• Carbon letters
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• v.13 no.2
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• pp.94-98
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• 2012

Herein, macroporous carbon foams were successfully prepared with phenol and formaldehyde as carbon precursors and an ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate ($BMIPF_6$), as a pore generator by employing a polymerization-induced phase separation method. During the polycondensation reaction of phenol and formaldehyde, $BMIPF_6$ forms a clustered structure which in turn yields macropores upon carbonization. The morphology, pore structure, electrical conductivity of carbon foams were investigated in terms of the amount of the ionic liquid. The as-prepared macroporous carbon foams had around 100-150 ${\mu}m$-sized pores. More importantly, the electrical conductivity of the carbon foams was linearly improved by the addition of $BMIPF_6$. To the best of the author's knowledge, this is the first result reporting the possibility of the use of an ionic liquid to prepare porous carbon materials.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.2
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• pp.342-350
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• 1993

Experiments are performed to determine the dependence of torsional rigidity upon the cross-sectional area for specimens of dense polyurethane foam. Testing equipment was designed and fabricated in the laboratory to satisfy the experimental characteristics. Results show the increase of torsional rigidity compared to the expected value based on the conventional elasticity. And this can be explained that the consideration of the internal motions of constitutive particles predicts the elastic behavior of the material better.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.21-22
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• 2018

Foamed concrete is a porous concrete that is cured by mixing bubbles into cement slurry. It is lighter than ordinary concrete and is characterized by higher insulation. Lightweight foamed concerte is mainly used as a sandwich panel in Korea, and is also used as a refractory filler in fireproof safes. Studies on lightwight foamed concrete have been carried out on strength,density and thermal conductivity. However, it is confirmed that the research on the fire resistance performance is very limited. Based on this study, fire resistance of lightweight foamed concrete using expanded polystyrene beads is investigated.

• Carbon letters
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• v.18
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• pp.11-17
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• 2016

Monolithic carbon foams with hierarchical porosity were prepared from polyurethane templates and resol precursors. Mesoporosity was achieved through the use of soft templating with surfactant Pluronic F127, and macroporosity from the polyurethane foams was retained. Conditions to obtain high porosity materials were optimized. The best materials have high specific surface areas (380 and 582 m² g^-1, respectively) and high electrical conductivity, which make them good candidates for supports in sensors. These materials showed an almost linear dependence between the potential and the pH of aqueous solutions.

• Nuclear Engineering and Technology
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• v.52 no.5
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• pp.1093-1097
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• 2020

A composite iodine sorbent was obtained in the form of porous polymer matrix with activated carbon particles impregnated with triethylenediamine deposited on its surface. A comparative assessment of the radioactive methyliodide capturing efficiency by the composite sorbent and a sample of industrial charcoal sorbent was conducted. It was shown that under the selected testing conditions, the hydraulic resistance of the composite sorbent is lower, and the sorption capacity is higher than that of the industrial charcoal sorbent. A method for comparing the effectiveness of iodine sorbents, based on the calculation of the ratio of the sorption capacity index to the minimum capacity index, needed for the required purification degree was proposed.

• Advances in aircraft and spacecraft science
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• v.6 no.4
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• pp.273-282
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• 2019

This article is concerned with the investigation of geometrically non-linear vibration response of refined thick porous nanobeams. To this end, non-local theory of elasticity has been adopted to provide the nanobeam formulation. Voids or pores can affect the material characteristics of the nanobeam. So, their effects have been considered in this research and also there are various void distributions. The closed form solution of the non-linear problem has been used that is adopted from previous articles. Then, it is focused on the impacts of non-local field, void distribution, void amount and geometrical properties on non-linear vibrational characteristic of a nano-size beam.

• Applied Chemistry for Engineering
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• v.28 no.5
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• pp.539-546
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• 2017

In this study, an outstanding anion exchange chemical filter was prepared for acidic gas removal. Commercial anion exchange resin was attached to polyurethane (PU) foam by using different types of pressure sensitive adhesive (PSA). The water and chemical resistance and also adhesive elongation were investigated. Also, the behavior of HCl and HF adsorption was evaluated as functions of the initial concentration and flow rate. ATE-701, AT-4000C and HCA-1000 showed 900, 1,500% and 2,400% of the elongation, respectively. It was confirmed that the desorption ratio of HCA-1000 was less than 6% and had excellent durability in water and chemical resistance tests. The adsorption occurred faster as the concentration and flow rate of HCl and HF increased. But 100% adsorption equilibrium occurred after 110 minutes, regardless of the concentration and flow rate. In addition, SEM morphology showed that the adhesive was uniformly dispersed, while the porous structure of the ion exchange resin was maintained, and the chemical filter exhibited excellent durability for the adsorption/desorption process.

• KSBB Journal
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• v.21 no.3
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• pp.188-193
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• 2006

A new type of biofilter, a rotating drum biotrickling filter(RDBF), was developed and operated for the removal of styrene from industrial waste gas. The porous polyurethane foam sheet was used as a packing materials for the RDBF and a pure culture of Gram-positive bacterium Brevibacillus sp. SP1 was used as an inoculum. The reactor showed a short start-up period of 18 days, during which uniform biofilms were developed on the packing. During a steady operation at an incoming styrene concentration of $200ppm_v$ and a retention time of 0.5 min, a high and stable removal of styrene over 95% was observed. The maximum elimination capacity was estimated to be $125g/m^3{\cdot}hr$. The outstanding performance was attributed to an efficient gas-liquid mass transfer and the appropriate supply of nutrient solution to the biofilm microorganisms on the packing by the rotation of the drum.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.31 no.2
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• pp.96-101
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• 2021

Developing effective and earth-abundant electrocatalyst for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is critical for the commercialization of a water splitting system. In particular, the overpotential of the OER is relatively higher than the HER, and thus, it is considered that one of the important methods to enhance the performance of the electrocatalyst is to reduce the overpotential of the OER. We report effects of incorporation of metalloid into Ni(OH)2 microcrystal on electrocatalytic activities. In this study, Te incorporated Ni(OH)2 (��Te-Ni(OH)2) were grown on three-dimensional porous NF by a facile solvothermal method with �� = 1, 3 and 5. Homogeneous microplate structure on the NF was clearly observed for the Ni(OH)2/NF and ��Te-Ni(OH)2/NF samples. However, irregular and collapsed nanostructures were found on the surface of nickel foam when Te precursor ratio is (��) over 3. Electrocatalytic OER properties were analysed by Linear sweep voltammetry (LSV) and Electrochemical impedance spectroscopy (EIS). The amount of Te incorporation used in the electrocatalytic reaction was found to play a crucial role in improving catalytic activity. The optimum Te amount (��) introduced into the Ni(OH)2/NF was discussed with respect to their OER performance.

• Steel and Composite Structures
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• v.43 no.1
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• pp.91-106
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• 2022

This paper has focused on presenting a three dimensional theory of elasticity for free vibration of 3D-graphene foam reinforced polymer matrix composites (GrF-PMC) cylindrical panels resting on two-parameter elastic foundations. The elastic foundation is considered as a Pasternak model with adding a Shear layer to the Winkler model. The porous graphene foams possessing 3D scaffold structures have been introduced into polymers for enhancing the overall stiffness of the composite structure. Also, 3D graphene foams can distribute uniformly or non-uniformly in the shell thickness direction. The effective Young's modulus, mass density and Poisson's ratio are predicted by the rule of mixture. Three complicated equations of motion for the panel under consideration are semi-analytically solved by using 2-D differential quadrature method. The fast rate of convergence and accuracy of the method are investigated through the different solved examples. Because of using two-dimensional generalized differential quadrature method, the present approach makes possible vibration analysis of cylindrical panels with two opposite axial edges simply supported and arbitrary boundary at the curved edges. It is explicated that 3D-GrF skeleton type and weight fraction can significantly affect the vibrational characteristics of GrF-PMC panel resting on two-parameter elastic foundations.