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101.
Pervaporation is promising in the separation of benzene/cyclohexane mixture for the petrochemical industry. Two kinds of pervaporation membrane materials, including PEA‐based polyurethaneurea (PUU) and polyurethaneimide (PUI), were successfully synthesized from the same soft segment of poly(ethylene adipate)diol (PEA) and different hard segments via a two‐step method. The hard segment of PUU was prepared from toluene diisocyanate (TDI) and 4,4′‐diaminodiphenyl methane (MDA), while that of PUI was from 4,4′‐methylene‐bis(phenylisocyanate) (MDI) and pyromellitic dianhydride (PMDA). The structures and properties of PUU and PUI were characterized by means of FT‐IR, DSC and TGA. During the pervaporation experiment, the PUI membranes had a flux of 12.13 kg µm m?2 h?1 and separation factor of 8.25, while the PUU membranes had a flux of 26.35 kg µm m?2 h?1 and separation factor of 6.29 for 50 wt% benzene in the benzene/cyclohexane mixture at 40°C. The effects of the structures of hard segments on pervaporation performances were discussed. The investigation of the relationship in molecular structure and PV performances will be helpful for the choice and design of membrane materials in the separation of benzene/cyclohexane mixture. 相似文献
102.
The main objective of this study is to provide an insight into the interactions involved during adsorption of the alcohols on β-CD composite nanostructured membrane. Interactions between β-cyclodextrin (β-CD) and alcohols (methanol, ethanol and butanol) are studied using the QM/MM method. Magnitude of interaction energies show that the alcohols are adsorbed on the membrane. In addition, the thermochemical analysis suggests that the formation of these host-guest complexes is enthalpy driven. 相似文献
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An ultrasonic-assisted separation of alkali chloride (LiCl, NaCl, and KCl) salts have been carried out using of an hydrophobic ionic liquid membrane (ILM). The ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate and tributyl phosphate mixture have been used as ILM. An ultrasonic probe with different frequencies (25, 100, and 250) kHz have been applied as source of ultrasound generator with different times of sonication (2, 5, and 10) min in three phases system containing feed, ILM, and receiver in osmotic U-shaped tube. Also, 250, 500, and 1000 ppm of the feed (alkali chloride) concentration have been used to separate. The frequency of 250 kHz with higher sonication time provides optimum condition for separation of LiCl with lower feed concentration. The thermodynamic properties such as density and speed of sound and the related thermodynamic properties have been calculated to optimize ILM composition (xIL = 0.45) for ultrasound-separation. 相似文献
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Dr. Muhammad Ehsan Dr. Yang Du Jonas S. Mortensen Dr. Parameswaran Hariharan Qianhui Qu Lubna Ghani Dr. Manabendra Das Anne Grethen Prof. Bernadette Byrne Prof. Georgios Skiniotis Prof. Sandro Keller Prof. Claus J. Loland Prof. Lan Guan Prof. Brian K. Kobilka Prof. Pil Seok Chae 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(49):11545-11554
Amphipathic agents are widely used in various fields including biomedical sciences. Micelle-forming detergents are particularly useful for in vitro membrane-protein characterization. As many conventional detergents are limited in their ability to stabilize membrane proteins, it is necessary to develop novel detergents to facilitate membrane-protein research. In the current study, we developed novel trimaltoside detergents with an alkyl pendant-bearing terphenyl unit as a hydrophobic group, designated terphenyl-cored maltosides (TPMs). We found that the geometry of the detergent hydrophobic group substantially impacts detergent self-assembly behavior, as well as detergent efficacy for membrane-protein stabilization. TPM-Vs, with a bent terphenyl group, were superior to the linear counterparts (TPM-Ls) at stabilizing multiple membrane proteins. The favorable protein stabilization efficacy of these bent TPMs is likely associated with a binding mode with membrane proteins distinct from conventional detergents and facial amphiphiles. When compared to n-dodecyl-β-d -maltoside (DDM), most TPMs were superior or comparable to this gold standard detergent at stabilizing membrane proteins. Notably, TPM-L3 was particularly effective at stabilizing the human β2 adrenergic receptor (β2AR), a G-protein coupled receptor, and its complex with Gs protein. Thus, the current study not only provides novel detergent tools that are useful for membrane-protein study, but also suggests a critical role for detergent hydrophobic group geometry in governing detergent efficacy. 相似文献
108.
Yanni Lv Xianpeng Shi Jia Fu Qianqian Jia Yuanyuan Lin Hongying Wang Xin Yang Shengli Han 《Biomedical chromatography : BMC》2019,33(9)
Marsdenia tenacissima, or Tongguanteng in Chinese, is a traditional Chinese herb and has a broad application in clinical practice for its pharmacological effects of treating asthma, pneumonia, tonsillitis, pharyngitis tumors, etc. However, few studies have reported the screening of the active components of this medicine for tumor therapy. In this work, a two‐dimensional analytical system was developed to screen antagonists of epidermal growth factor receptor (EGFR) from M. tenacissima. A fraction was retained on the EGFR cell membrane chromatography (CMC) column, separated and identified as tenacissoside G (TG), tenacissoside H (TH) and tenacissoside I (TI) by two‐dimensional HPLC–IT–TOF–MS. Molecular docking and 3‐(4,5‐dimethyl‐2‐thiazolyl)‐2,5‐diphenyl‐2‐H‐tetrazolium bromide (MTT) assay were carried out to assess the activity of TS (including TG, TH and TI). Molecular docking results showed that the binding mode of TS on EGFR is similar to that of gefitinib. The MTT assay demonstrated that gefitinib and TS (especially TI) could inhibit the growth of EGFR highly expressed cell lines in a dose‐dependent manner in the range of 5–50 μmol/L. In conclusion, the two‐dimensional EGFR/CMC–HPLC–IT–TOF–MS system could be a useful approach in drug discovery from traditional Chinese medicines for searching for potential antitumor candidates. 相似文献
109.
以聚苯醚(PPO)为基体材料, 通过溴甲基化及咪唑基团功能化, 与聚四氟乙烯(PTFE)复合、 硅氧烷基团水解交联及磷酸掺杂, 制备了兼具高磷酸掺杂含量、 高质子电导率和良好机械性能的高温质子交换膜材料. 以甲基咪唑(MeIm)和咪唑基硅氧烷化合物(SiIm)为功能化试剂(其中咪唑基团提供了磷酸作用位点, 同时SiIm中的硅氧烷基团水解后得到Si—O—Si交联网络结构), 提高了膜材料的机械稳定性. 与PTFE的复合进一步增强了膜材料的机械强度. 结果表明, 复合膜具有较高的电导率和一定的机械强度. 当磷酸掺杂质量分数为242.5%时, PPO-50%SiIm-50%MeIm/PTFE复合膜在160 ℃不加湿条件下的电导率为0.09 S/cm, 室温下的断裂拉伸强度为3.6 MPa. 相似文献
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