• Korean Journal of Materials Research
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• v.28 no.3
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• pp.189-194
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• 2018

Porous graphites were synthesized by removing the template in HF after cabothermal conversion for 3 h at $900^{\circ}C$, accompanied by intercalations of pyrolyzed fuel oil (PFO) in the interlayer of Co or Ni loaded magadiite. The X-ray powder diffraction pattern of the porous graphites exhibited 00l reflections corresponding to a basal spacing of 0.7 nm. The particle morphology of the porous graphites was composed of carbon plates intergrown to form spherical nodules resembling rosettes like a magadiite template. TEM shows that the cross section of the porous graphites is composed of layers with very regular spaces. In particular, crystallization of the porous graphite was dependent on the content of Co or Ni loaded in the interlayer. The porous graphite had a surface area of $328-477m^2/g$. This indicates that metals such as Co and Ni act as catalysts that accelerate graphite formation.

• Journal of the Korean Ceramic Society
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• v.45 no.9
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• pp.537-543
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• 2008

Effect of template size ratio on porosity and mechanical properties of porous zirconia ceramics were investigated using two different size (${\sim}8{\mu}m$ and ${\sim}50{\mu}m$ in diameter) of polymethyl methacrylate-coethylene glycol dimethacrylate (PMMA) microbeads as sacrificial templates. Porosity of the porous zirconia ceramics increased with decreasing the template size ratio ($8{\mu}m: 50{\mu}m$) whereas the compressive and flexural strengths of the porous zirconia ceramics increased with increasing the template size ratio. By controlling the template size ratio, sintering temperature and sintering time, it was possible to produce porous zirconia ceramics with porosities ranging from 57% to 69%. Typical flexural and compressive strength values of porous zirconia ceramics with ${\sim}60%$ porosity were ${\sim}37\;MPa$ and ${\sim}85\;MPa$, respectively.

• Journal of Integrative Natural Science
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• v.6 no.2
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• pp.82-86
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• 2013

This paper describes a method for the preparation of porous polymethylmethacrylate showing optical reflectivity from the porous silicon template. A porous polymethylmethacrylate showing optical reflectivity was prepared by replicating porous silicon template which was obtained by applying a computer-generated periodic square current density and resulted in a mirror with high reflectivity in a specific narrow spectral region. A porous polymethylmethacrylate showing an excellent reflectivity was successfully obtained by dissolving the Porous silicon template from the porous polymethylmethacrylate composite film. A porous polymethylmethacrylate exhibited a sharp reflection resonance in the reflectivity spectrum. Surface image of the porous polymethylmethacrylate indicated that the surface of the porous polymethylmethacrylate film had a porous structure. These porous polymethylmethacrylate films in aqueous solutions were stable for several days without any degradation.

• Journal of Powder Materials
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• v.12 no.2 s.49
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• pp.151-158
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• 2005

Porous graphite was synthesized by removal of template in HF after pyrolysis of pyrolyzed fuel oil (PFO) at $900^{\circ}C$ using the template of Co or Ni intercalated magadiite. Porous graphite had a plate structure like template, and d-spacing value of about 0.7 nm. The extent of crystallization of porous graphite was dependent on the contents of Co or Ni intercalated in interlayer. It can be explained that the metal such as Co and Ni acts as a promotion catalyst for graphite formation. Porous graphite shows the surface area of $328\sim477 m^2/g$.

• Journal of the Korean institute of surface engineering
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• v.43 no.5
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• pp.248-254
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• 2010

Porous $Al_2O_3$ film can be utilized as template for fabrication of nano-structured materials. Porous anodic alumina layer as template was prepared by anodization of aluminum in oxalic acid, and the pore diameter and barrier-type alumina layer can be controlled for proper anodizing parameter by widening process in $H_3PO_4$ solution. The $SiO_2$ nanodot and Ni nanowire was fabricated using anodic alumina template and their characteristics were investigated using SEM and TEM with EDS. Especially the growth mechanism of $SiO_2$ nanodot in alumina membrane compared with thinning of the alumina barrier layer during anodization was also investigated.

• Journal of Integrative Natural Science
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• v.6 no.3
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• pp.183-186
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• 2013

Well defined 1-dimentional (1-D) photonic crystals of polystyrene replicas have been successfully obtained by removing the porous silicon from the free-standing rugate porous silicon/phenylmethylpolysiloxane composite film. Rugate porous silicon was prepared by an electrochemical etching of silicon wafer in HF/ethanol mixture solution. Exfoliated rugate porous silicon was obtained by an electropolishing condition. A composite of rugate porous silicon/phenylmethylpolysiloxane composite film was prepared by casting a toluene solution of phenylmethylpolysiloxane onto the top of rugate porous silicon film. After the removal of the template by chemical dissolution, the phenylmethylpolysiloxane castings replicate the photonic features and the nanostructure of the master. The photonic phenylmethylpolysiloxane replicas are robust and flexible in ambient condition and exhibit an excellent reflectivity in their reflective spectra. The photonic band gaps of replicas are narrower than that of typical semiconductor quantum dots.

• Journal of the Korean Ceramic Society
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• v.40 no.6
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• pp.519-524
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• 2003

Porous carbon with high surface area and pore volume was prepared by a reverse replication process and its toluene equilibrium adsorption behavior was investigated. The preparation process of the porous carbon was composed of fellowing sub-processes in series: synthesis and template preparation of silica gel, impregnation and polymerization of DVB monomer in silica template, carbonization of DVB polymer in a silica-polymer composite, and HF-assisted selective etching of silica in carbon-silica composite. The prepared porous carbon was nano porous and had ultrahigh specific surface area (2007 ㎡/g) and large pore volume (3.07 ㎤/g). The nanoporous carbon showed rapid toluene adsorption rate and good toluene adsorption capacity, compared with a commercial Y-type zeolite. In the present study, a reverse replication process to prepare nanoporous carbons will be introduced and its application potential as a gas adsorbent will be discussed.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.1
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• pp.63-67
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• 2016

We present a method of fabricating poly (lactic-co-glycolic acid) (PLGA) porous microfibers using a pore template. PLGA microfibers were synthesized using a glass capillary tube in a poly-(dimethylsiloxane) (PDMS) microfluidic chip. Gelatin solution was used as a porous template to prepare pores in microfibers. Two phases of PLGA solutions in different solvents-DMSO (dimethyl sulfoxide) and DCM (dichloromethane)-were used to control the porosity and strength of the porous microfibers. The porosity of the PLGA microfibers differed depending on the ratio of flow rates in the two phases. The porous structure was formed in a spiral shape on the microfiber. The porous structure of the microfiber is expected to improve transfer of oxygen and nutrients, which is important for cell viability in tissue engineering.

• Journal of the Korean Ceramic Society
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• v.47 no.6
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• pp.509-514
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• 2010

Porous mullite-bonded SiC (MBSC) ceramics were fabricated at temperatures ranging from 1400 to $1500^{\circ}C$ for 2 h using silicon carbide (SiC), alumina ($Al_2O_3$), strontium oxide (SrO), and poly (methyl methacrylate-coethylene glycol dimethacrylate) (PMMA) microbeads. The effect of template content on porosity, pore morphology, and flexural strength were investigated. The porosity increased with increasing the template content at the same sintering temperature. The flexural strength showed maximum after sintering at $1450^{\circ}C$/2 h for all specimens due to small pores and dense strut. By controlling the template content and sintering temperature, it was possible to produce porous MBSC ceramics with porosities ranging from 30% to 54%. A maximum flexural strength of ~51MPa was obtained at 30% porosity when no template were used and specimens sintered at $1450^{\circ}C$/2 h.

• Applied Chemistry for Engineering
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• v.16 no.3
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• pp.408-412
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• 2005

Porous layered carbon was prepared by interlayer pyrolysis of pyrolysis fuel oil (PFO) using magadiite template and successive dissolution of template. Particle morphology was plate type with d-spacing of approximately 0.7 nm and it had constant interlayer space. Specific surface area was $147{\sim}385m^2/g$ depending upon template type, mixing ratios and pyrolysis time.