Knoevenagel condensation catalysed by poly（vinyl chloride） supported tetraethylenepentamine （PVC-TEPA）

Poly(vinyl chloride) supported tetraethylenepentamine (PVC-TEPA) has been found to be an efficient catalyst for the Knoevenagel condensation. A wide range of aromatic aldehydes easily undergo condensations with ethyl cyanoacetate and malononitrile in the commercial 95% ethanol in refluxing using PVC-TEPA as catalyst to afford the desired products of good purity in moderate to excellent yields. A recycling study confirmed that the catalyst could be reused, the yield of the desired condensation product were not reduced. The merits of this protocol are environmentally benign, simple operation, convenient work-up and good yields. Furthermore, the catalyst can easily be recovered and reused at five times with comparable yields.     

四乙烯五胺功能化纤维素负载纳米钯催化剂的制备及其对Suzuki反应催化性能的研究

利用四乙烯五胺对环氧化纤维素进行功能化改性,并以其为载体在95％乙醇溶液中现场还原氯化钯制备出四乙烯五胺功能化纤维素负载的纳米钯催化剂.利用IR,XRD,SEM,TEM等分析方法对其进行了表征并用于催化Suzuki交叉偶联反应.实验表明,该催化剂在温和条件下能有效催化卤代芳烃与芳基硼酸的Suzuki交叉偶联反应,该催化剂经回收重复利用5次后,仍具有较高的催化活性.     

Amine-functionalized low-cost industrial grade multi-walled carbon nanotubes for the capture of carbon dioxide

Industrial grade multi-walled carbon nanotubes (IG-MWCNTs) are a low-cost substitute for commercially purified multi-walled carbon nanotubes (P-MWCNTs). In this work, IG-MWCNTs were functionalized with tetraethylenepentamine (TEPA) for CO₂ capture. The TEPA impregnated IG-MWCNTs were characterized with various experimental methods including N₂ adsorption/desorption isotherms, elemental analysis, X-ray diffraction, Fourier transform infrared spectroscopy and thermogravimetric analysis. Both the adsorption isotherms of IG-MWCNTs-n and the isosteric heats of different adsorption capacities were obtained from experiments. TEPA impregnated IG-MWCNTs were also shown to have high CO₂ adsorption capacity comparable to that of TEPA impregnated P-MWCNTs. The adsorption capacity of IG-MWCNTs based adsorbents was in the range of 2.145 to 3.088 mmol/g, depending on adsorption temperatures. Having the advantages of low-cost and high adsorption capacity, TEPA impregnated IG-MWCNTs seem to be a promising adsorbent for CO₂ capture from flue gas.     

Process regulation for encapsulating pure polyamine via integrating microfluidic T-junction and interfacial polymerization

The quality of microcapsules directly determines the performance of microcapsule-based functional materials, such as self-healing materials. How to achieve high-quality microcapsules depends on not only the selected microencapsulation technique but also the process regulation. Herein, using tetraethylenepentamine (TEPA) as the core target to be encapsulated by a novel microencapsulation technique through integrating microfluidic T-junction and interfacial polymerization, this investigation studied how the process parameters influence the microencapsulation process and the quality of the synthesized microcapsules regarding the size, morphology, shell structure, and composition. The studied parameters include the solvent type and surfactant concentration in the co-flow solution, the fed volume of the co-flow solution, the types of the solvent, catalyst, and shell-forming monomer in the reaction solution for the shell-growth stage, and the reaction temperature at the shell-growth stage. The influence mechanisms were established based on the observations, and the optimized parameter combination for the process was achieved. Through the parametric study for the microencapsulation technique, this study also lays a solid foundation for the technique to fabricate microcapsules containing other functional substances with high quality.     

Intercalation of monomers into alpha tin(IV) hydrogen phosphate

Monomers which contain unsaturated linkages and amine groups have been intercalated to form either mono- or bi-layers. The monomertrans-N,N-diethyl-2-butene-1,4-diamine (NNBD) has been intercalated into -tin(IV) hydrogen phosphate. The guest molecule, NNBD, forms a monolayer (d ₀₀₁ = 1.35 nm) in which the amine groups are paired to protons on opposite faces of the phosphate layers. The resultant compound has the formula Sn(C₈H₁₈N₂)_0.73(HPO₄)₂·H₂O indicating that NNBD does not cover a large proportion of the available protons. 4-vinylpyridine slowly forms an intercalate in which the host molecule forms a bilayer (d ₀₀₁ = 1.56 nn). However, with 4-vinylpyridine there is surface modification in preference to intercalation.     

离子交换树脂固态胺复合材料的制备、表征及CO2吸附

以离子交换树脂（D001）为载体,四乙烯五胺（TEPA）为改性剂,采用三种不同的方法制备了一系列固态胺吸附剂。采用N₂吸附-脱附、傅里叶变换红外光谱（FT-IR）、热重分析（TGA）等手段对吸附剂进行表征。在固定床反应器中考察了TEPA负载量、吸附温度、进气流量和CO₂分压等因素对CO₂吸附性能的影响。结果表明,配位法制得的固态胺吸附剂分散性和稳定性较好,且在TEPA负载量为40%,吸附温度为65℃,进气流量为40 mL/min时有最大CO₂吸附量达4 mmol/g。经过10次吸附-脱附循环实验后,CO₂吸附量下降3.98%。热力学、动力学研究结果表明,CO₂吸附是物理吸附和化学吸附的结果。     

Tetraethylenepentamine-directed controllable synthesis of wurtzite ZnSe nanostructures with tunable morphology

A novel tetraethylenepentamine (TEPA)-directed method has been successfully developed for the controlled synthesis of ZnSe particles with distinctive morphologies, including nanobelts, nanowires, and hierarchically solid/hollow spheres. These structures, self-assembled from nanobelts and nanorods, have been synthesized by adjusting the reaction parameters, such as the solvent composition, reaction temperature, and the aging time. Results reveal that the volume ratio of H2O and TEPA plays a crucial role in the final morphology of ZnSe products. The mechanisms of phase formation and morphology control of ZnSe particles are proposed and discussed in detail. The products have been characterized by means of X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy (TEM), selected area electron diffraction, high-resolution TEM, Raman spectra and luminescence spectroscopy. The as-prepared ZnSe nanoparticles display shape- and size-dependent photoluminescent optical properties. This is the first time to report preparation of complex hollow structures of ZnSe crystals with hierarchy through a simple solution-based route. This synthetic route is designed to exploit a new H2O/TEPA/N2H4H2O system possibly for the preparation of other semiconductor nanomaterials.     

四乙烯五胺修饰介孔硅胶吸附CO2性能的研究

采用浸渍法将四乙烯五胺(TEPA)负载到介孔硅胶(SG)上,制备了一系列胺功能化的CO₂吸附材料(TEPA-SG).利用傅里叶变换红外光谱(FT-IR)、热重分析(TGA)和N₂吸脱附等分析方法对样品进行了表征,并在固定床反应器中考察了TEPA负载量、吸附温度对CO₂吸附性能的影响,同时通过添加不同质量分数的聚乙二醇(PEG)考察了羟基对吸附性能及再生性能的促进作用.结果表明,当TEPA负载量为40%(质量分数)、吸附温度为70 ℃时,TEPA-SG的吸附量高达2.21 mmol/g;PEG的加入改变了氨基与CO₂的相互作用机理,当TEPA与PEG的质量比为3:1,总负载量为40%时,CO₂的吸附量为2.70 mmol/g,且经过10次吸脱附循环实验后,CO₂吸附量仍保持在2.66 mmol/g,表现出较好的循环稳定性.Clausius-Clapeyron方程计算得该过程的等量吸附热为30~40 kJ/mol,且随吸附量的增大等量吸附热逐渐减小,表明TEPA30/PEG10-SG吸附剂表面存在能量不均匀性.     

新型多级微/介孔固态胺吸附剂的制备及其CO2吸附性能研究

将HZSM-5与MCM-41按不同质量比混合得到复合分子筛载体,以四乙烯五胺(TEPA)为改性剂,采用浸渍法将其负载到复合分子筛上,制备了一系列新型的具有多级微/介孔结构的固态胺吸附剂。采用N₂吸脱附、傅里叶变换红外光谱(FT-IR)、热重分析(TGA)等手段对吸附剂进行表征。在固定床反应器中考察了HZSM-5和MCM-41的质量比、TEPA负载量、吸附温度、进气流量和CO₂分压等因素对CO₂吸附性能的影响。结果表明,当HZSM-5与MCM-41的质量比为1:1、TEPA负载量为30%、吸附温度为55℃、进气流量为30 mL/min时,平衡吸附量高达3.57 mmol/g,且经10次吸脱附循环后,吸附量仅下降8.1%。HZSM-5/MCM-41-30%TEPA对CO₂的吸附过程包括快速的穿透吸附和相对缓慢的逐渐平衡阶段,且穿透吸附量接近于平衡吸附量的80%。HZSM-5/MCM-41-30%TEPA对CO₂的吸附过程符合Avrami动力学模型,表明CO₂吸附是物理吸附和化学吸附的结果。     

Effects of salt on the protonation in aqueous solution of triethylenetetramine and tetraethylenepentamine

Protonation constants of triethylenetetramine (trien) and tetraethylenepentamine (tetren) were determined, in NaCl aqueous solutions, at different ionic strengths, at 25°C, using the the pH-metric technique. The behavior of protonation constants as a function of ionic strength can be explained by a model which takes into account the formation of the species AH _q Cl _p [A=amine; q=1...4, p=1,2 (trien); q=1...5, p=1.3 (tetren)].