Batch equilibrium experiments were conducted to investigate cadmium （Cd） sorption by two permanent-charge soils, a yellow-cinnamon soil and a yellow-brown soil, and two variable-charge soils, a red soil and a latoso...Batch equilibrium experiments were conducted to investigate cadmium （Cd） sorption by two permanent-charge soils, a yellow-cinnamon soil and a yellow-brown soil, and two variable-charge soils, a red soil and a latosol, with addition of selected organic acids （acetate, tartrate, and citrate）. Results showed that with an increase in acetate concentrations from 0 to 3.0 mmol L^-1, Cd sorption percentage by the yellow-cinnamon soil, the yellow-brown soil, and the latosol decreased. The sorption percentage of Cd by the yellow-clnnamon soil and generally the yellow-brown soil （permanent-charge soils） decreased with an increase in tartrate concentration, but increased at low tartrate concentrations for the red soil and the latosol. Curves of percentage of Cd sorption for citrate were similar to those for tartrate. For the variable-charge soils with tartrate and citrate, there were obvious peaks in Cd sorption percentage. These peaks, where organic acids had maximum influence, changed with soil type, and were at a higher organic acid concentration for the variable-charge soils than for the permanent charge soils. Addition of cadmium after tartrate adsorption resulted in higher sorption increase for the varlable-charge soils than permanent-charge soils. When tartrate and Cd solution were added together, sorption of Cd decreased with tartrate concentration for the yellow-brown soil, but increased at low tartrate concentrations and then decreased with tartrate concentration for the red soil and the latosol.展开更多
Supramolecular liquid crystals(SLCs)are attractive materials for fabricating devices with new optoelectronic functions.Conventional SLCs are made from hydrogen-bonded mesogens.However,these mesogens suffer from high m...Supramolecular liquid crystals(SLCs)are attractive materials for fabricating devices with new optoelectronic functions.Conventional SLCs are made from hydrogen-bonded mesogens.However,these mesogens suffer from high melting points,and the types of formable aggregates are limited owing to the directionality of the hydro-gen bonding.Therefore,to fabricate non-hydrogen-bonded SLCs,we hypothesized that the introduction of tertiary amide groups into calamitic molecules would be advantageous because they have an L-shaped structure with N-or C-alkyl side chains not aligned along the long axis and theflexibility to undergo cis–trans isomeriza-tion.In this study,we developed a novel non-hydrogen-bonded SLC by assembling an L-shaped dimer composed of calamitic molecules(phenyltolanes)with tertiary amides at their ends.These molecules exhibited a smectic B phase.The phase tran-sition temperature of the SLCs from crystal to liquid crystal phase was low despite the longπ-conjugated core.Wide-angle X-ray diffraction and variable-temperature Fourier-transform infrared measurements revealed dimer formation by weak inter-molecular interactions,that is,the molecular recognition of L-shaped molecules,and mobility of the alkyl groups attached to amide driven by cis–trans isomerization in the liquid crystal phase.Thus,cis–trans isomerization of tertiary amides contributed enormously to the formation and lower clearing points of this SLC.The developed method can be used not only to develop non-hydrogen-bonded SLCs but also to develop novel soft matter with controlled properties by incorporating the SLCs,as the aggregates can be controlled to impart desired functionalities.展开更多
基金Project supported by the National Natural Sciences Foundation of China (No. 40371065).
文摘Batch equilibrium experiments were conducted to investigate cadmium （Cd） sorption by two permanent-charge soils, a yellow-cinnamon soil and a yellow-brown soil, and two variable-charge soils, a red soil and a latosol, with addition of selected organic acids （acetate, tartrate, and citrate）. Results showed that with an increase in acetate concentrations from 0 to 3.0 mmol L^-1, Cd sorption percentage by the yellow-cinnamon soil, the yellow-brown soil, and the latosol decreased. The sorption percentage of Cd by the yellow-clnnamon soil and generally the yellow-brown soil （permanent-charge soils） decreased with an increase in tartrate concentration, but increased at low tartrate concentrations for the red soil and the latosol. Curves of percentage of Cd sorption for citrate were similar to those for tartrate. For the variable-charge soils with tartrate and citrate, there were obvious peaks in Cd sorption percentage. These peaks, where organic acids had maximum influence, changed with soil type, and were at a higher organic acid concentration for the variable-charge soils than for the permanent charge soils. Addition of cadmium after tartrate adsorption resulted in higher sorption increase for the varlable-charge soils than permanent-charge soils. When tartrate and Cd solution were added together, sorption of Cd decreased with tartrate concentration for the yellow-brown soil, but increased at low tartrate concentrations and then decreased with tartrate concentration for the red soil and the latosol.
基金Japan Science and Technology Agency,Grant/Award Number:JPMJPR1096Japan Society for the Promotion of Science,Grant/Award Numbers:17H05145,23H02036Izumi Science and Technology Foundation。
文摘Supramolecular liquid crystals(SLCs)are attractive materials for fabricating devices with new optoelectronic functions.Conventional SLCs are made from hydrogen-bonded mesogens.However,these mesogens suffer from high melting points,and the types of formable aggregates are limited owing to the directionality of the hydro-gen bonding.Therefore,to fabricate non-hydrogen-bonded SLCs,we hypothesized that the introduction of tertiary amide groups into calamitic molecules would be advantageous because they have an L-shaped structure with N-or C-alkyl side chains not aligned along the long axis and theflexibility to undergo cis–trans isomeriza-tion.In this study,we developed a novel non-hydrogen-bonded SLC by assembling an L-shaped dimer composed of calamitic molecules(phenyltolanes)with tertiary amides at their ends.These molecules exhibited a smectic B phase.The phase tran-sition temperature of the SLCs from crystal to liquid crystal phase was low despite the longπ-conjugated core.Wide-angle X-ray diffraction and variable-temperature Fourier-transform infrared measurements revealed dimer formation by weak inter-molecular interactions,that is,the molecular recognition of L-shaped molecules,and mobility of the alkyl groups attached to amide driven by cis–trans isomerization in the liquid crystal phase.Thus,cis–trans isomerization of tertiary amides contributed enormously to the formation and lower clearing points of this SLC.The developed method can be used not only to develop non-hydrogen-bonded SLCs but also to develop novel soft matter with controlled properties by incorporating the SLCs,as the aggregates can be controlled to impart desired functionalities.
