Ionic conductivity in poly(vinyl butyral) based polymeric electrolytes: Effect of solvents and salts

Li⁺ conductive solid polymeric electrolytes (SPEs) have been prepared by complexing Li salts LiX (X = I, SCN, CLO4, CF3SO3) with poly(vinyl butyral) (PVB) an amorphous polymer with a low T_g value and well known for its outstanding laminating properties. These self-supporting SPEs have been prepared by the solution cast technique using cyclohexanone, tetrahydrofuran, and n-butyl alcohol as solvents. The XRD and DSC investigations correlated to measured ionic conductivities have revealed that in addition to the amorphous nature of the resulting complex, its T_g value, the concentration and the values of the lattice energies of the complexing salts, the solvent used in making the SPEs also govern the value of ionic conductivity. Highest ionic conductivity values attained in SPEs made with n-butyl alcohol are explained in terms of the interception of the hydrogen bonding due to solvation.     

Impurity Distribution Behavior in Caprolactam Extraction with Environmentally Benign Mixed Solvents

In a previous study a solvent mixture of heptane containing 40 mass % heptanol was selected as an alternative in the industrial extraction of caprolactam to replace benzene, toluene, or chlorinated hydrocarbons. This work reports the equilibrium distribution ratio of caprolactam and four model impurities of organic nature, namely, cyclohexanone, aniline, n‐methylcaprolactam, and cyclohexane‐carboxamide, comparing the mixed solvents with toluene as a reference. The resulting phase equilibria were interpreted using the equilibrium stage model. Based on these calculations it was found that, compared to toluene, the co‐extracted fraction of cyclohexanone and aniline was higher, that of n‐methylcaprolactam was comparable, and that of cyclohexane‐carboxamide was lower using the mixed solvent. Overall, the mixed solvent reduced the fraction of co‐extracted impurities by almost 10 %.     

溶剂抽提偏三甲苯-正辛烷三元体系液-液相平衡的对比分析

在70℃下采用浊点法分别测定了二甲亚砜、N-甲酰吗啉、四甘醇与偏三甲苯-正辛烷三元体系液-液相平衡数据，得到体系的液-液分层曲线和结点数据，并用液-液分层曲线和体系物性（折光指数、密度）相结合的方法对平衡数据进行了分析。结果表明：溶剂的溶解能力的次序为：N-甲酰吗啉＞二甲驱砜＞四甘醇；溶剂的选择性次序为：二甲亚砜＞四甘醇＞N-甲酰吗啉，三种溶剂中二甲亚砜同时具有较高的溶解能力和选择性，较适合萃取偏三甲苯-正辛烷的混合溶液。研究结果可以为溶剂抽提过程相平衡数据库提供基础数据，并为重芳烃抽提的溶剂选择提供参考。     

Ionomer-silica hybrids via sol-gel reaction

Ionomer-silica hybrid materials were made from polyethylene-co-acrylic acid neutralized by a zinc salt (PI) and tetraethoxy silane (TEOS) via the sol-gel reaction. The effects of various experimental parameters such as solvents, H₂O/Si ratio and the amount of TEOS in the ionomer solution on the hybrid structure and properties were examined. The spectroscopic results show that solvents do not affect the structure of the hybrids, but influence the thermal properties. The hybrids made using highly polar solvent exhibit better thermal stability and dynamic mechanical properties at high TEOS contents. The amount of water used for hydrolysis and subsequent condensation play a significant role in the network formation. The varying amount of TEOS in solutions gives rise to different silica content of the hybrid. Above 50 wt%, the sample becomes opaque due to silica aggregation. The high ratio of H₂O/Si leads to phase separation during the reaction. Transparent hybrid materials can only be obtained when the ratio of H₂O/Si is below 5.     

Treatment of Groundwater Contaminated with 1,4-Dioxane,Tetrahydrofuran, and Chlorinated Volatile Organic Compounds Using Advanced Oxidation Processes

Ozonation and four types of advanced oxidation processes, including O₃/H₂O₂, O₃/UV, O₃/H₂O₂/UV, and UV/H₂O₂, were evaluated for the treatment of contaminated groundwater at a Superfund site in Simpsonville, South Carolina using bench-scale, batch ozone and UV apparatuses. Although the contaminants of concern were 1,4-dioxane, 1,1-dichloroethene, and trichloroethene, several other chlorinated organics as well as tetrahydrofuran were found in the groundwater samples. The O₃/H₂O₂ treatment with O₃ and H₂O₂ doses of 6 and 1.5 mg/L, respectively, and the UV/H₂O₂ treatment with UV and H₂O₂ doses of 1,000 mJ/cm and 20 mg/L, respectively, were sufficient to degrade 200 µg/L of 1,4-dioxane, 110 µg/L of 1,1-dichloroethene, and 10 µg/L of trichloroethene below their performance standards of 10, 7, and 4 µg/L, respectively. Due to a high bromide concentration (0.35 mg/L) in the groundwater sample, bromate formation was found to be significant in ozone-based treatment, including O₃/H₂O₂.     

A Modified Indigo Method for the Determination of Ozone in Nonaqueous Solvents

The indigo method for the analysis of aqueous ozone was modified to allow analysis of dissolved ozone in nonaqueous liquid phases. The method was tested using the solvent decamethylcyclopentasiloxane 245 and a vegetable oil. The molar absorptivity at 600 nm of the indigo trisulphonate molecule was re-checked and found to be 20,069 ± 412 L mol^?1 cm^?1 which is in agreement with the generally accepted value. Linear correlation between liquid phase and gas phase ozone concentrations confirmed that ozone solubility in decamethylcyclopentasiloxane 245 obeyed Henry's law with a constant of 1.71 ± 0.09 mg L^?1 per mg L^?1 in the gas phase. Ozone solubility in the vegetable oil followed a power law model with k = 0.148 and n = 0.767 (liquid and gas phase concentrations in mg L^?1). The stoichiometry of the reaction between ozone in the nonaqueous phase and indigo trisulfonate in acidic solution was also confirmed as being about one. Moreover, the reaction products were confirmed by chromatographic analysis. This method was found effective to analyze ozone in nonaqueous solvents with a lower limit of detection of 2.6 μg L^?1 and upper limit of detection of 142.7 mg L^?1.     

Precipitation of asphaltenes from solvent-diluted heavy oil and thermodynamic properties of solvent-diluted heavy oil solutions

Ratios of n-heptane (hep) to toluene (tol) affect the solubility of the asphaltenes in heavy oil extraction processes. Consequently phase changes and time after mixing n-heptane and heavy oil in toluene are important for understanding produced emulsions. The kinetics of phase change when n-heptane is added to toluene-diluted heavy oils, and the thermodynamic properties of partially deasphalted heavy oils were studied. The methods used were monitoring precipitation in time using light microscopy, quantitative asphaltenes analysis by near infrared spectroscopy, refractive index and densities measurements, and calculated solubility parameters of mixtures. At critical mass ratios of hep/tol from 1.37 to 2.0 in diluted heavy oil the precipitated asphaltene particles were observed under the microscope after lag times from 2 h to instantly. Lag times were longer at low initial oil concentration. The floc growth time decreased as heavy oil concentration in toluene increased. The growth patterns in time appeared as dots to beads (strings) to clusters (fractal-like flocs). Final wt% precipitated asphaltenes vs. mass fraction (hep+tol)/heavy oil followed sigmoidal relationships. Curves showing wt% soluble asphaltenes vs. mass fraction hep/tol after 24 h initially followed the same shape as time zero curves and diverged at the onset ratios of hep/tol. Slope for precipitated asphaltenes vs. solubility parameters curve showed a break at 16.4 MPa^1/2. Linear correlations were established for concentrations of soluble asphaltenes in residual oils and density, for refractive index and density and for refractive index and solubility parameter. The latter correlation was in accordance with Lorenz-Lorentz theory. These equations provided a means by which oil density, refractive index and solubility parameter can be predicted when these measurements are difficult to measure practically.     

SLP油层解堵剂的研究与应用

SLP油层解堵剂包括SLP-1和SLP-2两种药剂。本文对SLP-1和SLP-2的性能进行了评定,提出了SLP油层解堵剂的施工配方与施工工序,介绍了SLP的解堵机理与现场应用情况。SLP油层解堵剂可解除油层中BaSO_4、SrSO_4等酸难溶盐及高分子量有机物质的堵塞。     

颗粒粘结高燃速推进剂药柱中溶剂迁移的研究

研究了颗粒粘结高燃速固体推进剂药柱中粘结剂与小粒药之间的溶剂双向迁移现象，并利用计算机模拟估算了溶剂迁移量的大致范围。     

Cloud point behavior for poly(isodecyl methacrylate)+supercritical solvents+cosolvent and vapor-liquid behavior for CO<Subscript>2</Subscript>+isodecyl methacrylate systems at high pressure

Experimental cloud-point data of binary and ternary mixtures for poly(isodecyl methacrylate) [P(IDMA)] in supercritical carbon dioxide, dimethyl ether (DME), propane, propylene, butane and 1-butene have been studied experimentally using a high pressure variable volume view cell. These systems show the phase behavior at temperature of 308 K to 473 K and pressure up to 255 MPa. The cloud-point curves for the P(IDMA)+CO₂+isodecyl methacrylate (IDMA) are measured in changes of the pressure-temperature (P-T) slope, and with cosolvent concentrations of 0-60.1 wt%. Also, experimental data of phase behaviors for IDMA in supercritical carbon dioxide is obtained at temperature range of 313.2–393.2 K and pressure range of 5.8–22.03 MPa. The experimental results were modeled with the Peng-Robinson equation of state. The location of the P(IDMA)+CO₂ cloud-point curve shifts to lower temperatures and pressures when DME is added to P(IDMA)+CO₂ solution. The P(IDMA)+C₄ hydrocarbons cloud-point curves are ca. 16.0 MPa lower pressures than the P(IDMA)+C₃ hydrocarbons curves at constant temperature. This article is dedicated to Professor Chul Soo Lee in commemoration of his retirement from Department of Chemical and Biological Engineering of Korea University.