A kind of temperature-sensitive nanotube array membrane was developed by modifying gold-nanotube array membranes with poly(N-isopropylacrylamide) (PNIPAm). The permeation ability of the mem-branes at different tempera...A kind of temperature-sensitive nanotube array membrane was developed by modifying gold-nanotube array membranes with poly(N-isopropylacrylamide) (PNIPAm). The permeation ability of the mem-branes at different temperatures was investigated using sodium fluorescein and quantum dots as probes. The results showed that the pore diameter of nanotube was changed due to the reversible re-sponse of PNIPAm-modified membranes to temperature, and then the permeation ability of the mem-branes was changed. The permeation of fluorescence probes was slow and even almost blocked at 25℃ (below the lower critical solution temperature, LCST), since PNIPAm formed expanded structures and decreased the pore size. While at 40℃ (above the LCST), the permeation was increased, since PNIPAm became compact structures and the pore diameter was increased. Furthermore, the permea-tion ability of the temperature-sensitive nanotube array membranes could be adjusted reversibly and it is possible to use the membranes in nanofluidic devices, nanogates, etc.展开更多
We have theoretically investigated the effect of the dielectric core and the dielectric embedding medium separately on the transmission spectra and plasmonic properties of coupled metallic nanotube arrays.It is found ...We have theoretically investigated the effect of the dielectric core and the dielectric embedding medium separately on the transmission spectra and plasmonic properties of coupled metallic nanotube arrays.It is found that the plasmonic properties of the nanotube arrays are strongly influenced by the presence of the dielectric which induces additional screening charges.We show that instead of one single photonic bandgap for the hollow nanotube arrays placed in air,an additional photonic bandgap arises from the presence of dielectric media in the transmission spectra.Based on the localized nature of the electric field distributions,we also clearly show the presence of the local plasmonic resonant modes that originate from multipolar plasmon polaritons in the cross section of these nanotube arrays,and that a large amount of opposing surface charges are built up in the gap between adjacent nanotubes.展开更多
基金Supported by the National Key Basic Research Program of China (Grant No. 2002CB513110)Key Technologies Research and Development Program of China (Grant Nos. 2003BA310A16 and 2005EP090026)+1 种基金Key Project of International Technologies Collaboration Program of China (Grant No. 2003DF000039)National Natural Science Foundation of China (Grant Nos. 90606003, 20475015 and 20620120107)
文摘A kind of temperature-sensitive nanotube array membrane was developed by modifying gold-nanotube array membranes with poly(N-isopropylacrylamide) (PNIPAm). The permeation ability of the mem-branes at different temperatures was investigated using sodium fluorescein and quantum dots as probes. The results showed that the pore diameter of nanotube was changed due to the reversible re-sponse of PNIPAm-modified membranes to temperature, and then the permeation ability of the mem-branes was changed. The permeation of fluorescence probes was slow and even almost blocked at 25℃ (below the lower critical solution temperature, LCST), since PNIPAm formed expanded structures and decreased the pore size. While at 40℃ (above the LCST), the permeation was increased, since PNIPAm became compact structures and the pore diameter was increased. Furthermore, the permea-tion ability of the temperature-sensitive nanotube array membranes could be adjusted reversibly and it is possible to use the membranes in nanofluidic devices, nanogates, etc.
基金the Excellent Doctorate Dissertation Foundation of Central South University (Grant No.2008yb039)the Postgraduate Innovative Project of Hunan Province (Grant No.CX2009B029)
文摘We have theoretically investigated the effect of the dielectric core and the dielectric embedding medium separately on the transmission spectra and plasmonic properties of coupled metallic nanotube arrays.It is found that the plasmonic properties of the nanotube arrays are strongly influenced by the presence of the dielectric which induces additional screening charges.We show that instead of one single photonic bandgap for the hollow nanotube arrays placed in air,an additional photonic bandgap arises from the presence of dielectric media in the transmission spectra.Based on the localized nature of the electric field distributions,we also clearly show the presence of the local plasmonic resonant modes that originate from multipolar plasmon polaritons in the cross section of these nanotube arrays,and that a large amount of opposing surface charges are built up in the gap between adjacent nanotubes.
