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1.
在半导体工业中,从四甲基硅烷(TMS)/异戊烷混合物中高效捕获异戊烷从而获得超高纯度的TMS是非常重要的。在本工作中,我们选择了具有笼结构的MOF-801,通过其对TMS和异戊烷吸附能力的差异,实现了TMS与异戊烷的分离。气体吸附测试结果表明,在298 K和60 kPa时,MOF-801对异戊烷吸附量为2.56 mmol·g-1,而其对TMS的吸附量为1.20 mmol·g-1。理想吸附溶液理论(IAST)计算结果表明,MOF-801对TMS/异戊烷(95∶5,体积比)混合物的分离选择性达到105.8。而之后的液相吸附分离实验进一步验证了MOF-801的分离效果,最终可以得到体积分数大于99.98%的TMS。 相似文献
2.
制备了MIL-101(Cr)材料,借助X-射线衍射和红外光谱技术确认了标题化合物的结构,利用扫描电子镜(SEM)技术及物理吸附技术表征了其形貌特征与孔结构特征。结果表明MIL-101(Cr)材料大小均匀,平均粒径为0.8μm, BET比表面积与总孔容积分别为1505 m2·g-1和0.11 cm3·g-1。随后进行了对布洛芬的吸附研究,结果表明MIL-101(Cr)对布洛芬的吸附在30 min即可达到平衡,且为拟一级动力学过程,符合Langmuir吸附模型,最大吸附量为136.3 mg·g-1。10 mg MIL-101(Cr)吸附剂可实现20 mg·L-1布洛芬溶液中溶质的98%去除率。以上实验结果可为探究MIL-101(Cr)在水中有机污染物的去除提供参考。 相似文献
3.
层状双氢氧化物(LDH)的光生电子-空穴对易复合,虽然纳米薄片的结构促进了载流子分离,但其光催化效率仍然较低。我们利用LDH薄片结构的优势,将FeNi LDH和TiO2通过静电自组装复合,设计制备出新型高效的FeNi LDH/TiO2复合光催化材料,评价了其光催化分解水产氢性能。对其结构、光催化性能和光电化学等进行了详细表征。结果表明,FeNi LDH的高比表面积、复合物的异质结结构都有利于光生电荷的转移。光催化产氢结果表明,FeNi LDH/TiO2复合材料的产氢速率(22.6mmol·g-1·h-1)分别比纯TiO2(0.1 mmol·g-1·h-1)和FeNi LDH(0.05 mmol·g-1·h-1)提高了226和452倍,表明了异质结在提高LDH光催化效率方面的重要作用。 相似文献
4.
建立了高效液相色谱-串联质谱法(HPLC-MS/MS)测定睫毛增长液化妆品中比马前列素含量的分析方法。样品经50%(体积分数)甲醇溶液提取,Agilent Poroshell 120 EC-C18柱(4.6 mm×100 mm,2.7μm)分离,以5 mmol·L-1乙酸铵水溶液(含0.02%甲酸)-乙腈(体积比55∶45)为流动相等度洗脱,流速0.3 mL·min-1,采用电喷雾正离子源(ESI+),多反应监测(MRM)扫描方式检测,外标法定量。结果表明,比马前列素在0.5~100 ng·mL-1质量浓度范围内线性良好,相关系数(r2)为0.998 2,在低、中、高3个加标水平下的平均回收率分别为98.6%、101%和99.2%,相对标准偏差(RSD)分别为2.4%、2.1%、1.2%,检出限(LOD,S/N=3)为0.015μg·g-1,定量下限(LOQ,S/N=10)为0.05μg·g-1。该方法快速简便、... 相似文献
5.
为实现从低浓度稀土溶液中高效富集稀土,通过动态吸附-解吸试验,研究了转型TP207树脂吸附稀土的规律。系统考察了离子交换线速度、吸附液体积、初始p H值、铝离子对树脂吸附稀土容量的影响,以及解吸液体积对稀土解吸率的影响。结果表明:在稀土浓度为1.65g·L-1,离子交换线速度为3 cm·min-1,吸附液体积为7.50 L,初始p H值为3.46的条件下,TP207树脂对稀土吸附量Qn1=0.18 g·g-1;稀土溶液中铝和稀土存在竞争吸附,当Al3+浓度为0.35 g·L-1时,TP207树脂对稀土吸附量Qn2降为0.11 g·g-1;采用5%的稀HCl对饱和树脂进行解吸,在解吸液体积为0.525 L时,稀土解吸率可达99.45%;树脂吸附稀土过程属于阳离子交换反应,符合Langmuir等温吸附模型,为单分子层吸附,树脂中C=O的O原子和C-N的N原子均参与配位反应。 相似文献
6.
以胶态SiO2纳米粒子为模板,壳聚糖为碳源,ZnCl2为活化剂,制备了具有不同比表面积和孔体积的氮掺杂介孔碳。采用多种表征手段对碳材料的微观形貌、比表面积和孔道结构进行了表征,探究了壳聚糖与SiO2纳米粒子的比例以及ZnCl2活化剂对碳材料孔体积和比表面积的影响。结果表明,在未使用活化剂时碳材料(CSi-1.75)的孔体积高达4.53 cm3·g-1,但其比表面积最小(729 m2·g-1);使用ZnCl2作为活化剂制备的碳材料(CSi-1.75-Zn)比表面积为1 032 m2·g-1,但其孔体积下降到1.99 cm3·g-1,且具有最多的吡啶氮和吡咯氮。在以6.0 mol·L-1KOH为电解液的三电极体系中,当电流密度为0.5 A·g-1时,CSi-1.75... 相似文献
7.
以高浓度氧化石墨烯(GO)溶液作为反应前驱体,纳米纤维素(NC)作为物理间隔物和电解液储存器,通过简单的一步水热法制备了纳米纤维素/还原氧化石墨烯(NC/rGO)复合材料,并探究了其作为超级电容器电极材料的潜力。结果如下:NC添加量为1 mL所制备的NC/rGO-1具有最佳电化学性能。基于NC/rGO-1的无黏合剂对称型超级电容器在0.3 A·g-1的电流密度下显示出了269.33 F·g-1和350.13 F·cm-3的高质量和体积比电容,并在10.0 A·g-1时仍能达到215.88 F·g-1和280.62 F·cm-3(其初始值的80.15%)。组装器件还显示出了较高的质量和体积能量密度(9.3 Wh·kg-1和12.13 Wh·L-1)和出色的循环性能(10 A·g-1下10 000次循环后其初始比电容仅减少6.02%)。 相似文献
8.
采用共价键结合法,利用戊二醛,将海藻酸钠与端氨基超支化聚酰胺进行共价交联,制备出海藻酸钠改性超支化聚酰胺吸附材料,通过FT-IR对其结构进行表征,并考察了海藻酸钠改性超支化聚酰胺对水体中Pb2+、Cd2+和Zn2+的吸附行为。研究结果表明,海藻酸钠改性超支化聚酰胺对Pb2+、Cd2+和Zn2+的饱和吸附能力分别为210.56 mg·g-1、130.53 mg·g-1和129.11 mg·g-1,且符合Langmuir等温吸附模型,可见海藻酸钠改性超支化聚酰胺对Pb2+有明显的吸附选择性;而多元混合体系中的吸附实验表明,Cd2+或Zn2+与Pb2+的共存可以对Pb2+的吸附产生协同促进作用,而Pb2+对共存重金属离子的吸附则是明显拮抗作用,二元混合体系中Pb 相似文献
9.
分别以含氮菲咯啉、四硼酸钾和醋酸锌为碳源、活化剂和模板,制备了B、N共掺杂多孔碳(BN-PC),并探究模板质量对BN-PC结构和储电性能的影响。当醋酸锌质量为5 g时,所得BN-PC5中B、N杂原子含量分别为20.21%、18.29%。电化学测试结果表明,以6 mol·L-1KOH为电解液,BN-PC5电极展现出高的比电容(在0.05 A·g-1电流密度下为255 F·g-1)、优异的倍率性能(在20 A·g-1电流密度下为188 F·g-1)和卓越的循环稳定性(在5 A·g-1的电流密度下循环10 000次比电容保持率为97%)。以3mol·L-1ZnSO4为电解液,在平均功率密度为56 W·kg-1时,BN-PC5电容器的能量密度可达27 Wh·kg-1。 相似文献
10.
以偏苯三甲酸和六水合硝酸钴为原料,通过水热法合成了2种反应时间不同的钴基金属有机聚合物(Co-MOP)。采用X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)和N2吸附-脱附对Co-MOP材料进行了结构和形貌表征。将2种Co-MOP材料用作锂离子电池负极材料,并进行了电化学性能测试。结果表明,Co-MOP-12(水热反应12 h)展示出了优异的电化学性能,在100 mA·g-1的电流密度下,Co-MOP-12电极的首圈可逆比容量达到979 mAh·g-1,循环100圈后比容量高达1 345 mAh·g-1。 相似文献
11.
用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%. 相似文献
12.
Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction
Laurent Gavara Thomas Boisse Jean-Pierre Hénichart Adam Daïch Philippe Gautret 《Tetrahedron》2010,66(38):7544-5571
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments. 相似文献
13.
The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula. 相似文献
14.
Rebecca J. Burton Mandy L. CrowtherNeal J. Fazakerley Shaun M. FilleryBarry M. Hayter Jason G. KettleCaroline A. McMillan Paula PerkinsPeter Robins Peter M. SmithEmma J. Williams Gail L. Wrigley 《Tetrahedron letters》2013
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines. 相似文献
15.
KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields. 相似文献
16.
N. A. Nedolya 《Chemistry of Heterocyclic Compounds》2008,44(10):1165-1219
The review contains a concise historical account and information on the most significant researches undertaken by the staff
at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry
of Heterocyclic Compounds.
Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee.
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008. 相似文献
17.
Regiospecific and direct imidation of the methyl C(sp3)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products. 相似文献
18.
19.
《Tetrahedron》2014,70(21):3377-3384
The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative. 相似文献
20.
Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields. 相似文献