TY  - JOUR
A1  - Lambers, Leen
A1  - Weber, Jens
T1  - Preface to the special issue on the 11th International Conference on Graph Transformation
JF  - Journal of Logical and Algebraic Methods in Programming
N2  - This special issue contains extended versions of four selected papers from the 11th International Conference on Graph Transformation (ICGT 2018). The articles cover a tool for computing core graphs via SAT/SMT solvers (graph language definition), graph transformation through graph surfing in reaction systems (a new graph transformation formalism), the essence and initiality of conflicts in M-adhesive transformation systems, and a calculus of concurrent graph-rewriting processes (theory on conflicts and parallel independence).
KW  - graph transformation
KW  - graph languages
KW  - conflicts and dependencies in
KW  - concurrent graph rewriting
Y1  - 2020
U6  - https://doi.org/10.1016/j.jlamp.2020.100525
SN  - 2352-2208
VL  - 112
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Unuabonah, Emmanuel
A1  - Nöske, Robert
A1  - Weber, Jens
A1  - Günter, Christina
A1  - Taubert, Andreas
T1  - New micro/mesoporous nanocomposite material from low-cost sources for the efficient removal of aromatic and pathogenic pollutants from water
JF  - Beilstein journal of nanotechnology
N2  - A new micro/mesoporous hybrid clay nanocomposite prepared from kaolinite clay, Carica papaya seeds, and ZnCl2 via calcination in an inert atmosphere is presented. Regardless of the synthesis temperature, the specific surface area of the nanocomposite material is between approximate to 150 and 300 m(2)/g. The material contains both micro- and mesopores in roughly equal amounts. X-ray diffraction, infrared spectroscopy, and solid-state nuclear magnetic resonance spectroscopy suggest the formation of several new bonds in the materials upon reaction of the precursors, thus confirming the formation of a new hybrid material. Thermogravimetric analysis/differential thermal analysis and elemental analysis confirm the presence of carbonaceous matter. The new composite is stable up to 900 degrees C and is an efficient adsorbent for the removal of a water micropollutant, 4-nitrophenol, and a pathogen, E. coli, from an aqueous medium, suggesting applications in water remediation are feasible.
KW  - 4-nitrophenol
KW  - Carica papaya seeds
KW  - clay
KW  - E. coli
KW  - micro/mesoporous
KW  - nanocomposite
KW  - water remediation
Y1  - 2019
U6  - https://doi.org/10.3762/bjnano.10.11
SN  - 2190-4286
VL  - 10
SP  - 119
EP  - 131
PB  - Beilstein-Institut zur Förderung der Chemischen Wissenschaften
CY  - Frankfurt, Main
ER  - 
TY  - JOUR
A1  - Behrens, Karsten
A1  - Mondal, Suvendu Selchar
A1  - Nöske, Robert
A1  - Baburin, Igor A.
A1  - Leoni, Stefano
A1  - Günter, Christina
A1  - Weber, Jens
A1  - Holdt, Hans-Jürgen
T1  - Microwave-Assisted Synthesis of Defects Metal-Imidazolate-Amide-Imidate Frameworks and Improved CO2 Capture
JF  - Inorganic chemistry
N2  - In this work, we report three isostructural 3D frameworks, named IFP-11 (R = Cl), IFP-12 (R = Br), and IFP-13 (R = Et) (IFP = Imidazolate Framework Potsdam) based on a cobalt(II) center and the chelating linker 2-substituted imidazolate-4-amide-5-imidate. These chelating ligands were generated in situ by partial hydrolysis of 2-substituted 4,5-dicyanoimidazoles under microwave (MW)-assisted conditions in DMF. Structure determination of these IFPs was investigated by IR spectroscopy and a combination of powder X-ray diffraction (PXRD) with structure modeling. The structural models were initially built up from the single-crystal X-ray structure determination of IFP-5 (a cobalt center and 2-methylimidazolate-4-amide-5-imidate linker based framework) and were optimized by using density functional theory calculations. Substitution on position 2 of the linker (R = Cl, Br, and Et) in the isostructural IFP-11, -12, and -13 allowed variation of the potential pore window in 1D hexagonal channels (3.8 to 1.7 angstrom A). The potential of the materials to undergo specific interactions with CO2 was measured by the isosteric heat adsorption. Further, we resynthesized zinc based IFPs, namely IFP-1 = Me), IFP-2 (R = Cl), IFP-3 (R = Br), and IFP-4 (R = Et), and cobalt based IFP-5 under MW-assisted conditions with higher yield. The transition from a nucleation phase to the pure crystalline material of IFP-1 in MW-assisted synthesis depends on reaction time. IFP-1, -3, and -5, which are synthesized by MW-assisted conditions, showed an enhancement of N-2 and CO2, compared to the analogous conventional electrical (CE) heating method based materials due to crystal defects.
Y1  - 2015
U6  - https://doi.org/10.1021/acs.inorgchem.5b01952
SN  - 0020-1669
SN  - 1520-510X
VL  - 54
IS  - 20
SP  - 10073
EP  - 10080
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Wessig, Pablo
A1  - Gerngross, Maik
A1  - Pape, Simon
A1  - Bruhns, Philipp
A1  - Weber, Jens
T1  - Novel porous materials based on oligospiroketals (OSK)
JF  - RSC Advances
N2  - New porous materials based on covalently connected monomers are presented. The key step of the synthesis is an acetalisation reaction. In previous years we used acetalisation reactions extensively to build up various molecular rods. Based on this approach, investigations towards porous polymeric materials were conducted by us. Here we wish to present the results of these studies in the synthesis of 1D polyacetals and porous 3D polyacetals. By scrambling experiments with 1D acetals we could prove that exchange reactions occur between different building blocks (evidenced by MALDI-TOF mass spectrometry). Based on these results we synthesized porous 3D polyacetals under the same mild conditions.
Y1  - 2014
U6  - https://doi.org/10.1039/c4ra04437a
SN  - 2046-2069
VL  - 4
IS  - 59
SP  - 31123
EP  - 31129
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Xie, Zai-Lai
A1  - White, Robin J.
A1  - Weber, Jens
A1  - Taubert, Andreas
A1  - Titirici, Magdalena M.
T1  - Hierarchical porous carbonaceous materials via ionothermal carbonization of carbohydrates
JF  - Journal of materials chemistry
N2  - We report on the ionothermal synthesis of porous carbon materials from a variety of carbohydrate precursors (i.e. D-glucose, D-fructose, D-xylose, and starch) using 1-butyl-3-methylimidazolium tetrachloroferrate(III), [Bmim][FeCl(4)] as a reusable solvent and catalyst. The carbon materials derived from these different carbohydrates are similar in terms of particle size and chemical composition, possessing relatively high surface areas from 44 to 155 m(2) g(-1) after ionothermal processing, which can be significantly increased to > 350 m(2) g(-1) by further thermal treatment (e. g. post-carbonization at 750 degrees C). CO(2) and N(2) sorption analysis, combined with Hg intrusion porosimetry, reveals a promising hierarchical pore structuring to these carbon materials. The ionic liquid [Bmim][FeCl(4)] has a triple role: it acts as both a soft template to generate the characterized pore structuring, solvent and as a catalyst resulting in enhanced ionothermal carbon yields. Importantly from a process point of view, the ionic liquid can be successfully recovered and reused. The current work shows that ionothermal synthesis has the potential to be an effective, low cost, and green reusable synthetic route towards sustainable porous carbon materials.
Y1  - 2011
U6  - https://doi.org/10.1039/c1jm00013f
SN  - 0959-9428
VL  - 21
IS  - 20
SP  - 7434
EP  - 7442
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Debatin, Franziska
A1  - Behrens, Karsten
A1  - Weber, Jens
A1  - Baburin, Igor A.
A1  - Thomas, Arne
A1  - Schmidt, Johannes
A1  - Senkovska, Irena
A1  - Kaskel, Stefan
A1  - Kelling, Alexandra
A1  - Hedin, Niklas
A1  - Bacsik, Zoltan
A1  - Leoni, Stefano
A1  - Seifert, Gotthard
A1  - Jäger, Christian
A1  - Günter, Christina
A1  - Schilde, Uwe
A1  - Friedrich, Alwin
A1  - Holdt, Hans-Jürgen
T1  - An isoreticular family of microporous metal-organic frameworks based on zinc and 2-substituted imidazolate-4-amide-5-imidate Syntheses, structures and properties
JF  - Chemistry - a European journal
N2  - We report on a new series of isoreticular frameworks based on zinc and 2-substituted imidazolate-4-amide-5-imidate (IFP-14, IFP=imidazolate framework Potsdam) that form one-dimensional, microporous hexagonal channels. Varying R in the 2-substitued linker (R=Me (IFP-1), Cl (IFP-2), Br (IFP-3), Et (IFP-4)) allowed the channel diameter (4.01.7 angstrom), the polarisability and functionality of the channel walls to be tuned. Frameworks IFP-2, IFP-3 and IFP-4 are isostructural to previously reported IFP-1. The structures of IFP-2 and IFP-3 were solved by X-ray crystallographic analyses. The structure of IFP-4 was determined by a combination of PXRD and structure modelling and was confirmed by IR spectroscopy and 1H MAS and 13C CP-MAS NMR spectroscopy. All IFPs showed high thermal stability (345400?degrees C); IFP-1 and IFP-4 were stable in boiling water for 7 d. A detailed porosity analysis was performed on the basis of adsorption measurements by using various gases. The potential of the materials to undergo specific interactions with CO2 was investigated by measuring the isosteric heats of adsorption. The capacity to adsorb CH4 (at 298 K), CO2 (at 298 K) and H2 (at 77 K) at high pressure were also investigated. In situ IR spectroscopy showed that CO2 is physisorbed on IFP-14 under dry conditions and that both CO2 and H2O are physisorbed on IFP-1 under moist conditions.
KW  - adsorption
KW  - metal- organic frameworks
KW  - microporous materials
KW  - N
KW  - O ligands
KW  - zinc
Y1  - 2012
U6  - https://doi.org/10.1002/chem.201200889
SN  - 0947-6539
VL  - 18
IS  - 37
SP  - 11630
EP  - 11640
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Unuabonah, Emmanuel I.
A1  - Günter, Christina
A1  - Weber, Jens
A1  - Lubahn, Susanne
A1  - Taubert, Andreas
T1  - Hybrid Clay - a new highly efficient adsorbent for water treatment
JF  - ACS sustainable chemistry & engineering
N2  - New hybrid clay adsorbent based on kaolinite clay and Carica papaya seeds with improved cation exchange capacity (CEC), rate of heavy metal ion uptake, and adsorption capacity for heavy metal ions were prepared. The CEC of the new material is ca. 75 meq/100 g in spite of the unexpectedly low surface area (approximate to 19 m(2)/g). Accordingly, the average particle size of the hybrid clay adsorbent decreased from over 200 to 100 pm. The hybrid clay adsorbent is a highly efficient adsorbent for heavy metals. With an initial metal concentration of 1 mg/L, the hybrid clay adsorbent reduces the Cd2+, Ni2+, and Pb2+ concentration in aqueous solution to <= 4, <= 7 and <= 20 mu g/L, respectively, from the first minute to over 300 min using a fixed bed containing 2 g of adsorbent and a flow rate of approximate to 7 mL/min. These values are (with the exception of Pb2+) in line with the WHO permissible limits for heavy metal ions. In a cocktail solution of Cd2+, and Ni2+, the hybrid clay shows a reduced rate of uptake but an increased adsorption capacity. The CEC data suggest that the adsorption of Pb2+, Cd2+, and Ni2+ on the hybrid clay adsorbent is essentially due to ion exchange. This hybrid clay adsorbent is prepared from materials that are abundant and by a simple means that is sustainable, easily recovered from aqueous solution, nonbiodegradable (unlike numerous biosorbent), and easily regenerated and is a highly efficient alternative to activated carbon for water treatment.
KW  - Kaolinite
KW  - Hybrid clay
KW  - Water treatment
KW  - Cation exchange Capacity
KW  - Adsorbent
KW  - Kinetics
Y1  - 2013
U6  - https://doi.org/10.1021/sc400051y
SN  - 2168-0485
VL  - 1
IS  - 8
SP  - 966
EP  - 973
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Goebel, Ronald
A1  - Hesemann, Peter
A1  - Weber, Jens
A1  - Moeller, Eléonore
A1  - Friedrich, Alwin
A1  - Beuermann, Sabine
A1  - Taubert, Andreas
T1  - Surprisingly high, bulk liquid-like mobility of silica-confined ionic liquids
N2  - Mesoporous silica monoliths were prepared by the sol - gel technique and. lled with 1-ethyl-3-methyl imidazolium [Emim]-X (X = dicyanamide [N(CN)(2)], ethyl sulfate [EtSO4], thiocyanate [SCN], and triflate [TfO]) ionic liquids (ILs) using a methanol-IL exchange technique. The structure and behavior of the ILs inside the silica monoliths were studied using X-ray scattering, nitrogen sorption, IR spectroscopy, solid-state NMR, and thermal analysis. DSC finds shifts in both the glass transition temperature and melting points (where applicable) of the ILs. Glass transition and melting occur well below room temperature. There is thus no conflict with the NMR and IR data, which show that the ILs are as mobile at room temperature as the bulk (not confined) ILs. The very narrow line widths of the NMR spectra suggest that the ILs in our materials have the highest mobility reported for confined ILs so far. As a result, our data suggest that it is possible to generate IL/silica hybrid materials (ionogels) with bulk-like properties of the IL. This could be interesting for applications in, e.g., the solar cell or membrane fields.
Y1  - 2009
UR  - http://xlink.rsc.org/jumptojournal.cfm?journal_code=CP
U6  - https://doi.org/10.1039/B821833a
SN  - 1463-9076
ER  - 
TY  - JOUR
A1  - Wessig, Pablo
A1  - Gerngroß, Maik
A1  - Pape, Simon
A1  - Bruhns, Philipp
A1  - Weber, Jens
T1  - Novel porous materials based on oligospiroketals (OSK)
JF  - RSC Advances : an international journal to further the chemical sciences
N2  - New porous materials based on covalently connected monomers are presented. The key step of the synthesis is an acetalisation reaction. In previous years we used acetalisation reactions extensively to build up various molecular rods. Based on this approach, investigations towards porous polymeric materials were conducted by us. Here we wish to present the results of these studies in the synthesis of 1D polyacetals and porous 3D polyacetals. By scrambling experiments with 1D acetals we could prove that exchange reactions occur between different building blocks (evidenced by MALDI-TOF mass spectrometry). Based on these results we synthesized porous 3D polyacetals under the same mild conditions.
KW  - microporous organic polymers
KW  - molecular rods
KW  - construction
KW  - frameworks
KW  - membranes
KW  - sorption
KW  - models
Y1  - 2014
U6  - https://doi.org/10.1039/c4ra04437a
SN  - 2046-2069
VL  - 2014
IS  - 4
SP  - 31123
EP  - 31129
ER  -