非常规介质强化清洁过程——离子液体Z键、团簇及过程创新

化工和冶金是国民经济发展的支柱产业,也是典型的高能耗行业,其能耗约占全国工业总能耗的一半,导致这一问题的主要原因之一是反应过程效率低,能耗高。开发源头创新的新反应和新工艺是节能降耗的有效途径。离子液体作为一类非常规绿色介质,其特殊的结构及性能为创建高效节能工艺提供了新方向。在原子/分子尺度,原创性提出了"Z-键"新概念,深化了对离子液体科学本质的认识[4-5];可望从氢键、Z键及其网络结构的新视角,深入揭示纤维素溶解、乙二醇反应、气体捕集分离等新工艺的微观机理[1-3]。在纳微尺度,研究离子液体团簇结构/界面的形成机理和调控机制,可为离子液体介质反应器中传递/反应过程强化提供理论指导。在宏观尺..

介孔SiO_2/Al_2O_3固体酸催化γ-戊内酯脱羰基制备丁烯

采用溶胶-凝胶法合成了介孔SiO2/Al2O3催化剂,用于γ-戊内酯脱羰基制丁烯,对催化剂进行了表征,考察了反应条件对丁烯生成的影响,并分析了γ-戊内酯脱羰基制丁烯的反应机理.结果表明,SiO2/Al2O3的平均吸附孔径为6.8768 nm,BET比表面积达398.4 m2/g,催化剂表面存在Lewis和Br?nsted酸位;在350℃、催化剂用量为γ-戊内酯量的5%(ω)、反应4 h的条件下,γ-戊内酯的转化率在99%以上,丁烯产率最高达97%;反应机理为,在SiO2/Al2O3作用下,γ-戊内酯先开环生成戊烯酸,戊烯酸发生α和β碳裂解生成丁烯和CO2

介孔SiO_2/Al_2O_3固体酸催化γ-戊内酯脱羰基制备丁烯

采用溶胶-凝胶法合成了介孔SiO2/Al2O3催化剂,用于γ-戊内酯脱羰基制丁烯,对催化剂进行了表征,考察了反应条件对丁烯生成的影响,并分析了γ-戊内酯脱羰基制丁烯的反应机理.结果表明,SiO2/Al2O3的平均吸附孔径为6.8768 nm,BET比表面积达398.4 m2/g,催化剂表面存在Lewis和Br?nsted酸位;在350℃、催化剂用量为γ-戊内酯量的5%(ω)、反应4 h的条件下,γ-戊内酯的转化率在99%以上,丁烯产率最高达97%;反应机理为,在SiO2/Al2O3作用下,γ-戊内酯先开环生成戊烯酸,戊烯酸发生α和β碳裂解生成丁烯和CO2

介孔SiO_2/Al_2O_3固体酸催化γ-戊内酯脱羰基制备丁烯

采用溶胶-凝胶法合成了介孔SiO2/Al2O3催化剂,用于γ-戊内酯脱羰基制丁烯,对催化剂进行了表征,考察了反应条件对丁烯生成的影响,并分析了γ-戊内酯脱羰基制丁烯的反应机理.结果表明,SiO2/Al2O3的平均吸附孔径为6.8768 nm,BET比表面积达398.4 m2/g,催化剂表面存在Lewis和Br?nsted酸位;在350℃、催化剂用量为γ-戊内酯量的5%(ω)、反应4 h的条件下,γ-戊内酯的转化率在99%以上,丁烯产率最高达97%;反应机理为,在SiO2/Al2O3作用下,γ-戊内酯先开环生成戊烯酸,戊烯酸发生α和β碳裂解生成丁烯和CO2

二元离子液体强化秸秆预处理

为了提高生物质秸秆的溶解率、优化秸秆组分再分布,采用1-丁基-3-甲基咪唑氯盐([Bmim]Cl)和1-乙基-3-甲基咪唑醋酸盐([Emim][OAc])的二元离子液体混合体系,考察溶剂组成、反应温度和处理时间三因素对预处理的影响。结果表明,随着[Bmim]Cl在二元离子液体中摩尔比的升高,秸秆溶解率呈先上升后下降的趋势;纤维素在处理后秸秆中所占比例也遵循此规律。随着温度升高,溶解率逐渐增加,当温度超过100℃时,二元离子液体溶解液的黏度发生突变,秸秆发生变性;此外,随着处理时间的延长,溶解率逐渐升高,但是超过3h以后,溶解效果提升并不明显。综合各因素作用效果,确定最佳反应温度为90℃,最佳处理时间3h。在此条件下,秸秆的溶解率达到46.53%,经处理后秸秆中纤维素比例达到55.77%

UPLC-HRMSⁿ 结合高能诱导裂解快速鉴定麦冬中高异黄酮类成分

应用UPLC-LTQ-Orbitrap法快速鉴定麦冬药材中高异黄酮类化合物,考察不同高能诱导裂解(HCD)能量下高异黄酮的裂解情况,优选特征碎片离子对进行鉴定,并探索麦冬中高异黄酮类成分的裂解规律。应用该方法在麦冬提取物中鉴定出68个高异黄酮类成分,其中包括26个高异黄酮成分,31个高异黄烷酮成分,11个高异黄酮糖苷类成分。结果表明,HCD模式能够提供丰富稳定的裂解碎片离子信息,结合UPLC-LTQ-Orbitrap技术能够快速准确地鉴定复杂组分中高异黄酮类成分,可为中药系列成分研究提供有价值的方法参考。Radix Ophiopogon,a kind of traditional Chinese medicine,is the root of Liliaceae Ophiopogon japonicus(Thunb.)Ker Gaw l.Modern research demonstrates that Ophiopogon japonicas can be used as a folk food medicine in free radical scavenging,reducing blood sugar,sedative hypnotic and anti-myocardial ischemia and arrhythmia,and so on.The major chemical compounds of this plant are mainly homoisoflavonoids,steroidal saponins and polysaccharides. According to the relevant reports,thehomoisoflavonoids is a kind of specific compounds in Ophiopogon japonicus.However,due to the large number of different types of homoisoflavonoids in the herbal medicine,the structures are too similar to be distinguished from each other.Meanwhile,the differences of their relative contents in Ophiopogon japonicas are great.In this paper,the rapid separation ability of UPLC-LTQ-Orbitrap and the higher energy collision induced dissociation mode(HCD mode)were used to acquire high resolution fragment ion information and studied on the fragmentation patterns of homoisoflavonoids.The chromatographic separation of Ophiopogon japonicus extract was used Waters Acuqity UPLCTMBEH C18 column,mobile phase was 0.05%formic acid in water and acetonitrile system,and the chromatographic conditions for the rapid separation were optimized.To avoid interference with other components and obtain the tandem mass spectrometry high content and low content data,a method based on parent ions detection list in the negative ion mode detection was established.Furthermore,the established method was helpful in investigating the dissociation pathways of homoisoflavonoids in different HCD cleavage energy and confirming the characteristic fragment ions for the identification.Meanwhile,68 constituents attributed to homoisoflavonoids in Ophiopogon japonicas are finally identified,including 26 homoisoflavonoids,31homoisoflavanones,and 11 homoisoflavonoids glycosides.The results indicate that the HCD model can provide abundant and stable information of fragment ions,which can be adopted to quickly and accurately clarify the homoisoflavonoids in complex system.This study can provide an effective analytical method to explore the material basis of sequential constituents in traditional Chinese medicines