A new trifluoromethylated bis(ether amine) monomer, 9,9-bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]xanthene (BATFPX), was prepared through the nucleophilic aromatic substitution reaction of 2-chloro-5-nitrobenzotrifluoride and 9,9-bis(4-hydroxyphenyl)xanthene in the presence of potassium carbonate, followed by catalytic reduction with hydrazine and Pd/C in ethanol. A series of novel fluorinated polyimides were synthesized from BATFPX with various commercially available aromatic tetracarboxylic dianhydrides by one-step polycondensation in m-cresol. The resulting polyimides were readily soluble in many organic solvents such as N,N-dimethylacetamide and tetrahydrofuran, and afforded transparent, flexible and strong films with low moisture absorption (0.28-0.51%), low dielectric constant (2.85-3.26 at 1 MHz) and good optical transparency with UV-visible absorption cut-off wavelengths at 352-410 nm. All the polyimides were amorphous and exhibited high thermal stability, with glass transition temperatures of 282-330 • C, 5% weight loss temperatures above 520 • C in nitrogen or air and char yields higher than 55% at 800 • C in nitrogen. Also, these polyimides had good mechanical properties with tensile strengths of 93-118 MPa, elongations at break of 9-16% and initial moduli of 2.07-2.58 GPa.

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We report localized surface plasmon resonance (LSPR) of silver nanoparticles (NPs) embedded in interface of phase separation of holographic polymer-dispersed liquid crystal (H-PDLC) gratings using Finite-Difference Time Domain method. We show that silver NPs exhibit double resonance peak at the interface, and these peaks are influenced by the angle of incident light. We observe a blue shift of the wavelength of resonance peak as the incident angle increases. However, the location of silver NPs at the interface has nearly no effect on the wavelength of resonance peak. Also we show near-field and far-field properties surrounding silver NPs and find that field distribution can be controlled through rotation of incident angle. Therefore, LSPR properties of silver NPs within H-PDLC gratings can be excited by appropriate wavelength and angle of the incident light.

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