• 한국광물학회지
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• 제15권4호
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• pp.273-282
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• 2002

국내산 Ca-몬모릴로나이트와 이것으로부터 이온치환에 의하여 합성된 Al-가교몬모릴로나이트의 특성을 비교하였다. Ca-몬모릴로나이트와 Al-가교몬모릴로나이트를 저면간격, 비표면적, 탈수 및 이온치환 등의 관점에서 그 특성을 비교 연구하였다. d(001) 간격은 Ca-몬모릴로나이트에서는 15.1 $\AA$이었으나 Al-가교몬모릴로나이트에서는 18.3 $\AA$으로 나타났다. 탈수는 Ca-몬모릴로나이트에서는 $350^{\circ}C$ 이하에서 일어났지만, Al-가교몬모릴로나이트에서는 $550 ^{\circ}C$까지도 선형적으로 일어났다. BET 비표면적은 Al-가교몬모릴로나이트( $192\m^2$/g)가 Ca-몬모릴로나이트보다 5～6배 높은 값을 보여주었다. Ca-Na 이온 용액과의 반응에서 Ca-몬모릴로나이트는$ Na^{＋}$ 에 대하여, 그리고 Al- 가교몬모릴로나이트는 $Ca^{2＋}$ 에 대하여 선택성을 보여주었다. Ca-몬모릴로나이트는 $Na^{＋}$ /가 증가할수록 d(001)간격이 감소하다가 $Ca^{ 2＋}$와 $Na^{＋}$ /가 같은 양일 경우에 구조적으로 불규칙한 혼합층구조 상태를 보여주었으며 Al-가교몬모릴로나이트는 $Ca^{2＋}$ 의 증가와 함께 d(001) 간격이 선형적으로 감소한 양상을 보여주었다.

• Bulletin of the Korean Chemical Society
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• 제25권7호
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• pp.965-968
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• 2004

H-montmorillonite was modified by interlayer surface silylation using 3-aminopropyltriethoxysilane and dodecylamine in ethanol without a pre-swelling step. Dodecylamine acts as a gallery expander and silylation catalyst. The evaporation of ethanol from the dispersion yields well-ordered silylated montmorillonites with large basal spacing between 1.50 and 4.20 nm. Solid-state $^29Si$ CP MAS NMR of the silylated samples showed $Q^2\;and\;Q^3$ signals as well as $T^2\;and\;T^3$ signals. The increase in the relative intensity of $Q^3\;for\;Q^2$ and the appearance of $T^2\;and\;T^3$ signals was attributed to the grafting of 3-aminopropyltriethoxysilane to the interlayer surface silanol groups.

• 한국재료학회지
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• 제28권3호
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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.

• Macromolecular Research
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• 제11권6호
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• pp.425-430
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• 2003

Two types of poly(n-butyl acrylate) copolymer/silicate nanocomposites have been produced: poly(n-butyl acrylate-co-methyl methacrylate) [P(BA-co-MMA)]/silicate nanocomposites and poly(n-butyl acrylate-co-styrene) [P(BA-co-ST)]/silicate nanocomposites. The P(BA-co-MMA)/silicate nanocomposites shows the exfoliated structures but a P(BA-co-ST)/silicate nanocomposites have intercalated structures, because the BA/MMA comonomer has a higher polarity (e-value in Q-e scheme) than the BA/ST comonomer. The BA/MMA comonomer expanded the interlayer space of the silicate wider than did the BA/ST comonomer. The thermal degradation onset point of the P(BA-co-MMA)/silicate nanocomposites was 43$^{\circ}C$ higher than that of pure P(BA-co-MMA). P(BA-co-MMA)T5%, P(BA-co-MMA)T10%, and P(BA-co-MMA)T20% exhibit 134,302, and 195% increases, respectively, in their storage moduli at -20$^{\circ}C$ relative to the pure copolymer.

• Bulletin of the Korean Chemical Society
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• 제32권6호
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• pp.1936-1938
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• 2011

Phosphonium montmorillonites (P-MMTs) were prepared by intercalating dodecyl tributyl phosphonium salt into sodium montmorillonite (Na-MMT) through an ion-exchange method. Microstructure and antibacterial activity of phosphonium montmorillonites were studied by FT-IR, TGA, XRD and Minimum Inhibitory Concentration (MIC), respectively. The results show that phosphonium montmorillonites exhibit higher thermal stability than conventional ammonium montmorillonites, the onset temperature of decomposition is higher than 300 $^{\circ}C$, and the basal spacing of phosphonium montmorillonites is enlarged compared to that of sodium montmorillonite. Phosphonium montmorillonites also show good antibacterial activity with the MIC against E. coli and S. aureus of 150 and 50 $mg{\cdot}L^{-1}$, respectively.

• 한국세라믹학회지
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• 제32권6호
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• pp.703-709
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• 1995

Octadecylenetrimethylammonium-montmorillonite as an organophilic montmorillonite intercalations complex was formed by cation exchange reaction between Na-montmorillonite and 9-octadecylenetrimethylammonium cation. After drying of this organophilic montmorillonite at $65^{\circ}C$ in high vacuum, the complexes were reacted with various swelling-solutions such as benzene, toluene, o-xylene, pyridine, $\alpha$-picoline, 2-ethyl-pyridine, 2-vinyl-pyridine and styrene, and the corresponding basal spacing obtained were 43.9$\AA$, 54.3$\AA$, 51.7$\AA$, 41.5$\AA$, 42.5$\AA$, 39.9$\AA$, 39.8$\AA$, 44.8$\AA$, respectively.

• 한국세라믹학회지
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• 제22권4호
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• pp.21-25
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• 1985

For studying the influence of addition of Polyvinyl alcohol (PVA)-montmorillonite complex on the hydration of Portland cement the PVA-montmorillonite derivatives were prepared in advance an characterized system-of Portland cement the PVA-montmorillonite derivatives were prepared in advance and characterized systema-tically. PVA with the polymerizationdegree ranging from 500 to 2000 have been intercalated into the lamellar structure of hydrated montmorillonites which were fractionated under 2㎛ by Stock's rule. In all cases the constant basal spacing of ∼20Å was determined whatever the molecular weight of PVA used. And the carbon chain orientation of PVA in the interfoliar space has been deduced to be parallel with bilayer structure.

• Bulletin of the Korean Chemical Society
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• 제23권12호
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• pp.1801-1805
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• 2002

The graphite intercalation compounds(GIC) were prepared by a dry process that led to the intercalation from the direct reaction of gaseous $SO_3$ with flake type graphite. The basal spacing of the GIC was increased from 8.3 ${\AA}$ to 12 in the gallery height. The ejection of interlayer $SO_3$ molecules by the heating for 1 minute at $950^{\circ}C$ resulted in an exfoliated graphite (EG) with surprisingly high expansion in the direction of c-axis. The expansion ratios of the exfoliated graphites were increased greatly between 220 times and 400 times compared to the original graphite particles, and the bulk density was range of 0.0053 to 0.01 $g/cm^3$, depending on reaction time. The pore size distribution of exfoliated graphite was in the range of $10-170{\mu}m$, which exhibites both mesoporosity and macroporosities. This result indicates that the direct reaction of graphite paricles with gaseous $SO_3$ can be proposed as an another route for the exfoliated graphite having excellent physical properties.

• Bulletin of the Korean Chemical Society
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• 제25권1호
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• pp.122-126
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• 2004

Biofunctional nanohybrids are synthesized from layered double hydroxide (LDH) and the vitamins such as ascorbic acid and topopherol acid succinate. Either ion exchange or copricipitaion leads to successful intercalation of the vitamins into gallery space of LDH that offers a new route to safe preservation of bioactivity as well as controlled release. Intercalations of vitamins are clearly reflected on the increase in the basal spacing of ZnAl-(Nitrate) LDH from 8.5 ${\AA}$ to 10.5 ${AA}$ for ascorbate, and 49.0 ${AA}$ for tocopherol acid succinate, respectively. No significant change in UV-Vis and IR absorption characteristics of the intercalated vitamins strongly supports the safe maintenance of their bioactivities without any deterioration of chemical and structural integrity. Furthermore, it is shown that the hybridized vitamins could be discharged in a controlled kinetics.

• 한국산업융합학회 논문집
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• 제13권2호
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• pp.93-98
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• 2010

Polypropylene / montmorillonite / wood flour nanocomposites are melt-mixed by using a twin screw extruder. The montmorillonite is intercalated by the wood flour and the basal spacing of montmorillonite is increased with increasing the content of wood flour. The exfoliation constantly occurs by adding more than 10 wt.% of maleic anhydride-grafted polypropylene as the compatibilizer, which is used for improving the interfacial adhesion between matrix and filler. Also, the maleic anhydride-grafted polypropylene enhances the mechanical properties of the nanocomposites.