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1.
以硅酸钠为硅源,十六烷基三甲基溴化铵(CTAB)为模板剂,合成介孔材料MCM-41.采用两步嫁接法,分别用三甲基氯化硅(TMSCL)和3-氨基三乙氧基硅烷(APTS)对合成的介孔分子筛进行化学修饰,首次将甲基和氨基同时嫁接到介孔材料MCM-41上,得到新型的介孔材料CH3-MCM-41-NH2.利用XRD和FT—IR对合成的新型功能化介孔材料进行表征.  相似文献   

2.
目的 研究γ-氨丙基修饰、Schiff类金属配合物修饰对MCM-41六方孔道结构的影响.方法 用元素分析,IR,UV-Vis等方法对所得配合物进行了表征.以十六烷基三甲基溴化铵为表面活性荆,Na_2SiO_3·9H_2O为硅源,用水热合成法在碱性条件下合成了介孔分子筛MCM-41,采用嫁接法使γ-氨丙基三乙氧基硅烷与介孔分子筛MCM-41在无水乙醇中回流12 h,反应得到γ-氨丙基功能化的MCM-41,使该产物与所合成Mn(Ⅲ),Fe(Ⅲ)配合物进行化学组装.结果 合成了4个Schiff配体N,N-双(5-氯水杨醛)缩乙二胺,N,N-双(5-溴水杨醛)缩乙二胺,N,N-双(5-硝基水杨醛)缩乙二胺,N,N-双(5-氯水杨醛)缩邻苯二胺,5个Mn(Ⅲ),Fe(Ⅲ)的过渡金属配合物.用IR,XRD等谱学技术对组装产物进行了初步的表征.组装产物的IR光谱呈现出金属配合物的schiff碱配体相应基团的特征吸收且特征峰位移不明显,配合物成功固载到MCM-41上.XRD谱表明所有组装产物仍保持六方孔道结构.结论 γ-氨丙基修饰、Schiff类金属配合物修饰对MCM-41六方孔道结构没有影响.  相似文献   

3.
以二甲基二氯硅烷为偶联剂修饰了介孔分子筛MCM-41,将有机官能团引到介孔分子筛MCM-41表面,制备了一种无机-有机复合材料CH3-MCM-41.研究了溶剂、偶联剂量、反应时间等因素对反应的影响,并用元素分析和红外光谱对复合材料进行了表征.  相似文献   

4.
以正硅酸乙脂为硅源,十六烷基三甲基溴化铵为结构模板剂,苯基三甲氧基硅烷为偶联剂,根据共水解缩聚一步合成了苯基官能化的介孔二氧化硅(C6H5-MCM-41).用小角X-射线衍射表征其孔道特征,红外光谱、元素分析和滴定法表征其有机键合量和表面覆盖率.结果表明,介孔二氧化硅具有MCM-41的孔道结构特征,苯基成功键合至孔道表面而形成无机/有机介孔复合体(C6H5-MCM-41),高键合量的苯基导致介孔二氧化硅具有很强的疏水性和热稳定性;与高效液相色谱联用,以C6H5-MCM-41为固相微萃取的涂层对苯并芘有较高的萃取效率.  相似文献   

5.
自1992年问世以来,新型介孔分子筛MCM-41因其在多相催化、吸附与分离以及离子交换等多个领域的潜在应用而成为国内外热点研究课题之一。本文通过在分子筛MCM-41的空腔内进行表面功能化制备出中间体NH2-MCM-41,然后将其与N-3,5-(二硝基苯甲酰)-亮氨酸进行不同类型有机化学反应成功获得手性分离固定相CSP1和CSP2。所得MCM-41经过红外、X射线粉末衍射、扫描电镜、氮气吸附-脱附进行表征,而元素分析结果则表明在CSP1和CSP2内部:有机基团进入MCM-41的孔道,并修饰了孔壁。  相似文献   

6.
制备了扩孔的介孔氧化硅MCM-41,然后以其为载体,通过化学接枝法将3-[2-(2-氨基乙基氨基)乙基氨基]丙基-三甲氧基硅烷嫁接到其介孔结构中,制备了氨基官能化的介孔氧化硅复合材料.通过N2吸附脱附实验、红外光谱、热重分析等手段对氨基官能化前后扩孔MCM-41的物理化学属性进行了表征,然后考察了复合材料对CO2的吸附捕集性能.结果表明:与单纯扩孔MCM-41相比,氨基官能化的扩孔MCM-41复合材料的比表面积、总孔容及孔径均减小;同时,所制复合材料对CO2的吸附量明显增大(两者的CO2吸附量分别为28 mg/g和76 mg/g),且在循环CO2吸附脱附实验中呈现出优异的稳定性.  相似文献   

7.
以二甲基二氯硅烷(Dimethyl dichlorosilane,DMCS)、辛基三甲氧基硅烷(Octyltrimethoxysi-lane,C11H26O3Si)和十八烷基三氯硅烷(Octadecyltrichlorosilane,C18H37C13Si)为硅烷化试剂,采用后处理接枝技术对介孔分子筛MCM-4l表面进行烷基化修饰,合成了无机-有机复合材料R-MCM-41(R-烷基),并用XRD、元素分析和FT-lR对复合材料进行了表征。结果表明,有机基团进入了MCM-41孔道。  相似文献   

8.
采用氨基化MCM-41介孔分子筛(NH2-MCM-41)接枝改性聚偏氟乙烯(PVDF)超滤膜,并用于水中重金属Cr(VI)的去除。NH2-MCM-41成功接枝于超滤膜表面,并在表面形成均匀的亲水层,显著提高了膜的抗污染性能,过水通量衰减率从51.4%降低到了24.8%。在pH值3.5,初始浓度20 mg/L时,改性超滤膜对Cr(VI)的吸附可以在5 min达到快速平衡,吸附容量达到2.8 mg/g。超滤实验表明,NH2-MCM-41改性超滤膜对低浓度Cr(VI)进水可以实现进一步净化,在超滤运行时长达到11 h,出水Cr(VI)浓度始终维持在0.5 mg/L以下。因此,本研究通过在膜表面接枝氨基化的MCM-41分子筛,可以有效提升膜的抗污染能力和对重金属的去除能力。  相似文献   

9.
用Al2(SO4)3对中孔分子筛MCM-41进行改性,制备了中孔分子筛Al/SO24-/MCM-41.采用X射线多晶衍射(XRD)、红外光谱(FT-IR)、N2吸附-脱附和NH3程序升温脱附(NH3-TPD)等测试技术对样品的结构和表面酸性进行了表征.结果表明,用Al2(SO4)3改性中孔分子筛MCM-41,能得到仍保持着六方介孔结构的中孔分子筛Al/SO24-/MCM-41.  相似文献   

10.
氨基酸分子首次用以制备构筑稀土介孔发光材料。L-丝氨酸通过分子修饰得到新配体2-烟酰氨基-3-羟基丙酸(L),并进一步引入MCM-41介孔基质中,最后和稀土Tb3+离子复合得发光介孔材料Tb-L-MCM-41。通过核磁共振、紫外、XRD、氮吸附和荧光光谱等对配体和杂化材料的结构和性质进行了表征。结果表明,配体L很好的引入到MCM-41介孔基质中,Tb-LMCM-41介孔材料呈现L的特征紫外吸收。同时,稀土配合物的引入占据了MCM-41基质的部分孔道,使其比表面和孔体积都有所降度。Tb-L-MCM-41呈现稀土Tb3+离子的特征光。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

14.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

15.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

16.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

17.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

18.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

19.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

20.
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