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1.
谷氨酸柱撑水滑石超分子结构层柱材料的插层组装   总被引:33,自引:1,他引:33  
用返混沉淀方法实现了谷氨酸柱撑水滑石超分子结构层柱材料的插层组装,得到结晶度高、晶相单一且谷氨酸在层间有序排列的超分子结构层柱材料.用X射线衍射、原子光谱、元素分析、红外光谱及热重-差热分析表征了超分子结构层柱材料的结构,给出其结构模型.  相似文献   

2.
甲氨蝶呤柱撑水滑石超分子结构层柱材料的插层组装   总被引:1,自引:0,他引:1  
用共沉淀和离子交换法将抗肿瘤类药物甲氨蝶呤(MTX)插层组装到水滑石层间,制备了一种新型的结晶度高、晶相单一且MTX在层间有序排列的超分子结构的药物-无机复合层柱材料.用XRD、原子光谱、元素分析、FT/IR、SEM及TG-DSC分析表征了超分子结构层柱材料的结构,并给出其结构模型.  相似文献   

3.
插层组装超分子结构有机物柱撑阴离子层状材料   总被引:22,自引:0,他引:22  
通过改变插层组装条件对有机物柱撑阴离子层状材料(organic pillared layered double hydrox-ide,简称organo-LDHs)进行调控,可获得在光化学、电化学、催化、控制释放等方面具有广阔应用前景的新型无机—有机功能性超分子结构复合材料。本文以插层组装概念及超分子结构为理论基础,介绍了超分子结构organo-LDHs的插层组装方法、表征手段、层间有机物客体的定位及应用研究。  相似文献   

4.
以高岭石/尿素插层复合物作为中间相,利用简单的直接置换插层法制备了d001=0.85 nm的水合高岭石。利用X射线衍射、红外光谱、扫描电镜表征处理前后高岭石结构与形貌的变化。结果表明:尿素插层后的高岭石层间距从d001=0.72 nm增大到d001=1.08 nm,经不同温度酸洗或水洗后,插层复合物转变成层间有水分子的水合高岭石(d001=0.85 nm),且高岭石晶粒厚度明显从约25 nm减小到约10 nm。在高温条件下形成的水合高岭石含量最高,90℃水洗时d001=0.85 nm水合高岭石的转化率接近70%,这种水合高岭石具有进一步的置换插层能力,是一种制备其他高岭石插层复合物很好的前驱体。与乙二醇形成d001=1.10nm乙二醇/高岭石插层复合物,其置换率达到100%。  相似文献   

5.
以ZnAl-NO3-LDHs为前体,采用离子交换法将2-苯基苯并咪唑-5-磺酸(PBSA)插入到ZnAl-NO3-LDHs层间,借助XRD、FTIR、TG-DTA和UV-Vis等手段对样品进行表征。结果表明,PBSA阴离子可以完全取代前体层间的NO3-离子,组装得到晶体结构良好的ZnAl-PBSA-LDHs。对其结构进行研究发现,ZnAl-PBSA-LDHs中存在主体与客体以及客体与客体之间的相互作用,具有超分子结构特征。ZnAl-PBSA-LDHs在350 nm以下的紫外吸收能力较PBSA客体和ZnAl-NO3-LDHs前体显著增强,热稳定性也有所提高。将ZnAl-PBSA-LDHs以1.0%的质量比加入到聚丙烯(PP)中制备成ZnAl-PBSA-LDHs/PP薄膜,显著提高了PP的耐紫外光老化性能。  相似文献   

6.
五氧化二钒具有二维空间层状结构,层间伸缩性好,具有纳米尺寸,且有可做成无定形、高比表面积的溶胶.凝胶、干凝胶、气凝胶和类气凝胶等多种形态的优点.目前以其为主体的插层纳米复合材料研究十分活跃,本文综述了近年来合成的五氧化二钒插层化合物的组装及其电化学性能研究的进展.  相似文献   

7.
[LiAl_2(OH)_6]Cl·yH_2O was prepared by co-precipitation. The competitive intercalation of geometric isomers of hydroxybenzoic acid into the interlayer of layered double hydroxides (LDHs) was studied by the reaction of [LiAl_2(OH)_6]Cl·yH_2O with various mixtures of o-hydroxybenzoic acid, m-hydroxybenzoic acid and p-hydroxybenzoic acid. Powder X-ray diffraction (XRD) results confirmed the intercalation of the isomers, and high performance liquid chromatography (HPLC) was used for the quantitative study. The order of the preferential intercalation of the three isomers was found to be: o-hydroxybenzoic acid (1,2-C_7H_6O_3)》 p-hydroxybenzoic acid (1,4-C_7H_6O_3) > m-hydroxybenzoic acid (1,3-C_7H_6O_3).  相似文献   

8.
用焙烧复原法插层组装有机层柱双氢氧化物   总被引:4,自引:0,他引:4  
有机酸根插层双氢氧化物(简记为:LDHs OA)是制备具有特殊性质和功能的层柱材料的一类重要前驱体[1 3]。本文以Mg6Al2(OH)16CO2-3·6H2O(简记为MgAl CO2-3)和Zn6Al2(OH)16CO2-3·4H2O(简记为ZnAl CO2-3)为前体,用焙烧复原法将十四酸根(简记为14A)和十八酸根(简记为18A)分别插层组装到了MgAl LDHs和ZnAl LDHs层板间而制得了具有大的层间距、良好的结晶度和规整的层状结构的14A(18A)插层LDHs层柱材料(分别简记为MgAl 14A,mgAl 18A,ZnAl 14A,ZnAl 18A),用XRD谱、IR谱表征了插层交换产物的结构。1 实验部分1.1 仪…  相似文献   

9.
本文基于水滑石类插层材料(LDHs)特有的超分子结构及其功能可调控性,采用离子交换法成功合成了邻、间、对硝基苯甲酸阴离子(o-、m-、p-NBA-)插层的锌铝水滑石,并研究了插层产物的光敏性能。插层后这3种异构体化合物都在紫外光照射下表现出不同的光响应程度,即光敏作用:m-NBA-LDHo-NBA-LDH≈p-NBA-LDH。用PXRD、FTIR、UV/Vis和理论计算研究了光敏性能,并提出了可能的光敏机理,为其应用于新型感光材料提供了一定的理论基础。  相似文献   

10.
制备了一系列不同Mg/Al比氟插层的水滑石(LDH-F),并用X射线衍射、傅里叶变换红外光谱、扫描电镜和BET比表面积检测法对催化剂进行了表征,考察了不同Mg/Al比的LDH-F在苯乙烯环氧化反应中的催化活性.结果表明,Mg/Al=5的LDH-F具有最佳催化活性.通过以乙腈和苯甲腈分别作为反应用腈的对比实验发现,苯甲腈的效果优于乙腈.以Mg/Al=5的LDH-F为催化剂,H2O2和苯甲腈为氧化剂对不同官能团化烯烃进行环氧化反应,结果表明,此催化体系具有良好的催化性能,在苯乙烯、茚、丙烯醇和烯丙基氯环氧化反应中转化率和选择性均在95%以上。  相似文献   

11.
苟国敬  马培华  褚敏雄 《化学学报》2004,62(21):2150-2160
用共沉淀法制备前驱体后,在水热、微波和沸热等不同晶化方式下合成了一系列层状氯离子柱撑镁铝复合氢氧化物(LDH-Cl),在EDS,XRD,IR,TG-DTA,TEM和N2吸附-解吸测试表征的基础上,讨论了LDH-Cl的组成与结构的关系及制备条件对组成、结构和性质的影响.研究结果表明:LDH-Cl具有超分子结构和水滑石型层状结构的特征;微晶生长习性在不同晶化过程中的差异决定了粒子发育程度的不同、组成与结构相关性的不同;微晶粒子在不同合成条件和晶化方式下表现了不同的结晶度水平从而引起红外吸收、热稳定性及比表面积等基本属性的变化.  相似文献   

12.
以共沉淀法合成的磁性层状复合氢氧化物(Magnetic layered double hydroxide, MLDH)为前驱体, 通过对原位反应系统液相数据的拟合与固相样品的表征, 研究了0~50 ℃条件下MLDH与氟尿嘧啶(5-FU)的离子交换动力学特征. 结果表明, MLDH及离子交换产物MLDH-FU为以六方晶系为主并混杂微量氧化铁的复合磁性晶相; MLDH-FU离子交换速率随温度的升高而显著加快, FU, OH-和Cl- 3种客体的浓度变化分别服从二级、 零级及一级反应速率模型, 反应活化能依次为12.69, 27.88和3.580 kJ/mol. 固相表征参数的变化与液相动力学过程、 主-客体结构调整及MLDH-FU粒子陈化过程相符; 离子交换限定在LDH层间, 不涉及层板内部秩序, 不改变前驱体的结构与形貌特征, 具有侧向非断层反应习性, 是交换剂在MLDH外周经吸附亲和、 侧向进攻、 层间置换及柱撑模型转换再到新的插层客体主导调整及晶粒发育陈化的有序过程.  相似文献   

13.
以层状镁铝双金属氢氧化物(MgAlLayeredDoubleHydroxides,Mg-AlLDHs)为主体,以有机紫外光稳定剂2-羟基-4-甲氧基二苯甲酮-5-磺酸(BP)为客体,结合焙烧复原法和阴离子交换法合成了具有超分子结构有机-无机插层复合物(MgAl-BPLDHs),研究了层间阴离子、反应介质、pH值、反应时间等因素对于插层材料超分子结构的影响。用FTIR、XRD、TG-DTA、UV-Vis和粒度分析对其不同尺度的结构、热稳定性和紫外光稳定性等进行表征。结果表明,采用阴离子交换法难以进行插层反应;通过焙烧复原法可显著降低MgAl-LDHs层间CO2-离子,从而有利于BP阴离子交换进入MgAl-LDHs层间,在去离子水中,水温100℃,pH=7,反应时间为48h,BP过饱和的条件下合成得到最高插层率的MgAl-BP-LDHs;主体水滑石层板与客体以静电力和氢键相互作用,得到的超分子结构材料具有良好的热稳定及兼具优异的紫外屏蔽、吸收性能,是一种新型的有机-无机复合光热稳定剂。  相似文献   

14.
以层状镁铝双金属氢氧化物(MgAl Layered Double Hydroxides,Mg-Al LDHs)为主体,以有机紫外光稳定剂2-羟基-4-甲氧基二苯甲酮-5-磺酸(BP)为客体,结合焙烧复原法和阴离子交换法合成了具有超分子结构有机-无机插层复合物(MgAl-BP-LDHs),研究了层间阴离子、反应介质、pH值、反应时间等因素对于插层材料超分子结构的影响。用FTIR、XRD、TG-DTA、UV-Vis和粒度分析对其不同尺度的结构、热稳定性和紫外光稳定性等进行表征。结果表明,采用阴离子交换法难以进行插层反应;通过焙烧复原法可显著降低MgAl-LDHs层间CO2-离子,从而有利于BP阴离子交换进入MgAl-LDHs层间,在去离子水中,水温100℃,pH=7,反应时间为48 h,BP过饱和的条件下合成得到最高插层率的MgAl-BP-LDHs;主体水滑石层板与客体以静电力和氢键相互作用,得到的超分子结构材料具有良好的热稳定及兼具优异的紫外屏蔽、吸收性能,是一种新型的有机-无机复合光热稳定剂。  相似文献   

15.
Norfloxacin (NFX)-layered double hydroxide (LDH) intercalated nanocomposite was synthesized by delamination/restacking process. In this method, LDH particles were first delaminated to well-dispersed two-dimensional nanosheets in formamide, and then the LDH nanosheets and NFX anions co-assembled into NFX-LDH nanocomposite. Characterization by powder x-ray diffraction, Fourier transform infrared spectroscopy, elemental analysis, and thermogravimetry revealed that the product had an expanded LDH structure. This finding indicated that NFX was successfully intercalated into LDH layers, and NFX had both horizontal and vertical orientation in the interlayers of NFX-LDH nanocomposite. Additionally, the delamination/restacking method displayed various remarkable advantages such as simple procedure, short reaction time, and mild conditions compared with the conventional methods of ion exchange, co-precipitation, and reconstruction. Results further showed that the thermal stability of NFX greatly improved after intercalation into LDH layers and that NFX release of the NFX-LDH nanocomposite was gradual, suggesting potential use as an effective drug delivery system.  相似文献   

16.
The aim of the present work was to synthesize and characterize layered doublehydroxides (LDHs), in the magnesium/aluminum form, intercalated with copper(II)phthalocyanine tetrasulfonate (CuPcTs). The metal complex was immobilized intothe LDH gallery region through the reconstitution method and this material wascharacterized by X-ray diffraction (XRD), surface area and porosity measurements,elementary analysis, thermogravimetry (TGA), vibrational (IR) and electronic(UV-visible) spectroscopies, and electronic paramagnetic resonance (EPR). Thecatalytic performance of CuPcTs intercalated and supported on the LDH wasevaluated by carrying out the hydrogen peroxide dismutation. The CuPcTs wassuccessfully intercalated into the LDH layers according to XRD data (the basalspacing of the carbonate precursors increases by approximately 15Å inthe intercalated samples). The surface area and porosity analysis suggested thatthe CuPcTs intercalated materials are not microporous solids. Samples containingthe metal complex confined between the LDH layers have an appreciable thermalstability: decomposition is not observed at least up to 400 °C. TGA experiments also show that the weight-loss curves of the CuPcTs supported samples superimpose those recorded for the CuPcTs complex and the LDH-carbonate while the curves for theintercalated materials are unique. CuPcTs intercalated or supported on LDHs is notactive in the hydrogen peroxide dismutation although the free form shows activity at pH above 8.  相似文献   

17.
In this work the synthesis and characterization of a magnetic composite is described. It was prepared by deposition of Nap‐Mg‐Al‐LDH on Fe3O4 by a coprecipitation method. The structures of the obtained products were studied by powder X‐ray diffraction, FT‐IR spectroscopy, elemental analysis, and thermogravimetric analysis. From the X‐ray diffraction results, it was found that Fe3O4 was successfully distributed into the layered double hydroxide (LDH) phase. Furthermore, the increase in the basal spacing of LDHs from 0.881 nm to 2.157 nm shows that naproxen was successfully intercalated into the interlayer space. The particle size was estimated using transmission electron microscopy. Thermogravimetric studies indicate that the thermal stability of naproxen was enhanced after intercalation. Moreover, in vitro drug release experiments in phosphate buffer solution (pH = 7.4) were investigated.  相似文献   

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