Synthesis,Characterization and Control of Proportion of Polymorph C in ITQ-16 and ITQ-17 Films

Continuous ITQ-16 and ITQ-17 films on silicon wafer were prepared in fluoride media using TEAOH as organic structure-directing agent. The proportion of polymorph C in the as-synthesized ITQ-16 and ITQ-17 films was determined via X-ray diffraction characterization. The proportion of polymorph C in the ITQ-16 and ITQ-17 films was controlled via optimizing the compositions of the reaction mixtures and reaction conditions, such as varying the Si/Ge molar ratio and adding n-propyl alcohol as a solvent in the reaction mixture. The Ge atoms in the reaction media strongly increased the crystallization of polymorph C in ITQ-16 and ITQ-17 films. Moreover, the stabilizing and buffering effect of n-propyl alcohol on crystal growth further enhanced the proportion of polymorph C in the ITQ-16 and ITQ-17 films. For potential catalytic applications, Al was incorporated into the framework of polymorph C, and a pure phase of polymorph C in Al-ITQ-17 film was achieved from the synthesis gel in the n-propyl alcohol phase.     

ITQ-3分子筛中二元混合分子扩散性质的模拟

采用平衡分子动力学方法先是模拟研究了纯组分Ar、SF_6以及CF4在ITQ-3分子筛中的扩散行为,结果表明,在窄孔道中Ar的扩散系数随负载的增加呈现先增加再减小的变化趋势,在宽孔道中则随负载逐渐减小。纯组分的大分子SF_6以及CF4只在y方向扩散,扩散系数与小分子在z方向的变化规律一致。随后,又模拟了二元混合组分SF_6和CF4在ITQ-3分子筛中的扩散行为,模拟结果与各自纯组分SF_6和CF4进行了对比,发现二元混合的SF_6和CF4整体变化趋势与其单组分保持一致,在y方向的扩散系数都是随着负载的增加而先增大后减小,但是两者之间还存在一种相互作用,使得在整个负载范围内扩散较快的CF4的扩散系数比纯组分的扩散系数相对小一些,而纯组分时扩散相对缓慢的SF_6在二元混合中的扩散系数则相对增大。     

ITQ-1分子筛中二甲苯吸附特征的计算机模拟

用巨正则蒙特卡罗模拟研究了邻二甲苯和间二甲苯在ITQ-1分子筛中的吸附特征。模拟结果表明两种吸附质分子在分子筛骨架中的吸附特征不存在明显的差别。从两种吸附质分子在l2员环超笼之间运动的势能曲线,可以说明在通过l0员环窗口时,邻二甲苯和间二甲苯都需要克服较大的势垒,但邻二甲苯需要的激发能量明显大于间二甲苯,计算机模拟以及实验结果表明间二甲苯可以通过l0员环窗口到达分子筛的内部,而邻二甲苯则只能在分子筛的表面发生吸附或扩散。     

以季磷化合物为模板剂合成超大孔分子筛ITQ-33

以四丁基氢氧化磷为模板剂, 在中温水热条件下, 利用浓溶胶法合成了具有一维18元环孔道的含铝硅锗酸盐分子筛ITQ-33. 系统研究了ITQ-33的合成条件, 并利用原位变温X射线衍射(XRD), 扫描电子显微镜(SEM), 固体核磁共振波谱(NMR), 电感耦合等离子体发射光谱(ICP), 氮气吸附-脱附程序升温脱附(TPD), 热重(TG)及元素分析等手段对其结构、 稳定性及催化性能进行了表征. 结果表明, 以季磷化合物为模板剂可以合成含铝的ITQ-33纯相, 产物具有较高的热稳定性, 其骨架结构可以稳定至400℃以上, 煅烧后的ITQ-33具有Lewis酸位点, 在酸催化方面有潜在的应用价值.     

硅源对ITQ-13分子筛水热合成的影响

通过三种硅源, 正硅酸已脂(TEOS)、胶体二氧化硅、气相法白炭黑, 成功地合成出ITQ-13分子筛, 并用X射线衍射(XRD)、扫描电子显微镜(SEM)、BET表面积测试和氘代乙腈吸附等方法对合成的材料进行表征. 结果表明, 用硅胶和白炭黑为硅源合成出的ITQ-13具有较好的晶化度和较大的晶体尺寸.     

分子在ITQ-3分子筛窄孔道内扩散的过渡态理论模型

建立了一个基于过渡态理论的分子在ITQ-3窄孔道方向扩散的模型. 该模型中, 由于分子从空腔中的一个吸附位越过势垒到相邻的另一个空腔中的吸附位需要克服很大的势垒能, 因而分子在势垒处可以简化处理为只存在排斥势, 可得到扩散系数依赖温度和Lennard-Jones作用参数的解析关系. 用分子动力学方法对CF₄在ITQ-3上扩散进行了模拟并验证了解析关系的合理性. 分子动力学模拟计算得到的扩散活化能、势垒能和吸附位势能与实际值相吻合. 模拟结果也显示了扩散系数依赖于附载量, 表现为先增大后减小的变化模式. 扩散活化能的计算证实了这一变化机理, 即当附载量增加时, 由于处于空腔中的分子彼此抬高了势能, 降低了扩散活化能, 使得扩散系数随附载量的增加而增大, 之后由于堵塞效应, 扩散系数随附载量的增加而逐步减小.     

The Grand Canonical Monte Carlo Simulations of Benzene and Propylene in ITQ-1 Zeolite

Thealkylationofbenzenewithpropylenetoproducecumene,astartingmaterialfortheproductionofacetoneandphenol,isveryimportantinhydrocarbonprocess.ComparedwithsomemineralacidsincludingAlCl,andothers,zeolitesseemtobemorecleancatalysts,moreoveF,theycaneffectivelyreducetheamountoflessdesiredproductssuchasdiisopropylbenzenes.SeveralzeoIitesincludingH-ZSM-5,USYflandMCM-22havebeentestedforthereactionoftheaIkylationofbenzenewithpropylene,andithasbeenfoundthatP,USYandMCM-22areveryreactiveI.ZeoIiteMC…     

芳香类化合物在ITQ-1分子筛中吸附特性的蒙特卡罗模拟

用巨正则统计系综蒙特卡罗模拟研究了苯、甲苯以及间二甲苯分子在ITQ-1分子筛中的吸附特性.从这3种分子的粒子分布云图上,可发现分子的扩散和吸附主要在十二元环超笼内发生,在十元环通道内的吸附和扩散则相对较难.从一系列不同压力下的蒙特卡罗模拟还预测了3种分子的吸附等温线,预测结果与实验结果相符.这3种分子在一定压力下,都可通过十元环通道或连接十二元环超笼的十元环窗口到达分子筛孔道内部,达到较好的吸附平衡状态.     

8－羟基喹啉铝掺杂聚乙烯基咔唑薄膜的光致发光及电致发光

８－羟基喹啉铝掺杂聚乙烯基咔唑薄膜的光致发光及电致发光马於光,唐建国,沈家骢,刘式墉（吉林大学分子光谱与分子结构开放实验室,集成光电子学国家联合重点实验室,长春,１３００２３）关键词聚合物,光致发光,电致发光,８－羟基喹啉铝某些有机染料作为波长转换介...     

残留凝胶对聚辛基芴薄膜光致发光性能的影响

用荧光光谱、紫外可见吸收光谱、原子力显微镜表征了在55℃的条件下分别溶解12min、30min、80min的聚辛基芴甲苯溶液通过旋涂法制备的薄膜。结果表明用溶解时间较短的条件制备的薄膜内有平均尺寸约为120nm×80nm的凝胶团,这使荧光光谱呈现部分卢相发光。当溶解时间增长后薄膜完全呈现非晶相发光,薄膜内部凝胶团消失。...     

β沸石中堆垛层错结构的研究

含TEA＋离子的化合物作为模板剂会成的β沸石是由有序结构A、B、C到沿[001]方向堆积成堆垛层错结构．三种有序结构出现的几率分别为0．31、0．36和0．33；其数值不受样品中硅铝出的影响．几率值如此相近的原因是构成β沸石的结构单元Ⅰ的四种连接方式（见图2）能量相等.几率值之间的微小差别,是基于在晶体生长过程中支撑赶A、B和C型三维通道结构的TEA＋离子以不同排列形成的难易程度不同所引起．B型对应的排列略易于C型、C型又略易于A型，因此使用此种模板剂时，A、B、C三种结构均可能出现，只能合成出具有堆垛层错结构的β沸石．由于三维通道的特点，合成β沸石对模板剂的用量必须大于具有二维通道或一维通道的分子筛合成时的用量．而且要求有机控离子不宜过大、反应温度相对较低、晶化时间相对较长，以利于有机按高子不同取向排列的形成     

β分子筛的物化性质对其催化活性的影响

研究了β分子筛的物化性质对其催化活性的影响。实验发现,β分子筛对甲基叔丁基醚(MTBE)反应的催化活性是各类酸中心共同作用的结果,但强Lewis酸密度对其活性的影响较大;比表面积、二次孔体积及微孔比表面积等因素与异丁烯转化率无明显的相关性;C4原料中的惰性组分对MTBE反应的影响较小,但以混合C4为原料时MTBE反应的初始反应速率较低。     

恒电位脉冲法制备聚苯胺薄膜及其表征

采用恒电位脉冲法制备聚苯胺薄膜, 利用扫描电子显微镜(SEM)、红外光谱(IR)、X射线衍射(XRD)及荧光光谱对所制备的薄膜进行比较与表征. 分别考察了循环周期、占空比及脉冲时间对薄膜形貌的影响. SEM形貌分析结果表明, 随着占空比的减小, 聚苯胺薄膜表面颗粒细化; 随循环周期的增加, 聚苯胺薄膜由片层结构转变为纵向生长的颗粒状结构. 荧光光谱分析结果表明, 聚苯胺薄膜具有光致发光性能, 发射峰位置约520 nm, 且发光强度随占空比的增大而增强. 电化学性能测试结果表明, 恒电位脉冲电位法制备的聚苯胺薄膜具有良好的电容特性.     

MCM-22型分子筛中苯分子吸附行为的分子动力学模拟

用分子动力学方法研究了纯硅ＭＣＭ－２２型分子筛中苯分子的吸附行为。计算结果表明,模拟采用刚性骨架或柔性骨架对苯分子的扩散系数并没有大的差别,这表明在较低吸附值的情况下,分子筛骨架的柔性对苯分子吸附和扩散并没有产生大的影响。     

氨基功能化石墨烯量子点表面缺陷钝化及其发光增强

通过酸氧化法将氧化石墨烯进一步“切割”制备石墨烯量子点（GQDs）,在100℃水热条件下,用氨水处理石墨烯量子点制备得到氨基功能化石墨烯量子点（N-GQDs）。傅里叶变换红外光谱证明NH₃可以有效地进攻环氧基碳和羧基碳,形成羟胺和酰胺基。原子力显微镜结果表明NH₃不仅能够有助于产生更小的量子点,还对石墨烯纳米片有致孔作用。氨基功能化之后,由于C-O-C相关的n-π^*跃迁受到抑制,N-GQDs发光具有更弱的激发波长依赖性,并使其荧光量子产率从0.3%提高至9.6%。时间分辨发光光谱表明,相比含氧基团,含氮基团相关的局域电子激发态具有更长的荧光寿命和更弱的发射光谱依赖性。     

Self‐Assembly Film of Zeolite Y Nanocrystals Loading Palladium on an Au Electrode for Electrochemical Applications

Nano‐scale zeolite Y crystals were synthesized, and palladium nanoparticles were prepared in the supercage of the zeolite by “ship‐in‐a‐bottle” approach. A novel method to fabricate zeolite‐modified electrode (ZME) loading Pd nanoparticles was developed, in which the zeolite Y loading Pd²⁺ ions was self‐assembled on (3‐mercaptopropyl) trimethoxysilane‐attached Au surface to form the stable and density packed multilayers (SAM‐ZME). The structures of zeolite Y and the SAM‐ZME were investigated by using TEM, XRD and SEM techniques. Pd²⁺ ions in the SAM‐ZME were converted into Pd nanoparticles (Pd_n⁰) by two steps consisting of the electrochemical reduction as well as the succeeding admission and release of CO. The redox couple [Fe(CN)₆]^3?/4? was used to probe the electron‐transfer barrier properties during self‐assembling process. Moreover, the special properties of the SAM‐ZME loading Pd_n⁰ were studied by using cyclic voltammetry and CO‐probe in situ FTIR spectroscopy. The results illustrated that Pd_n⁰ in the SAM‐ZME exhibits higher electrocatalytic activity for oxidation of adsorbed CO than that of ZME prepared in our previous study by zeolite coating method. The present study is of importance in design and preparation of SAM‐ZME, which poccesseses excellent properties for the immobilization of electrocatalysts or biomolecules.     

八-羟基喹啉铝薄膜光致发光的厚度依赖性质

In situ thickness dependent photoluminescence (PL) measurements of tris(8-hydroxyquinoline) aluminum(Alq3) film were performed. At the beginning of Alq3 deposition on the glass substrate, the Alq3 emission showed a sharp red-shift. Further deposition of Alq3 resulted slight red-shift, and finally tended to saturated value. The total red-shift of about 12 nm was observed for the Alq3 film thickness range from 2 to 500 nm.This red-shift was attributed to the change from the 2D to 3D exciton state with increasing Alq3 film thickness. Meanwhile, the PL intensity of Alq3 emission increased continuously, and showed a rate change at the initial deposition of Alq3 due to non-rediative decay of excitons arised from the interaction between excitons and the substrate, and finally tended to saturation with the Alq3 thickness.     

Intercalation of Polyaniline in Montmorillonite and Zeolite

The anilinium ion was encapsulated into the interlayer space of montmorillonite and the intrachannel space of NaY zeolite by the ion exchange method. After addition of ammonium peroxodisulfate, the loaded anilinium ions were polymerized to polyaniline (PAN). The structures of PAN in NaM and CsM are compared with that in NaY by means of UV-Vis, FTIR and EPR spectroscopies. The structures of PAN in NaY zeolite and montmorillonite hosts were shown to have the typical spectral features of emeraldine base and emeraldine salt respectively. Intercalation of polyaniline in montmorillonite was confirmed by the variation of the basal spacing, the resonances in EPR and the reduction of bulk conductivity.     

高岭土原位晶化产品及全合成Y型沸石的稀土离子交换平衡

本文测定了钠式高岭土原位晶化产品及全合成Ｙ型沸石与稀土离子铽Ｔｂ（Ⅲ）的离子交换等温线和平衡数据，采用了三种不同的热力学方法处理平衡数据，求得该离子交换反应Ｎａ→Ｔｂ的选择系数、修正选择系数、热力学平衡常数以及标准自由能、热焓、熵的改变量。对这两种离子交换剂的结果及三种热力学处理方法进行了对比及讨论。     

模型分子筛对水分子的吸附

用PM3半经验量子化学方法研究了模型分子筛对水分子吸附的性质.通过模拟计算确定了两个低能吸附位点及相应的吸附热,结果与实验值非常接近.同时,从两个不同低能吸附位点可以看出,大笼内的吸附流动性比β笼内的流动性好,即对水分子的吸附有较宽的区域.