TY - GEN A1 - Mondal, Suvendu Sekhar A1 - Bhunia, Asamanjoy A1 - Demeshko, Serhiy A1 - Kelling, Alexandra A1 - Schilde, Uwe A1 - Janiak, Christoph A1 - Holdt, Hans-Jürgen T1 - Synthesis of a Co(II)–imidazolate framework from an anionic linker precursor BT - gas-sorption and magnetic properties N2 - A Co(II)–imidazolate-4-amide-5-imidate based MOF, IFP-5, is synthesized by using an imidazolate anion-based novel ionic liquid as a linker precursor under solvothermal conditions. IFP-5 shows significant amounts of gas (N2, CO2, CH4 and H2) uptake capacities. IFP-5 exhibits an independent high spin Co(II) centre and antiferromagnetic coupling. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 235 KW - building-blocks KW - carbon-dioxide capture KW - exchange KW - ionic liquids KW - ionothermal synthesis KW - ligand KW - metal-organic frameworks KW - solvent KW - surface KW - zeolitic imidazolate frameworks Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-94424 SP - 39 EP - 42 ER - TY - GEN A1 - Mondal, Suvendu Sekhar A1 - Bhunia, Asamanjoy A1 - Baburin, Igor A. A1 - Jäger, Christian A1 - Kelling, Alexandra A1 - Schilde, Uwe A1 - Seifert, Gotthard A1 - Janiak, Christoph A1 - Holdt, Hans-Jürgen T1 - Gate effects in a hexagonal zinc-imidazolate-4-amide-5-imidate framework with flexible methoxy substituents and CO2 selectivity N2 - A new imidazolate-4-amide-5-imidate based MOF, IFP-7, is generated, having flexible methoxy groups, which act as molecular gates for guest molecules. This allows highly selective CO2 sorption over N2 and CH4 gases. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 233 KW - adsorption KW - capacity KW - carbon-dioxide capture KW - coordination polymer KW - flexibility KW - hydrogen storage KW - ligand KW - metal-organic frameworks KW - mixed-matrix membranes KW - separation Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-94341 SP - 7599 EP - 7601 ER - TY - JOUR A1 - Mondal, Suvendu Sekhar A1 - Bhunia, Asamanjoy A1 - Attallah, Ahmed G. A1 - Matthes, Philipp R. A1 - Kelling, Alexandra A1 - Schilde, Uwe A1 - Müller-Buschbaum, Klaus A1 - Krause-Rehberg, Reinhard A1 - Janiak, Christoph A1 - Holdt, Hans-Jürgen T1 - Study of the Discrepancies between Crystallographic Porosity and Guest Access into Cadmium-Imidazolate Frameworks and Tunable Luminescence Properties by Incorporation of Lanthanides JF - Chemistry - a European journal N2 - An extended member of the isoreticular family of metal-imidazolate framework structures, IFP-6 (IFP=imidazolate framework Potsdam), based on cadmium metal and an in situ functionalized 2-methylimidazolate-4-amide-5-imidate linker is reported. A porous 3D framework with 1D hexagonal channels with accessible pore windows of 0.52nm has been synthesized by using an ionic liquid (IL) linker precursor. IFP-6 shows significant gas uptake capacity only for CO2 and CH4 at elevated pressure, whereas it does not adsorb N-2, H-2, and CH4 under atmospheric conditions. IFP-6 is assumed to deteriorate at the outside of the material during the activation process. This closing of the metal-organic framework (MOF) pores is proven by positron annihilation lifetime spectroscopy (PALS), which revealed inherent crystal defects. PALS results support the conservation of the inner pores of IFP-6. IFP-6 has also been successfully loaded with luminescent trivalent lanthanide ions (Ln(III)=Tb, Eu, and Sm) in a bottom-up one-pot reaction through the in situ generation of the linker ligand and in situ incorporation of photoluminescent Ln ions into the constituting network. The results of photoluminescence investigations and powder XRD provide evidence that the Ln ions are not doped as connectivity centers into the frameworks, but are instead located within the pores of the MOFs. Under UV light irradiation, Tb@IFP-6 and Eu@IFP-6 ((exc)=365nm) exhibit observable emission changes to a greenish and reddish color, respectively, as a result of strong Ln 4f emissions. KW - adsorption KW - cadmium KW - ionic liquids KW - luminescence KW - metal-organic frameworks Y1 - 2016 U6 - https://doi.org/10.1002/chem.201504757 SN - 0947-6539 SN - 1521-3765 VL - 22 SP - 6905 EP - 6913 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Mondal, Suvendu Sekhar A1 - Kreuzer, Alex A1 - Behrens, Karsten A1 - Schütz, Gisela A1 - Holdt, Hans-Jürgen A1 - Hirscher, Michael T1 - Systematic experimental study on quantum sieving of hydrogen isotopes in metal-amide-imidazolate frameworks with narrow 1-D channels JF - ChemPhysChem : a European journal of chemical physics and physical chemistry N2 - Quantum sieving of hydrogen isotopes is experimentally studied in isostructural hexagonal metal-organic frameworks having 1-D channels, named IFP-1, -3, -4 and -7. Inside the channels, different molecules or atoms restrict the channel diameter periodically with apertures larger (4.2 angstrom for IFP-1, 3.1 angstrom for IFP-3) and smaller (2.1 angstrom for IFP-7, 1.7 angstrom for IFP-4) than the kinetic diameter of hydrogen isotopes. From a geometrical point of view, no gas should penetrate into IFP-7 and IFP-4, but due to the thermally induced flexibility, so-called gate-opening effect of the apertures, penetration becomes possible with increasing temperature. Thermal desorption spectroscopy (TDS) measurements with pure H-2 or D-2 have been applied to study isotope adsorption. Further TDS experiments after exposure to an equimolar H-2/D-2 mixture allow to determine directly the selectivity of isotope separation by quantum sieving. IFP-7 shows a very low selectivity not higher than S=2. The selectivity of the materials with the smallest pore aperture IFP-4 has a constant value of S approximate to 2 for different exposure times and pressures, which can be explained by the 1-D channel structure. Due to the relatively small cavities between the apertures of IFP-4 and IFP-7, molecules in the channels cannot pass each other, which leads to a single-file filling. Therefore, no time dependence is observed, since the quantum sieving effect occurs only at the outermost pore aperture, resulting in a low separation selectivity. KW - gas adsorption KW - hydrogen isotopes KW - isotope separation KW - metal-organic frameworks KW - quantum sieving Y1 - 2019 U6 - https://doi.org/10.1002/cphc.201900183 SN - 1439-4235 SN - 1439-7641 VL - 20 IS - 10 SP - 1311 EP - 1315 PB - Wiley-VCH CY - Weinheim ER - TY - THES A1 - Schmidt, Bernhard V. K. J. T1 - Polymers, self-assembly and materials BT - from polymer synthesis to applications BT - von der Polymersynthese bis zur Anwendung N2 - In der vorliegenden Arbeit wurden die Selbstorganisation von hydrophilen Polymeren, verstärkte Hydrogele, sowie anorganische/Polymer Hybridmaterialien untersucht. Dabei beschreibt die Arbeit den Weg von Polymersynthese mittels verschiedener Methoden über Polymerselbstanordnung bis zur Herstellung von Polymermaterialien mit vielversprechenden Eigenschaften für zukünftige Anwendungen. Hydrophile Polymere wurden verwendet, um Mehrphasensysteme herzustellen, Wasser-in-Wasser Emulsionen zu bilden und selbstangeordneten Strukturen zu erzeugen, z. B. Partikel/Aggregate oder hohle Strukturen aus komplett wasserlöslichen Bausteinen. Die Strukturbildung in wässriger Umgebung wurde ferner für supramolekulare Hydrogele mit definierter Unterstruktur und reversiblem Gelierungsverhalten eingesetzt. Auf dem Gebiet der Hydrogele wurde das anorganische Material graphitisches Kohlenstoffnitrid (g-CN) als Photoinitiator für die Hydrogelsynthese und als Verstärker der Gelstruktur beschrieben. Hierbei konnten Hydrogele mit herausragenden Eigenschaften generiert werden, z. B. hohe Kompressibilität, hohe Speichermodule oder Gleitfähigkeit. Die Kombinationen von g-CN mit verschiedenen Polymeren erlaubte es zudem neue Materialien für die Photokatalyse bereitzustellen. Als weiteres anorganisches Material wurden Metall-organische Gerüste (MOFs) mit Polymeren kombiniert. Es konnte gezeigt werden, dass die Verwendung von MOFs in der Polymersynthese einen starken Einfluss auf die erzeugte Polymerstruktur hat und MOFs als Katalysator für Polymerisationen verwendet werden können. Zuletzt wurde die MOF Synthese an sich untersucht, wobei Polymeradditive oder Lösungsmittel eingesetzt wurden um die kristalline Struktur der MOFs zu modulieren. Insgesamt wurden hier verschiedene Errungenschaften für die Polymerchemie beschrieben, z.B. neuartige hydrophile Polymere und Hydrogele, die zur Zeit wichtige Materialien im Polymerbereich durch ihre vielversprechenden Anwendungen im biomedizinischen Sektor darstellen. Außerdem ergab die Kombination von Polymeren mit Materialien aus anderen Bereichen der Chemie, z. B. g-CN und MOFs, neue Materialien mit bemerkenswerten Eigenschaften, die ebenfalls von Interesse für zukünftige Anwendungen sind, z. B. Beschichtungen, Partikeltechnologie und Katalyse. N2 - In the present thesis, self-assembly of hydrophilic polymers, reinforced hydrogels and inorganic/polymer hybrids were examined. The thesis describes an avenue from polymer synthesis via various methods over polymer self-assembly to the formation of polymer materials that have promising properties for future applications. Hydrophilic polymers were utilized to form multi-phase systems, water-in-water emulsions and self-assembled structures, e.g. particles/aggregates or hollow structures from completely water-soluble building blocks. The structuring of aqueous environments by hydrophilic homo and block copolymers was further utilized in the formation of supramolecular hydrogels with compartments or specific thermal behavior. Furthermore, inorganic graphitic carbon nitride (g-CN) was utilized as photoinitiator for hydrogel formation and as reinforcer for hydrogels. As such, hydrogels with remarkable mechanical properties were synthesized, e.g. high compressibility, high storage modulus or lubricity. In addition, g-CN was combined with polymers for a broad range of materials, e.g. coatings, films or latex, that could be utilized in photocatalytic applications. Another inorganic material class was combined with polymers in the present thesis as well, namely metal-organic frameworks (MOFs). It was shown that the pore structure of MOFs enables improved control over tacticity and achievement of high molar masses. Furthermore, MOF-based polymerization catalysis was introduced with improved control for coordinating monomers, catalyst recyclability and decreased metal contamination in the product. Finally, the effect of external influence on MOF morphology was studied, e.g. via solvent or polymer additives, which allowed the formation of various MOF structures. Overall, advances in several areas of polymer science are presented in here. A major topic of the thesis was hydrophilic polymers and hydrogels that currently constitute significant materials in the polymer field due to promising future applications in biomedicine. Moreover, the combination of polymers with materials from other areas of research, i.e. g-CN and MOFs, provided various new materials with remarkable properties also of interest for applications in the future, e.g. coatings, particle structures and catalysis. T2 - Polymere, Selbstanordnungen und Materialien KW - block copolymers KW - carbon nitride KW - metal-organic frameworks KW - Blockcopolymere KW - Kohlenstoffnitrid KW - Metall-organische Gerüste Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-484819 ER -