• Journal of the Korean Applied Science and Technology
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• v.26 no.3
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• pp.240-247
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• 2009

The purpose of this study is to develop a method to evaluate solubility parameter interactions of cosmetic ingredients in formulations. This experimentation relates to the fabrication of new multi-layer cleansing oil which can remove make-up products such as lipstick, foundation, mascara, eye shadow, etc., and also can wash away dirt and sebum from the skin just in one stage process. Solubility parameter and specific gravity of various cosmetic ingredients are measured to explain the cleanliness of interface, detergency of make-up cosmetics on the skin surface. The results suggest that it is possible for cosmetic chemists to use solubility parameter of cosmetic materials for fabrication of new formulation of 3-layer cleansing oil.

• Nuclear Engineering and Technology
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• v.29 no.2
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• pp.127-137
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• 1997

Equilibrium concentrations of major elements in an underground repository with a capacity of 100,000 drums have been simulated using the geochemical computer code (EQMOD). The simulation has been carried out at the conditions of pH 12 to 13.5, and Eh 520 and -520 mV. Solubilities of magnesium and calcium decrease with the increase of pH. The solubility of iron increases with pH at Eh -520 mV of reducing environment while it almost entirely exists as the precipitate of Fe(OH)$_3$(s) at Eh 520 mV of oxidizing environment. All of cobalt and nickel are predicted to be dissolved in the liquid phase regardless of pH since the solubility limit is greater than the total concentration. In the case of cesium and strontium, all forms of both ions are present in the liquid phase because they have negligible sorption capacity on cement and large solubility under disposal atmosphere. And thus the total concentration determines the equilibrium concentration. Adsorbed amount of iodide and carbonate are dependent on adsorption capacity and adsorption equilibrium constant. Especially, the calcite turns out to be a solubility-limiting phase on the carbonate system. In order to validate the model, the equilibrium concentrations measured for a number of systems which consist of iron, cement, synthetic groundwater and radionuclides are compared with those predicted by the model. The concentrations between the model and the experiment of nonadsorptive elements cesium, strontium, cobalt nickel and iron, are well agreed. It indicates that the assumptions and the thermodynamic data in this work are valid. Using the adsorption equilibrium constant as a free parameter, the experimental data of iodide and carbonate have been fitted to the model. The model is in a good agreement with the experimental data of the iodide system.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.353-356
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• 2001

The relation between the flocculation and dispersion of metal oxide powders and the properties of solvents, such as dielectric constant and solubility parameter, was investigated for TiO$_2$, $Al_2$O$_3$and Fe$_2$O$_3$particles. The particle size and median diameter of these metal oxides were measured in many organic solvents, from which the effect of solvents on the flocculation and dispersion of metal oxide powders was considered. The metal oxide powders of TiO$_2$, $Al_2$O$_3$and Fe$_2$O$_3$tend to disperse in a solvent of higher polarity, whereas they are apt to flocculate in a solvent of low dielectric constant, because the Hamaker constant between the particles becomes larger in such a solvent. There we, however, some solvents that do not obey these tendencies. It is possible to evaluate the flocculation and dispersion of these metal oxide powders in many solvents by using numeral balances of Hansen’s three-dimensional solubility parameter (f$_{d}$, f$_{p}$ and f$_{h}$). There exists a solvent giving the optimal dispersion for each metal oxide, and the optimal dispersion point of f$_{d}$, f$_{p}$ and f$_{h}$ is determined by the combination of various metal oxide powders and solvents.nts.nts.nts.

• Membrane Journal
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• v.28 no.5
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• pp.320-325
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• 2018

The sorption amounts of butanol/water and isopropanol/water solution on the surface modified with FASs (fluoroalkylsilanes) hydrophobic membrane were measured and analyzed using Hansen's solubility parameters. The difference of the solubility parameter of butanol (${\delta}_t=20.4$) and that of the surface modified with FASs hydrophobic membrane (${\delta}_t=16.9$) was greater than the case of isopropanol (${\delta}_t=24.6$), which might explain the result that the sorption amount of butanol was much higher than that of isopropanol. We might also explain the effect of the polar force (${\delta}_p$) on the sorption amount. The difference (${\Delta}$) between FASs polar force (${\delta}_p=4.6$) and butanol polar force (${\delta}_p=6.3$) was much smaller than that between FASs polar force (${\delta}_p=4.6$) and isopropanol polar force (${\delta}_p=9.0$), which meant that the interaction of butanol-FASs was much greater than that of isopropanol-FASs, and resulted in greater sorption amount of butanol on the FASs. This study showed Hansen's solubility parameters might be used for analysis of sorption characteristics of alcohol on membrane and solubility of solute in solvent.

• Membrane Journal
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• v.8 no.3
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• pp.157-169
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• 1998

The effects of solvents (DMAc, NMP, 1,4-dioxane) and nonsolvents ($H_2O$, Methanol, n-hexane) on the morphology of 6FDA-p-TeMPD polyimide membrane, prepared by the wet phase inversion method, were studied. In the polymer/solvent/nonsolvent ternary system, the binodal curve, the coagulation value and the relative light transmission were measured, and the solubility parameter difference was calculated. The onset state and rate of liquid-liquid alemixing were predicted and the morphology of membrane was analyzed. It is found that the finger-like pores are formed within discontinuous polymer nodules when the binoclal curve is close to the polymer-solvent (P-S) axis, the coagulation value is small, the reduction of light transmission is easy to occur and the order of solubility parameter difference ($\Delta \delta_{i-j}$) is $\Delta \delta_{S-NS} > \Delta \delta_{P-NS} > \Delta \delta_{P-S}$. The dense skin with small nodules and the sponge type sublayer with macrovoid are formed in the case that the binodal curve is distant from the P-S axis, the onset time of liquid-liquid demixing is long and the order of $\Delta \delta_{i-j}$ is $\Delta \delta_{P-NS} >(\Delta \delta_{S-NS} < > \Delta \delta_{P-S})$. The thick layer of fine nodule coagulation and loosely grown sublayer of nodules appear when the binodal curve is distant from the P-S axis, the onset time of liquid-liquid demixing is very long and the order of $\Delta \delta_{i-j}$가 $\Delta \delta_{S-NS} > (\Delta \delta_{P-NS}$\lessgtr$ > (\Delta \delta_{P-NS} < >)\Delta \delta_{P-S}$ ).

• Restorative Dentistry and Endodontics
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• v.36 no.2
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• pp.139-148
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• 2011

Objectives: This study investigated the effect of the strength and wetting characteristics of adhesives on the bond strength to dentin. The experimental adhesives containing various ratios of hydrophobic, low-viscosity Bis-M-GMA, with Bis-GMA and TEGDMA, were made and evaluated on the mechanical properties and bond strength to dentin. Materials and Methods: Five experimental adhesives formulated with various Bis-GMA/Bis-MGMA/TEGDMA ratios were evaluated on their viscosity, degree of conversion (DC), flexural strength (FS), and microtensile bond strength (MTBS). The bonded interfaces were evaluated with SEM and the solubility parameter was calculated to understand the wetting characteristics of the adhesives. Results: Although there were no significant differences in the DC between the experimental adhesives at 48 hr after curing (p > 0.05), the experimental adhesives that did not contain Bis-GMA exhibited a lower FS than did those containing Bis-GMA (p < 0.05). The experimental adhesives that had very little to no TEGDMA showed significantly lower MTBS than did those containing a higher content of TEGDMA (p < 0.05). The formers exhibited gaps at the interface between the adhesive layer and the hybrid layer. The solubility parameter of TEGDMA approximated those of the components of the primed dentin, rather than Bis-GMA and Bis-M-GMA. Conclusions: To achieve a good dentin bond, a strong base monomer, such as Bis-GMA, cannot be completely replaced by Bis-M-GMA for maintaining mechanical strength. For compatible copolymerization between the adhesive and the primed dentin as well as dense cross-linking of the adhesive layer, at least 30% fraction of TEGDMA is also needed.

• Restorative Dentistry and Endodontics
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• v.31 no.4
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• pp.290-299
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• 2006

Objectives: The purpose of this study is to evaluate the effect of ethylene glycol analogs on modulus of elasticity and ultimate tensile strength of moist, demineralized dentin matrix. Methods: Dentin disks 0.5 mrn thick were prepared from mid-coronal dentin of extracted. unerupted, human third molars. 'I' beam and hour-glass shaped specimens were prepared from the disks, the ends protected with nail varnish and the central regions completely demineralized in 0.5M EDTA for 5 days. Ultimate tensile stress (UTS) and low strain modulus of elasticity (E) were determined with specimens immersed for 60 min in distilled water $(H_{2}O)$, ethylene glycol $(HO-CH_{2}-CH_{2}-OH)$, 2-methoxyethanol $(H_{3}CO-CH_{2}-CH_{2}-OH)$, and 1,2-dimethoxyethane $(H_{3}CO-CH_{2}-CH_{3}-OCH_{3})$ prior to testing in those same media. Modulus of elasticity was measured on the same specimens in a repeated measures experimental design. The results were analyzed with a one-way ANOVA on ranks, followed by Dunn's test at ${\alpha}\;=\;0.05$. Regression analysis examined the relationship between UTS or E and hoy's solubility parameter for hydrogen bonding $({\delta}_{h})$ of each solvent. Results: The UTS of demineralized dentin in water, ethylene glycol, 2-methoxyethanol, and 1,2-dimethoxyethane was 24 (3), 30 (5), 37 (6), and 45 (6) MPa, ${\times}$ (SD) N = 10. Low strain E for the same media were 16 (13), 23 (14), 52 (24), and 62 (22) MPa. Regression analysis of UTS vs ${\delta}_{h}$ revealed a significant $(p\;<\;0.0001,\;r\;=\;-0.99,\;R^{2}\;=\;0.98)$ inverse, exponential relationship. A similar inverse relationship was obtained between low strain E vs ${\delta}_{h}\;(p\;<\;0.0005,\;r\;=\;-0.93,\;R^{2}\;=\;0.86)$. Significance: The tensile properties of demineralized dentin are dependent upon the hydrogen bonding ability of polar solvents $({\delta}_{h})$. Solvents with low ${\delta}_{h}$ values may permit new interpeptide H-bonding in collagen that increases its tensile properties. Solvents with high ${\delta}_{h}$ values prevent the development of these new interpeptide H-bonds.