1992 Fiscal Year Final Research Report Summary
Molecular Design of Novel NLO Ferroelectric Thin Films
| Project/Area Number |
03044090
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| Research Category |
Grant-in-Aid for international Scientific Research
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| Allocation Type | Single-year Grants |
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| Section | Joint Research |
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| Research Institution | Kyoto Institute of Technology |
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Principal Investigator |
KIYOTSUKURI Tsuyoshi Kyoto Institute of Technology, Professor, 繊維学部, 教授 (60027860)
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| Co-Investigator(Kenkyū-buntansha) |
MICHAEL A. Schen National Institute of standards & Technology, USA, 国立標準局・高分子部門, 研究員
AIME S. Dereggi National Institute of standards & Technology, USA, 国立標準局・高分子部門, 研究員
G.THOMAS Dayis National Institute of standards & Technology, USA Group Leader, 国立標準局・高分子部門, グループリーダー
NAGATA Minoru Kyoto Prefectural University. Professor, 短期大学部, 教授 (40046511)
TSUTSUMI Naoto Kyoto Institute of Technology, Associate Professor, 繊維学部, 助教授 (50172036)
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| Project Period (FY) |
1991 – 1992
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| Keywords | Ferroelectric polymer / Crystallite dipoles / Inrernal electric field / Noncentrosymmetricity / Nonlinear optical effect / Nonlinear optical dye / Second harmonic generation / Curie transition temperature |
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| Research Abstract |
We have studied the internal electric field E_i created by the preferentially oriented beta-crystallite dipoles in the blend of 80 Wt% poly(vinylidene fluoride) (PVDF) and 20 Wt% poly(methyl methacrylate) (PMMA) and the blends of vinylidene fluoride-trifluoroethylene copolymer P(VDF-TrFE) and PMMA, and the second harmonic generation (SHG) from the noncentrosymmetrically oriented beta-crysrallite dipoles and nonlinear optical (NLO) dyes aligned by the internal electric field. We preparedmethyl methacrylate (MMA) copolymer having a NLO pendant group such as Disperse Red 1 (P(MMA-co-MMA-DR1)) as a SHG active polymer.
For both blends. E_i is 2 - 4 MV/cm which is three or four times larger the poling field. E_i for PVDF/PMMA blend is stabilized by the space charge. P(VDF-TrFE)/PMMA and P(VDF-TrFE)/P(MMA-co-MMA-DR1) have the clear Curie transition at the temperature around 105ﾟC. SHG coefficient d_<33> are 3.3 X 10^<-9> and 2.3 X 10^<-9> esu for P(VDF-TrFE) and (90/10) P(VDF-TrFE)/PMMA, respectively. For P(VDF-TrFE)/PMMA, E_i and d_<33> are thermally stable at the temperature above the glass transition temperature (T_g) and the abrupt decrease of them occurs when one approaches to the Curie temperature. Profile of d_<33> - temperature for P(VDF-TrFE)/P(MMA-co-MMA-DR1) is almost the same as that for P(VDF-TrFE)/PMMA. However, d_<33> for P(MMA-co-MMA-DR1) decreases at the temperature above 40ﾟC corresponding to the beta-relaxation of PMMAcomponenent and the large decrease starts at the temperature above 90ﾟC which is lower than T_g. It is particularly important to note that d_<33> for P(VDF-TrFE)/P(MMA-co-MMA-DR1) blend is thermally stable above T_g because the main contribution to SHG activity is due to noncentrosymmetric alignment of beta-crystallite dipoles NLO dye oriented by E_i.
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