微波法合成(SBA-15)-Eu_2O_3纳米复合材料研究

本文采用了水热合成法制备出介孔分子筛SBA-15,并创新性地利用微波液相介质法、微波固相法把纳米Eu2O3成功的组装到介孔分子筛SBA-15孔道内。所制备的(SBA-15)-Eu2O3主-客体纳米复合材料表现出与Eu2O3不同的发光现象,它发出单色光,使光谱纯化。     

微波法合成(SBA-15) -Et2O3纳米复合材料研究

本文采用了水热合成法制备出介孔分子筛SBA-15,并创新性地利用微波液相介质法、微波固相法把纳米Eu2O3成功的组装到介孔分子筛SBA-15孔道内.所制备的(SBA-15) -Eu2O3主-客体纳米复合材料表现出与Eu2O3不同的发光现象,它发出单色光,使光谱纯化.     

新型稀土农用转光剂(Eu,Gd)(C_(15)H_(11)O_2)_3Phen的合成及性质

以Eu~(3+)为中心发光离子,Gd~(3+)为敏化离子,二苯甲酰甲烷(DBM)为主配体,1,10-邻菲罗啉(Phen)为第二配体,合成了系列(Eu, Gd)(C_(15)H_(11)O_2)_3Phen转光剂。实验表明:在Eu(DBM)3Phen中以共沉淀方式掺杂Gd~(3+)敏化离子后形成的(Eu_(0.5)Gd_(0.5))(DBM)3Phen转光材料,其相对发光强度提高1.90倍,产品成本降低26%,热稳定性也优于Eu(DBM)3Phen,是一种具有实用价值的稀土农用有机转光剂。     

稀土钐聚丙烯酰胺发光材料的合成及性能

以钐离子为中心体,利用二苯甲酰基甲烷(DBM)为第一配体,1,10-菲罗啉(phen)为第二配体与氯化钐在乙醇中反应,加入钆离子(Gd~(3+))对其敏化,合成了具有发光性能的稀土钐三元配合物Sm/Gd(DBM)3phen。将钐三元配合物与丙烯酰胺(AM)进行共聚反应,制备了一种键合型稀土聚丙烯酰胺共聚物[Sm/Gd(DBM)3phen/PAM]。通过元素分析、傅里叶变换红外光谱、紫外光谱、荧光光谱分析、热重分析测定了配合物及共聚物的组成、结构、发光性能及稳定性。结果表明:Sm/Gd(DBM)3phen/PAM的发光性能优于Sm/Gd(DBM)3phen,在紫外光的激发下于559、597、643 nm处发射出Sm~(3+)的4G5/2—6H5/2、4G5/2—6H7/2、4G5/2—6H9/2跃迁特征荧光。其中,不发光的Gd~(3+)对于发光的Sm~(3+)有明显的荧光增强作用。     

二元、三元二苯甲酰甲烷铕配合物的荧光研究

以发光的三价铕离子为中心体，二苯甲酰甲烷（DBM）、邻菲罗啉（Phen)和2，2‘-联吡啶（Dipy）为配体，在无水乙醇溶液中反应，合成了二元铕配合物Eu(DBM)3和三元配合物Eu(Phen）（DBM）3及Eu(Dipy)（DBM)3,经元素分析，确定了其组成。红外光谱及荧光光谱测试表明，配体中氧原子和氮原子均与铕（Ⅲ）离子配位，三元配合物的荧光强度高于二元配合物，三元配合物中含吡啶的配合物Eu(Dipy)(DBM)3荧光强度又高于含邻菲罗啉的配合物Eu(Phen)-(DBM)。     

Eu(DBM)·phen三元配合物薄膜的制备和表征

合成了三元配合物Eu(DBM) 3 ·phen ,并采用Sol-Gel提拉法制备了Eu(DBM) 3 ·phen薄膜 ,对其性质进行了详细的研究     

由沸石纳米粒子自组装制备具有高催化活性中心和水热稳定的新型介孔分子筛材料

人们合成了一系列介孔分子筛材料,并发现它们在催化、吸附与分离以及化学组装制备先进材料和分子器件等方面具有很大的潜在应用价值.但是,介孔分子筛材料相对于微孔沸石分子筛存在着两个致命弱点:较低的水热稳定性和较不活泼的催化活性中心.这两个弱点大大地影响了介孔分子筛在催化反应中的广泛应用.本文系统地综述了最近几年利用沸石纳米粒子自组装制备具有高催化活性中心和水热稳定的介孔分子筛材料的研究进展.这包括利用硅铝沸石纳米粒子自组装制备具有强酸性和水热稳定的新型介孔硅铝分子筛材料,利用钛硅沸石纳米粒子自组装制备具有高催化氧化活性中心和水热稳定的新型钛硅介孔分子筛材料,以及利用含有不同杂原子的沸石纳米粒子自组装制备一系列水热稳定的新型介孔分子筛催化材料.     

金属及其化合物固载的介孔分子筛研究进展

介绍了金属及其化合物固载于介孔分子筛(主要是HMS、MCM-41、SBA-15、MSU)的主要方法如进入骨架、表面修饰以及组装等的研究进展,指出开发新型模板剂是改善介孔分子筛水热稳定性的有效方法.     

聚丙烯荧光材料制备及其3D打印测试

通过配位反应合成了三种荧光配合物:铕配合物[Eu(DBM)3phen],8-羟基喹啉铝配合物(AlQ3)和8-羟基喹啉锌配合物(ZnQ2),然后通过熔融共混的方式在聚丙烯(PP)材料中分别掺杂这三种荧光配合物,制得三种PP/荧光配合物复合材料,以提高PP发光性能.对这三种复合材料进行了一系列的荧光和力学性能测试.结果表...     

纳米梯级孔MOR分子筛的一步制备及其在重芳烃转化中的应用

在纳米mordenite(MOR)分子筛的制备基础上,以十六烷基三甲基溴化铵(CTAB)为介孔模板剂,一步水热晶化合成了具有微-介孔结构的纳米梯级孔MOR分子筛,考察了合成条件对MOR分子筛晶粒尺寸和孔结构的影响以及Pt/MOR催化剂催化异丙苯脱烷基的性能。结果表明:在晶化温度130℃,晶化时间48 h,水硅比18,碱硅比0.36和转速20 r/min条件下,制备的MOR分子筛晶粒大小约为30.0 nm;在合成体系中引入适量的CTAB可获得纳米梯级孔MOR分子筛,与纳米MOR分子筛相比,其具有较高的介孔面积和介孔体积以及适宜的酸量与酸强度。以纳米梯级孔MOR分子筛为载体制得的Pt/MOR催化剂显示出优异的加氢脱烷基性能。     

Near-infrared luminescent mesoporous MCM-41 materials covalently bonded with ternary thulium complexes

Two β-diketones 4,4,4-trifluoro-1-2-thenoyl-1,3-butanedione (Htta) and 4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedione (Htfnb), which contain trifluoroalkyl chain, were selected as the main sensitizer for synthesizing Tm(L)₃phen (L = tta, tfnb) complexes. The two near-infrared (NIR) luminescent thulium complexes have been covalently bonded to the ordered mesoporous material MCM-41 via a functionalized 1,10-phenanthroline (phen) group 5-(N,N-bis-3-(triethoxysilyl)propyl)ureyl-1,10-phenanthroline (phen-Si) [The resultant mesoporous materials are denoted as Tm(L)₃phen–MCM-41 (L = tta, tfnb)]. The Tm(L)₃phen–MCM-41 (L = tta, tfnb) mesoporous materials were characterized by small-angle X-ray diffraction (XRD) and N₂ adsorption/desorption, and they show characteristic mesoporous structure of MCM-41. Luminescence spectra of the Tm(L)₃phen–MCM-41 (L = tta, tfnb) mesoporous materials were recorded and the corresponding luminescence decay curves were obtained. After ligand-mediated excitation, the emission spectra of the Tm(L)₃phen–MCM-41 (L = tta, tfnb) mesoporous materials show the characteristic NIR-luminescence of the Tm³⁺ ion. The full width at half maximum (fwhm) of the 1474-nm emission band are 96 and 100 nm for Tm(tta)₃phen–MCM-41 and Tm(tfnb)₃phen–MCM-41, respectively. The good luminescent performances enable these NIR-luminescent mesoporous materials to have potential applications in optical amplification [broadening amplification band from C band (1530–1560 nm) to S⁺ band (1450–1500 nm)]. Furthermore, the comparison of the luminescence behavior for Tm(tta)₃phen–MCM-41 and Tm(tfnb)₃phen–MCM-41 mesoporous materials was investigated. It shows that Tm(tfnb)₃phen–MCM-41 is somewhat superior to Tm(tta)₃phen–MCM-41 as optical amplifier.     

Bidentate salen Cu(II) complex functionalized on mesoporous MCM-41 as novel nano catalyst for the oxidative coupling of thiols into disulfides using urea hydrogen peroxide (UHP)

Functionalized Copper(II) complex into nano dimensional mesoreactor was successfully prepared. The Copper(II) complex with N–O donor Schiff base ligand was readily trapped into mesoporous silica MCM-41 through the post grafting method. N–O Chelating Schiff-base-MCM-41 has been derived from 5-bromo-salicylaldehyde and 3-aminopropyltriethoxysilane which was functionalized on MCM-41 via silicon alkoxide route. This compound was characterized by FT-IR, TGA, small angle X-ray diffraction patterns, ICP/MS analysis and N₂ sorption–desorption analysis. The catalytic property of Cu–salen–MCM-41 was considered for the preparation of disulfides using urea hydrogen peroxide as oxidant. The reaction progress is simple and proceeds under mild and heterogeneous conditions in acetonitrile at the ambient of temperature. The corresponding disulfides have been achieved with high purity and good to excellent yields; also, no over oxidation to sulfoxide or sulfone was observed in all cases. The catalyst can be recovered and reused several times without significant loss of stability and activity.     

Covalently bonding assembly and photophysical properties of luminescent molecular hybrids Eu–TTA–Si and Eu–TTASi–MCM-41 by modified thenoyltrifluoroacetone

In the context, the two novel kinds of hybrid materials, TTA–Si directly chemically bonded molecular hybrids and the corresponding MCM-41 host assembling hybrids were prepared. The organic–inorganic mesoporous luminescent materials were synthesized by linking Eu³⁺ complexes to the functionalized ordered mesoporous MCM-41 with modified thenoyltrifluoroacetone (TTA–Si) by co-condensation of tetraethoxysilane (TEOS) in the presence of the cetyltrimethylammonium bromide (CTAB) surfactant as template. Thenoyltrifluoroacetone (TTA) was grafted with coupling agent 3-(triethoxysilyl)-propyl isocyanate and the as-derived functional bridge molecule (denoted as TTA–Si) was introduced into inorganic polymeric host MCM-41 through covalent bonds, resulting in the molecular hybrid material. The luminescence properties of these resulting materials were characterized in detail, and the results reveal that they all have high surface area, uniformity in the mesostructure and crystallinity. The efficient intramolecular energy transfer in mesoporous material Eu–TTASi–MCM-41 mainly occurs between the modified ligand TTA–Si and the central Eu³⁺ ion. In addition, the constructed covalently bonded hybrids present the longer luminescent lifetimes than common Eu(III) β-diketones complexes for improvement of stability. Especially the mesoporous luminescent material Eu–TTASi–MCM-41possesses high luminescence quantum efficiency.     

Photosensized controlling benzyl methacrylate-based matrix enhanced eu(3+) narrow-band emission for fluorescence applications

This study synthesized a europium (Eu(3+)) complex Eu(DBM)(3)Cl-MIP (DBM = dibenzoyl methane; Cl-MIP = 2-(2-chlorophenyl)-1-methyl-1H-imidazo[4,5-f][1,10]phenanthroline) dispersed in a benzyl methacrylate (BMA) monomer and treated with ultraviolet (UV) light for polymerization. Spectral results showed that the europium complex containing an antenna, Cl-MIP, which had higher triplet energy into the Eu(3+) energy level, was an energetically enhanced europium emission. Typical stacking behaviors of π-π interactions between the ligands and the Eu(3+)-ion were analyzed using single crystal X-ray diffraction. Regarding the luminescence performance of this europium composite, the ligand/defect emission was suppressed by dispersion in a poly-BMA (PBMA) matrix. The underlying mechanism of the effective enhancement of the pure Eu(3+) emission was attributed to the combined effects of structural modifications, defect emissions, and carrier charge transfer. Fluorescence spectra were compared to the composite of optimized Eu3+ emission where they were subsequently chelated to four metal ions via carboxylate groups on the BMA unit. The optical enhanced europium composite clearly demonstrated highly efficient optical responses and is, therefore a promising application as an optical detection material.     

Distinct composite structure and properties of Eu(phen)2Cl3(H2O)2 in poly(methyl methacrylate) and polyvinylpyrrolidone

The luminescent europium complex Eu(phen)₂ Cl₃(H₂O)₂ (phen refers to 1,10‐phenanthroline) was doped in poly(methyl methacrylate) (PMMA) and polyvinylpyrrolidone (PVP), respectively. The formed composite systems with different molar ratios of C?O groups in polymers and Eu ions were characterized by X‐ray diffractometry (XRD), FTIR, and photoluminescent (PL) spectroscopy and lifetime measurement. The XRD diffractograms show that the composites of PMMA/Eu(phen)₂Cl₃(H₂O)₂ and PVP/Eu (phen)₂Cl₃(H₂O)₂ have crystalline and amorphous structures, respectively, arising from different interactions between the polymers and the complex, as revealed by FTIR spectra. This leads to distinct luminescent characteristics arising from the ⁵D₀→⁷F_J transitions of Eu(III) ion (J = 0–4). For the composite systems of PMMA/complex, the characteristics of the emission lines change with decreasing molar ratios of C?O/Eu and approach that of the pure complex; whereas the composite systems of PVP/complex have similar spectral features, regardless of the molar ratios, differing from that of the pure complex. The polymer matrices have a substantial influence on the structure and properties of the composites. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3524–3530, 2004     

Design and synthesis of near-IR luminescent mesoporous materials covalently linked with tris(8-hydroxyquinolinate)lanthanide(III) complexes

By using the bifunctional ligand, 8-hydroxyquinoline-functionalized organosilane (Q-Si), the new mesoporous material Q–MCM-41 covalently bonded with 8-hydroxyquinoline was synthesized. Through the ligand exchange reaction, the new near-infrared (NIR) luminescent mesoporous LnQ₃–MCM-41 (Ln = Er, Nd, Yb) materials were prepared by linking the lanthanide quinolinate complexes to the ordered mesoporous Q–MCM-41 material. The LnQ₃–MCM-41 materials were characterized by powder X-ray diffraction and N₂ adsorption/desorption, and they all show the characteristic mesoporous structure of MCM-41 with highly uniform pore size distributions. Fluorescence spectra of these LnQ₃–MCM-41 materials were recorded and the corresponding luminescence decay analyses were measured. After ligand-mediated excitation, all the emission spectra of the LnQ₃–MCM-41 materials show the characteristic NIR-luminescence of the corresponding lanthanide ions via the intramolecular energy transfer from the ligands to the lanthanide ions. The good luminescent performances enable these NIR-luminescent mesoporous materials to have potential applications in optical amplification (operating at 1.3 or 1.5 μm) and laser systems, etc.     

配合物Eu(Sal)_2(phen)_2(NO_3)的合成及荧光性能的研究

用硝酸铕、水杨酸与邻菲罗啉为原料合成了配合物Eu(Sal)2(phen)2(NO3),考察了配体用量和溶剂用量等因素对反应的影响。通过元素分析、红外光谱和紫外光谱确定了配合物的组成及结构,并通过荧光光谱对其荧光性质进行了研究。     

Novel luminescent europium(III) complexes covalently bonded to bis(phosphino)amine oxide functionalized MCM-41

A novel organo-functionalized mesoporous MCM-41 type of hybrid materials MCM–Si–DPBB was synthesized by co-condensation of bidentate Si(OR)₃ substituted N,N-2-diphenyloxyphosphine-4-bromomethyl-benzenamine (Si–DPBB) and tetraethoxysilane (TEOS) in the presence of the cetyltrimethylammonium bromide (CTAB) surfactant as template. Its ternary europium complex covalently bonded to the silica-based network MCM–Si–DPBB–Eu was also prepared by introduction the Eu(DBM)₃(H₂O)₂ into the hybrid materials. The hybrid material MCM–Si–DPBB–Eu has strong luminescence, and when excited by the ligands absorption wavelength (386 nm), it displays the emission of the Eu^{3+ 5}D₀-⁷F_J (J = 0, 1, 2, 3 and 4) transition lines due to the efficient energy transfer from the ligands to Eu³⁺.     

Ni and Mo interaction with Al-containing MCM-41 support and its effect on the catalytic behavior in DBT hydrodesulfurization

A series of Mo and NiMo catalysts supported on Al-containing MCM-41 was prepared and characterized by N₂ physisorption, XRD, ammonia TPD, temperature programmed reduction (TPR), UV-Vis diffuse reflectance spectroscopy (DRS) and ²⁷Al MAS-NMR. It was shown that the incorporation of Al atoms into the siliceous MCM-41 framework causes a deterioration of the textural characteristics and some loss in the periodicity of the MCM-41 pore structure. However, the acidity of the Al-containing MCM-41 is substantially higher. The dispersion of Mo and Ni oxidic species increases with the incorporation of aluminum in the MCM-41 support due to the strong interaction of Mo and Ni oxidic species with aluminum atoms of the support. However, the strong interaction of metal species with the Al-containing MCM-41 supports, up to the formation of Al₂(MoO₄)₃ in the case of unpromoted Mo catalysts, produces an increase in the proportion of Ni and Mo species difficult to reduce. When Ni and Mo are impregnated simultaneously the formation of Al₂(MoO₄)₃ is prevented because of the competitive interaction of both, Ni and Mo species, with Al atoms of the support. For both, Mo and NiMo catalysts, maximum catalytic activity in dibenzothiophene (DBT) hydrodesulfurization is observed for the catalysts supported on Al-MCM-41 with SiO₂/Al₂O₃ molar ratio of 30. When Al-containing MCM-41 is used as a support for NiMo catalyst, some cracking of the main reaction products (biphenyl (BiP), cyclohexylbenzene (CHB) and dicyclohexyl (DCH)) is observed.     

Atomistic simulations for adsorption and separation of flue gas in MFI zeolite and MFI/MCM-41 micro/mesoporous composite

Adsorption of pure CO₂ and N₂ and separation of CO₂/N₂ mixture in MFI zeolite and MFI/MCM-41 micro/mesoporous composite have been studied by using atomistic simulations. Fully atomistic models of MFI and MFI/MCM-41 are constructed and characterized. A bimodal pore size distribution is observed in MFI/MCM-41 from simulated small- and broad-angle X-ray diffraction patterns. The density of MFI/MCM-41 is lower than MFI, while its free volume and specific surface area are greater than MFI due to the presence of mesopores. CO₂ is preferentially adsorbed than N₂, and thus, the loading and isosteric heat of CO₂ are greater than N₂ in both MFI and MFI/MCM-41. CO₂ isotherm in MFI/MCM-41 is similar to that in MFI at low pressures, but resembles that in MCM-41 at high pressures. N₂ shows similar amount of loading in MFI, MCM-41 and MFI/MCM-41. The selectivity of CO₂ over N₂ in the three adsorbents decreases in the order of MFI>MFI/MCM-41>MCM-41. With increasing pressure, the selectivity increases in MFI and MFI/MCM-41, but decreases in MCM-41. The self-diffusivity of CO₂ and N₂ in MFI decreases as loading increases, while in MFI/MCM-41, it first increases and then drops.