• Polymer(Korea)
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• v.38 no.3
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• pp.299-306
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• 2014

ZnO pillared saponite was synthesized via a microwave hydrolysis method. To enhance interfacial compatibility between zinc oxide (ZnO) pillared saponite and poly lactic acid (PLA), ZnO pillared organic saponite was prepared by intercalation modification of cetyltrimethylammonium bromide. Moreover, PLA/ZnO pillared organic saponite nanocomposites were prepared by melting processing. The microstructure analysis of PLA/ZnO pillared organic saponite nanocomposites showed that ZnO pillared organic saponite was exfoliated and homogeneouslydispersed in PLA matrix. The property results showed that ZnO pillared organic saponite improved the mechanical properties and thermal stabilities of PLA/ZnO pillared organic saponite nanocomposites. Differential scanning calorimetry (DSC) demonstrated that ZnO pillared organic saponite restrained the appearance of cold crystallization, lowered the glass transition temperature and melting temperature of PLA, and improved the crystallinity of PLA. The results demonstrated that ZnO pillared organic saponite had a good interfacial compatibility and heterogeneous nucleation effect in PLA matrix, and also played an active role in accelerating the crystallization process of PLA.

• Journal of the Mineralogical Society of Korea
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• v.16 no.2
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• pp.125-133
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• 2003

Saponite was synthesized from talc by hydrothermal method. The starting material was prepared by adding ($NO_3$)$Al_3$$.$$9H_2$O and Mg($NO_3$)$_2$$.$$6H_2$O solution to the talc powder. which was previously activated in air at 800 $^{\circ}C$ together with $Na_2$$CO_3$. The alkalinity of the solution was controlled by $NH_4$OH solution. The autoclaving was carried out in the closed stainless steel vessel (about 1 liter) for 40 hours under the pressure of 25 kgf/$\textrm{cm}^2$ at $ 230^{\circ}C$ The characterization of the reaction product shows that saponite was crystallized successfully. After the experimental results, pressure was not sensitive parameter in the range of 25 ∼ 75 kgf/$\textrm{cm}^2$, but longer reaction time results in better crystallinity.

• Polymer(Korea)
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• v.35 no.5
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• pp.402-408
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• 2011

To improve $Na^+$-saponite(SPT) film flexibility, we prepared SPT hybrid clay films with various poly(vinyl alcohol) (PVA) concentrations(0~10 wt%) using the solution intercalation method. In this study, we investigated the thermo-optical properties, morphology, and gas permeability of the SPT hybrid films. We also examined the relationship between the film properties and PVA content using wide angle X-ray diffraction measurements(XRD), field emission scanning electron microscopy(FESEM), differential scanning calorimetry(DSC), thermogravimetric analysis(TGA), thermomechanical analysis(TMA), ultraviolet-visible(UV-vis) spectroscopy, and oxygen transmission rate($O_2$TR) testing. The properties of the clay hybrid films were strongly affected by PVA filler content. The presence of a small amount of PVA was sufficient to improve the flexibility of SPT hybrid films.

• Journal of the Mineralogical Society of Korea
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• v.4 no.1
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• pp.11-21
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• 1991

XRD patterns of biedellite-nontronite and saponite-iron saponite series were investigated using one-dimensional pattern simulation method. Ethylene-glycolate smectites show stronger 002 and 003 reflections than hydrated specimens do. The intensities of the 002 and 003 reflections change systematically as a function of Fe enrichment in both types of smectites. The intensity ratio of 002/003 increases with increasing. Fe in both dioctahedral to the higher scattering factor of Fe than those of Al and Mg, and the scattering power of various smectites can be compared quantitatively by calculating the scattering factors of octahedral cations. Interlayer cations cause less effect on XRD profile than octahedral cations as Fe do. Although 001 reflections provide informations about the overall scattering power of the octahedral sheet, some ferrous dioctahedtal smectite cannot be distinguished unambiguously from trioctahedral smectites on the basis of XRD profile. Simulation showed that heterogeneous smectites exhibit 001 intensity distribution that is almost identical to that of homogeneous smectites having the average composition of heterogeneous ones. The broadening of 001 reflections may not be useful in evaluating the degree of heterogeneity of smectite unless other factors affecting the broadening are well known.

• Polymer(Korea)
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• v.37 no.5
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• pp.579-586
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• 2013

Poly(vinyl alcohol)(PVA) nanocomposite films containing various saponite (SPT) clay contents were synthesized using a solution intercalation method. The thermal property, morphology, optical transparency, and gas permeability of the PVA nanocomposite films with various SPT contents in the range of 0 to 10 wt% were examined. PVA nanocomposite film containing 5 wt% SPT showed excellent thermal and gas barrier property. The hybrid films containing 5 wt% SPT were equibiaxially stretched with stretching ratios ranging from 150 to 250%. The clay dispersion, optical transparency, and gas permeability were also examined as a function of equibiaxial stretching ratio. The PVA nanocomposite films with various equibiaxial stretching ratios showed excellent optical transparency and barrier to oxygen permeability.

• Economic and Environmental Geology
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• v.52 no.1
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• pp.13-28
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• 2019

This study analyzed precipitation environment, heavy metal contamination, and mineral composition of white, reddish brown and mixed precipitates occurring at the Osip stream drainage, Gangwondo. Furthermore, spectral characteristics of the precipitates associated with heavy metal contamination and mineral composition was investigated based on spectroscopic analysis. The pH range of the precipitates was 4.43-6.91 for white precipitates, 7.74-7.94 for reddish brown precipitates, and 7.59-7.9 for the mixed precipitates, respectively. XRF analysis revealed that these precipitates were contaminated with Ni, Cu, Zn, and As. The white precipitates showed high Al concentration compared to reddish brown precipitates as much as 3.3 times, and the reddish brown precipitates showed high Fe concentration compared to white precipitates as much as 15 times. XRD analysis identified that the mineral composition of the white participates was aluminocoquimbite, gibbsite, quartz, saponite, and illite, and that of reddish brown precipitates was aluminum isopropoxide, kaolinite, goethite, dolomite, pyrophyllite, magnetite, quartz, calcite, pyrope. The mineral composition of the mixed precipitates was quartz, albite, and calcite. The spectral characteristics of the precipitates was manifested by gibbsite, saponite, illite for white precipitates, goethite, kaolinite, pyrophyllite for reddish brown precipitates, and albite for the mixed precipitates, respectively. The spectral reflectance of the precipitates decreased with increase in heavy metal contamination, and absorption depth of the precipitates indicated that the heavy metal ions were adsorbed to saponite and illite for white precipitates, and goethite and magnetite for reddish brown precipitates.

• Polymer(Korea)
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• v.37 no.2
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• pp.225-231
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• 2013

Poly(vinyl alcohol) (PVA) hybrid films containing 5 wt% pristine clay mineral were synthesized in the water solution. The various PVA hybrid films were synthesized from structurally different pristine clays: saponite (SPT), montmorillonite (MMT), hectorite (SWN), hydrophilic bentonite (PGV), and mica (Mica). The thermo-optical properties and morphologies of the PVA hybrid films were evaluated with various pristine clays. The nanostructure of the hybrid films was observed using transmission electron microscopy, which showed that the clay layers were well dispersed into the matrix polymer, although some clusters or agglomerated particles were also detected. The addition of pristine clay was more effective with regard to improving the thermal properties and gas barrier characteristics, whereas the optical transparency of the PVA hybrid films deteriorated with pristine clay.

• Polymer(Korea)
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• v.30 no.6
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• pp.545-549
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• 2006

Blends of poly(acrylic acid- co-maleic acid) (PAM) with poly (vinyl alcohol) (PVA) were pre -pared in distilled water PVA/PAM/saponite (PVA/PAM/SPT) nanocomposite films were prepared with various clay contents by using the solution intercalation method. The variations of the dispersion, morphology, and thermo-mechanical properties of the nanocomposites with clay content in the range 0 to 9 wt% were examined. Up to 3 wt% clay loading, the clay particles were homogeneously dispersed in the PVA/PAM blends. However, some agglomerated structures form in the polymer matrix above a clay content of 7 wt%. The thermal stability of the hybrids was increased linearly with increasing the clay loading up to 9 wt%. The maximum strength and modulus were obtained at a clay content of 7 wt%. Thus, the addition of small amounts of clay to the PVA/PAM blends produced PVA/PAM nano-composites with improved the thermo-mechanical properties.

• Journal of the Mineralogical Society of Korea
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• v.10 no.1
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• pp.33-44
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• 1997

The reaction path of water-gneiss in 200m borehole at the Soorichi site of Yugu Myeon, Chungnam was simulated by the EQ3NR/EQ6 program. Mineral composition of borehole core and fracture-filling minerals, and chemical composition of groundwater was published by authors. In this study, chemical evolution of groundwater and formation of secondary minerals in water-gneiss system was modelled on the basis of published results. The surface water was used as a starting solution for reaction. Input parameters for modelling such as mineral assemblage and their volume percent, chemical composition of mineral phases, water/rock ratio reactive surface area, dissolution rates of mineral phases were determined by experimental measurement and model fit. EQ6 modelling of the reaction path in water-gneiss system has been carried out by a flow-centered flow through open system which can be considered as a suitable option for fracture flow of groundwater. The modelling results show that reaction time of 133 years is required to reach equilibrium state in water-gneiss system, and evolution of present groundwater will continue to pH 9.45 and higher na ion concentration. The secondary minerals formed from equeous phase are kaolinite, smectite, saponite, muscovite, mesolite, celadonite, microcline and calcite with uincreasing time. Modeling results are comparatively well fitted to pH and chemical composition of borehole groudwater, secondary minerals identified and tritium age of groundwater. The EQ6 modelling results are dependent on reliability of input parameters: water-rock ratio, effective reaction surface area and dissolution rates of mineral phases, which are difficult parameters to be measured.

• Korean Journal of Heritage: History & Science
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• v.51 no.1
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• pp.4-31
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• 2018

The Neolithic pottery excavated from the Jungsandong site has been classified into four types of pottery (I: feldspar type, II: mica type, III: talc type and IV: asbestos type) according to their mineral composition. These four types of potteries generally appear to have undergone incomplete firing, while the level of oxidation in the type I pottery objects, which have a relatively higher clay content, was found to be particularly low. The type III objects, which have a high talc content, are judged to have been somewhat slow in removing carbon because they contain saponite belonging to the smectite group. Of the four types of pottery, type IV showed the highest redness and the most uniform characteristics, thus indicating a good level of oxidation. In particular, fixed carbide (C; 33.7 wt.%) with a thickness of about 1mm, and originating from organic substances, was detected inside the walls of the type I pottery, while the deep radial cracks in the outer surfaces of the pottery are thought to have been caused by repeated thermal shocks. Given that all of the pottery except for the type I artifacts are considered to be have been made for storage purposes, those containing talc and tremolite are easy to done liquid storing vessels based on an analysis of their material characteristics. As for the type II relics, which are composed of various minerals and exhibit poor physical properties, they seem to have been used for simple storage purposes. As domestic talc and asbestos mines were concentrated in the areas of Gyeonggi, Gangwon, Chungbuk, and Chungnam, it seems likely that talc and tremolite were produced as contiguous minerals. Considering the distance between the remains in Jungsandong and these mines and their geographical distribution, there is a possibility - albeit somewhat slight - that these mines were developed for the mining of various minerals. Although ultramafic rock masses - such as serpentine capable of generating talc and tremolite - have not been found in the Jungsandong area, limestone and biotite granite containing mica schist have been identified in the northwestern part of Yeongjong Island, indicating that small rock masses might have formed there in the past. Therefore, it is judged necessary to accumulate data on pottery containing talc and tremolite, other than the remains in Jungsandong, and to investigate the rocks and soils in the surrounding area with greater precision. The firing temperatures of the pottery found at the Jungsandong site were interpreted by analyzing the stability ranges of the mineral composition of each type. As a result, they have been estimated to range from 550 to $800^{\circ}C$ for the type I artifacts, and from 550 to $700^{\circ}C$ for the type I, II and IV artifacts. However, these temperatures are not the only factors to have affected their physical properties and firing temperature, and the types, particle sizes, and firing time of the clay should all be taken into consideration.