RSC Advances
·
2015
·Vol. 5
·期 47
·37697-37702
·
IF 3.84
Liuyi Yin,Yufeng Hu,Xianming Zhang,Jianguang Qi,Weiting Ma
Batch reaction experiments were performed to investigate the salt effect on the yield of trioxane in the reaction solution. The salts considered include NaHSO4, Na2SO4, NaH2PO4, Na2HPO4, KCl, NaCl, LiCl, ZnCl2, MgCl2, and FeCl3. The effects of the anionic structure and the cation charge density on the yield of trioxane in the reaction solution were elucidated and the mechanisms that govern such effects were established. It is shown that the first four salts exerted a negative effect on the yield of trioxane in the reaction solution and such an effect increased progressively from left to right. This trend is due to the formation of NaHSO4, H3PO4, or (H3PO4 and NaH2PO4), which decreased the concentration of H+ in the solution. The latter six salts showed a positive effect on the yield of trioxane in the reaction solution. The salt effect paralleled the ability of the salt to decrease the water activity of the reaction solution and followed the order KCl < NaCl < LiCl < ZnCl2 < MgCl2 < FeCl3. Continuous production experiments were performed to investigate the salt effect on the concentration of trioxane in the distillate. The salts considered were KCl, NaCl, LiCl, ZnCl2, MgCl2, and FeCl3, and the salt effect increased progressively from left to right. Such an effect was shown to be determined by the ability of the salt to increase the yield of trioxane in the reaction solution and to increase the relative volatilities of trioxane and water and of trioxane and oligomers.
研究领域:
化学工程
·
工业化学
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产品关联
DOI
高影响因子
FLUID PHASE EQUILIBRIA
·
2016
·
IF 1.846
Jianguang Qi,Yufeng Hu,Yue Gao,Weiting Ma,Shuqin Mo,Zhenyu Yang,Xianming Zhang,Liuyi Yin
Extraction was a key step in industrial process of trioxane . NaOH was utilized in industrial production of trioxane to maintain appropriate pH to prevent trioxane decomposition. Here efforts were made to investigate the salt effects that can produce an alkaline medium to prevent trioxane decomposition and, simultaneously, can induce salting-out effect to considerably increase the efficiency of extraction of trioxane from aqueous formaldehyde solutions. The salt considered included K 3 PO 4 , Na 3 PO 4 , sodium tartrate (Na 2 C 4 H 4 O 6 ) and sodium citrate (Na 3 C 6 H 5 O 7 ). The decomposition measurements were made for the (trioxane + formaldehyde + salt + H 2 O) solutions at 323.15 K for 96 h. No trioxane decomposition was detectable over the whole experimental time. Extraction measurements were made using each of the selected salts or NaOH as accelerant salt and benzene, dichlorobenzene or dimethylbenzene as extraction solvent . The results showed that both the extraction efficiency and the distribution coefficient were considerably increased and that such effects followed the order Na 3 PO 4 > K 3 PO 4 > Na 3 C 6 H 5 O 7 > Na 2 C 4 H 4 O 6 > NaOH. The results also showed that the effects of these salts on the water content in the organic phase and on the organic phase residual in the water phase were generally similar to or even more favorable than those of NaOH. The liquid−liquid phase equilibrium data were measured for the (trioxane + formaldehyde + K 3 PO 4 + H 2 O + benzene) solutions at (313.15, 323.15 and 333.15) K and were found to be well described by the Othmer−Toblas and the Hand equations.
研究领域:
化学工程
·
工业化学
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DOI
高影响因子
Food Analytical Methods
·
2017
·Vol. 10
·期 10
·3338-3349
·
IF 2.038
Tang Zhong-Sheng,Zeng Xin-An,Brennan Charles S.,Xie Wei-Qi
Fusel oils (FOs) are higher alcohols (including propanol, isobutanol, isoamylol, and active amyl alcohol), which affect the aroma profiles and flavor profiles of wine. A novel method for determination of FOs in lychee wine was developed using headspace gas chromatography (HS-GC). Results showed that 12% standard curve (SC) can be used to determinate the FOs of low alcoholic beverages, yet 40% SC can be used for high alcoholic beverages (e.g., brandy). Optimization of the parameters of equilibrium temperature at 50 °C was maintained for 30 min. The stabilized gas-liquid phase ratio of 3:1 for further research had no significant differences with others, which is caused by the distribution coefficient of K ≫ 100. The addition of sodium chloride (NaCl) decreased the partition coefficient of FOs markedly, and an inverse situation was observed for the extraction of FOs saturating at 1.25 g NaCl in 5 mL LW. Relative standard deviations (RSD) of reproducibility tests were in the range of 1.03–4.91%. Meanwhile, the mean recoveries of low, middle, and high concentration levels were 100.94, 103.2, and 96.74%, respectively. HS-GC was a stabilized, concise, and efficient method compared with the International Organization of Vine and Wine (OIV) method of OIV-MA-BS-14. These findings provide a foundation to determine higher alcohols of alcoholic beverages.
研究领域:
食品科学
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分析化学
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DOI
高影响因子
FLUID PHASE EQUILIBRIA
·
2019
·
IF 2.514
Xianming Zhang,Yufeng Hu,Weiting Ma,Jianguang Qi,Shuqin Mo
The salt effect on vapor–liquid phase equilibrium (VLE) has potential applications in industrial production of 1,3,5-trioxane. Optimizing reactive distillation process and developing new catalysts for industrial production of 1,3,5-trioxane require a reliable model for VLE of the reaction mixtures. Here an extended UNIFAC model combined a Debye–Hückel type is developed to describe the vapor–liquid and chemical equilibria of the multi-solvent salt-containing reactive mixtures associated with the 1,3,5-trioxane synthesis. New experimental data for the VLE of the quinary systems (formaldehyde + 1,3,5-trioxane + methanol + salt + water) and their ternary subsystems (1,3,5-trioxane + salt + water), (methanol + salt + water), and (formaldehyde + salt + water) are systematically measured at atmospheric pressure. The salts considered include LiCl, NaCl, KCl, NaBr, MgSO 4 , MgCl 2 , and Na 2 SO 4 . The model parameters, which are either obtained from the literature or determined from the VLE data of the above-mentioned ternary systems , are used to provide predictions for the quinary systems (formaldehyde + 1,3,5-trioxane + methanol + salt + water). The agreements between measured and predicted results are accurate. Furthermore, the model is used to uncover the effects of the salts considered on the VLE of these chemical reactive systems. The results show that MgSO 4 is a potential additive that can be used to improve the vapor–liquid phase separation during the reactive distillation process of 1,3,5-trioxane production.
研究领域:
化学工程
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物理化学
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DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2021
·
IF 2.694
Xiaoyu Wang,Jiale Wang,Lijun Ji,Bin Wu,Kui Chen,Yanyang Wu
Wastewater containing DMF (N,N-dimethylformamide) and salt is generated in production of many chemicals and medicines. The composition of phase equilibrium should be known primarily for the recovery of DMF from salt-containing wastewater by solvent extraction. In this study, liquid–liquid equilibrium (LLE) and solubility data of water + DMF + chloroform in the presence of NaCl with various concentrations of 0, 2.5, 5.0, 7.5, 10.0, and 13.3 wt % and Na2SO4 with concentrations of 1.5 and 2.5 wt % were determined at T = 298.2 K and atmospheric pressure. Besides, the salt effect on the LLE data was investigated. Compared with the salt-free system, the salt led to an enhancement in the maximum DMF distribution coefficient by 13.4–102.6% for 2.5–13.3 wt % NaCl and 16.2–31.7% for 1.5–2.5 wt % Na2SO4, respectively. Since the distribution coefficient of water increased concurrently, the separation factor barely changed and the two-phase region expanded outward slightly. At the same salt mass fraction, the order of salting-out effect strength on extraction was Na2SO4 > NaCl, which was in good agreement with the Hofmeister series. The reliability of the experimental values was verified through the Eisen–Joffe equation. The NRTL thermodynamic model was applied to correlate the experimental data with a root-mean-square deviation less than 0.0062. The coherent consistency of the model parameters for the salt-free system was checked by topological analysis based on the Gibbs tangent plane test.
研究领域:
化学工程
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环境科学
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Shaoping Feng,Kun Huang
Specific ion effects are known to influence the interfacial behavior of ions in the aqueous phase and thus affect their extraction and separation. There are many studies on enhanced extraction and separation of the target ions based on the specific ion effects. A microscopic level understanding of the competitive mass transfer and selectivity of ions at the interface between heterogeneous phases is crucial importance for the precise control of numerous chemical reaction and separation processes. The conventional salt effect (i.e., background coexisting ions promoting the mass transfer of the target ions) are only observed at higher coexisting ion concentrations. However, the present work reveals an interesting phenomenon: the adsorption enrichment and competitive hydration of coexisting salt cations at the liquid–liquid interface can significantly influence the mass transfer rate of the target rare earth ions in the near-interface boundary layer. Notably, such a distinct interfacial salt effect can promote the separation between coexisting and target ions at lower coexisting ion concentrations, and it cannot be explained by the traditional theory for the salt effect. A thin-layer organic oil film extraction system was employed here as a simplified model experiment to investigate this new interfacial salt effect on the non-equilibrium extraction and separation of target rare earth ions. The results demonstrated that the diffusion rate of the target ions (Er 3+ ) is subject to the local concentration gradient of coexisting salt cations (Mg 2+ ) in the near-interface boundary layer. At the lower bulk concentrations, the Mg 2+ ions enriched at the interface would compete for water molecules around the hydration shell of target Er 3+ ions, resulting in the dehydration of Er 3+ ions. Therefore, an enhanced diffusion rate of Er 3+ ions and their adsorption affinity towards the interface were observed. However, at a higher bulk concentration of Mg 2+ ions, the diffusion resistance of Er 3+ ions increased due to the competitive adsorption and hydration of Mg 2+ ions at the interface. The thickness of the organic oil film layer also plays an important role in the diffusion of Er 3+ ions. In particular, a thinner oil layer makes it easier to perceive the interfacial salt effect, which enhances the separation between Er 3+ and Mg 2+ compared to the case of a thicker oil layer. A quantitative correlation between the diffusion rate of Er 3+ ions and the concentration of coexisting Mg 2+ ions was established to describe the interfacial salt effect. This work highlights the microscopic nature of the salt effect induced by the competitive adsorption kinetics of coexisting ions in the near-interface boundary layer on promoting the extraction and separation of target metal ions. The results will help the development of new approaches to control the separation selectivity and enhance the mass transfer of target metal ions in practical applications.
研究领域:
化学工程
·
物理化学
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产品关联
DOI
高影响因子
JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY
·
2019
·
IF 1.479
Kaihe Lv,Kaile Jia,Yuping Yang,Wenjian Huang,Hongyan Wu,Wei Pan,Han Jia
Zwitterionic gemini surfactants, which have the advantages of both zwitterionic and gemini surfactants, have been widely used in various disciplines. Sulfobetaine-type zwitterionic gemini surfactants consisting of 1,2-bis[N-methyl-N-(3-sulfopropyl)-alkylammonium]ethane (2CnSb with 6, 8 and 10 carbon atoms) were evaluated for their interfacial activities at the water/crude oil interface. The 2C10Sb molecules showed a remarkable ability to decrease the interface tension (IFT) of water/crude oil, and the degree of decrease was much greater than those in either zwitterionic or gemini surfactant systems by at least two orders of magnitude. Furthermore, the effects of salts (NaCl, CaCl2, and MgCl2) on the IFT of the 2C10Sb system were thoroughly investigated. Interestingly, the delicate balance between the effects of additional cations and the intramolecular interactions of 2C10Sb molecules played crucial roles in the interfacial arrangements of 2C10Sb molecules, which were mainly dependent on the bonding abilities of the cations. Moreover, a zwitterionic surfactant and a cationic gemini surfactant were employed in control experiments to verify the proposed mechanisms.
研究领域:
化学工程
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石油科学
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界面科学
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产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2019
·
IF 2.298
Yang Liu,Yan Wang,Wangfeng Cai
In this work, the salting effect of sodium hydroxide (NaOH) and sodium formate (HCOONa) on the liquid–liquid equilibrium (LLE) of polyoxymethylene dimethyl ethers (DMMn) in aqueous solution was studied. The LLE data of the systems (DMM1 + water) and (DMM2 + water) and the system (DMM1 + water + DMM2) under different concentrations of NaOH and HCOONa at 293.15 and 308.15 K were measured. According to the verification with the Marcilla-modified Eisen–Joffe equation, the experimental data has a good consistency. Distribution coefficients were calculated and compared, and the results showed that NaOH and HCOONa have a significant salting-out effect on DMMn and water separation. Based on the experimental LLE data, the original nonrandom two liquid (NRTL) and the electrolyte NRTL activity coefficient models were correlated by the maximum-likelihood principle, which showed that the electrolyte NRTL model was more appropriate. The experimental data and the binary interaction parameters could provide a useful reference for DMMn product reaction extraction before rectification.
研究领域:
化学工程
·
物理化学
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产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2022
·
IF 6.633
Bingying Wang,Zaisheng Zhu,Jiayu Yin,Xiaoxing Lu
The intensive use of ionic liquid (IL) in various researches and applications induces the imperative need of specific functional ILs. Present work introduces a novel piperazinium-based surface-active IL (SAIL) which shows great potential for the preparation of microemulsion (ME), namely 1-(2-hydroxyethyl)piperazinium laurate ([HEP][C 11 CO 2 ]). Important fundamental physicochemical properties have been investigated, revealing higher surface activity for the SAIL than common surfactants. [HEP][C 11 CO 2 ] is able to solubilize different oil components and water with short-chain alcohol as cosurfactant, forming stable ME in a wide range of ratio of water to oil, and a broad microemulsion region covering over 50 % of the pseudo-ternary phase diagram can be found. The structural transition of water-in-oil to bicontinuous occurs at the water content of 0.60 to 0.65 for the SAIL/1-butanol/ n -heptane/water systems at the ratios of SAIL to 1-butanol of 1:1 and 1:2, as confirmed by electrical conductivity measurements. Moreover, the solubilization of oil and water was investigated in the presence of NaCl, KCl or MgCl 2 , and the optimal salinity was determined. While Mg 2+ induces formation of emulsion probably due to the poor solubility of Mg 2+ /[C 11 CO 2 ] − complexes, the ME system is much more stable with the presence of monovalent ions like Na + and K + . For the NaCl-contained system, the salinity window of the bicontinuous phase changes from 0.030 to 0.025 and 0.020 when the temperature rises from 15 °C to 25 °C and 35 °C, which mainly results from the enhanced hydrophobic interactions and the weakened electrostatic interactions. Present studies elucidate that [HEP][C 11 CO 2 ] is feasible to form various microemulsion systems which may have extensive potential in further applications like size-controlled syntheses and oil recovery.
研究领域:
化学
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材料科学
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DOI
高影响因子
JOURNAL OF SOLUTION CHEMISTRY
·
2015
·Vol. 44
·期 6
·1163-1176
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IF 1.177
Long Jian,Tian Senlin,Li Guang,Li Lin
For the purpose of studying the potential of a novel nonionic switchable surfactant, 11-ferrocenylundecyl polyoxyethylene ether (FPEG), applied to surfactant-enhanced remediation (SER), the surface properties and micelle solubilization behavior of FPEG were investigated with different inorganic salts. With the addition of inorganic salts (NaCl and CaCl 2 ), the critical micelle concentration (CMC) of FPEG dropped from 15 to 12 and 8 mg·L −1 , respectively, due to the salting-out effect on the alkyl chain. Thermodynamic parameters based on the CMCs indicated that micelle formation was an entropy-driven process. Dynamic light scattering measurements verified that these inorganic salts can decrease the hydrodynamic diameters ( D
h ) of the micelles. Solubilization experiments with three typical polycyclic aromatic hydrocarbons (PAHs) demonstrated that the system of FPEG with NaCl shows the highest solubilization ability, and the molar solubilization ratio and micelle–water partition coefficient ( K
m
) values follow the order pyrene > phenanthrene > acenaphthene. After oxidation, PAHs can be released from the micelles through breaking up of the micelles, and the cumulative release efficiency of pyrene, phenanthrene and acenaphthene are 31.2, 42.8 and 44.6 %; the order of release efficiency is opposite to that of the reduced form for solubilization abilities. All the results suggest that the ferrocene-containing, redox-active surfactant FPEG has the potential to be recycled in SER technology through electrochemistry approaches.
研究领域:
环境化学
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胶体与界面科学
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电化学
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污染物修复
·
功能材料
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2024
·
IF 5.3
Li Zhang,Kun Yan,Qianqian Hou,Bin Zheng,Jinlei Wang,Lianli Wang,Lei Wang
Aqueous foams are widely used in many fields and ionic surfactants are commonly used foaming agent. However, potential trouble may arise when they are used in hard water or at low temperatures. The anionic surfactants like sodium dodecyl sulfate (SDS) may precipitate to form crystals when the concentration of counterions such as K + and Ca 2+ exceeds a certain limit. In this paper, an attempt has been made to study the effect of surfactant crystals on the properties of aqueous foams by adding the inorganic salts KCl and CaCl 2 to SDS. The results showed that the stability of the CaCl 2 -SDS system was better than that of the KCl-SDS in the range of surfactant concentrations that produced crystalline precipitates. The straight line separated the stable and unstable foam regions with an equation of [KCl] = 0.6 [SDS] + 25 mM and [CaCl 2 ] = 0.5 [SDS] − 30 mM, suggesting that smaller concentrations of CaCl 2 are needed to prepare stable foams compared to KCl. The effect of crystal size on the properties of foams was investigated by ultrasonication, and it was found that changing the crystal size only changed the foaming properties of foams, and had almost no effect on the stability. A two-phase molecular dynamics model at the foam interface was constructed to study the effects of different metal ion valences on the stability of surfactant foam. The results showed that the metal ion Ca 2+ inhibited the diffusion of water in the foam wall more than K + and the binding ability between Ca 2+ - DS - head-groups are stronger than that of K + − DS - , thus the stability of the foam liquid film obtained in CaCl 2 -containing solution is better.
研究领域:
化学工程
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材料科学
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DOI
高影响因子
COLLOID AND POLYMER SCIENCE
·
2016
·Vol. 295
·期 2
·327-340
·
IF 1.89
Guo Yi,Dong Xiuyan,Ruan Wenjing,Shang Yazhuo,Liu Honglai
The interactions between poly(2-(2-methoxyethoxy)ethyl methacrylate 90 -co-oligo(ethylene glycol) methacrylate 10 ) (P(MEO 2 MA 90 -co-OEGMA 10 )) and sodium dodecyl sulfate (SDS) or dodecyltrimethyl ammonium bromide (DTAB) in aqueous solutions with and without salt are explored. The influence rule of surfactant on thermo-sensitive behavior of polymer and the corresponding mechanism is revealed. The results have suggested that both surfactants have moderate interactions with P(MEO 2 MA 90 -co-OEGMA 10 ), which result in the formation of P(MEO 2 MA 90 -co-OEGMA 10 )/surfactant complexes. Meanwhile, the self-aggregation of polymer chains is hindered causing the lower critical solution temperatures (LCSTs) increase due to the electrostatic repulsion and “locking water” effect caused by surfactant head groups. Tetra-n-butylammonium bromide (Bu 4 NBr) and tetra-n-propylammonium bromide (Pr 4 NBr) can associate with SDS and form mixed micelles. Interestingly, the formed mixed micelles apt to attach on the polymer chain and the polymer-bound necklace-like structure forms in the ternary polymer/salt/surfactant system. The structure of the complexes formed in the ternary system is confirmed by 2D NOESY NMR and the interaction mode is proposed. The relations between LCST of different systems and surfactant concentrations are also established quantitatively.
研究领域:
高分子化学
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物理化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）