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991.
Wetting on nanoporous alumina surface: transition between Wenzel and Cassie states controlled by surface structure 总被引:2,自引:0,他引:2
Ran C Ding G Liu W Deng Y Hou W 《Langmuir : the ACS journal of surfaces and colloids》2008,24(18):9952-9955
This paper reports a systematic study on the relationship between surface structure and wetting state of ordered nanoporous alumina surface. The wettability of the porous alumina is dramatically changed from hydrophilicity to hydrophobicity by increasing the hole diameter, while maintaining the hole interval and depth. This phenomenon is attributed to the gradual transition between Wenzel and Cassie states which was proved experimentally by comparing the wetting behavior on these porous alumina surfaces. Furthermore, the relationship between surface wettability and hole depth at a fixed hole interval and diameter was investigated. For those porous alumina with relatively larger holes in diameter, transition between Wenzel and Cassie states was also achieved with increasing hole depth. A capillary-pressure balance model was proposed to elucidate the unique structure-induced transition, and the criteria for the design and construction of a Cassie wetting surface was discussed. These structure-induced transitions between Wenzel and Cassie states could provide further insight into the wetting mechanism of roughness-induced wettability and practical guides for the design of variable surfaces with controllable wettability. 相似文献
992.
Zhao Y Zhang J Han B Zhang C Li W Feng X Hou M Yang G 《Langmuir : the ACS journal of surfaces and colloids》2008,24(17):9328-9333
Lecithin is a very useful biosurfactant. In this work, the effects of compressed CO 2 on the critical micelle concentration (cmc) of lecithin in cyclohexane and solubilization of water, lysozyme, and PdCl 2 in the lecithin reverse micelles were studied. The micropolarity and pH value of the polar cores of the reverse micelles with and without CO 2 were also investigated. It was found that CO 2 could reduce the cmc of the micellar solution and enhance the capacity of the reverse micelles to solubilize water, the biomolecule, and the inorganic salt significantly. Moreover, the water pools could not be formed in the reverse micelles in the absence of CO 2 because of the limited amount of water solubilized. However, the water pools could be formed in the presence of CO 2 because large amounts of water could be solubilized. All of these provide more opportunity for effective utilization of this green surfactant. The possible mechanism for tuning the properties of the reverse micelles by CO 2 is discussed. 相似文献
993.
Adsorption behavior of Pb(II) on montmorillonite 总被引:1,自引:0,他引:1
Shu Qin Zhang Wan Guo Hou 《Colloids and surfaces. A, Physicochemical and engineering aspects》2008,320(1-3):92-97
The present work investigated the adsorption and desorption behaviors of Pb(II) on montmorillonite. The adsorption experiments were carried out using batch process. The results show that the adsorption is dependent on the pH value of the medium, and the uptake of Pb(II) increases with the pH increasing in the pH range of 2.0–10.0. The adsorption kinetics is in better agreement with pseudo-second order kinetics, and the adsorption data is a good fit with Langmuir isotherm. The presence of EDTA may result in a decrease of the amount of Pb(II) adsorbed. The presence of electrolyte and EDTA may enhance the desorption of Pb(II) ions adsorbed. The adsorption mechanism of Pb(II) on montmorillonite may be explained in two aspects: the chemical binding between Pb(II) ions and surface hydroxyl groups; and the electrostatic binding between Pb(II) ions and the permanent negatively charged sites of montmorillonite. 相似文献
994.
Bo Deng Jingye Li Zhengchi Hou Side Yao Liuqing Shi Guoming Liang Kanglong Sheng 《Radiation Physics and Chemistry》2008,77(7):898-906
Polyethersulfone (PES) powder was grafted with acrylic acid (AAc) by simultaneous γ-ray irradiation. The kinetics of the radiation induced graft polymerization was studied and the grafted PES powder was characterized. Then, microfiltration (MF) membranes were prepared from PES-g-PAAc powder with different degrees of grafting (DG) under phase inversion method. The swelling behavior and the mean pore size of MF membranes were measured, and the filtration property was tested. The results showed that the pore size and the flux of MF membranes increased with the increase in DG. And, MF membranes’ properties were dependent on the pH value. 相似文献
995.
Hou J Chen HY Zhang S Li G Yang Y 《Journal of the American Chemical Society》2008,130(48):16144-16145
A new low band gap silole-containing conjugated polymer, PSBTBT, was designed and synthesized. Photovoltaic properties of PSBTBT were initially investigated, and an average power conversion efficiency (PCE) of 4.7% with a best PCE of 5.1% was recorded under illumination (AM 1.5G, 100 mW/cm(2)). The response range of the device covers the whole visible range from 380 to 800 nm. These results indicate that PSBTBT is a promising polymer material for applications in polymer solar cells. 相似文献
996.
New JM118 (active form of satraplatin) analogues with N-cyclohexyl-1,3-propanediamine (N-chpda) as the carrier, cis-[Pt(N-chpda)X2] (X2=2Cl(-) (1), oxalate (2), malonate (3), 1,1-cyclobutanedicarboxylate (CBDCA) (3), and 3-hydroxy-1,1-cyclobutanedicarboxylate(HO-CBDCA) (4)), have been synthesized and characterized by elemental analysis and spectroscopic data along with X-ray crystal structure for a representative compound cis-[Pt(N-chpda)Cl2]. The complexes have also been evaluated for their in vitro anticancer activity. All these analytical data are in good agreement with the structures of the desired compounds. The Pt(II) is in a square planar environment and is coordinated by a chelating N-chpda ligand and 2Cl(-) in cis position, and there are two crystallographically independent cis-[Pt(N-chpda)Cl2] molecules linked together by intermolecular N-H...Cl hydrogen bonds. Compounds 1 and 2 are very active against human lung cancer cell line (AGZY) and human lymphocytic leukemia cell line (Raji), and are much more active than carboplatin. Platinum(II) complexes with N-cyclohexyl-1,3-propanediamine is an alternative choice for mixed ammine/aminoplatinum anticancer drugs. 相似文献
997.
The radiometric methods, alpha (α)-, beta (β)-, gamma (γ)-spectrometry, and mass spectrometric methods, inductively coupled plasma mass spectrometry, accelerator mass spectrometry, thermal ionization mass spectrometry, resonance ionization mass spectrometry, secondary ion mass spectrometry, and glow discharge mass spectrometry are reviewed for the determination of radionuclides. These methods are critically compared for the determination of long-lived radionuclides important for radiation protection, decommissioning of nuclear facilities, repository of nuclear waste, tracer application in the environmental and biological researches, these radionuclides include 3H, 14C, 36Cl, 41Ca, 59,63Ni, 89,90Sr, 99Tc, 129I, 135,137Cs, 210Pb, 226,228Ra, 237Np, 241Am, and isotopes of thorium, uranium and plutonium. The application of on-line methods (flow injection/sequential injection) for separation of radionuclides and automated determination of radionuclides is also discussed. 相似文献
998.
Yilin Zhao Tingting Hou Liming Zhang Xue Wang Jingli Hou Yangping Liu Guifang Han Yuguang Song 《European journal of organic chemistry》2023,26(18):e202300253
An iron-catalyzed trifluoromethylation of indole-tethered alkene with Togni's reagent to construct CF3-containing spiro[indole-3,3′-pyrrolidine] and tetrahydrocarbazole derivatives under mild and convenient conditions has been disclosed. Mechanistic studies indicate that the reaction proceed through a CF3 radical addition to the alkene, followed by sequential dearomatizing spiocyclization of the indole and oxidation to afford the spiro[indole-3,3′-pyrrolidine] derivatives. Meanwhile, when the substituent at the C2 position of the indole is hydrogen, the CF3-containing tetrahydrocarbazole is obtained through trifluoromethylation of alkene and cyclization of indole. 相似文献
999.
Jiaying Duan Jiapeng Wang Liangpeng Hou Peixuan Ji Wusheng Zhang Jin Liu Xiaodong Zhu Zhixiang Sun Yanqing Ma Lei Ma 《Chemical record (New York, N.Y.)》2023,23(10):e202300120
Colloidal quantum dots display remarkable optical and electrical characteristics with the potential for extensive applications in contemporary nanotechnology. As an ideal instrument for examining surface topography and local density of states (LDOS) at an atomic scale, scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS) has become indispensable approaches to gain better understanding of their physical properties. This article presents a comprehensive review of the research advancements in measuring the electronic orbits and corresponding energy levels of colloidal quantum dots in various systems using STM and STS. The first three sections introduce the basic principles of colloidal quantum dots synthesis and the fundamental methodology of STM research on quantum dots. The fourth section explores the latest progress in the application of STM for colloidal quantum dot studies. Finally, a summary and prospective is presented. 相似文献
1000.
Hongni Teng Xiuyun Wang Yixiao Hou Cuiying Yang Teng Shen 《Journal of Dispersion Science and Technology》2016,37(6):830-835
The properties and extraction for [Ni(NH3)6]2+ of anionic aqueous two-phase systems (ATPS-a) that formed in mixtures of cetyltrimethylammonium bromide (CTAB) and excess sodium dodecyl sulfate (SDS) aqueous solutions were investigated. The results showed that the properties and extraction effects were strongly affected by the surfactant concentration, the temperature of system, and the mole fraction of surfactants. The increase of temperature induces narrower phase region and larger phase volume ratio. In addition, [Ni(NH3)6]2+ was extracted into the surfactant-rich phase with higher distribution coefficient when the liquid crystal had the birefringent properties. Moreover, the distribution coefficient can be improved through reducing the concentration of surfactant from 0.15 to 0.05 mol · L?1 or increasing mole fraction of CTAB from 21.9% to 23.1%. The results showed that ATPS of cationic–anionic surfactants was efficient for [Ni(NH3)6]2+ extraction with distribution coefficients of 13.5 when the total surfactant concentration was 0.05 mol · L?1, mole fraction of CTAB was 21%, and temperature was 34°C. 相似文献