Light exposure dependence of molecular orientation of glassy polyfluorene layers formed on photo-aligned polyimide films

2007 ◽  
Vol 56 (1-2) ◽  
pp. 260-264 ◽  
Author(s):  
Kenji Sakamoto ◽  
Kiyoaki Usami ◽  
Kazushi Miki
Keyword(s):  
Molecular Orientation ◽  
Light Exposure ◽  
Polyimide Films

Molecular Orientation and Photocurrent of Alkyl-Aromatic Polyimide Films Prepared by Vapor Deposition Polymerization

1989 ◽  
Vol 28 (Part 1, No. 12) ◽  
pp. 2552-2555 ◽  
Author(s):  
Kazuo Iida ◽  
Tsukasa Nohara ◽  
Kazuyuki Totani ◽  
Shuhei Nakamura ◽  
Goro Sawa
Keyword(s):  
Vapor Deposition ◽  
Molecular Orientation ◽  
Polyimide Films ◽  
Aromatic Polyimide

Incident Angle Dependence of the Infrared Absorbance of Thin Rubbed Polyimide Films on CaF2 and Si Substrates

1997 ◽  
Vol 51 (4) ◽  
pp. 541-544 ◽  
Author(s):  
K. Sakamoto ◽  
R. Arafune ◽  
S. Ushioda
Keyword(s):  
Molecular Orientation ◽  
Incident Angle ◽  
Experimental Result ◽  
Ir Absorption ◽  
Polyimide Films ◽  
Si Substrates ◽  
Angle Dependence ◽  
Fitting Procedure ◽  
Solid Substrates ◽  
Inclination Angles

We have measured the incident angle dependence of the infrared (IR) absorption of thin rubbed polyimide films on CaF2 and Si substrates. The molecular orientation of the films was determined by fitting the experimental result with a theoretical calculation. The incident angle dependence for the rubbed film on CaF2 was very different from that for the rubbed film on Si. On the other hand, the actual molecular orientation determined by the fitting procedure is similar in both samples. Thus this result clearly shows that the incident angle dependence is strongly dependent on the substrate. This effect arises from the interference between the forward and backward propagating light in the film. This experiment demonstrates that the interference effect must be taken into account in determining the molecular orientation of thin films on solid substrates. We have also calculated the incident angle dependence for rubbed films with different inclination angles of polyimide chains on CaF2 and Si substrates. We found that CaF2 is a more suitable substrate than Si for determining the molecular orientation of rubbed films with a relatively high inclination angle of polyimide chains.

Molecular Orientation of Polyimide Films for Liquid Crystal Alignment Studied by Infrared Dichroism

1994 ◽  
Vol 33 (Part 1, No. 11) ◽  
pp. 6273-6276 ◽  
Author(s):  
Kyoko Sawa ◽  
Ken Sumiyoshi ◽  
Yoshihiko Hirai ◽  
Kazuo Tateishi ◽  
Taibun Kamejima
Keyword(s):  
Liquid Crystal ◽  
Molecular Orientation ◽  
Polyimide Films ◽  
Liquid Crystal Alignment ◽  
Crystal Alignment ◽  
Infrared Dichroism

Spontaneous molecular orientation of polyimides induced by thermal imidization (6). Mechanism of negative in-plane CTE generation in non-stretched polyimide films

2010 ◽  
Vol 46 (4) ◽  
pp. 681-693 ◽  
Author(s):  
Junichi Ishii ◽  
Aya Takata ◽  
Yoko Oami ◽  
Rikio Yokota ◽  
Leonid Vladimirov ◽  
...  
Keyword(s):  
Molecular Orientation ◽  
Polyimide Films ◽  
Thermal Imidization

Internal Stress Development In Spin Coated Polyimide Films

1991 ◽  
Vol 227 ◽  
Author(s):  
Michael T. Pottiger ◽  
John Coburn
Keyword(s):  
Internal Stress ◽  
Molecular Orientation ◽  
Coefficient Of Thermal Expansion ◽  
Internal Stresses ◽  
Processing Conditions ◽  
Heating Rates ◽  
Polyimide Films ◽  
Plane Orientation ◽  
Relaxation Effects ◽  
Cte Mismatch

ABSTRACTThe effect of processing on the development of internal stresses in spin coated polyimide films was investigated. The internal stresses are a result of the coefficient of thermal expansion (CTE) mismatch between the polymer and the substrate. Birefringence and CTE were used to characterize the in-plane molecular orientation. In-plane orientation was shown to be sensitive to processing conditions. Increasing the spin speed results in higher in-plane orientation as observed by an increase in birefringence and a corresponding decrease in CTE. Heating rate during cure was observed to have a significant effect on in-plane orientation. Faster heating rates during cure resulted in a lower birefringence. The lower birefringence is attributed to relaxation effects that can occur during a rapid cure. The decrease in orientation was accompanied by an increase in internal stress.

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