The surface tension, foaming and viscosity for C7F15COO^-N^＋H（C2H4OH）χ（C2Hs）3-x and C8F17SO3- N^＋H（C2H4OH）χ（C2H5）3-χ （x = 0, 1, 2, 3） were measured to systematically study the effects of hydroxyl groups...The surface tension, foaming and viscosity for C7F15COO^-N^＋H（C2H4OH）χ（C2Hs）3-x and C8F17SO3- N^＋H（C2H4OH）χ（C2H5）3-χ （x = 0, 1, 2, 3） were measured to systematically study the effects of hydroxyl groups in organic ammonium counterions on the properties of perfluorooctanoates and perfluorooctanesulfonates. The results showed that the critical micelle concentration （cmc） and the surface tension at cmc （γcmc） were both increased with the increase of number of hydroxyl groups （χ） in the two series. The perfluorooctanesulfonate had smaller cmc but higher γ=cmc than perfluorooctanoate with the same counterion. The minimum molecular area of surface adsorption （Amin） of C8F17zSO3^-N^＋H（C2H4OH）χ（C2H5）3-χ were 0.64, 0.57, 0.63 and 0.72 nm^2 while the Amin values of C7F15COO^-N^＋H（C2H4OH）χ（C2H5）3-χ were 0.61, 0.62, 0.61 and 0.71 nm^2 when χ = 0, 1, 2 and 3, respectively. For the investigated systems of surfactants, the results of foam expansion ratio agreed with those of surface activity, while the 25% drainage time were consistent with the results of viscosity.展开更多
The dispersibility of vermiculite is the key factor that affects the application of vermiculite.In this paper,the milled natural vermiculite was pillared by organic quaternary ammonium salts.Then the pillared vermicul...The dispersibility of vermiculite is the key factor that affects the application of vermiculite.In this paper,the milled natural vermiculite was pillared by organic quaternary ammonium salts.Then the pillared vermiculite was ground and homogenized under the existence of dispersive agent to form a stable vermiculite hydrosol system.Small angle X-ray diffraction(SA-XRD),fourier transform infrared spectroscopy(FTIR),and thermogravimetric analyses(TGA)were used to characterize the structure and thermal property of the vermiculite.The results indicate that the exfoliated vermiculite is successfully obtained.The analyses of laser particle size analyzer,transmission electron microscope(TEM),and Tyndall phenomenon analyzer demonstrate that the vermiculite hydrosol prepared is a stable hydrosol system.展开更多
O6-Corona[3]arene[3]pyridazines were synthesized from the one-pot macrocyclic condensation reaction of 3,6-dichlorotetrazine with 1,4-dihydroquinone derivatives followed by the inverse electron demand Diels-Alder reac...O6-Corona[3]arene[3]pyridazines were synthesized from the one-pot macrocyclic condensation reaction of 3,6-dichlorotetrazine with 1,4-dihydroquinone derivatives followed by the inverse electron demand Diels-Alder reaction of the tetrazine rings with a cyclopentanone-derived enamine. Conversion of six ester groups within macrocycle into all sodium acetate moieties afforded a water soluble O6-corona[3]arene[3]pyridazine. The coronary macrocycle host formed complexes selectively with organic ammoniums and dinitrile guests in a 1 ： 1 stoichiometric ratio in organic solvents with association constants ranging from （2.96± 0.10）× 10^1 to （2.53±0.33）× 10^5 L·mol^-1. Water soluble O6-corona[3]arene[3]pyridazine was also able to complex strongly with organic ammoniums in water to give an association constant up to （2.67 ± 0.21） × 10^4 L·mol^-1. The pseudo-rotaxane and inclusion structures of the host-guest complexes were revealed by the X-ray crystallography.展开更多
Perovskite solar cells(PSCs)have attracted intense attention based on their high power conversion efficiency and low production cost.However,due to the polycrystalline nature and the intrinsic hydrophilicity of the me...Perovskite solar cells(PSCs)have attracted intense attention based on their high power conversion efficiency and low production cost.However,due to the polycrystalline nature and the intrinsic hydrophilicity of the metal halide perovskite moieties,the photovoltaic performance of PSCs is largely limited by defects within the polycrystalline perovskites and the sensitivity to moisture.In this perspective,we focus on the chemically tailored interface materials to passivate the defects and improve the moisture stability of PSCs.First,we provide a brief overview of various molecular interface modifiers.Thereafter we provide examples from our recent work on organic ammonium halide‐based passivation materials as representatives to illustrate the design strategies and the modification effects.In the end,we shed light on the future devel-opment of organic ammonium halides for applications in PSCs.展开更多
基金supported by the Applied Chemistry Key Subject of Gansu Province (No. GSACKS20130113)Youth Science and Technology Innovation Project of Longdong University (No.XYZK1512, No.XYZK1511)
文摘The surface tension, foaming and viscosity for C7F15COO^-N^＋H（C2H4OH）χ（C2Hs）3-x and C8F17SO3- N^＋H（C2H4OH）χ（C2H5）3-χ （x = 0, 1, 2, 3） were measured to systematically study the effects of hydroxyl groups in organic ammonium counterions on the properties of perfluorooctanoates and perfluorooctanesulfonates. The results showed that the critical micelle concentration （cmc） and the surface tension at cmc （γcmc） were both increased with the increase of number of hydroxyl groups （χ） in the two series. The perfluorooctanesulfonate had smaller cmc but higher γ=cmc than perfluorooctanoate with the same counterion. The minimum molecular area of surface adsorption （Amin） of C8F17zSO3^-N^＋H（C2H4OH）χ（C2H5）3-χ were 0.64, 0.57, 0.63 and 0.72 nm^2 while the Amin values of C7F15COO^-N^＋H（C2H4OH）χ（C2H5）3-χ were 0.61, 0.62, 0.61 and 0.71 nm^2 when χ = 0, 1, 2 and 3, respectively. For the investigated systems of surfactants, the results of foam expansion ratio agreed with those of surface activity, while the 25% drainage time were consistent with the results of viscosity.
基金National High Technology Research and Development Program(863 Program),China(No.2007AA03Z336)Program for New Century Excellent Talents in University,China(No.NCET-07-0174)
文摘The dispersibility of vermiculite is the key factor that affects the application of vermiculite.In this paper,the milled natural vermiculite was pillared by organic quaternary ammonium salts.Then the pillared vermiculite was ground and homogenized under the existence of dispersive agent to form a stable vermiculite hydrosol system.Small angle X-ray diffraction(SA-XRD),fourier transform infrared spectroscopy(FTIR),and thermogravimetric analyses(TGA)were used to characterize the structure and thermal property of the vermiculite.The results indicate that the exfoliated vermiculite is successfully obtained.The analyses of laser particle size analyzer,transmission electron microscope(TEM),and Tyndall phenomenon analyzer demonstrate that the vermiculite hydrosol prepared is a stable hydrosol system.
基金We also thank the National Natural Science Foundation of China （Nos. 21732004, 91427301, 21421064） and Tsinghua University for financial Support.
文摘O6-Corona[3]arene[3]pyridazines were synthesized from the one-pot macrocyclic condensation reaction of 3,6-dichlorotetrazine with 1,4-dihydroquinone derivatives followed by the inverse electron demand Diels-Alder reaction of the tetrazine rings with a cyclopentanone-derived enamine. Conversion of six ester groups within macrocycle into all sodium acetate moieties afforded a water soluble O6-corona[3]arene[3]pyridazine. The coronary macrocycle host formed complexes selectively with organic ammoniums and dinitrile guests in a 1 ： 1 stoichiometric ratio in organic solvents with association constants ranging from （2.96± 0.10）× 10^1 to （2.53±0.33）× 10^5 L·mol^-1. Water soluble O6-corona[3]arene[3]pyridazine was also able to complex strongly with organic ammoniums in water to give an association constant up to （2.67 ± 0.21） × 10^4 L·mol^-1. The pseudo-rotaxane and inclusion structures of the host-guest complexes were revealed by the X-ray crystallography.
基金Higher Education Discipline Innovation Project,Grant/Award Number:B16027National Thousand Talent Program for Young Professionals。
文摘Perovskite solar cells(PSCs)have attracted intense attention based on their high power conversion efficiency and low production cost.However,due to the polycrystalline nature and the intrinsic hydrophilicity of the metal halide perovskite moieties,the photovoltaic performance of PSCs is largely limited by defects within the polycrystalline perovskites and the sensitivity to moisture.In this perspective,we focus on the chemically tailored interface materials to passivate the defects and improve the moisture stability of PSCs.First,we provide a brief overview of various molecular interface modifiers.Thereafter we provide examples from our recent work on organic ammonium halide‐based passivation materials as representatives to illustrate the design strategies and the modification effects.In the end,we shed light on the future devel-opment of organic ammonium halides for applications in PSCs.
