分子筛材料在小分子吸附分离中的应用

吸附分离技术与工艺在工业上具有重要意义. 常见的吸附剂包括沸石分子筛、 金属有机框架材料、 活性炭等材料. 分子筛具有比表面积大、 稳定性高、 生产成本低等优势, 可以满足吸附分离技术中高效、 节能和环保的需求, 是一种非常有应用前景的小分子混合物分离吸附剂. 本文综合评述了吸附分离领域中常用的吸附剂材料的特点和吸附分离机理与评价方法, 总结了分子筛在空气分离、 烃类分离、 二氧化碳吸附、 芳香硫化物脱除、 一氧化碳吸附、 氮氧化物吸附、 氢气储存吸附及氢同位素分离等领域的应用, 并对基于分子筛膜的小分子混合物分离现状进行了介绍. 此外, 本文还系统分析了分子筛对不同混合物的吸附分离性能与其拓扑结构、 骨架组成及改性方法之间的关系, 并对未来的研究前景进行了展望.     

硅基分子筛及其在精细化学品合成中的应用

本文综述了沸石分子筛及中孔硅基材料在合成方面的最新进展,总结了这类分子筛材料在精细化学品合成中的应用及取得的成果,详细介绍了中孔分子筛的表面改性尤其是有机－无机杂化分子筛的合成、性质、特点及其作为催化剂在有机合成反应中的应用。     

水热合成法在分子筛中组装功能材料

采用水热合成法将ZnS、MoO₃和邻苯二甲酸铕组装到ZSM-5分子筛孔道之中,制得了具有纳米尺寸的功能材料,通过XRD、IR、发射光谱和探针分子吸附等手段进行了表征.     

分子筛材料研究及其在催化裂化过程中的应用前景

对近年来新合成的分子筛材料,如超大微孔分子筛、介孔分子筛、含D4R结构单元的分子筛的孔结构及合成技术进行综述,并探讨了这些新分子筛材料在催化裂化过程中的应用前景。     

沸石分子筛在有机合成中的应用

阐述了沸石作为选择性吸附剂和催化剂在有机合成中的应用,包括杂环化合物的合成、氧化还原反应、傅一克反应、不对称合成、制备高聚物及在萜类化学中的应用进展情况。     

分子筛在光催化中的应用*

以太阳能利用为背景光解水制H₂及由此开辟的光催化研究领域日益受到重视。分子筛在催化、吸附、分离等领域早已有广泛应用,而在光催化中的应用近10年来也已成为光催化领域中的一个热点。本文就分子筛光催化剂的优点,在光催化中应用的意义、研究现状和前景作了介绍和分析。     

介孔与介孔主客体材料在催化领域的应用

 综述了近年来介孔分子筛催化材料制备的研究成果及其在催化领域特别是精细化学品合成中的应用. 文章分为两部分,分别讨论了介孔材料本身作为催化剂以及介孔主客体催化材料的应用.     

分子筛型声学增强材料的储存耐候性能

研究了湿度和有机物小分子等储存耐候条件对声学增强材料谐振频率偏移值的影响,探讨了由不同硅铝比分子筛组成的声学增强材料在不同湿度及有机物小分子气氛中储存后的谐振频率及偏移值的变化规律.研究结果表明,由既定硅铝比分子筛组成的声学增强材料在25℃/50%相对湿度(RH)和25℃/95%RH条件下储存后,其谐振频率偏移值未发生明显变化.氮气吸附实验结果表明, 25℃下氮气分子占据了较少的比表面积,水分子的存在不影响声学增强材料对氮气分子的吸附.在25℃/50%RH条件下放置后,声学增强材料在25℃/95%RH条件下吸附的水分子会逐渐脱附.声学增强材料在不同种类有机物小分子气氛中储存后,其谐振频率偏移值呈不同的变化趋势.对于尺寸较小的有机物小分子,由于存在可逆吸附,声学增强材料的谐振频率偏移值未有明显变化;对于尺寸较大或具有小尺寸端基基团的有机物小分子,由于存在嵌入式吸附,声学增强材料的谐振频率偏移值明显降低.     

分子筛在医学领域的应用及作用机制

沸石分子筛由于其特殊的结构特点, 优异的生物活性、生物稳定性及生物相容性, 研究人员对其进行了大量临床应用方面的研究. 研究表明, 分子筛可用作抗肿瘤治疗的佐剂、抗微生物治疗、药物的载体、快速凝血剂、防止血栓制剂等. 本文将阐述分子筛在医学领域的应用进展及发挥作用的相关机制.     

Controlled “Grafting-from” of poly[styrene-co-maleic anhydride] onto polydienes using nitroxide chemistry

High-throughput experimentation was used for the functionalization of polybutadiene and polyisoprene with several kinds of nitroxide moieties at 135 °C, as well as for kinetic investigations of the controlled free radical grafting of styrene and maleic anhydride onto the functionalized polydienes at 125 °C. The functionalized polymers were analyzed by GPC, ¹H NMR and FT-IR and the control of the grafting process was assessed by kinetic measurements and GPC analysis. The best control in the molecular weight of the grafts was observed for the polydienes functionalized with 4-oxo-TEMPO. TEMPO functionalization did not render sufficient nitroxide moieties to achieve controlled grafting, while polydienes functionalized with other 4-hydroxy TEMPO derivatives exhibited some level of grafting control at early reaction times, which was lost in later stages of the polymerization reaction. SG1 apparently decomposed at the tested reaction temperatures, as polydienes functionalized with SG1 did not show any level of control during the grafting process.     

The effects of mass accuracy,data acquisition speed,and search algorithm choice on peptide identification rates in phosphoproteomics

Proteomic analyses via tandem mass spectrometry have been greatly enhanced by the recent development of fast, highly accurate instrumentation. However, successful application of these developments to high-throughput experiments requires careful optimization of many variables which adversely affect each other, such as mass accuracy and data collection speed. We examined the performance of three shotgun-style acquisition methods ranging in their data collection speed and use of mass accuracy in identifying proteins from yeast-derived complex peptide and phosphopeptide-enriched mixtures. We find that the combination of highly accurate precursor masses generated from one survey scan in the FT-ICR cell, coupled with ten data-dependent tandem MS scans in a lower-resolution linear ion trap, provides more identifications in both mixtures than the other examined methods. For phosphopeptide identifications in particular, this method identified over twice as many unique phosphopeptides as the second-ranked, lower-resolution method from triplicate 90-min analyses (744 ± 50 vs. 308 ± 50, respectively). We also examined the performance of four popular peptide assignment algorithms (Mascot, Sequest, OMSSA, and Tandem) in analyzing the results from both high-and low-resolution data. When compared in the context of a false positive rate of approximately 1%, the performance differences between algorithms were much larger for phosphopeptide analyses than for an unenriched, complex mixture. Based upon these findings, acquisition speed, mass accuracy, and the choice of assignment algorithm all largely affect the number of peptides and proteins identified in high-throughput studies. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.