RSC Advances
·
2016
·Vol. 6
·期 109
·108028-108033
·
IF 3.289
Yu-Ling Liu,Zhongxia Wang,Xiang-Bin Han,Yu-Ling Sun,Donald E. Pryor
A new thiourea-based supramolecular compound (TA)[(TU)2Cl] (1, TA = thiazolium, TU = thiourea) has been successfully synthesized and systematically characterized, including differential scanning calorimetry (DSC), variable-temperature structural analysis and dielectric measurements. 1 undergoes a structural phase transition at 213.7 K (Tc), accompanied by distinct switchable dielectric anomalies. The TA cation is disordered over four equivalent positions above the Tc and becomes less-disordered over the two equivalent positions below the Tc. The structural relative disorder-order transition of the TA cation contributes to the switching of the dielectric constant between high- and low-dielectric states. Supramolecular inclusion compounds designed with dynamic components have been proved to be a good strategy for searching for new phase transition and switchable dielectric materials.
研究领域:
材料科学
·
晶体学
✓ 已验证
DOI
高影响因子
SEPARATION SCIENCE AND TECHNOLOGY
·
2012
·
IF 1.088
Xiaochun Chen,Ge Liu,Shan Yuan,Charles Asumana,Wenbo Wang,Guangren Yu
A new class of green solvents, known as ionic liquids (ILs), has recently been the subject of intensive research on the extractive desulfurization of fuel oils because of the limitation of the traditional hydrodesulfurization method in catalytically removing thiophenic sulfur compounds. In this work, four thiazolium-based ILs, that is, 3-butyl-4-methylthiazolium dicyanamide ([BMTH][DCA]), 3-butyl-4-methylthiazolium thiocyanate ([BMTH][SCN]), 3-butyl-4-methylthiazolium hexafluorophosphate ([BMTH][PF6]), and 3-butyl-4-methylthiazolium tetrafluoroborate ([BMTH][BF4]), are synthesized. The extractive capability of these ILs in removing thiophene (TS) and dibenzothiophene (DBT) from model fuel oils is investigated. [BMTH][DCA] and [BMTH][SCN] present better extractive desulfurization capability than [BMTH][BF4] and [BMTH][PF6], which may be ascribed to the additional π−π interaction between –C≡N (in [BMTH][DCA] and [BMTH][SCN]) and thiophenic ring (in TS and DBT); DBT in diesel fuel is more efficiently extracted than TS in gasoline. [BMTH][DCA] offers the best desulfurization results, where 64% and 45% sulfur removal are obtained for DBT and TS, respectively, at IL:oil mass ratio of 1:1, 25°C, 20 min. [BMTH][DCA] is thus selected to systematically investigate the effects of temperature, IL:oil mass ratio, initial sulfur content, multiple-extraction, and IL regeneration on desulfurization. The mutual solubility of [BMTH][DCA] with fuel oil is also determined. It is observed that the desulfurization capability is not too sensitive to temperature and initial sulfur content, which is desired in industrial application; the sulfur contents in gasoline and diesel fuel are reduced from 558 ppm to 20 ppm (after 5 cycles) and from 547 ppm to 8 ppm (after 4 cycles), respectively. This work may show a new option for deep desulfurization of fuel oils.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 80
·76707-76715
·
IF 3.289
Bing Yan,Hongjun Zang,Yi Jiang,Songbai Yu,Eugene Y.-X. Chen
Six Na+/montmorillonite (MMT) – supported thiazolium (TM) ionic liquids (ILs), MMT–[TM], which are precatalysts to N-heterocyclic carbene (NHC) catalysts, have been synthesized and employed to catalyze the highly selective condensation of furfural (FF) and 5-hydroxymethylfurfural (HMF) into C10 and C12 furoins, respectively. Among them, five supported [TM] salts carrying the electron-donating group exhibit excellent catalytic activity. Thus, supported NHC catalysts, generated in situ from activation of MMT–[TM] with Et3N, afford C10 and C12 furoins in 97–99% and 97–98% yield, respectively. This condensation reaction is also carried out under solvent-free conditions, and the catalysts can be readily recycled, showing no noticeable loss in their catalytic activity over four consecutive recycles. Thus, these desired features possessed by the current catalyst system have enabled the development of the greener and more environmentally benign process for the upgrading of FF and HMF.
研究领域:
化学工程
·
绿色化学
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2014
·
IF 0.872
Zhijian HE,Xiaomin WANG,Tian YAO,Hang SONG,Shun YAO
Four novel benzothiazolium ionic liquids with PF − 6 ([C 1 Bth][PF 6 ], [C 4 Bth][PF 6 ], [C 5 Bth][PF 6 ] and [C 6 Bth][PF 6 ]) were synthesized, and the rang of their melting points were determined between 358.35 K–424.05 K. The relationship of their melting points and the length of the straight alkyl chain on cation reflected ‘S’ type tendency. Then, the solubilities of the four ionic liquids in six lower alcohols (methanol, ethanol, 1-propanol, 2-propanol, 1-butanol and 2-methyl-1-propanol) were measured in the temperature rang of 253.15–383.15 K at atmospheric pressure with static analytical method, respectively. It was found that [C 6 Bth][PF 6 ] in all investigated ionic liquids had the largest solubility in six alcohols and the solubility of [C 4 Bth][PF 6 ] in methanol was very sensitive for temperature in 313.15–333.15 K, which was so-called “temperature-sensitivity”. This feature is of great significance to their application of catalyzing reaction or extraction process, and makes the recovery and reuse of ionic liquids (ILs) become easier. Moreover, the experimental solubility data were correlated with the modified Apelblat equation and λ h equation, respectively. It was found that the result of correlation using two divided temperature ranges was better than that of using the whole temperature range.
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2021
·
IF 6.986
Lijun Ma,Shu Yang,Yufan Ma,Yuzhi Chen,Zhenguo Wang,Tony D. James,Xuefei Wang,Zhuo Wang
Alzheimer’s disease (AD) is a neurodegenerative disease, and β-amyloid (Aβ) is believed to be a causative factor in AD pathology. The abnormal deposition of Aβ is believed to be responsible for progression of AD. In order to facilitate the imaging of Aβ in vivo, suitable probe molecules with a near-infrared emission wavelength that can penetrate the blood–brain barrier (BBB) were utilized. The commercial fluorescent probe thioflavin-T (ThT) is used to image Aβ; however, because of its short emission wavelength and poor BBB penetration, ThT can only be used in vitro. With this research, based on ThT, we design three fluorescent probes (SZIs) having a longer emission wavelength in order to image Aβ aggregates. SZIs with different numbers of double bonds respond to Aβ aggregates. The SZIs have a structure similar to ThT, and as such, the SZIs are also unable to penetrate the BBB. To deal with the problem, we develop nanocomposites (MSN-Lf@SZIs) to deliver SZIs into the brain of AD mouse and image Aβ successfully. These new nanocomposites are able to deliver the dyes into the brain and facilitate Aβ imaging in vivo.
研究领域:
神经科学
·
纳米技术
·
生物医学工程
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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