wallacher, D.; Wang, J.L.: Magnetic Order in YbMn2Si2 - Neutron Scattering Investigation. Journal of the Korean Physical Society 63 (2013), p. 314-319


Hofmann, T.; Kumar, P.; Enderle, M.; Wallacher, D.: Growth of Highly Oriented Deuterium Crystals in Silicon Nanochannels. Physical Review Letters 110 (2013), p. 065505/1-5


Jalarvo, N.; Casolo, S.; Aliouane, N.; Wallacher, D.; Lovvik, O.M.; Norby, T.: On the Complex Structural Picture of the Ionic Conductor Sr6Ta2O11. Journal of Physical Chemistry C 117 (2013), p. 9543-9549


Karg, M.; Prévost, S.; Brandt, A.; Wallacher, D.; von Klitzing, R.; Hellweg, T.: Poly-NIPAM Microgels with Different Cross-Linker Densities : Scaling Behavior of the Network Fluctuations in the Vicinity of the Volume Phase Transition. In: Gabriele Sadowski ... [Ed.] : Intelligent hydrogels. Cham [u.a.]: Springer, 2013 (Progress in Colloid and Polymer Science ; 140). - ISBN 978-3-319-01682-5 , p. 63-76


Rother, G.; Ilton, E.S.; Wallacher, D.; Hauß, T.; Schaef, H.T.; Qafoku, O.; Rosso, K.M.; Felmy, A.R.; Krukowski, E.G.; Stack, A.G.; Grimm, N.; Bodnar, R.J.: CO2 Sorption to Subsingle Hydration Layer Montmorillonite Clay Studied by Excess Sorption and Neutron Diffraction Measurements. Environmental Science & Technology 47 (2013), p. 205-211


Stehle, R.; Goerigk, G.; Wallacher, D.; Ballauff, M.; Seiffert, S.: Small-angle X-ray scattering in droplet-based microfluidics. Lab on a Chip 13 (2013), p. 1529-1537

2012


Erko, M.; Wallacher, D.; Findenegg, G.H.; Paris, O.: Repeated sorption of water in SBA-15 investigated by means of in situ small-angle x-ray scattering. Journal of Physics / Condensed Matter 24 (2012), p. 284112/1-8


Erko, M.; Wallacher, D.; Hoell, A.; Hauß, T.; Zizak, I.; Paris, O.: Density minimum of confined water at low temperatures: a combined study by small-angle scattering of X-rays and neutrons. Physical Chemistry Chemical Physics 14 (2012), p. 3852-3858


Erko, M.; Wallacher, D.; Paris, O.: Deformation mechanism of nanoporous materials upon water freezing and melting. Applied Physics Letters 101 (2012), p. 181905/1-4


Gruszkiewicz, M.S.; Rother, G.; Wesolowski, D.J.; Cole, D.R.; Wallacher, D.: Direct Measurements of Pore Fluid Density by Vibrating Tube Densimetry. Langmuir 28 (2012), p. 5070-5078


Hofmann, T.; Wallacher, D.; Mayorova, M.; Zorn, R.; Frick, B.; Huber, P.: Molecular dynamics of n-hexane: A quasi-elastic neutron scattering study on the bulk and spatially nanochannel-confined liquid. Journal of Chemical Physics 136 (2012), p. 124505/1-9


Kalisvaart, W.P.; Luber, E.J.; Poirier, E.; Harrower, C.T.; Teichert, A.; Wallacher, D.; Grimm, N.; Steitz, R.; Fritzsche, H.; Mitlin, D.: Probing the Room Temperature Deuterium Absorption Kinetics in Nanoscale Magnesium Based Hydrogen Storage Multilayers Using Neutron Reflectometry, X-ray Diffraction, and Atomic Force Microscopy. Journal of Physical Chemistry C 116 (2012), p. 5868-5880


Kandemir, T.; Wallacher, D.; Hansen, T.; Liss, K.-D.; Naumann d'Alnoncourt, R.; Schlögl, R.; Behrens, M.: In situ neutron diffraction under high pressure - Providing an insight into working catalysts. Nuclear Instruments & Methods in Physics Research A 673 (2012), p. 51 - 55


Remhof, A.; Yan, Y.; Friedrichs, O.; Kim, J.W.; Mauron, Ph.; Borgschulte, A.; Wallacher, D.; Buchsteiner, A.; Hoser, A.; Oh, K.H.; Cho, Y.W.; Züttel, A.: Towards room temperature, direct, solvent free synthesis of tetraborohydrides. Journal of Physics : Conference Series 340 (2012), p. 012111/1-8


Rother, G.; Krukowski, E.G.; Wallacher, D.; Grimm, N.; Bodnar, R.J.; Cole, D.R.: Pore size effects on the sorption of supercritical CO2 in mesoporous CPG-10 silica. Journal of Physical Chemistry C 116 (2012), p. 917-922


Sharifi, M.; Wallacher, D.; Wark, M.: Distribution of functional groups in periodic mesoporous organosilica materials studied by small-angle neutron scattering with in situ adsorption of nitrogen. Beilstein Journal of Nanotechnology 3 (2012), p. 428-437

2011


Demeter, J.; Teichert, A.; Kiefer, K.; Wallacher, D.; Ryll, H.; Menendez, E.; Paramanik, D.; Steitz, R.; Van Haesendonck, C.; Vantomme, A.; Temst, K.: Simultaneous polarized neutron reflectometry and anisotropic magnetoresistance measurements. Review of Scientific Instruments 82 (2011), p. 033902


Hauptvogel, I.M.; Biedermann, R.; Klein, N.; Senkovska, I.; Cadiau, A.; Wallacher, D.; Feyerherm, R.; Kaskel, S.: Flexible and Hydrophobic Zn-Based Metal-Organic Framework. Inorganic Chemistry 50 (2011), p. 8367-8374


Mihalik, M.; Pospisil, J.; Rudajevová, A.; Marti, X.; Wallacher, D.; Hoser, A.; Hofmann, T.; Divis, M.; Sechovský, V.: Structure phase transitions of polymorphic compounds with layered crystal structures: The REIr2Si2 case. Intermetallics 19 (2011), p. 1622 - 1626


Poirier, E.; Harrower, C.T.; Kalisvaart, P.; Bird, A.; Teichert, A.; Wallacher, D.; Grimm, N.; Steitz, R.; Mitlin, D.; Fritzsche, H.: Deuterium absorption in Mg70Al30 thin films with bilayer catalysts: A comparative neutron reflectometry study. Journal of Alloys and Compounds 509 (2011), p. 5466-5471


Sharifi, M.; Marschall, R.; Wilhelm, M.; Wallacher, D.; Wark, M.: Detection of Homogeneous Distribution of Functional Groups in Mesoporous Silica by Small Angle Neutron Scattering and in Situ Adsorption of Nitrogen or Water. Langmuir 27 (2011), p. 5516 - 5522

2010


Erko, M.; Wallacher, D.; Brandt, A.; Paris, O.: In-situ small-angle neutron scattering study of pore filling and pore Emptying in ordered mesoporous silica. Journal of Applied Crystallography 43 (2010), p. 1 - 7


Friedrichs, O.; Kim, J.W.; Remhof, A.; Wallacher, D.; Hoser, A.; Cho, Y.W.; Oh, K.H.; Züttel, A.: Core shell structure for solid gas synthesis of LiBD4. Physical Chemistry Chemical Physics 12 (2010), p. 4600 - 4603


Getzschmann, J.; Senkovska, I.; Wallacher, D.; Tovar, M.; Fairen-Jimenez, D.; Dueren, T.; van Baten, J.M.; Krishna, R.; Kaskel, S.: Methane storage mechanism in the metal-organic framework Cu3(btc)2: An in situ neutron diffraction study. Microporous and Mesoporous Materials 136 (2010), p. 50-58


Kandemir, T.; Wallacher, D.; Tovar, M.; Behrens, M.: In situ Neutron Diffraction Study of a Methanol Synthesis Catalyst under Working Conditions. Zeitschrift für Anorganische und Allgemeine Chemie 636 (2010), p. 2088


Martelli, P.; Remhof, A.; Borgschulte, A.; Mauron, P.; Wallacher, D.; Kemner, E.; Russina, M.; Pendolino, F.; Züttel, A.: BH4- Self-Diffusion in Liquid LiBH4. Journal of Physical Chemistry A 114 (2010), p. 10117 - 10121


Mascotto, S.; Wallacher, D.; Kuschel, A.; Polarz, S.; Zickler, G.A.; Timmann, A.; Smarsly, B.M.: Adsorption in Periodically Ordered Mesoporous Organosilica Materials Studied by in Situ Small-Angle X-ray Scattering and Small-Angle Neutron Scattering. Langmuir 26 (2010), p. 6583-6592

2009


Friedrich, O.; Kim, J.W.; Remhof, A.; Buchter, F.; Borgschulte, A.; Wallacher, D.; Cho, Y.W.; Fichtner, M.; Oh, K.H.; Züttel, A.: The effect of Al on the hydrogen sorption mechanism of LiBH4. Physical Chemistry Chemical Physics 11 (2009), p. 1515-1520


Gruener, S. ; Hofmann, T. ; Wallacher, D. ; Kityk, A.V. ; Huber, P.: Capillary rise of water in hydrophilic nanopores. Physical Review E 79 (2009), p. 067301/1-4


Himsl, D. ; Wallacher, D. ; Hartmann, M: Improving the Hydrogen-Adsorption Properties of a Hydroxy-Modified MIL-53(Al) Structural Analogue by Lithium Doping. Angewandte Chemie / International Edition 48 (2009), p. 4639-4642


Jung, D.; Paradiso, M.; Wallacher, D.; Brandt, A.; Hartmann, M.: Formation of Cross-Linked Chloroperoxidase Aggregates in the Pores of Mesocellular Foams: Characterization by SANS and Catalytic Properties. ChemSusChem 2 (2009), p. 161-164


Mascotto, S.; Wallacher, D.; Brandt, A.; Hauss, T.; Thommes, M.; Zickler, G.A.; Funari, S.S.; Timmann, A.; Smarsly, B.M.: Analysis of Microporosity in Ordered Mesoporous Hierarchically Structured Silica by Combining Physisorption With in Situ Small-Angle Scattering (SAXS and SANS). Langmuir 25 (2009), p. 12670-12681


Remhof, A.; Friedrichs, O.; Buchter, F.; Mauron, Ph.; Kim, J.W.; Oh, K.H.; Buchsteiner, A.; Wallacher, D.; Züttel, A.: Hydrogen cycling behavior of LiBD4/Al studied by in situ neutron diffraction. Journal of Alloys and Compounds 484 (2009), p. 654-659

2008


Knorr, K. ; Huber, P. ; Wallacher, D.: Thermodynamic and Structural Investigations of Condensates of Small Molecules in Mesopores. Zeitschrift für Physikalische Chemie 222 (2008), p. 257-285


Remhof, A. ; Friedrichs, O. ; Buchter, F. ; Mauron, Ph. ; Züttel, A.; Wallacher, D.: Solid-state synthesis of LiBD4 observed by in situ neutron diffraction. Physical Chemistry Chemical Physics 10 (2008), p. 5859-5862


Wiedenmann, A. ; Keiderling, U. ; Meissner, M. ; Wallacher, D. ; Gähler, R. ; May, R.P. ; Prévost, S. ; Klokkenburg, M. ; Erné, B.H. ; Kohlbrecher, J.: Low-temperature dynamics of magnetic colloids studied by time-resolved small-angle neutron scattering. Physical Review B 77 (2008), p. 184417/1-11

2007


Sel, O; Brandt, A; Wallacher, D; Thommes, M; Smarsly, B : Pore hierarchy in mesoporous silicas evidenced by in-situ SANS during nitrogen physisorption. LANGMUIR 23 (2007), p. 4724-4727