A reversed duckweed polymeric LB film was fabricated by a new kind of amphiphilic polymer which was composed of hexanedlamine-epichlorohydrin slightly crosslinked hydrophilic network and hydrophobic chains conatining ...A reversed duckweed polymeric LB film was fabricated by a new kind of amphiphilic polymer which was composed of hexanedlamine-epichlorohydrin slightly crosslinked hydrophilic network and hydrophobic chains conatining p-nitroazobenzene group. This amphiphilic polymer can form stable liquid-condensed monolayer and be transferred as Z-type polymeric LB films. This LB film combines the order and mobility and it has a well-estab- lished layer structure and azo chromphore is in an isotropic state in each layer. Optical birefringence and dichroism can be laser induced and erased and this reversible birefringence and dichroism can be cycled many times without appearance of any fatigue and show a very good stability. On the basis of photo-induced optical blrefringence and dichroism, it is greatly anticipated that this polymer thin films bearing azo groups can be used as advanced materialsfor optical information storage.展开更多
The spectra of Cm and Cm thin films over a wide energy range (0.6 to 6.5eV) are measured by transmission spectroscopy and photothermal deflection spectroscopy (PDS), and the optical absorption coefficients are obtaine...The spectra of Cm and Cm thin films over a wide energy range (0.6 to 6.5eV) are measured by transmission spectroscopy and photothermal deflection spectroscopy (PDS), and the optical absorption coefficients are obtained. The optical transitions for the Cm and Cw thin films are analyzed according to the molecular orbital model. The weak absorption spectra of the fullerenes are similar to that of amorphous silicon. The optical energy gaps are given by Tauc’s plots as 1.75 and 1.65eV for C60 and C70 thin films, respectively. The disorders in the fullerene films, which resulted in band-tail state or defect state, are indicated by Urbach edge and sub-gap absorption. It is the disorder that brought the difficulty in determination of the energy gap for fullerenes. The effects of the deflection medium and substrate on the weak absorption spectra of fullerene films are also discussed.展开更多
文摘A reversed duckweed polymeric LB film was fabricated by a new kind of amphiphilic polymer which was composed of hexanedlamine-epichlorohydrin slightly crosslinked hydrophilic network and hydrophobic chains conatining p-nitroazobenzene group. This amphiphilic polymer can form stable liquid-condensed monolayer and be transferred as Z-type polymeric LB films. This LB film combines the order and mobility and it has a well-estab- lished layer structure and azo chromphore is in an isotropic state in each layer. Optical birefringence and dichroism can be laser induced and erased and this reversible birefringence and dichroism can be cycled many times without appearance of any fatigue and show a very good stability. On the basis of photo-induced optical blrefringence and dichroism, it is greatly anticipated that this polymer thin films bearing azo groups can be used as advanced materialsfor optical information storage.
基金Project supported by the National Natural Science Foundation of China.
文摘The spectra of Cm and Cm thin films over a wide energy range (0.6 to 6.5eV) are measured by transmission spectroscopy and photothermal deflection spectroscopy (PDS), and the optical absorption coefficients are obtained. The optical transitions for the Cm and Cw thin films are analyzed according to the molecular orbital model. The weak absorption spectra of the fullerenes are similar to that of amorphous silicon. The optical energy gaps are given by Tauc’s plots as 1.75 and 1.65eV for C60 and C70 thin films, respectively. The disorders in the fullerene films, which resulted in band-tail state or defect state, are indicated by Urbach edge and sub-gap absorption. It is the disorder that brought the difficulty in determination of the energy gap for fullerenes. The effects of the deflection medium and substrate on the weak absorption spectra of fullerene films are also discussed.
