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Low-temperature synthesis of allyl dimethylamine by selective heating under microwave irradiation used for water treatment 总被引:1,自引:0,他引:1
Low-temperature synthesis of allyl dimethylamine (ADA) by selective heating under microwave irradiation (MI) used for water treatment is investigated. The effect of MI, ultrasound irradiation (UI) and conventional heating on yield of ADA, reaction time and the flocculation efficiency of polydiallyl dimethylammunion chloride (PDADMAC) prepared form ADA were studied. The results show that by selective heating at low temperature, MI not only increases yield of ADA and reduces reaction time, but also greatly enhances the flocculation efficiency of PDADMAC. 相似文献
13.
金属离子掺杂对TiO2光催化性能的影响 总被引:14,自引:1,他引:14
TiO2光催化反应过程涉及光生电荷、电荷迁移、电荷在TiO2表面的反应和溶液体相反应4个顺序相接并相互影响的步骤.在TiO2中掺杂金属离子对以上4个步骤均有重要影响,合理的掺杂可有效地提高其光催化性能.本文综合了国内外此方面的最新研究成果,从提高TiO2光催化性能和优化光催化反应的角度出发,在材料吸光能力、电荷扩散、表面反应、粒径和晶型等方面,全面地分析总结了金属离子掺杂的影响效果和规律性认识,并对TiO2基光催化材料的金属离子掺杂改性研究的未来发展方向提出了建议.文中还简要介绍了相关的掺杂方法和材料表征手段. 相似文献
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Jingfei Luan Zhigang Zou Minghui Lu Guoyou Luan Yanfeng Chen 《Research on Chemical Intermediates》2006,32(1):31-42
In2BiTaO7 was synthesized using the solid-state reaction method and its photocatalytic properties were investigated. The results of
powder X-ray diffraction (XRD) indicated that the compound crystallizes in the pyrochlore-type structure, cubic system with
space group Fd-3m. The lattice parameter is 10.6972(1) ?. In addition, the compound shows strong optical absorption in the
visible region (λ > 420 nm) and the band gap of In2BiTaO7 was estimated to be about 2.47 eV. For the photocatalytic reaction, H2 or O2 evolution was observed from CH3OH/H2O or AgNO3 solution respectively with In2BiTaO7 as the photocatalyst under visible light irradiation, indicating that In2BiTaO7 is responsive to visible light for splitting water. Furthermore, the catalyst remained photoactive in the wavelength range
up to 510 nm. Photocatalytic degradation of methylene blue (MB) dye over the compound was further investigated under visible
light irradiation. The results showed that complete removal of aqueous MB could be achieved after irradiation for 135 min
over In2BiTaO7. Furthermore, under visible light irradiation In2BiTaO7 showed markedly higher catalytic activity compared to P-25 for MB photocatalytic degradation. 相似文献
16.
Ag/Al2O3选择性催化丙烯还原氮氧化物表面反应机理的原位红外光谱研究 总被引:2,自引:0,他引:2
在富氧条件下Ag/Al2O3对以丙烯为还原剂选择性催化还原NOx的反应有很高的催化活性.本实验成功地利用原位红外光谱分析手段,在真实的催化反应条件下,探讨了丙烯选择性还原NOx的反应机理,证实了催化剂表面反应中间体Al-NCO和Ag-NCO虽在真空中稳定,但在实际反应条件下极为活泼.催化剂表面上R-ONO和R-NO2分解成NCO是整个反应的速度控制步骤.这一结论与在真空系统条件下对其反应机理的研究结果一致,证明了在这一反应体系中两种研究方法的相关性.同时本实验还从反应机理上探讨了催化剂的水蒸气中毒现象.水蒸气的存在阻碍了催化剂表面R-ONO和R-NO2的生成,并进一步阻碍了反应的速度控
制步骤,即R-ONO和R-NO2向Al-NCO和Ag-NCO的转化,但这是一种完全可逆的暂时中毒现象.结合相应的催化剂活性评价结果对表面反应机理进行了讨论. 相似文献
17.
A hierarchy of Hamiltonian systems obtained from the Lax pair of KdV hierarchy under the constraint condition on potentialu = q, q is presented. The independent integrals for these Hamiltonian systems are constructed by using recursion operator and shown to be in involution. Thus this hierarchy of Hamiltonian systems is completely integrable in the sense of Liouville, and they commute with each other.This project is supported by the National Natural Science Foundation of China. 相似文献
18.
A novel solvent-relief-self-seeding (SRSS) process was applied to grow bulk polygonal tubular single crystals of Sb(2)E(3) (E = S, Se), using SbCl(3) and chalcogen elements E (E = S, Se) as the raw materials at 180 degrees C for 7 days in ethanol solution. The products were characterized by various techniques, including X-ray powder diffraction (XRD), scanning electronic microscope (SEM), transmission electronic microscope (TEM), electronic diffraction (ED), and X-ray photoelectron spectra (XPS). The calculated electrical resistivities of the tubular single crystals in the range 20-320 K were of the order of 10(5)-10(6) Omega cm for Sb(2)S(3) and 10(3)-10(4) Omega cm for Sb(2)Se(3), respectively. The studies of the optical properties revealed that the materials formed had a band gap of 1.72 eV for Sb(2)S(3) and 1.82 eV for Sb(2)Se(3), respectively. The optimal reaction conditions for the growth of bulk tubular single crystals were that the temperature was not lower than 180 degrees C and the reaction time was not shorter than 7 days. The possible growth mechanism of tubular crystals was also discussed. 相似文献
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Ângelo M.L. Denadai André M. de Oliveira Izabela M.P. Daniel Luan A. Carneiro Kherolayne C. Ribeiro Heloísa de O. Beraldo 《Supramolecular chemistry》2013,25(3):204-212
Chlorhexidine is a widely used, di-cationic, broad-spectrum antimicrobial agent and losartan is a well-known, anionic-specific antagonist of AT1 renin–angiotensin receptor that acts as an anti-hypertensive agent. The combination of these molecules gives a chlorhexidine di-losartanate (ClxLos2) hydrophobic ion pair that spontaneously aggregates into nanoparticles (NPs). This work investigated the formation of ClxLos2 NPs using the analysis of the solid state by fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry and scanning electron microscopy and in aqueous environment by calorimetric, zeta potential and dynamic light scattering titrations. Furthermore, to demonstrate the potential antimicrobial activity of ClxLos2, in vitro antibacterial tests were conducted against Staphylococcus aureus (ATCC 27664), Streptococcus viridans (ATCC 11563) and Enterococcus faecalis (ATCC 14508). Based on these studies, it is proposed that ClxLos2 could be used for controlled drug release based on ionic dissociation during dilution, thereby avoiding the use of any solid matrix. 相似文献