Experimentalphysiker und Experte auf dem Gebiet der Erforschung nanostrukturierter und grenzflächenbestimmter Materialien sowie deren Charakterisierung durch Gasadsorptionsanalyse kombiniert mit Techniken der Neutronen- und Röntgenbeugung. Forschungsschwerpunkte sind die Grundlagen der Thermodynamik und Struktur mesoskaliger Porenkondensate sowie die Sorptionseigenschaften von Gasspeichermaterialien und Molekularsieben. Verantwortlicher im Helmholtz-Zentrum Berlin für wissenschaftliche und technische Nutzerunterstützung an der Neutronenquelle BER-II und der Synchrotronlichtquelle BESSY-II für Probenumgebung in den Bereichen: hohe Drücke und Temperaturen, kontrollierte Gasatmosphären, Trockenkryostate, sowie für den Betrieb des komplementären HZB-Nutzerlabors DEGAS für Gasadsorptionsuntersuchungen.

Publikationen

Publikationsliste am HZB

2019


Badaczewski, F.; Loeh, M.O.; Pfaff, T.; Dobrotka, S.; Wallacher, D.; Clemens, D.; Metz, J.; Smarsly, B.: Peering into the structural evolution of glass-like carbons derived from phenolic resin by combining small-angle neutron scattering with an advanced evaluation method for wide-angle X-ray scattering. Carbon 141 (2019), p. 169-181


Casco, M.E.; Zhang, En; Grätz, S.; Krause, S.; Bon, V.; Wallacher, D.; Grimm, N.; Többens, D.M.; Hauß, T.; Borchardt, L.: Experimental Evidence of Confined Methane Hydrate in Hydrophilic and Hydrophobic Model Carbons. The Journal of Physical Chemistry C 123 (2019), p. 24071-24079


Czub, J.; Jamka, W.; Przewoznik, J.; Zarzecka, A.; Hoser, A.; Wallacher, D.; Grimm, N.; Gondek, Gondek: Structural peculiarities in the beta phase of the La0.75Ce0.25Ni4.8Al0.2 deuterides. Journal of Alloys and Compounds 788 (2019), p. 533-540


Gonthier, J.; Barrett, M.; Aguettaz, O.; Baudoin, S.; Bourgeat-Lami, E.; Demé, B.; Grimm, N.; Hauß, T.; Kiefer, K.; Lelièvre-Berna, E.; Perkins, A.; Wallacher, D.: BerILL: The ultimate humidity chamber for neutron scattering. Journal of Neutron Research 21 (2019), p. 65-76


Krause, S.; Evans, J.D.; Bon, V.; Senkovska, I.; Iacomi, P.; Kolbe, F.; Ehrling, S.; Troschke, E.; Getzschmann, J.; Többens, D.; Franz, A.; Wallacher, D.; Yot, P.G.; Maurin, G.; Brunner, E.; Llewellyn, P.L.; Coudert, F.-X.; Kaskel, S.: Towards general network architecture design criteria for negative gas adsorption transitions in ultraporous frameworks. Nature Communications 10 (2019), p. 3632/1-12


Ranieri, U.; Koza, M.M.; Kuhs, W.F.; Gaal, R.; Klotz, S.; Falenty, A.; Wallacher, D.; Ollivier, J.; Gillet, P.; Bove, L.E.: Quantum Dynamics of H2 and D2 Confined in Hydrate Structures as a Function of Pressure and Temperature. The Journal of Physical Chemistry C 123 (2019), p. 1888-1903

2018


Krause, S.; Bon, V.; Senkovska, I.; Többens, D.; Wallacher, D.; Pillai, R.; Maurin, G.; Kaskel, S.: The effect of crystallite size on pressure amplification in switchable porous solids. Nature Communications 9 (2018), p. 1573


Russina, M.; Guenther, G.; Grzimek, V.; Gainov, R.; Schlegel, M.; Drescher, L.; Kaulich, T.; Graf, W.; Urban, B.; Daske, A.; Grotjahn, K.; Hellhammer, R.; Buchert, G.; Kutz, H.; Rossa, L.; Sauer, O.-P.; Fromme, M.; Wallacher, D.; Kiefer, K.; Klemke, B.; Grimm, N.; Gerischer, S.; Tsapatsaris, N.; Rolfs, K.: Upgrade project NEAT'2016 at Helmholtz Zentrum Berlin - What can be done on the medium power neutron source. Physica B 551 (2018), p. 506-511

2017


Auer, H.; Wallacher, D.; Hansen, T.C.; Kohlmann, H.: In Situ Hydrogenation of the Zintl Phase SrGe. Inorganic Chemistry 56 (2017), p. 1072-1079


Busch, M.; Kityk, A.V.; Piecek, W.; Hofmann, T.; Wallacher, D.; Calus, S.; Kula, P.; Steinhart, M.; Eich, M.; Huber, P.: A ferroelectric liquid crystal confined in cylindrical nanopores: reversible smectic layer buckling, enhanced light rotation and extremely fast electro-optically active Goldstone excitations. Nanoscale 9 (2017), p. 19086-19099


Hofmann, T.; Wallacher, D.; Toft-Petersen, R.; Ryll, B.; Reehuis, M.; Habicht, K.: Phonons in mesoporous silicon: The influence of nanostructuring on the dispersion in the Debye regime. Microporous and Mesoporous Materials 243 (2017), p. 263-270


Jafta, C.J.; Petzold, A.; Risse, S.; Clemens, D.; Wallacher, D.; Goerigk, G.; Ballauff, M.: Correlating pore size and shape to local disorder in microporous carbon: A combined small angle neutron and X-ray scattering study. Carbon 123 (2017), p. 440-447


Klimkowicz, A.; Swierczek, K.; Zheng, K.; Wallacher, D.; Takasaki, A.: Oxygen release from BaLnMn2O6 (Ln: Pr, Nd, Y) under reducing conditions as studied by neutron diffraction. Journal of Materials Science 52 (2017), p. 6476-6485


Krause, S.; Bon, V.; Stoeck, U.; Senkovska, I.; Többens, D.; Wallacher, D.; Kaskel, S.: A Stimuli-Responsive Zirconium Metal-Organic Framework Based on Supermolecular Design. Angewandte Chemie - International Edition 56 (2017), p. 10676-10680


Krause, S.; Bon, V.; Stoeck, U.; Senkovska, I.; Többens, D.; Wallacher, D.; Kaskel, S.: A Stimuli-Responsive Zirconium Metal–Organic Framework Based on Supermolecular Design. Angewandte Chemie 129 (2017), p. 10816-10820


Schaber, J.; Krause, S.; Paasch, S.; Senkovska, I.; Bon, V.; Többens, D.; Wallacher, D.; Kaskel, S.; Brunner, E.: In Situ Monitoring of Unique Switching Transitions in the Pressure-Amplifying Flexible Framework Material DUT-49 by High-Pressure 129Xe NMR Spectroscopy. The Journal of Physical Chemistry C 121 (2017), p. 5195-5200

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


Borchardt, L.; Nickel, W.; Casco, M.; Senkovska, I.; Bon, V.; Wallacher, D.; Grimm, N.; Krause, S.; Silvestre-Albero, J.: Illuminating solid gas storage in confined spaces – methane hydrate formation in porous model carbons. Physical Chemistry Chemical Physics 18 (2016), p. 20607/1-8


Cairns, A.J.; Eckert, J.; Wojtas, L.; Thommes, M.; Wallacher, D.; Georgiev, P.A.; Forster, P.M.; Belmabkhout, Y.; Ollivier, J.; Eddaoudi, M.: Gaining Insights on the H2–Sorbent Interactions: Robust soc-MOF Platform as a Case Study. Chemistry of Materials 28 (2016), p. 7353-7361


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


Schlegel, M.-C.; Többens, D.M.; Svetogorov, R.; Krüger, M.; Stock, N.; Reinsch, H.; Wallacher, D.; Stewart, R.; Russina, M.: Conformation-controlled hydrogen storage in the CAU-1 metal-organic framework. Physical Chemistry Chemical Physics 18 (2016), p. 29258-29267

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. The 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. The 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. The 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. The 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. The 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. The 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. The 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