@article{25910,
  abstract     = {{We describe the synthesis of mesoporous Al2O3 and MgO layers on silicon wafer substrates by using poly(dimethylacrylamide) hydrogels as porogenic matrices. Hydrogel films are prepared by spreading the polymer through spin-coating, followed by photo-cross-linking and anchoring to the substrate surface. The metal oxides are obtained by swelling the hydrogels in the respective metal nitrate solutions and subsequent thermal conversion. Combustion of the hydrogel results in mesoporous metal oxide layers with thicknesses in the μm range and high specific surface areas up to 558 m2∙g−1. Materials are characterized by SEM, FIB ablation, EDX, and Kr physisorption porosimetry.}},
  author       = {{Chen, Zimei and Kuckling, Dirk and Tiemann, Michael}},
  issn         = {{2079-4991}},
  journal      = {{Nanomaterials}},
  title        = {{{Porous Aluminum Oxide and Magnesium Oxide Films Using Organic Hydrogels as Structure Matrices}}},
  doi          = {{10.3390/nano8040186}},
  year         = {{2018}},
}

@article{25913,
  abstract     = {{Ordered mesoporous CMK-5 carbon exhibits two distinct pore systems that can be modified individually. This work demonstrates how one of the pore systems can be selectively filled with elemental sulfur, while the other pore system remains empty. The resulting sulfur–carbon composite material with high residual porosity can be used as the cathode material in lithium–sulfur battery cells. We present a systematic investigation of the loading of CMK-5 carbon with variable relative amounts of sulfur and compare the results to the preparation of SnO2 (as well as TiO2, Mn2O3/Mn3O4, NiO) nanoparticle-loaded CMK-5 carbon.}},
  author       = {{Weinberger, Christian and Ren, Sai and Hartmann, Marc and Wagner, Thorsten and Karaman, Didem. Ş. and Rosenholm, Jessica M. and Tiemann, Michael}},
  issn         = {{2574-0970}},
  journal      = {{ACS Applied Nano Materials}},
  pages        = {{455--462}},
  title        = {{{Bimodal Mesoporous CMK-5 Carbon: Selective Pore Filling with Sulfur and SnO2 for Lithium Battery Electrodes}}},
  doi          = {{10.1021/acsanm.7b00307}},
  year         = {{2018}},
}

@article{25909,
  abstract     = {{Organic polymer-hydrogels are known to be capable of directing the nucleation and growth of inorganic materials, such as silica, metal oxides, apatite or metal chalcogenides. This approach can be exploited in the synthesis of materials that exhibit defined nanoporosity. When the organic polymer-based hydrogel is incorporated in the inorganic product, a composite is formed from which the organic component may be selectively removed, yielding nanopores in the inorganic product. Such porogenic impact resembles the concept of using soft or hard templates for porous materials. This micro-review provides a survey of select examples from the literature.}},
  author       = {{Weinberger, Christian and Kuckling, Dirk and Tiemann, Michael}},
  issn         = {{2310-2861}},
  journal      = {{Gels}},
  title        = {{{Hydrogels as Porogens for Nanoporous Inorganic Materials}}},
  doi          = {{10.3390/gels4040083}},
  year         = {{2018}},
}

@article{25911,
  abstract     = {{Different types of reduced graphene oxide and graphene oxide particles have been studied regarding their influence on the curing behaviour of epoxy-amine resins. Especially the specific surface area of reduced graphene oxide was selectively influenced by controlled drying of the material. The different types of reduced graphene oxide particles were used to produce epoxy-amine composites that significantly change their curing behaviour and mechanical properties. A variety of surface areas and compositions were prepared by combination of a fast heating rate and different drying methods. The combination of freeze drying with a fast heating rate leads to a large specific surface area of 680 m2/g. The morphologies of the particles were observed by scanning electron microscope and the BET surface area was measured with nitrogen-physisorption. The exfoliation quality was measured by XRD. The generated graphene oxide and thermally reduced graphene oxide particles were mixed with epoxy-amine resin. The curing behaviour was studied with rheological and differential scanning calorimetry (DSC) measurements. We observed that different surface functionalities lowers the Glass transition temperature and the gel time of an epoxy-amine curing system. In addition, we found that generated graphene oxide acts as flexibilizer. An increase of the deformation from 2.5 mm to 3.1 mm was measured by Erichsen Cupping Test.}},
  author       = {{Wolk, Andreas and Rosenthal, Marta and Weiß, Julia and Voigt, Markus and Wesendahl, Jan-Niklas and Hartmann, Marc and Grundmeier, Guido and Wilhelm, Rene and Meschut, Gerson and Tiemann, Michael and Bremser, Wolfgang}},
  issn         = {{0300-9440}},
  journal      = {{Progress in Organic Coatings}},
  pages        = {{280--289}},
  title        = {{{Graphene oxide as flexibilizer for epoxy amine resins}}},
  doi          = {{10.1016/j.porgcoat.2018.05.028}},
  year         = {{2018}},
}

@article{25916,
  abstract     = {{<p>We determine ozone decomposition on indium oxide by utilizing the gas transducing properties of hierarchically porous monoliths.</p>}},
  author       = {{Klawinski, Danielle and Weinberger, Christian and Klaus, Dominik and Smått, Jan-Henrik and Tiemann, Michael and Wagner, Thorsten}},
  issn         = {{1463-9076}},
  journal      = {{Physical Chemistry Chemical Physics}},
  pages        = {{10326--10332}},
  title        = {{{Kinetics of ozone decomposition in porous In2O3 monoliths}}},
  doi          = {{10.1039/c6cp08874k}},
  year         = {{2017}},
}

@article{25915,
  abstract     = {{Dimethylacrylamide-based hydrogels were utilized as porogenic matrices in the synthesis of mesoporous aluminum oxide (γ-Al2O3) with specific BET surface areas up to 360 m2 g–1. Polymers with molecular mass in the range 12000–35000 g mol–1 were synthesized from dimethylacrylamide and various comonomers by free-radical polymerization. Photo-cross-linking of the polymers and impregnation with aluminum nitrate [Al(NO3)3] was carried out in a single step, followed by formation of Al(OH)3/AlO(OH) and subsequent calcination. Calcination led to the formation of mesoporous Al2O3 and simultaneous combustion of the hydrogel. The structural properties of the products were characterized by powder XRD, N2 physisorption analysis, Hg intrusion porosimetry, and thermogravimetric analysis.}},
  author       = {{Weinberger, Christian and Chen, Zimei and Birnbaum, Wolfgang and Kuckling, Dirk and Tiemann, Michael}},
  issn         = {{1434-1948}},
  journal      = {{European Journal of Inorganic Chemistry}},
  pages        = {{1026--1031}},
  title        = {{{Photo-Cross-Linked Polydimethylacrylamide Hydrogels as Porogens for Mesoporous Alumina}}},
  doi          = {{10.1002/ejic.201601364}},
  year         = {{2017}},
}

@article{25914,
  abstract     = {{Dimethylacrylamide-based hydrogels were utilized as porogenic matrices in the synthesis of mesoporous aluminum oxide (γ-Al2O3) with specific BET surface areas up to 360 m2 g–1. Polymers with molecular mass in the range 12000–35000 g mol–1 were synthesized from dimethylacrylamide and various comonomers by free-radical polymerization. Photo-cross-linking of the polymers and impregnation with aluminum nitrate [Al(NO3)3] was carried out in a single step, followed by formation of Al(OH)3/AlO(OH) and subsequent calcination. Calcination led to the formation of mesoporous Al2O3 and simultaneous combustion of the hydrogel. The structural properties of the products were characterized by powder XRD, N2 physisorption analysis, Hg intrusion porosimetry, and thermogravimetric analysis.}},
  author       = {{Chen, Zimei and Weinberger, Christian and Tiemann, Michael and Kuckling, Dirk}},
  issn         = {{2227-9717}},
  journal      = {{Processes}},
  title        = {{{Organic Polymers as Porogenic Structure Matrices for Mesoporous Alumina and Magnesia}}},
  doi          = {{10.3390/pr5040070}},
  year         = {{2017}},
}

@article{25919,
  abstract     = {{The sorption properties of mixed-linker CAU-10 type metal organic frameworks (MOFs), [Al(OH)(1,3-BDC-X)n(1,3-BDC-SO3H)m] with 1,3-BDC = 1,3-benzenedicarboxyliate, X = H, NO2 or OH, 0.76 ≤ n ≤ 0.89 and 0.11 ≤ m ≤ 0.24, can be varied by surface modification through variation of the respective linker molecules. It is thus possible to design surface-modified CAU-10 type MOFs with variable affinity and accessibility of the pores for water vapour. When used as a dielectric in a capacitor, the MOF material will change its permittivity depending on the amount of physisorbed water; this is the working principle of capacitive humidity sensors. Three different mixed-linker compounds with CAU-10 structure are compared regarding their water sorption and impedance characteristics. A setup was developed allowing the characterization of the MOF samples under exposure to different relative humidity values in air by impedance spectroscopy. Interpretation of the results by means of standard models shows that the MOFs are qualified for functional layers of capacitive humidity sensors. Since the prepared MOFs are more temperature-stable than many commonly used polymers they offer the potential to build a new generation of high-temperature (up to 350 °C) humidity sensors.}},
  author       = {{Weiss, Alexander and Reimer, Nele and Stock, Norbert and Tiemann, Michael and Wagner, Thorsten}},
  issn         = {{1387-1811}},
  journal      = {{Microporous and Mesoporous Materials}},
  pages        = {{39--43}},
  title        = {{{Screening of mixed-linker CAU-10 MOF materials for humidity sensing by impedance spectroscopy}}},
  doi          = {{10.1016/j.micromeso.2015.08.020}},
  year         = {{2016}},
}

@article{25917,
  abstract     = {{Ordered, bimodal mesoporous CMK-5 carbon is prepared by using mesoporous SBA-15 silica as a structural mold. The carbon material is chemically modified by oxidative treatment with acidic persulfate solution. This leads to the creation of oxygen-containing functionalities at the pore walls of the carbon (up to 13 wt% oxygen), as confirmed by IR spectroscopy. The oxidative treatment is carried out before removal of the silica mold which ensures that only one of the two distinct modes of mesopores (namely, the intra-tubular pores) is affected; the other mode (inter-tubular pores) is protected from oxidation by the presence of the silica mold. This is proven by water vapor physisorption analysis. The oxidatively treated (intra-tubular) pores are significantly more polar and, hence, better wettable than the untreated (inter-tubular) pores.}},
  author       = {{Weinberger, Christian and Cao, X. and Tiemann, Michael}},
  issn         = {{2050-7488}},
  journal      = {{Journal of Materials Chemistry A}},
  pages        = {{18426--18431}},
  title        = {{{Selective surface modification in bimodal mesoporous CMK-5 carbon}}},
  doi          = {{10.1039/c6ta07772b}},
  year         = {{2016}},
}

@article{25918,
  abstract     = {{Characterization and application of (meso)porous materials often require information about the density of the respective samples. For example, the BET surface area is, by definition, normalized to the sample mass; hence, any comparison between samples of different composition needs to take into account their respective densities. Literature data on the densities of porous materials are scarce. Frequently, only bulk-phase densities are available which sometimes differ from those of porous samples, especially for amorphous systems, such as silica or carbon. The apparent density, i.e. the density of the sample excluding the gas-accessible pore volume, is typically determined by helium gas pycnometry utilizing specialized pycnometers. We demonstrate how to obtain the same data from standard N2 physisorption measurements as part of the regular measurement routine. We evaluate the method by reference measurements utilizing a non-porous reference sample (glass rod) to confirm the validity of the method. Then we present results on apparent density measurements of several mesoporous silica materials (MCM-41, MCM-48, SBA-15, KIT-6), mesoporous carbon (CMK-3, -5, -8, -9), and a variety of mesoporous metal oxides obtained by nanocasting.}},
  author       = {{Weinberger, Christian and Vetter, Simon and Tiemann, Michael and Wagner, Thorsten}},
  issn         = {{1387-1811}},
  journal      = {{Microporous and Mesoporous Materials}},
  pages        = {{53--57}},
  title        = {{{Assessment of the density of (meso)porous materials from standard volumetric physisorption data}}},
  doi          = {{10.1016/j.micromeso.2015.10.027}},
  year         = {{2016}},
}

@article{25940,
  abstract     = {{Metal–organic frameworks (MOFs) are crystalline microporous materials with tunable chemical and physical properties. By combining various metal clusters with different interconnecting organic linkers, the pore structure, crystallinity, as well as the surface properties can be modified. In the present work, modification of the organic linker molecules is utilized to synthesize CAU-10 type MOFs with variable affinity of the pore surface to water. In principle, this should influence the accessibility of the pores for water vapor and therefore offer a tool to control its sorption properties. For a deeper understanding we studied the water sorption characteristics and compared the results to the conductive and dielectric properties studied by impedance spectroscopy. Spectra in a wide frequency range from 1 mHz to 1 MHz were recorded. Data analysis is performed using the Havriliak–Negami model. The MOFs are also tested as sensitive layers for capacitive humidity sensing by correlating the change in permittivity of the materials with the amount of physisorbed water. Such an MOF-based sensor was tested with respect to environmental monitoring and compared to a commonly used commercial humidity sensor.}},
  author       = {{Weiss, Alexander and Reimer, Nele and Stock, Norbert and Tiemann, Michael and Wagner, Thorsten}},
  issn         = {{1463-9076}},
  journal      = {{Physical Chemistry Chemical Physics}},
  pages        = {{21634--21642}},
  title        = {{{Surface-modified CAU-10 MOF materials as humidity sensors: impedance spectroscopic study on water uptake}}},
  doi          = {{10.1039/c5cp01988e}},
  year         = {{2015}},
}

@article{25939,
  abstract     = {{A variety of metal nitrates were filled into the pores of an ordered mesoporous CMK-3 carbon matrix by solution-based impregnation. Thermal conversion of the metal nitrates into the respective metal oxides, and subsequent removal of the carbon matrix by thermal combustion, provides a versatile means to prepare mesoporous metal oxides (so-called nanocasting). This study aims to monitor the thermally induced processes by thermogravimetric analysis (TGA), coupled with mass ion detection (MS). The highly dispersed metal nitrates in the pores of the carbon matrix tend to react to the respective metal oxides at lower temperature than reported in the literature for pure, i.e., carbon-free, metal nitrates. The subsequent thermal combustion of the CMK-3 carbon matrix also occurs at lower temperature, which is explained by a catalytic effect of the metal oxides present in the pores. This catalytic effect is particularly strong for oxides of redox active metals, such as transition group VII and VIII metals (Mn, Fe, Co, Ni), Cu, and Ce.}},
  author       = {{Weinberger, Christian and Roggenbuck, Jan and Hanss, Jan and Tiemann, Michael}},
  issn         = {{2079-4991}},
  journal      = {{Nanomaterials}},
  pages        = {{1431--1441}},
  title        = {{{Synthesis of Mesoporous Metal Oxides by Structure Replication: Thermal Analysis of Metal Nitrates in Porous Carbon Matrices}}},
  doi          = {{10.3390/nano5031431}},
  year         = {{2015}},
}

@article{25941,
  abstract     = {{Ordered mesoporous In2O3 particles of variable size synthesized by the nanocasting method are used for preparation of resistive gas-sensing layers. Light activation by a LED (blue light, 460 nm) permits room-temperature ozone sensing. Apart from differences in base-line resistance in sensing layers containing small (diameter approx. 170 nm) or large particles (approx. 870 nm), differences in the response amplitude and response time constant are also observed. Signal stabilization is achieved faster for small particles. In addition, sensors show a particle size-dependent reaction threshold for low ozone concentration. Larger particles show negligible response to 50 ppb ozone whereas a significant response is observed for the small-particle sensors. A simple model based on geometrical properties and formation of depletion layers explaining the observed behavior is presented.}},
  author       = {{Klaus, Dominik and Klawinski, Danielle and Amrehn, Sabrina and Tiemann, Michael and Wagner, Thorsten}},
  issn         = {{0925-4005}},
  journal      = {{Sensors and Actuators B: Chemical}},
  pages        = {{181--185}},
  title        = {{{Light-activated resistive ozone sensing at room temperature utilizing nanoporous In2O3 particles: Influence of particle size}}},
  doi          = {{10.1016/j.snb.2014.09.021}},
  year         = {{2015}},
}

@article{25942,
  abstract     = {{Cobalt oxide spinel (Co3O4) with an ordered nanostructure is used as a resistive gas sensor for carbon monoxide (CO) in low ppm concentrations. The operating temperature has a strong impact on the concentration-dependent sensing behavior. At lower temperature (473 K) the sensor response is governed mainly by surface coverage with CO and/or CO2, whereas at higher temperature (563 K) oxygen diffusion in the crystal lattice of Co3O4 strongly affects the sensing behavior.}},
  author       = {{Vetter, S. and Haffer, S. and Wagner, T. and Tiemann, Michael}},
  issn         = {{0925-4005}},
  journal      = {{Sensors and Actuators B: Chemical}},
  pages        = {{133--138}},
  title        = {{{Nanostructured Co3O4 as a CO gas sensor: Temperature-dependent behavior}}},
  doi          = {{10.1016/j.snb.2014.09.025}},
  year         = {{2015}},
}

@article{25945,
  abstract     = {{Catalysis plays a central role in many fields of life, e.g., in biochemical processes, to reduce energy costs and resources in chemical industry and to decrease or even avoid environmental pollution and in energy management. Porous alumina (Al2O3) is an essential material in various applications, especially as a support material for catalysts. It is often prepared by nanocasting using porous carbon materials that serve as rigid structure matrices. In this work, an alternative way to synthesize mesoporous Al2O3 by using hydrogels as porogenic material is presented. Hydrogels can easily be patterned by light and used to imprint their structure onto alumina opening a new approach to fabricate patterned Al2O3. The hydrogels used in this work are based on poly(dimethylacrylamide) and were photo-chemically cross-linked. Followed by a nanocasting process, mesoporous alumina samples were synthesized and characterized by N2 physisorption and X-ray diffraction. The cross-linker amount in the polymer network was varied and the influence on the properties of the Al2O3 is analyzed.}},
  author       = {{Birnbaum, Wolfgang and Weinberger, Christian and Schill, Verena and Haffer, Stefanie and Tiemann, Michael and Kuckling, Dirk}},
  issn         = {{0303-402X}},
  journal      = {{Colloid and Polymer Science}},
  pages        = {{3055--3060}},
  title        = {{{Synthesis of mesoporous alumina through photo cross-linked poly(dimethylacrylamide) hydrogels}}},
  doi          = {{10.1007/s00396-014-3379-5}},
  year         = {{2014}},
}

@article{25946,
  abstract     = {{The synthesis of a periodically ordered, nanostructured composite consisting of CoFe2O4 and BaTiO3 is presented. In a first step, mesoporous CoFe2O4 is prepared by the structure replication method (nanocasting) using mesoporous KIT-6 silica as a structural mold. Subsequently, BaTiO3 is created inside the pores of CoFe2O4 by the citrate route, resulting in a well-ordered composite material of both phases. The two components are known for their distinct ferroic properties, namely ferrimagnetism (CoFe2O4) and ferroelectricity (BaTiO3), respectively. Therefore, this proof of synthesis concept offers new perspectives in the fabrication of composite materials with multiferroic properties.}},
  author       = {{Haffer, Stefanie and Lüder, Christian and Walther, Till and Köferstein, Roberto and Ebbinghaus, Stefan G. and Tiemann, Michael}},
  issn         = {{1387-1811}},
  journal      = {{Microporous and Mesoporous Materials}},
  pages        = {{300--304}},
  title        = {{{A synthesis concept for a nanostructured CoFe2O4/BaTiO3 composite: Towards multiferroics}}},
  doi          = {{10.1016/j.micromeso.2014.05.023}},
  year         = {{2014}},
}

@article{25948,
  abstract     = {{Ordered mesoporous silica phases (e.g. KIT-6, SBA-15) are used as structure matrices for negative replica structures of mesoporous In2O3. We present a detailed study on how the controlled synthesis of mono-, bi- and trimodal pore systems in the products is accomplished by systematic variation of the procedure of infiltrating a precursor species (In(NO3)3) into the pores of the silica matrix and subsequent thermal conversion into In2O3. Melt impregnation and conversion in a closed reactor facilitates a one-step casting process for ordered mesoporous indium oxide (In2O3). We present a model based on variation of the pore filling.}},
  author       = {{Klaus, Dominik and Amrehn, Sabrina and Tiemann, Michael and Wagner, Thorsten}},
  issn         = {{1387-1811}},
  journal      = {{Microporous and Mesoporous Materials}},
  pages        = {{133--139}},
  title        = {{{One-step synthesis of multi-modal pore systems in mesoporous In2O3: A detailed study}}},
  doi          = {{10.1016/j.micromeso.2014.01.007}},
  year         = {{2014}},
}

@inbook{25944,
  abstract     = {{Recently indium oxide (In2O3) attracted attention as a material for sensing layers in semiconducting gas sensors. Compared to frequently investigated materials like tin dioxide (SnO2), tungsten trioxide (WO3), or gallium oxide (Ga2O3) indium oxide offers some unique properties. The most prominent one is its selectivity to oxidizing gases such as ozone (O3) or nitrogen dioxide (NO2) at low operating temperatures (<150°C). Combined with the photoreduction properties of nanocast, porous In2O3 highly selective sensing layers with a fast response can be prepared. In some cases even room temperature measurements are possible; therefore this material allows for designing low-power sensors without the need for special sensor substrates (e.g., μ-hotplates). Detailed analysis of the sensing mechanism reveals that known sensing models are not able to describe the observed effects. Therefore a new sensing model for ordered nanoporous In2O3 is presented which will be applicable for nonstructured material too.}},
  author       = {{Wagner, Thorsten and Donato, Nicola and Tiemann, Michael}},
  booktitle    = {{Springer Series on Chemical Sensors and Biosensors}},
  issn         = {{1612-7617}},
  title        = {{{New Sensing Model of (Mesoporous) In2O3}}},
  doi          = {{10.1007/5346_2013_57}},
  year         = {{2014}},
}

@inbook{25950,
  abstract     = {{In this paper, the development and validation of a shield prototype for resistive sensor array characterization with Arduino UNO, a platform based on ATmega328 microcontroller provided by ATMEL, is reported. The resistance variation of the sensor can be evaluated by properly choosing the capacitance value and by measuring the period (frequency) of a custom inverter-based oscillator. The GUI and the developed firmware are able to perform the real-time monitoring of the sensor responses. The developed shield is able to measure the response of up to six sensors under UV radiation by means of LED devices. First results carried out with resistive sensors based on mesoporous In2O3-based material under UV light exposure are reported.}},
  author       = {{Aloisio, D. and Donato, N. and Neri, G. and Latino, M. and Wagner, T. and Tiemann, Michael and Capra, P. P.}},
  booktitle    = {{Lecture Notes in Electrical Engineering}},
  issn         = {{1876-1100}},
  title        = {{{Arduino-Based Shield for Resistive Gas Sensor Array Characterization Under UV Light Exposure}}},
  doi          = {{10.1007/978-3-319-00684-0_79}},
  year         = {{2014}},
}

@inbook{25949,
  abstract     = {{Due to their unique properties, ordered mesoporous carbon (OMC) materials prepared by nanocasting have raised great attention in recent years. Their synthesis usually comprises multiple cycles of impregnating a porous structure matrix with an aqueous solution of a suitable precursor, such as sucrose or other, often hazardous, compound. We present a more straightforward variation of this method by using fructose as the precursor compound. By using a solvent-free melt of the precursor, the impregnation requires only a single step. After carbonization by thermal decomposition and removal of the mesoporous silica structure matrix (SBA-15), ordered mesoporous carbon with one (CMK-3) or two (CMK-5) pore modes in two-dimensional, hexagonal symmetry (p6mm) is obtained.}},
  author       = {{Weinberger, Christian and Haffer, S. and Wagner, T. and Tiemann, Michael}},
  booktitle    = {{ACS Symposium Series}},
  issn         = {{0097-6156}},
  title        = {{{Fructose as a Precursor for Mesoporous Carbon: Straightforward Solvent-Free Synthesis by Nanocasting}}},
  doi          = {{10.1021/bk-2014-1183.ch001}},
  year         = {{2014}},
}